A 100-Year Review: Advances in goat milk research

Leucine-Mediated SLC7A5 Promotes Milk Protein and Milk Fat Synthesis through mTOR Signaling Pathway in Goat Mammary Epithelial Cells

The SLC7A5 gene encodes a Na+ and pH-independent transporter protein that regulates cell growth by regulating the uptake of AA. This study, utilizing RNA-seq, aimed to explore the effect of SLC7A5 on the synthesis of milk proteins and fats in goat mammary epithelial cells (GMECs) through gene interference and overexpression techniques. The results demonstrated that the overexpression of SLC7A5 resulted in a significant increase in the expression of CSN1S1, SCD, CEBPB, ACACA, αS1-casein, p-S6K, and p-S6. The levels of p-S6K and p-S6 gradually increased as the AA/Leu stimulation time lengthened. The overexpression of SLC7A5 rescued the role of Torin1 in GMECs. In conclusion, SLC7A5 plays a crucial role in promoting the synthesis of milk proteins and milk fats through the mTOR signaling pathway in GMECs, providing a theoretical foundation for improving the quality of goat milk.

Knockdown of PROX1 promotes milk fatty acid synthesis by targeting PPARGC1A in dairy goat mammary gland

Goat milk is rich in various fatty acids that are beneficial to human health. Chromatin immunoprecipitation followed by sequencing (ChIP-seq) and RNA-seq analyses of goat mammary glands at different lactation stages revealed a novel lactation regulatory factor, Prospero homeobox 1 (PROX1). However, the mechanism whereby PROX1 regulates lipid metabolism in dairy goats remains unclear. We found that PROX1 exhibits the highest expression level during peak lactation period. PROX1 knockdown enhanced the expression of genes related to de novo fatty acid synthesis (e.g., SREBP1 and FASN) and triacylglycerol (TAG) synthesis (e.g., DGAT1 and GPAM) in goat mammary epithelial cells (GMECs). Consistently, intracellular TAG and lipid droplet contents were significantly increased in PROX1 knockdown cells and reduced in PROX1 overexpression cells, and we observed similar results in PROX1 knockout mice. Following PROX1 overexpression, RNA-seq showed a significant upregulation of peroxisome proliferator-activated receptor gamma coactivator-1 alpha (PPARGC1A) expression. Further, PPARGC1A knockdown attenuated the inhibitory effects of PROX1 on TAG contents and lipid-droplet formation in GMECs. Moreover, we found that PROX1 promoted PPARGC1A transcription via the PROX1 binding sites (PBSs) located in the PPARGC1A promoter. These results suggest a novel target for manipulating the goat milk-fat composition and improving the quality of goat milk.

Goat milk exosomal microRNAs alleviate LPS-induced intestinal inflammation in mice

Intestinal inflammation is a common digestive system disease. Milk-derived exosomes can participate in intercellular communication and transport a variety of bioactive components, and the microRNAs (miRNAs) they carry play important roles in a variety of biological processes in the body. At present, the preventive effect and mechanism of action of goat milk exosomes and their derived miRNAs on intestinal inflammation are still unclear. In this study, the protective effect of goat milk exosomes on LPS-induced intestinal inflammation was investigated using mouse intestinal inflammation model and IEC-6 cell inflammation model. Small RNA sequencing was used to analyze the miRNA expression profile of goat milk exosomes. In this study, C-Exo and M-Exo alleviated intestinal inflammation by reducing the LPS-induced release of proinflammatory cytokines, inhibiting the increase in the NLRP3 protein and the activation of the TLR4/NFκB signaling pathway. C-Exo has a more significant inhibitory effect on them, and better therapeutic efficacy than M-Exo. Notably, the target genes of miRNAs in C-Exo and M-Exo were significantly enriched in immune-related pathways. Furthermore, their derived miR-26a-5p and miR-30a-5p were found to ameliorate the IEC-6 inflammatory response. These findings suggest that miRNAs in goat milk exosomes have the potential to attenuate LPS-induced intestinal inflammation.

Dynamic In Vitro Gastric Digestion Behaviour of Commercial Infant Formulae Made with Cow, Goat and Sheep Milk

There are a wide range of commercial infant formulae available on the market. These are made using milk from different species, such as goat, sheep, and cow. The different protein compositions of these milks and the process used during infant-formulae manufacture, such as heat treatment, may impact the digestion of nutrients. This study compared the effect of protein composition and heat treatment on the in vitro gastric digestion behaviour of commercial infant formulae made with cow, goat, and sheep milk using a dynamic infant human gastric simulator (IHGS). During the simulated dynamic gastric digestion, the goat milk infant formula (GIF) showed earlier signs of aggregate formation compared to cow milk infant formula (CIF) and sheep milk infant formula (SIF). In addition, the microstructures of GIF chyme showed fragmented and porous structures. On the contrary, CIF formed dense protein networks that trapped oil droplets, whereas SIF exhibited a microstructure of smooth oil droplets surrounded by fewer protein networks. The different aggregation behaviours and aggregate structures of the three infant-formulae chyme were related to their different protein compositions, especially the different casein compositions. Furthermore, the open fragile structure of GIF aggregates provided easier access to pepsin, allowing it to hydrolyse protein. The results from the present study provided some information to assist in understanding the coagulation and digestion behaviours of commercial infant formulae made from different species of milk.

Impact of Processing Methods on the Distribution of Mineral Elements in Goat Milk Fractions

Milk and dairy products are excellent sources of mineral elements, including Ca, P, Mg, Na, K and Zn. The purpose of this study was to determine the effect of non-thermal (homogenization) and thermal (heat treatment) treatments on the distribution of mineral elements in 4 milk fractions: fat, casein, whey protein, and aqueous phase. The study results revealed that the distribution of mineral elements (such as Mg and Fe) in fat fractions is extremely low, while significant mineral elements such as Ca, Zn, Fe, and Cu are mostly dispersed in casein fractions. For non-treated goat milk, Mo is the only element identified in the whey protein fraction, while K and Na are mostly found in the aqueous phase. Mineral element concentrations in fat (K, Zn, etc.) and casein fraction (Fe, Mo, etc.) increased dramatically after homogenization. Homogenization greatly decreased the concentration of mineral elements in the whey protein fraction (Ca, Na, etc.) and aqueous phase (Fe, Cu, etc.). After heat treatment, the element content in the fat fraction and casein fraction increased greatly when compared with raw milk, such as Cu and Mg in the fat fraction, Na and Cu in the whey protein fraction, the concentration of components such as Mg and Na in casein fraction increased considerably. On the other hand, after homogenization, Zn in the aqueous phase decreased substantially, whereas Fe increased significantly. Therefore, both homogenization and heat treatment have an effect on the mineral element distribution in goat milk fractions.

