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.

Effect of Crude Glycerin in the Feed of Lactating Goats on Concentrations of Essential and Toxic Metals in Serum, Urine, Milk, and Artisanal "Coalho" Cheese

Goat farming is concentrated in semi-arid and tropical regions in Brazil. From 2006 to 2017, the number of goats sold in the country increased by 65.7%. The dairy products from these animals present higher digestibility, high vitamin A and B content, hypoallergenicity, and less lactose compared to dairy products from cows, in addition to having a higher sales value. Since corn and soybean meal generate an expense for feed management, crude glycerin, originating from the manufacture of biodiesel, has been studied as an energy substitute. However, this product contains heavy metals, posing risks to animal and human health. Few data are available on trace elements in biological samples and products derived from goats' milk with the dietary introduction of glycerin. The objective was to quantify aluminum (Al), cadmium (Cd), cobalt (Co), chromium (Cr), copper (Cu), iron (Fe), manganese (Mn), molybdenum (Mo), nickel (Ni), lead (Pb), and zinc (Zn) in the serum, urine, milk, and artisanal "coalho" cheese of dairy goats fed different levels of crude glycerin in feed management. In total, 16 Saanen goats were selected, lactating females, that were distributed in four Latin squares and randomly treated with different levels of crude glycerin (0, 5, 10, and 15%). After the end of each experiment cycle, serum, urine, milk, and artisanal "coalho" cheese samples were collected at the four moments. The samples were submitted to digestion assisted by microwave radiation. The multi-element analysis was carried out using inductively coupled plasma optical emission spectrometry (ICP OES). There was no influence of crude glycerin levels replacing corn in serum, milk, urine, and artisanal "coalho" cheese. The serum concentration of the metals Cu, Fe, Zn, and Mn; urine concentrations of Cu, Zn, Mn, Mo, and Cr; and milk and artisanal "coalho" cheese concentrations of Cu, Zn, and Mn remained within the standards found in the literature. The inclusion of 5 to 15% of crude glycerin, derived from cotton oil, in the diets of dairy goats in partial replacement of corn, does not alter the concentration of essential and toxic metals in serum, urine, milk, and artisanal "coalho" cheese and does not, therefore, present a risk factor for intoxication.

The prevalence and species of Mycoplasma identified from dairy goats in Taiwan

Except for Mycoplasma capricolum subsp. capripneumoniae, which only causes pneumonia, Mycoplasma species can cause otitis, arthritis, septicemia, mastitis, pneumonia and encephalitis in goats. After a mycoplasma outbreak was recorded in Taiwan in 2016, an increasing number of mycoplasma infection cases have been observed. It is important to understand how many Mycoplasma species are currently prevalent in Taiwan. In this study, 57-61 bulk milk samples were collected from dairy goats in Taiwan every year from 2017 to 2020 to identify the presence of mycoplasma DNA fragments by polymerase chain reaction (PCR). The mycoplasma species were identified based on colony characteristics, PCR, and DNA sequences. In total, 39 out of 236 samples (16.52%) tested mycoplasma positive. The annual mycoplasma prevalence rates from 2017 to 2020 were 24.59% (15/61), 8.20% (5/61), 17.54% (10/57) and 15.79% (9/57), respectively. Mycoplasma mycoides subsp. capri (n = 19), Mycoplasma putrefaciens (n = 10), Mycoplasma ovipneumoniae (n = 5) and Mycoplasma bovis (n = 5) were present in Taiwan. No M. capricolum subsp. capripneumoniae was detected. Except for the large drop in 2018, the prevalence of mycoplasma infection declined to a consistent level for the final two years of the study. However, the seasonal pattern is still worth investigating. This is the first survey of mycoplasma infection in goats, and we believe that a larger survey is still needed to understand the pathogenicity and diversity of these mycoplasma isolates.