Gels of carrageenan-caprine whey protein concentrate: A physicochemical study

Mixed gels of carrageenan (Car) and caprine whey protein concentrate (WPCc) (pH 7) were studied and compared with those prepared with Car and commercial bovine whey protein concentrate (WPCb). Dynamic rheology studies indicate that gels with WPCc were weaker (lower G') than those made with WPCb. However, textural parameters such as, hardness, springiness and cohesiveness were similar in both type of gels. The addition of CaCl2 incremented the elastic modulus (G'), hardness and adhesiveness of gels. The samples with caprine whey showed higher water holding capacity than samples with bovine whey. Confocal laser scanning microscope images of the gels, showed very different aspects according to the type of WPC used: WPCc-Car gels exhibited aggregates of proteins that interrupt the carrageenan network, while WPCb-Car gels showed a homogeneous appearance with proteins distributed throughout all the matrix.

Enhancing milk quality and modulating rectal microbiota of dairy goats in starch-rich diet: the role of bile acid supplementation

BACKGROUND

Diets rich in starch have been shown to increase a risk of reducing milk fat content in dairy goats. While bile acids (BAs) have been used as a lipid emulsifier in monogastric and aquatic animals, their effect on ruminants is not well understood. This study aimed to investigate the impact of BAs supplementation on various aspects of dairy goat physiology, including milk composition, rumen fermentation, gut microbiota, and BA metabolism.

RESULTS

We randomly divided eighteen healthy primiparity lactating dairy goats (days in milk = 100 ± 6 d) into two groups and supplemented them with 0 or 4 g/d of BAs undergoing 5 weeks of feeding on a starch-rich diet. The results showed that BAs supplementation positively influenced milk yield and improved the quality of fatty acids in goat milk. BAs supplementation led to a reduction in saturated fatty acids (C16:0) and an increase in monounsaturated fatty acids (cis-9 C18:1), resulting in a healthier milk fatty acid profile. We observed a significant increase in plasma total bile acid concentration while the proportion of rumen short-chain fatty acids was not affected. Furthermore, BAs supplementation induced significant changes in the composition of the gut microbiota, favoring the enrichment of specific bacterial groups and altering the balance of microbial populations. Correlation analysis revealed associations between specific bacterial groups (Bacillus and Christensenellaceae R-7 group) and BA types, suggesting a role for the gut microbiota in BA metabolism. Functional prediction analysis revealed notable changes in pathways associated with lipid metabolism, suggesting that BAs supplementation has the potential to modulate lipid-related processes.

CONCLUSION

These findings highlight the potential benefits of BAs supplementation in enhancing milk production, improving milk quality, and influencing metabolic pathways in dairy goats. Further research is warranted to elucidate the underlying mechanisms and explore the broader implications of these findings.

Rumen bacterial cluster identification and its influence on rumen metabolites and growth performance of young goats

Enterotypes, which are defined as bacterial clusters in the gut microbiome, have been found to have a close relationship to host metabolism and health. However, this concept has never been used in the rumen, and little is known about the complex biological relationships between ruminants and their rumen bacterial clusters. In this study, we used young goats (n = 99) as a model, fed them the same diet, and analyzed their rumen microbiome and corresponding bacterial clusters. The relationships between the bacterial clusters and rumen fermentation and growth performance in the goats were further investigated. Two bacterial clusters were identified in all goats: the P-cluster (dominated by genus Prevotella, n = 38) and R-cluster (dominated by Ruminococcus, n = 61). Compared with P-cluster goats, R-cluster goats had greater growth rates, concentrations of propionate, butyrate, and 18 free amino acids¸ and proportion of unsaturated fatty acids, but lower acetate molar percentage, acetate to propionate ratio, and several odd and branched chain and saturated fatty acids in rumen fluid (P < 0.05). Several members of Firmicutes, including Ruminococcus, Oscillospiraceae NK4A214 group, and Christensenellaceae R-7 group were significantly higher in the R-cluster, whereas Prevotellaceae members, such as Prevotella and Prevotellaceae UCG-003, were significantly higher in P-cluster (P < 0.01). Co-occurrence networks showed that R-cluster enriched bacteria had significant negative correlations with P-cluster enriched bacteria (P < 0.05). Moreover, we found the concentrations of propionate, butyrate and free amino acids, and the proportions of unsaturated fatty acids were positively correlated with R-cluster enriched bacteria (P < 0.05). The concentrations of acetate, acetate to propionate ratio, and the proportion of odd and branched chain and saturated fatty acids were positively correlated with P-cluster enriched bacteria (P < 0.05). Overall, our results indicated that rumen bacterial clusters can influence rumen fermentation and growth performance of young goats, which may shed light on modulating the rumen microbiome in early life to improve the growth performance of ruminant animals.

Characteristic of the components and the metabolism mechanism of goat colostrum: a review

Colostrum contains large number of nutrients that promote the growth, differentiation, and biological functions for goat kids early somatic cells, which is crucial to meet the nutritional demands, immune function, and the health of goat kids later growth. Great attention has been given not only to nutritional ingredient differences between colostrum and normal milk, but also to function differences, and their effect on the physical and sensory properties of goat kid's growth performance and health status. This paper reviews the research progress of goat colostrum in recent years, mainly including the colostrum yield, components, i.e., proteins, lactose, and immunoglobulin, as well as the influence factor, i.e., number of lactation and littler size, nutrition during the gestation, and breeding environment. In addition, this review aims to summarize the synthesis and secretion mechanisms, and the digestion and absorption mechanism of goat colostrum. We conclude that even though the composition and physicochemical properties of goat colostrum are highly dynamic and variable, and the digestion and absorption mechanism has not been made fully clear until now, direct feed microbial (DFM) may be a promising alternative for improving the quality of colostrum that should be further explored for their practical usage.

Genetic analysis of prolificacy, milk production and composition traits in Egyptian Zaraibi goats

This study was conducted to genetically and environmentally characterize prolificacy (litter size and weight at birth; LSB and LWB and litter size and weight at weaning; LSW and LWW, respectively), milk yield at the 7th (MY7), 15th (MY15), 30th (MY30), 60th (MY60), 90th (MY90) day of lactation and monthly milk yield (MMY) and milk composition traits in Egyptian Zaraibi goats. A total of 443 and 421 records produced by 121 Zaraibi lactating goats were used to assess prolificacy and milk production traits, respectively. The milk composition traits were measured using 371 milk samples obtained at random from 53 goats. The fourth parity showed the highest values for LWB, LWW, and MMY (3.62, 18.15, and 28.99 kg, respectively). Milk composition traits revealed an inverse tendency, decreasing until the second month and then increasing until the seventh month. The heritability estimates ranged from 0.07 to 0.13, from 0.04 to 0.39, and from 0.07 to 0.33 for prolificacy, milk yield, and milk composition traits, respectively. Negatively high genetic correlations between MMY and all milk composition traits were found. MMY had the highest estimate of heritability (0.39 ± 0.07), this means that the genetic improvement of this trait could be achieved through direct selection.

Association of new SNPs at DGAT1 gene with milk quality in Egyptian Zaraibi goat breed

This study aimed to detect putative genomic loci in candidate genes associated with milk composition in Egyptian Zaraibi goats. A total number of 50 samples were tested to detect polymorphism in exons 15 and 16 of the diacylglycerol acyltransferase 1 (DGAT1) gene. The PCR products were sequenced and aligned. Sequence analysis showed three new genotypes in the studied samples: T1C1 (T12C SNP), T2C2 (T84C), and AG (G219A), then three groups were created: the first group was BB with C1T1 and AG genotypes, the second was DD which contains C2T2 and AG genotypes, and the third was AG with only AG genotype. GLM showed that the DD group with C84T and G219A SNPs had significantly the highest fat percent. Meanwhile, the BB group with C84T and G219A SNPs recorded significantly the highest total solids levels. On the other hand, the AG group which has G219A SNP showed a non-significant effect on milk components. Those new SNPs were submitted to GenBank and approved to be published. Moreover, translation of those sequences showed that the G219A SNP causes a substitution of Glycine to Serine in exon 16 at position 106. This SNP (G106S) was predicted to be tolerated by SIFT with a score of 0.48.

Effect of pH and protein composition on proteolysis of goat milk proteins by pepsin and pancreatin

The roles of protein composition, pH and enzymes in goat milk protein hydrolysis is still unclear and the proteolysis of low abundant goat milk proteins has received limited attention. The aim of this study was to study the impact of protein composition and proteolytic conditions on goat milk protein hydrolysis in a simplified digestion model. Both whole milk and infant formula were hydrolyzed at pH 2 and 4, using pepsin as well as pepsin combined with pancreatin. Intact proteins were separated from digests using spin filters, followed by bottom-up proteomics of the separated proteins. Results show that under all conditions, caseins are hydrolyzed quickly. Goat casein hydrolysis in infant formula was slightly faster than in goat whole milk, possibly due to less casein coagulation during pepsin hydrolysis at both pH 2 and 4. Several low abundant immunoactive goat milk proteins, especially immunoglobulins, GLYCAM-1 and osteopontin, resisted proteolysis more than high abundant proteins, independent of the pH and enzyme used for hydrolysis. Fast hydrolysis of casein and slow hydrolysis of immunoactive proteins may indicate a good balance between protein utilization and protection of the infant by goat milk proteins.

Multiorgan Failure in a Malnourished Infant: Inappropriate Use of Goat Milk, Dilution, or Both?

Goat milk is gaining popularity in the United States as an alternative to cow and soy milk. The milk is presented as a healthier and less allergenic alternative, with casein and more MCT oil. The interest in goat milk has increased significantly with the recent formula shortage. Goat milk is available in many forms in the United States, including liquid and powdered formulations. However, there are no approved infant formulas in the United States that are goat milk-based. This case describes an infant who became critically ill due to family confusion over goat milk feeds, highlighting the importance of understanding the nutritional components and safety of various goat milk formulations.

Changes in colostrum ingredients of Hu sheep, as well as the missense mutation genes associated with colostrum yield

This study focused on the changes in the composition and immune evolution in milk from birth to 144 h postpartum and the genes associated with the colostrum yield of Hu sheep. Twelve Hu sheep, which were bred carefully under animal health standards and have a litter size of two kids and similar gestation length (149 ± 1 days), were used. Lambs were transferred into their own cots to avoid interference. The compositional content (i.e., fat, protein, and lactose) and some other properties, including daily colostrum yield, DM, and SNF, were determined. In addition, immunity molecules (IgG, IgA, and IgM concentrations) received remarkable attention. The DM, SNF, fat, and protein contents were higher in the first days postpartum and then dropped quickly from the time of birth to 144 h postpartum. However, the lactose content displayed an increasing pattern and reached normal milk percentage at 48 h. The highest IgG (103.17 mg/mL), IgA (352.82 μg/mL), and IgM (2.79 mg/mL) colostrum concentrations were observed at partum, decreased quickly, and finally stabilized. The change law of concentration of IgA and IgM in colostrum are the same with IgG. Furthermore, the whole-genome resequencing was performed, and a missense variant locus in the SRC gene and two missense locus variants in the HIF1A gene were significantly associated with the colostrum yield of sheep by using the whole-genome selection signal detection analysis. In conclusions, colostrum contains abundant nutrients especially immunoglobulin, and the HIF1A gene may be used as candidate genes for colostrum yield, which has important information as a basic knowledge for the Hu sheep breeding program.

Possibility of Using Different Calcium Compounds for the Manufacture of Fresh Acid Rennet Cheese from Goat's Milk

Calcium can be added to cheese milk to influence the coagulation process and to increase cheese yield. Calcium compounds used in the dairy industry show substantial differences in their practical application. Therefore, this study aimed to evaluate the potential use of 0, 5, 10, 15, and 20 mg Ca 100 g-1 of milk in the form of calcium gluconate, lactate, and carbonate as alternatives to calcium chloride in manufacturing fresh acid rennet cheese from high-pasteurized (90 °C, 15 s) goat's milk. The pH value of the cheese was reduced most strongly by the addition of increasing doses of calcium lactate (r = -0.9521). Each cheese sample showed increased fat content with the addition of calcium. Only calcium chloride did not reduce protein retention from goat's milk to cheese. The addition of 20 mg Ca 100 g-1 of milk in the form of gluconate increased cheese yield by 4.04%, and lactate reduced cheese yield by 2.3%. Adding each calcium compound to goat's milk significantly increased Ca and P levels in the cheese (p ≤ 0.05). The highest Ca levels were found in cheese with the addition of 20 mg Ca 100 g-1 of milk in the form of lactate. In all groups, similar contents of Mn, Mo, and Se were found. Calcium addition significantly affected cheese hardness, while higher calcium concentrations increased hardness. Carbonate caused the greatest increase in the cohesiveness of cheese. The addition of calcium compounds increased the adhesiveness and springiness of cheese compared to controls. The cheese with calcium chloride had the highest overall acceptability compared to the other cheese samples. The addition of calcium carbonate resulted in a lower score for appearance and consistency, and influenced a slightly perceptible graininess, sandiness, and stickiness in its consistency, as well as provided a slightly perceptible chalky taste.

Exploring the health benefits and functional properties of goat milk proteins

Goat milk proteins are unique in their nutritional and functional properties and have become increasingly popular in recent years. A variety of methods have been studied for extracting and isolating these proteins, with coprecipitation being a particularly effective approach. Compared to cow milk proteins, goat milk proteins contain higher levels of certain amino acids such as tryptophan and cysteine, while maintaining similar nutritional properties. Additionally, they have superior functional properties, including better emulsifying and foaming properties, which make them an attractive option for developing new food products. Research has shown that goat milk proteins have several health benefits, including immunomodulatory effects, allergy management, anti-inflammatory, and antioxidant effects, as well as antimicrobial and anticancer properties. They have the potential to be used as a treatment for autoimmune diseases, allergies, and other immune system disorders due to their ability to modulate the production of cytokines and other immune system components. Furthermore, their antimicrobial properties can help prevent the growth of harmful bacteria and reduce the risk of infection. Future research will focus on the potential of goat milk proteins as a functional food ingredient, their effects on gut health and microbiota, and their therapeutic potential for various health conditions. This research may lead to the development of new functional foods that promote health and prevent disease, and potentially pave the way for the use of goat milk proteins as a therapeutic agent for various health conditions.