Rearing goat kids away from their dams 1. A survey to understand rearing methods

Despite an estimated global goat population of over one billion, little is known about methods being used to feed milk to artificially reared kids (reared away from their dams) and how kids are weaned from these systems. Quantifying and characterising current methods utilised on farms will enable future targeted research to investigate best practice methods for milk feeding and weaning of artificially rearedkids.A recall-based survey that investigated on-farmkid-rearingpractices (focusing on the milk feeding and weaning stages) was distributed via social media, and regional goat organisations across multiple countries. A total of 242 responses from 16 countries were collected and geographically grouped. Responses that could not be grouped sufficiently were removed (nine responses from eight countries). A total of 233 responses from eight countries (United States of America (USA) 72; United Kingdom (UK) 71; Australia 33; Canada 23; New Zealand 20; European Union (EU) 14), were analysed. Most farms (217; 93%) bred their own kids. The most common milk feeding method was bottle feeding, used on 135 farms (57.9%), followed by ad libitum feeding used by 72 (30.9%). A relationship between number of kids reared and feeding system was identified, χ²(3, N = 233) = 89.605,P < 0.001, with farms rearing > 100 kids more likely to feed milk ad libitum. A total of 170 farms (72.9%) were weaned based on a target age and 85 (36.4%) on a target weight, 53 (22.7%) used both and 45 (19.3%) neither. Target weaning ages and weights varied across countries; the median age was 84 days (interquartile range (IQR) 56-84), and the median weight was 16 kg (IQR 15-18). A difference was found between milk feeding systems for weaning method (Χ²(2, N = 232) = 63.797,P≤0.001), with kids most likely to be abruptly weaned from ad libitum systems (or gradually weaned from bottle feeding). Abrupt weaning was used by 67 farms (28.8%), and gradual weaning was used by 165 (71.1%). Gradual weaning strategies included reducing milk quantity (150 farms; 93% of farms providing detail) and diluting milk (six farms; 4%). A total of 169 (72.5%) supplied enrichment that met the survey's definition; items to climb on/hide in were most common, provided by 157 farms (92.8%). Findings suggest differing practices in smaller-scalebottle-fedversuslarger-scalead libitummilksystems, likely reflecting differing system needs.This highlights a requirement for welfare-focused research in kids reared artificiallyin order to identify and communicatebest practices to ensure on-farm welfare is optimised within each system.

pseudotuberculosis by TMT-based quantitative proteomics approach

Corynebacterium pseudotuberculosis (C.pseudotuberculosis) is a zoonotic pathogen that can cause cheese lymphadenitis in goats. In order to obtain detailed information about the pathogenesis and host immune response of goats infected with C.pseudotuberculosis, we used tandem mass tag (TMT)-labeling proteomic analysis to detect differentially expressed proteins (DEPs) in dairy goats infected with C.pseudotuberculosis, and confirmed the altered proteins with western blot. A total of 6611 trusted proteins were identified, and 126 proteins were differentially abundant. Gene ontology (GO) analysis showed that all DEPs were annotated as biological processes, cell composition, and molecular functions. Biological processes mainly involve acute inflammation and immune response; cell components mainly involve extracellular areas and high-density lipoprotein particles; molecular functions are mainly antigen binding, ferric iron binding, and iron ion binding. KEGG analysis showed that a total of 102 pathways were significantly enriched, mainly lysosomes, phagosomes, and mineral absorption pathways. Our findings provided the relevant knowledge of spleen protein levels in goats infected with C.pseudotuberculosis and revealed the complex molecular pathways and immune response mechanisms in the process of C.pseudotuberculosis infection. SIGNIFICANCE: C.pseudotuberculosis is the most fatal infectious disease in dairy goats, causing huge economic losses. However, the molecular pathways and immune response mechanisms of C.pseudotuberculosis infection in goats remain unclear. Therefore, we conducted a comparative quantitative proteomics study on dairy goats infected with C.pseudotuberculosis. The results provide a basis for better understanding the complexity of C.pseudotuberculosis infection, reveal the complex molecular pathways and immune response mechanisms in C.pseudotuberculosis infection, and provide some clues for identifying potential therapeutic targets. This is the first report to show that C.pseudotuberculosis infection in dairy goats can disrupt the immune response mechanism and lead to massive immune cell death. The study provided new findings on the interaction between C.pseudotuberculosis and the host.

Energy requirements and efficiency of Alpine goats in early lactation

Dairy goats may rely heavily on body fat and protein reserves in early lactation. Therefore, we aimed to determine the energy requirement and estimate the efficiency of utilization the nutrients of tissues mobilized in the first 8 weeks of lactation for milk production using the comparative slaughter technique. The average initial body mass of 51 multiparous goats was 57.19 ± 8.38 kg and a body condition score of 3.0 ± 0.5. Three goats were slaughtered at the beginning of the experiment to serve as baseline animals to estimate initial empty BW and initial body composition. We used a complete randomized design in which the factor was the day of lactation for slaughtering (the 7th, 14th, 21st, 28th, 35th, 42nd, 49th and 56th day), with six repeats, totalling 48 goats. No fasting before slaughtering. All animals received a single experimental diet. The efficiency of transferring energy from body reserves to milk was estimated using a multiple linear regression equation yielding a value of 0.76. The total energy stored in the empty body decreased over the eight lactation weeks, from 726.47 ± 26.19 to 316.18 ± 49.21 MJ, a 56.47% reduction, mainly because of a reduction in the energy from internal fat of 3.96 ± 1.98 MJ/day. In conclusion, the net energy required for maintenance is 60 ± 30 kJ/BW^0.75 per day, and the net energy required for lactation decreases 70 ± 30 kJ/day during the first eight lactation weeks.