Effect of different post-partum therapeutic protocols with intrauterine oxytetracycline, oxytocin and/or GnRH injection in post-kidding goats on oxytetracyclines residues in goat milk and postpartum ovarian resumption with referring to clinical and haematological pictures

BACKGROUND

The post-parturient period in goat had marked changes in an animal's endocrine and metabolic status as well as by reduction in feed intake when the nutrient demand for impending lactogenesis was increasing. The current study aimed to monitor the residues of oxytetracycline in Baladi goat milk and their hazards on public health as well as the time required until complete disappearance of this medicament from milk through following up periods included 0, 12, 24, 36, 48, 60, 72, 84, 96 and 120 h in post-kidding goat following intrauterine application of oxytetracycline. The study also compared between the efficacy of oxytetracycline only, oxytetracycline with oxytocin, or oxytetracycline with GnRH, through monitoring the clinical findings and haematological pictures at days 0, 5 and 7 post-partum as well as studying the changes in numbers and size of follicles at days 15, 30 and 45 postpartum after different treatments strategies in different groups i.e. Control healthy goat (Contgr), Oxytetracycline treated goat (Oxytetgr), Oxytetracycline-oxytocin treated goat (Oxytet-Oxytogr) and Oxytetracycline-GnRH treated goat (Oxytet-GnRHgr). The study was carried out on clinically healthy Baladi goats (n = 40) that gave birth recently. They were divided into 4 equal groups (n = 10 goats for each); Contgr which received no medication after birth, Oxytetgr which administrated oxytetracycline tablets intrauterine at day of birth, Oxytet-Oxytogr which treated by oxytetracycline tablets intrauterine at day of birth followed by oxytocin injection at 3rd day after birth, and Oxytet-GnRHgr which treated by oxytetracycline tablets intrauterine at day of birth followed by GNRH injection at 3rd day after birth.

RESULTS AND CONCLUSIONS

The study concluded the highest oxytetracyclines residues in goats' milk were reported after 36 h following intrauterine oxytetracycline application where complete disappearance of oxytetracyclines residues in goats' milk required 120 h elapsed after intrauterine oxytetracycline application in which the goats milk became safe for human consumption. The study also reported powerful influence of the applied variable therapeutic regimens on post-partum ovarian resumption through clear significant variations in numbers and sizes of follicles either between different goats' groups within the same day, or between days 15, 30 and 45 post-partum within each independent goat group.

Revolutionizing goat milk gels: A central composite design approach for synthesizing ascorbic acid-functionalized iron oxide nanoparticles decorated alginate-chitosan nanoparticles fortified smart gels

Goat milk gels (GMGs) are popular food due to their high water content, low-calorie density, appealing taste, texture enhancers, stability, and satiety-enhancing characteristics, making them ideal for achieving food security and zero hunger. The GMGs were optimized using the central composite design matrix of response surface methodology using goat milk powder (35-55 g), whole milk powder (10-25 g), and potato powder (10-15 g) as independent variables. In contrast, complex modulus, flow stress, and forward extrudability were chosen as dependent variables. The maximum value of complex modulus 33670.9 N, good flow stress 7863.6 N, and good extrudability 65.32 N was achieved under optimal conditions. The optimized goat milk gel was fortified with ascorbic acid-coated iron oxide nanoparticle (magnetic nature) decorated alginate-chitosan nanoparticles (AA-MNP@CANPs), making it nutritionally rich in an economically feasible way-the decorated AA-MNP@CANPs characterized for size, shape, crystallinity, surface charge, and optical characteristics. Finally, the optimized fortified smart GMGs were further characterized via Scanning electron microscopy, Rheology, Texture profile analysis, Fourier transforms infrared (FTIR), and X-Ray Diffraction (XRD). The fortified smart GMGs carry more nutritional diversity, targeted iron delivery, and the fundamental sustainability development goal of food security.

Effect of Herbal Feed Additives on Goat Milk Volatile Flavor Compounds

The aim of this study is to investigate the effects of herbal supplements administered to goats on sensory quality and volatile flavor compounds in their milk. The experiment was conducted on sixty Polish white improved goats randomly allocated into five feeding groups (four experimental and one control) of twelve goats each. The trial lasted 12 weeks. The experimental animals received supplements containing a mixture of seven or nine different species of herbs at 20 or 40 g/animal/day. The control group received feed without any herbal supplements. Milk obtained from experimental and control groups of animals was characterized by a low content of aroma compounds, with only 11 chemical compounds being identified. Decanoic methyl ester, methylo 2-heptanone and methylo-butanoic methyl ester had the highest share in the total variability of the tested aroma compounds (PCA). During the sensory evaluation, the smell and taste of most of the samples were similar (p > 0.05). However, the addition of herbal feed supplements lowered the concentration of Caproic acid (C6:0), Caprylic acid (C8:0) and Capric acid (C10:0), which caused a significant reduction in the goaty smell of milk. The obtained results indicate that the studied herbal supplements can reduce the intensity of goaty smell and allow goat milk production without modification of other sensory features.

A Study on Differential Biomarkers in the Milk of Holstein Cows with Different Somatic Cells Count Levels

Dairy cow mastitis is one of the common diseases of dairy cows, which will not only endanger the health of dairy cows but also affect the quality of milk. Dairy cow mastitis is an inflammatory reaction caused by pathogenic microorganisms and physical and chemical factors in dairy cow mammary glands. The number of SCC in the milk of dairy cows with different degrees of mastitis will increase in varying degrees. The rapid diagnosis of dairy cow mastitis is of great significance for dairy cow health and farm economy. Based on the results of many studies on the relationship between mastitis and somatic cell count in dairy cows, microflora, and metabolites in the milk of Holstein cows with low somatic cell level (SCC less than 200,000), medium somatic cell level (SCC up to 200,000 but less than 500,000) and high somatic cell level (SCC up to 5000,00) were analyzed by microbiome and metabolic group techniques. The results showed that there were significant differences in milk microbiota and metabolites among the three groups (p < 0.05), and there was a significant correlation between microbiota and metabolites. Meanwhile, in this experiment, 75 differential metabolites were identified in the H group and L group, 40 differential metabolites were identified in the M group and L group, and six differential microorganisms with LDA scores more than four were found in the H group and L group. These differential metabolites and differential microorganisms may become new biomarkers for the diagnosis, prevention, and treatment of cow mastitis in the future.

Milk Transmission of Mammalian Retroviruses

The transmission of viruses from one host to another typically occurs through horizontal or vertical pathways. The horizontal pathways include transmission amongst individuals, usually through bodily fluids or excretions, while vertical transmission transpires from mother to their offspring, either during pregnancy, childbirth, or breastfeeding. While there are more than 200 human pathogenic viruses to date, only a small number of them are known to be transmitted via breast milk, including cytomegalovirus (CMV), human immunodeficiency virus type 1 (HIV-1), and human T cell lymphotropic virus type 1 (HTLV-1), the latter two belonging to the family Retroviridae. Breast milk transmission is a common characteristic among mammalian retroviruses, but there is a lack of reports summarizing our knowledge regarding this route of transmission of mammalian retroviruses. Here, we provide an overview of the transmission of mammalian exogenous retroviruses with a focus on Orthoretrovirinae, and we highlight whether they have been described or suspected to be transmitted through breast milk, covering various species. We also elaborate on the production and composition of breast milk and discuss potential entry sites of exogenous mammalian retroviruses during oral transmission.

Effect of Fish Oil and Linseed Oil on Intake, Milk Yield and Milk Fatty Acid Profile in Goats

This study aimed to evaluate the effect of incorporating linseed oil and fish oil in the diet on intake, ruminal fermentation, milk yield, and milk fatty acid profiles in dairy goats. Four crossbred Saanen lactating goats in mid-lactation and milking 1.30 ± 0.28 g/day were used in a 4 × 4 Latin square design. The basal diet contained concentrate and Para grass (C:F 40:60). Treatments included a basal diet without oil supplementation (Ctrl) or with 2.5% linseed oil (LO_2.5), 2.5% linseed oil and fish oil (3:2, w/w, LFO_2.5), and 4.16% linseed oil and fish oil (3:2, w/w, LFO_4.16). Diets had no effect on intake, milk yield, milk composition, or ruminal fermentation (p > 0.05). Compared with Ctrl, lower (p < 0.05) proportions of C10:0-C14:0 in milk fat were observed with LFO_4.16. Compared with the Ctrl and linseed oil added alone, feeding LFO_4.16 led to a greater (p < 0.01) concentration of C18:1 t11. Compared with both the Ctrl and LO_2.5 diets, milk c9,t11 CLA was 4.53 and 2.94 times greater with the LFO_4.16 diet. Compared with Ctrl and LO_2.5 diets (0.06% and 0.08%), goats fed LFO_2.5, and LFO_4.16 had greater (p < 0.001) concentrations of C22:6n-3 (0.63% and 0.87%). Overall, the combined data suggested that including 4.16% linseed oil and fish oil in the diet of dairy goats was effective in improving the concentrations of health-promoting fatty acids in milk without affecting milk production.

The protein dynamics of bovine and caprine β-lactoglobulin differ as a function of pH

The properties of milk proteins differ between mammalian species. β-Lactoglobulin (βlg) proteins from caprine and bovine milk are sequentially and structurally highly similar, yet their physicochemical properties differ, particularly in response to pH. To resolve this conundrum, we compared the dynamics of both the monomeric and dimeric states for each homologue at pH 6.9 and 7.5 using hydrogen/deuterium exchange experiments. At pH 7.5, the rate of exchange is similar across both homologues, but at pH 6.9 the dimeric states of the bovine βlg B variant homologue have significantly more conformational flexibility compared with caprine βlg. Molecular dynamics simulations provide a mechanistic rationale for the experimental observations, revealing that variant-specific substitutions encode different conformational ensembles with different dynamic properties consistent with the hydrogen/deuterium exchange experiments. Understanding the dynamic differences across βlg homologues is essential to understand the different responses of these milks to processing, human digestion, and differences in immunogenicity.

The Evaluation of Activity of Selected Lactic Acid Bacteria for Bioconversion of Milk and Whey from Goat Milk to Release Biomolecules with Antibacterial Activity

The aim of the study was to assess the antibacterial features of functional macromolecules released during the fermentation of goat milk and whey from goat milk by selected lactic acid bacteria strains that are components of kefir grain microflora. Two milk sources were used: goat milk and whey from goat milk. The lactic acid bacteria (LAB) and indicator microorganisms used were Lactobacillus plantarum PCM 1386, Lactobacillus fermentum PCM 491, Lactobacillus rhamnosus PCM 2677, Lactobacillus acidophilus PCM 2499, Escherichia coli PCM 2793, Salmonella enteritidis PCM 2548, Micrococcus luteus PCM 525, and Proteus mirabilis PCM 1361. The metabolic activity of LAB was described by the Gompertz model, and the parameters proposed for this experiment were the maximum rate of change of electrical impedance and potential biodegradability. Antibacterial activity was examined using the culture method in a liquid medium, determination of the reduction in indicator microorganisms, and optical density changes. Results show that the selective LAB produced certain active biomolecules with antibacterial activity from whey, a by-product that is sometimes troublesome for goat milk processors to manage. Lactobacillus acidophilus is a microorganism that is characterized by the highest metabolic activity in goat milk and whey from goat milk. It has the possibility to produce macromolecules with antibacterial activity.

N-glycan profiles as a tool in qualitative and quantitative analysis of goat milk adulteration

Goat milk is closer to human milk in some respects than cow milk, and therefore preferred by many consumers. Because of the short lactation period and consequently less milk production of goats, the price of goat milk is often higher than that of cow milk, so that adulteration of goat milk is common. N-glycans have stability and thus have a good potential for acting as a new biomarker for identifying dairy adulteration. In this study, the N-glycan structures of goat milk and cow milk were analyzed by Ultra-high performance liquid chromatography (UPLC) and MALDI-TOF-MS. Based on the high species specificity of N-glycans, a method for identifying goat milk mixed with cow milk was established. The adulteration content of 5% cow milk in goat milk could be qualitatively and quantitatively detected. A prediction model of adulteration in goat milk was established by using partial least squares (PLS).

Novel Method for Adulterated Identification of Saneen Goat Milk Based on Free Oligosaccharides α3'-Galactosyllactose and N-Acetylhexaminyllactose as Marker Molecules

Methods for the detection of adulterated milk are essential for assessing the quality of goat milk products. We hypothesized that goat milk oligosaccharides could provide a basis for this purpose and compared the levels of α3'-galactosyllactose (α3'-GL) and N-acetylhexaminyllactose (NHL) between goat milk and bovine milk oligosaccharides using reverse-phase high-performance liquid chromatography. The α3'-GL was detected to be three times more abundant in goat milk than in bovine milk, whereas NHL showed the opposite trend. Linear relationships were established between the relative proportions of α3'-GL and NHL levels for different ratios of bovine and goat milk, with a minimum detection limit of 2% bovine milk. The new method was validated by analyses of adulterants in eight commercially available goat dairy products. Overall, the degree of adulteration in goat milk products can be determined based on the relative proportions of α3'-GL and NHL.

A Rapid RPA-CRISPR/Cas12a Detection Method for Adulteration of Goat Milk Powder

Because of the serious adulteration of goat milk, the rapid on-site detection of goat milk powder adulteration is needed. In this study, the CRISPR/Cas12a detection system combined with recombinase polymerase amplification (RPA) was employed to qualitatively detect the adulteration of goat milk powder with cattle-derived components. Specific primers and crRNA were designed and screened. After the optimization of RPA and the Cas system, the RPA-CRISPR/Cas12a detection method was established. The detection can complete the rapid identification of cattle-derived components in 45 min, without the assistant of large equipment. The absolute detectability of the RPA-CRISPR/Cas12a assay could reach 10^-2 ng/μL for cattle genomic DNA, and 1% (w/w) for cattle milk powder, which is suitable to meet the testing requirements for on-site detection. In total, 55 commercial goat milk powder products were collected for blind testing. The results showed that 27.3% of the samples were adulterated with cattle ingredients, revealing a serious adulteration situation in goat milk powder market. The RPA-CRISPR/Cas12a assay established in this research exhibited its potential for practical use of on-site detection to detect cow milk powder in goat milk powder and can provide reliable technical reference for combating food fraud of adulteration of goat milk products.

Goat milk powder supplemented with branched-chain fatty acid: influence on quality and microstructure

BACKGROUND

Branched-chain fatty acid (BCFA) is effective in preventing and helping to treat neonatal necrotizing enterocolitis. It is essential to supplement goat-milk powder for formula-fed preterm infants with BCFA. In this study, the quality and microstructures of milk powders supplemented with different concentrations of BCFA were evaluated, using goat milk powder without BCFA as the control group (CG).

RESULTS

In comparison with the CG, goat milk powder supplemented with BCFA exhibited smaller fat globules and a significant drop in overall particle size. During 16 weeks of storage, BCFA-supplemented groups showed suitable moisture content and viscosity and good solubility. The BCFA also helped reduce the number of folds on the surface of the milk powder particles.

CONCLUSION

The findings of this study indicate that goat milk powders with BCFA exhibit differences in quality and microstructure in comparison with ordinary goat milk powder, which is relevant for the future development and application of BCFA in foods. © 2022 Society of Chemical Industry.

Associations between Somatic Cell Count and Milk Fatty Acid and Amino Acid Profile in Alpine and Saanen Goat Breeds

The main goal of this study was to evaluate the relation of different SCC levels in goat milk with goat milk yield, milk composition, FA, and AA profiles. Whereas the investigated herd was composed of Alpine and Saanen goats, the influence of breed on milk parameters and milk yield was also assessed. The research was carried out in 2022 at a Lithuanian dairy goat farm with 135 goats (Saanen = 66 and Alpine = 69) without evidence of clinical mastitis. The current research revealed a relationship between SCC with goat milk yield and composition. Goats with a high SCC had significantly lower milk yield (p < 0.001), lower content of lactose (p < 0.01), fat (p < 0.001) and higher protein content (p < 0.05) in their milk. The increase in most AA was significantly associated with increased SCC. The higher quantity of Asp, Glu, Ala, Met, His, Lys, Arg, EAA, NEAA, and TAA (compared with the low SCC group) (p < 0.05–0.01), Leu, Tyr, and BCAA (compared with the low and medium SCC group) were found in the milk of the high SCC group (p < 0.05–0.01). The distribution of the main FA groups was also related to SCC and showed a significant decrease in SCFA (p < 0.01–0.001) and an increase in LCFA, PUFA, and BCFA in the high SCC group (p < 0.05). All individual AA and their groups (EAA, NEAA, TAA, BCAA) were significantly lower in the milk of the Saanen goat breed (p < 0.001). The most individual FA ranged between goat breeds, while the total amount of SFA, UFA, and MUFA wasn’t affected by breed (p > 0.05). The research revealed a statistically significant relationship between SCC, AA, and FA, suggesting that these traits may be used as a biomarker in the goat selection process.

Cross-reactivity analysis of milk proteins from different goat breeds with cow's milk allergens using a proteomic approach

INTRODUCTION

Goat's milk thought to be a good substitute for cow's milk protein allergic (CMPA) individuals. However, there is growing evidence that their proteins have cross-reactivities with cow's milk allergens. This study aimed to profile and compare milk proteins from different goat breeds that have cross-reactivity to cow's milk allergens.

METHODOLOGY

Proteomics was used to compare protein extracts of skim milk from Saanen, Jamnapari, and Toggenburg. Cow's milk was used as a control. IgE-immunoblotting and mass spectrometry were used to compare and identify proteins that cross-reacted with serum IgE from CMPA patients (n = 10).

RESULTS

The analysis of IgE-reactive proteins revealed that the protein spots identified with high confidence were proteins homologous to common cow's milk allergens such as α-S1-casein (αS1-CN), β-casein (β-CN), κ-casein (κ-CN), and beta-lactoglobulin (β-LG). Jamnapari's milk proteins were found to cross-react with four major milk allergens: α-S1-CN, β-CN, κ-CN, and β-LG. Saanen goat's milk proteins, on the other hand, cross-reacted with two major milk allergens, α-S1-CN and β-LG, whereas Toggenburg goat's milk proteins only react with one of the major milk allergens, κ-CN.

CONCLUSION

These findings may help in the development of hypoallergenic goat milk through cross-breeding strategies of goat breeds with lower allergenic milk protein contents.

Potential of Capric Acid in Neurological Disorders: An Overview

To solve the restrictions of a classical ketogenic diet, a modified medium-chain triglyceride diet was introduced which required only around 60% of dietary energy. Capric acid (CA), a small molecule, is one of the main components because its metabolic profile offers itself as an alternate source of energy to the brain in the form of ketone bodies. This is possible with the combined capability of CA to cross the blood-brain barrier and achieve a concentration of 50% concentration in the brain more than any other fatty acid in plasma. Natural sources of CA include vegetable oils such as palm oil and coconut oil, mammalian milk and some seeds. Several studies have shown that CA has varied action on targets that include AMPA receptors, PPAR-γ, inflammatory/oxidative stress pathways and gut dysbiosis. Based on these lines of evidence, CA has proved to be effective in the amelioration of neurological diseases such as epilepsy, affective disorders and Alzheimer's disease. But these studies still warrant more pre-clinical and clinical studies that would further prove its efficacy. Hence, to understand the potential of CA in brain disease and associated comorbid conditions, an advance and rigorous molecular mechanistic study, apart from the reported in-vitro/in-vivo studies, is urgently required for the development of this compound through clinical setups.

Lebanese fermented goat milk products: From tradition to meta-omics

Ambriss, Serdaleh and Labneh El Darff are traditional Lebanese products made from fermented goat's milk. A questionnaire completed by 50 producers of these products showed that they are prepared by periodic percolation either by milk or by Laban in amphora or goat skins during the lactation season. Production is carried out on a small scale and in a limited number of production units, often by elderly people, resulting in a real risk of disappearance of these products and loss of the corresponding microbial resources. In this study, 34 samples from 18 producers were characterized by culture-dependent and -independent analyses. The results obtained from these two methods were radically different, the latter revealing in Ambriss and Serdaleh the co-dominance of Lactobacillus kefiranofaciens, a fastidious-growing species, and Lactococcus lactis in a viable but not culturable state. Overall, their composition is reminiscent of kefir grains. Phylogenomic and functional analyses of the genomes of the key species Lb. kefiranofaciens have revealed differences from those found in kefir, particularly in their polysaccharide genes, which may explain the absence of grains. However, Labneh El Darff displayed a dominance of Lactobacillus delbrueckii, probably due to the addition of Laban. In addition, the study identified several zoonotic pathogens, including Streptococcus parasuis, which dominated in one sample. Metagenome-Assembled Genome (MAG) analysis indicated that this pathogen acquired lactose utilization genes through horizontal gene transfer. The contamination of the herd with Mycoplasmopsis agalactiae in the Chouf region was also revealed by MAG analysis of the Serdaleh samples. Antibiotic resistance genes were detected in most of the samples, particularly in the Serdaleh ones, where the dominant L. lactis strains possessed a plasmid with a multi-resistance island. Finally, this study paves the way for further analyses to shed light on the resilience of these ecosystems established in amphora or in goatskins and to improve hygiene practices for milk production.

Effects of Macleaya Cordata Extract on Performance, Nutrient Apparent Digestibilities, Milk Composition, and Plasma Metabolites of Dairy Goats

In this study, we aimed to investigate the effects of Macleaya cordata extract (MCE) supplementation on performance, nutrient apparent digestibilities, plasma metabolites, and milk quality in dairy goats. Twenty-four lactating Guanzhong dairy goats (n = 24) were randomly divided into two groups (each containing 12 goats) in a 52-day trial: the CON group was fed a basal diet; the MCE group was fed a basal diet supplemented with 400 mg/kg MCE. The results indicated that the 4% fat corrected milk yield (4% FCM); uncorrected milk yield; milk-fat concentration; content of C4:0, C18:0, and C18:1n9c fatty acids in milk; and apparent digestibility of neutral detergent fiber (NDF) and acid detergent fiber (ADF) in the MCE group were significantly higher (p < 0.05). Furthermore, the lactoferrin (LTF), alpha-lactalbumin (α-La), and beta-lactoglobulin (β-Lg) of the milk and feed conversion rate (FCR) of the goats were significantly greater (p < 0.01) in the MCE group than in the CON group. In contrast, the somatic cell count (SCC) (p < 0.01), content of C14:0 fatty acids (p < 0.01) of milk, and blood urea nitrogen (BUN) concentrations (p < 0.05) were significantly lower in the in the MCE goats. These results show that the feeding of MCE can increase the performance and apparent nutrient digestibility of fiber in dairy goats, improving the quality of goat milk.

Whole-genome resequencing reveals genetic diversity and selection characteristics of dairy goat

The dairy goat is one of the earliest dairy livestock species, which plays an important role in the economic development, especially for developing countries. With the development of agricultural civilization, dairy goats have been widely distributed across the world. However, few studies have been conducted on the specific characteristics of dairy goat. In this study, we collected the whole-genome data of 89 goat individuals by sequencing 48 goats and employing 41 publicly available goats, including five dairy goat breeds (Saanen, Nubian, Alpine, Toggenburg, and Guanzhong dairy goat; n = 24, 15, 11, 6, 6), and three goat breeds (Guishan goat, Longlin goat, Yunshang Black goat; n = 6, 15, 6). Through compared the genomes of dairy goat and non-dairy goat to analyze genetic diversity and selection characteristics of dairy goat. The results show that the eight goats could be divided into three subgroups of European, African, and Chinese indigenous goat populations, and we also found that Australian Nubian, Toggenburg, and Australian Alpine had the highest linkage disequilibrium, the lowest level of nucleotide diversity, and a higher inbreeding coefficient, indicating that they were strongly artificially selected. In addition, we identified several candidate genes related to the specificity of dairy goat, particularly genes associated with milk production traits (GHR, DGAT2, ELF5, GLYCAM1, ACSBG2, ACSS2), reproduction traits (TSHR, TSHB, PTGS2, ESR2), immunity traits (JAK1, POU2F2, LRRC66). Our results provide not only insights into the evolutionary history and breed characteristics of dairy goat, but also valuable information for the implementation and improvement of dairy goat cross breeding program.

Genome-wide analysis for the melatonin trait associated genes and SNPs in dairy goat (Capra hircus) as the molecular breeding markers

Previous studies have reported that the endogenous melatonin level is positively associated with the quality and yield of milk of cows. In the current study, a total of 34,921 SNPs involving 1,177 genes were identified in dairy goats by using the whole genome resequencing bulked segregant analysis (BSA) analysis. These SNPs have been used to match the melatonin levels of the dairy goats. Among them, 3 SNPs has been identified to significantly correlate with melatonin levels. These 3 SNPs include CC genotype 147316, GG genotype 147379 and CC genotype 1389193 which all locate in the exon regions of ASMT and MT2 genes. Dairy goats with these SNPs have approximately 5-fold-higher melatonin levels in milk and serum than the average melatonin level detected in the current goat population. If the melatonin level impacts the milk production in goats as in cows, the results strongly suggest that these 3 SNPs can serve as the molecular markers to select the goats having the improved milk quality and yield. This is a goal of our future study.

Licury Cake in Diets for Lactating Goats: Qualitative Aspects of Milk and Cheese

The study was carried out to evaluate the effects of licury cake (LC) inclusion in diets for lactating goats on milk chemical composition and fatty acid profile, and physicochemical composition and sensory attributes of Minas Frescal cheese. Twelve lactating goats were used (eight Saanen and four Anglo Nubian goats, with 35 ± 5 days in lactation and average body weight of 37.93 ± 9.22 kg), distributed in a triplicate 4 × 4 Latin Square design. The increasing levels of LC studied were: 0, 67, 133 and 200 g/kg of dry matter (DM). The analyses were adjusted using orthogonal polynomial contrasts, in which the probability level of 5% was considered. For sensory attributes, principal component analysis was performed. The LC inclusion promoted the reduction in moisture (p = 0.013) and mineral matter (p < 0.001) content in cheese. The ether extract content in cheese showed a quadratic effect (p = 0.021). Lauric acid showed a linear (p = 0.002) increasing effect, and myristic (p < 0.001) and rumenic (p = 0.018) acids showed quadratic effects. The sensory attributes analysis in cheese indicated that the inclusion of 133 and 200 g/kg of LC improve its texture. Flavor was improved with the inclusion of 67 and 133 g/kg. The inclusion of up to 133 g/kg of LC in the diet of lactating goats is recommended because it promotes improvements in flavor and texture of Minas Frescal cheese.

Review: Genetic and protein variants of milk caseins in goats

The milk casein genes in goats, are highly polymorphic genes with numerous synonymous and non-synonymous mutations. So far, 20 protein variants have been reported in goats for alpha-S1-casein, eight for beta-casein, 14 for alpha-S2-casein, and 24 for kappa-casein. This review provides a comprehensive overview on identified milk casein protein variants in goat and non-coding DNA sequence variants with some affecting the expression of the casein genes. The high frequency of some casein protein variants in different goat breeds and geographical regions might reflect specific breeding goals with respect to milk processing characteristics, properties for human nutrition and health, or adaptation to the environment. Because protein names, alongside the discovery of protein variants, go through a historical process, we linked old protein names with new ones that reveal more genetic variability. The haplotypes across the cluster of the four genetically linked casein genes are recommended as a valuable genetic tool for discrimination between breeds, managing genetic diversity within and between goat populations, and breeding strategies. The enormous variation in the casein proteins and genes is crucial for producing milk and dairy products with different properties for human health and nutrition, and for genetic improvement depending on local breeding goals.

Meta-analytic effect of Saccharomyces cerevisiae on dry matter intake, milk yield and components of lactating goats

The results of investigations on the impact of Saccharomyces cerevisiae (SC) on performance characteristics of lactating goats are inconsistent. Thus, this study aimed to summarize available evidence on the effect of SC supplementation on dry matter intake (DMI), milk yield and composition in lactating goats using meta-analysis. A systematic search performed on Scopus, Google Scholar and PubMed databases yielded 1,368 studies of which 18 were used for the meta-analysis. Subgroup and meta-regression analyses were performed to explore the sources of heterogeneity in response to dietary SC supplementation. A random-effects model showed that SC had a moderate effect on milk yield [standardized mean differences (SMD) = 0.51; 95% CI: 0.20 to 0.82, p = 0.001] and milk fat (SMD = 0.30; 95% CI: 0.05 to 0.55, p = 0.02) in lactating goats when compared to the controls. Subgroup analysis by SC type indicated that live SC had a large to moderate effect on milk yield (SMD = 1.46; 95% CI: 0.96 to 1.96, p < 0.001) and milk fat (SMD = 0.51; 95% CI: 0.19 to 0.84, p = 0.002), whereas dead SC had a large negative effect on DMI (SMD = -0.82; 95% CI: -1.28 to -0.7, p < 0.001) and a moderate reduction effect on milk yield (SMD = -0.55; 95% CI: -0.99 to -1.96, p = 0.015). We found significant heterogeneity across studies that evaluated the effect of SC treatment on DMI and milk yield in lactating goats and meta-regression analysis explained most of the sources of heterogeneity. In conclusion, pooled results showed that dietary SC supplementation increased milk yield and fat in lactating goats. In addition, subgroup analysis revealed that both live and fermented SC increased milk yield and fat in lactating goats, while dead SC reduced DMI and milk yield.

Comparative characteristics of goat milk products in farms of Akmola and North Kazakhstan regions

Providing the population with high-quality products is a priority intention of the government. North Kazakhstan and Akmola regions are the most promising in developing the country's dairy cattle breeding and milk processing. An assessment of the qualitative indicators of milk production and processing in these areas would allow us to assess the dynamics of the development of the country's dairy industry and identify the main problems, so research on this issue is relevant. The study aimed to analyze the qualitative indicators of milk production and processing at the enterprises of the North Kazakhstan and Akmola regions, the factors affecting the quality of dairy products, and the prospects for expanding the range of enterprises. In the study, an InfraXact infrared analyzer was used to determine the quality of haylage in the diet of goats and for goat milk - the CombiFoss FT + analyzer. Generally, the quality of milk on the goat farms "Zeren" and "Tamasha-2050" in terms of fat, protein, lactose, fatty acid composition of milk fat, and somatic cells meets the regulatory requirements. The specificity of the goat farm "Tamasha-2050" is the production of various hard and soft cheese types. Farm "Zeren" is focused on the production scale and a wide range of products (drinking milk, yogurt, kefir, and ice cream). It was concluded that there is a wide choice for the consumer of high-quality dairy products from goat milk in enterprises.

Multi-Objective Optimization of Beverage Based on Lactic Fermentation of Goat’s Milk Whey and Fruit Juice Mixes by Kefir Granules

Numerous fruits are produced in Ecuador, of which about 40% are never eaten. In addition, fresh goat cheeses are in high demand. However, goat cheese generates goat milk whey with high contamination loads, and, therefore, it must be adequately treated before being discharged into ecosystems. This research aims to use a mixture of tree tomato, common strawberry juices, and goat’s milk whey, to be statically fermented by milk and water kefir grains (WKG) for 48 h. For this, a dual mixture design of L-optimal response surface methodology was carried out to find the conditions that maximized all the responses evaluated (lactic-acid bacteria and yeasts concentrations and the overall acceptability assessed on a 7-point scale). Experiments were carried out in San Gabriel, Ecuador. Temperatures during the day and night were 20.2 ± 0.3 °C and 18.7 ± 0.3 °C, respectively. Three conditions were selected, where the highest response values were reached. Complementary experiments demonstrated the validity of the models. When comparing the results of the present study with similar ones carried out previously, higher values were observed in the concentration of yeasts, which seems related to the presence of the WKG. It is concluded that they could be suitable functional beverage candidates.

Changes in Caprine Milk Fat Globule Membrane Proteins after Heat Treatment Using a Label-Free Proteomics Technique

Milk proteins are prone to changes during the heat treatment process. Here, we aimed to study the changes in caprine milk fat globule membrane (MFGM) proteins with three heat treatment processes—ultra-pasteurization (85 °C, 30 min), ultra-high-temperature instant sterilization (135 °C, 5 s), and spray-drying (inlet, 160 °C and outlet, 80 °C)—using the label-free proteomics technique. A total of 1015, 637, 508, and 738 proteins were identified in the raw milk, ultra-pasteurized milk, ultra-high-temperature instant sterilized milk, and spray-dried reconstituted milk by using label-free proteomics techniques, respectively. Heat treatment resulted in a significant decrease in the relative intensity of MFGM proteins, such as xanthine dehydrogenase/oxidase, butyrophilin subfamily 1 member A, stomatin, and SEA domain-containing protein, which mainly come from the membrane, while the proteins in skimmed milk, such as β-lactoglobulin, casein, and osteopontin, increased in MFGM after heat treatment. Among these different heat treatment groups, the procedure of spray-drying resulted in the least abundance reduction of caprine milk MFGM proteins. Additionally, it showed heating is the key process affecting the stability of caprine MFGM protein rather than the spray-drying process. These findings provide new insights into the effects of heat treatment on caprine MFGM protein composition and potential biological functions.

Nutritional Profile, Processing and Potential Products: A Comparative Review of Goat Milk

Goat milk contains an abundance of different macro and micro-nutrients. Compared with other milk, goat milk is a viable option due to its low allergy levels and is preferred for infants with cow milk allergies. A wide variety of goat milk-based products, including yoghurt, ice cream, fermented milk, and cheese, are available on the market. They are produced using effective processing technology and are known to exhibit numerous health benefits after consumption. However, goat milk consumption is limited in many nations (compared with cow, buffalo, camel, and sheep milk) due to a lack of awareness of its nutritional composition and the significance of its different byproducts. This review provides a detailed explanation of the various macronutrients that may be present, with special attention paid to each component, its purpose, and the health benefits it offers. It also compares goat milk with milk from other species in terms of its superiority and nutritional content, as well as the types, production methods, health advantages, and other beneficial properties of the various goat milk products that are currently available on the market.