Transcriptome analysis of Corynebacterium pseudotuberculosis-infected spleen of dairy goats

Caseous lymphadenitis is a chronic disease of goats caused by Corynebacterium pseudotuberculosis (C.pseudotuberculosis) which causes great harm to the dairy goats industry. In order to obtain detailed information about the pathogenesis and host immune response in C.pseudotuberculosis-infected goats, in this study, the gene expression difference of spleen tissue after infection with C.pseudotuberculosis was analyzed by high-throughput sequencing. Transcripts obtained over 412 700 462 clean reads after reassembly were 21 343 genes detected, of which 14 720 were known genes and 7623 new genes were predicted. There were 448 up-regulated and 519 down-regulated differentially expressed genes (DEGs). Gene Ontology (GO) analysis indicated that all of the DEGs were annotated into biological process, cellular component and molecular function. Most of these unigenes are annotated in cellular processes, the cell and binding. KEGG analysis of the DEGs showed that a total of 8733 DEGs unigenes were annotated into 459 pathways classified into 6 main categories. Most of these annotated unigenes were related to immune system response to the infectious diseases pathways. In addition, 14 DEGs were verified by quantitative real-time PCR. As the first, in vivo, RNAseq analysis of dairy goats and C.pseudotuberculosis infection, this study provides knowledge about the transcriptomics of spleen in C.pseudotuberculosis-infected goats, from which a complex molecular pathways and immune response mechanism are involved in C.pseudotuberculosis infection.

Isolation and characterization of Staphylococcus aureus and methicillin-resistant Staphylococcus aureus (MRSA) from milk of dairy goats under low-input farm management in Greece

The presence of Staphylococcus aureus and methicillin-resistant S. aureus (MRSA) in raw milk is a challenge for veterinarians and public health professionals. In this study, we investigated the presence and clonality of S. aureus and MRSA in milk of individual dairy goats with subclinical mastitis reared under the low-input farming system in Greece and determined the isolates' enterotoxin gene carriage and their ability to form biofilms. S. aureus was isolated from 162 out of the 559 milk samples examined (29 %) and one isolate per S. aureus-positive sample was further characterized. S. aureus isolates were very closely related even among farms of distant geographical regions. Nine S. aureus isolates carried a functional mecA gene and were classified as MRSA. The S. aureus protein A (spa) typing in the MRSA isolates showed that four belonged to spa type t127 (44.4 %), three to t2049 (33.3 %) and two to t7947 (22.2 %). The spa type t7947 is reported for the first time in Greece. The MRSA isolates originated from two very distantly located farms, one located in the island of Skopelos and the other in Central Macedonia. Four of the MRSA isolates carried the staphylococcal enterotoxin genes sea or sec. Most of the isolates (92 % of S. aureus and 77.8 % of the MRSA) possessed moderate or weak biofilm-formation ability. Raw milk from low-input goat herds may serve as a potential vector of antimicrobial-resistant S. aureus to raw-milk consumers.

A comparative analysis of gene expression induced by the embryo in the caprine endometrium

Transcriptomics is an established powerful tool to identify potential mRNAs and ncRNAs (non‐coding RNAs) for endometrial receptivity. In this study, the goat endometrium at estrus day 5 (ED5) and estrus day 15 (ED15) were selected to systematically analyse the differential expressed genes (DEGs) what were induced by the embryo. There were 1,847 genes which were significantly differential expressed in endometrium induced by the embryo at ED5, and 1,346 at ED15 (p‐value < .05). Secreted phosphoprotein 1 (SPP) was the responsive genes for embryo in the goat endometrium during estrus cycle, neurotensis (NTS) and pleiotrophin (PTN) were the responsive genes for embryo in the goat endometrium at ED5, Testin (TES) and Phosphate and Tension Homology Deleted on Chromsome ten (PTEN) at ED15. Furthermore, Gene Ontology (GO) and Kyoto Encyclopedia of Genes (KEGG) analysis revealed cytoplasm and Endocytosis were indispensable for the endometrium development in dairy goat. In a word, this resulting view of the transcriptome greatly uncovered the global trends in mRNAs expression induced by the embryo in the endometrium of dairy goats.

Blood lactate, pH, base excess and pCO2 as prognostic indicators in caesarean-born kids from goats with pregnancy toxaemia

The objective of this study was to identify the prognostic value for survival of blood parameters in the immediate post-caesarean surgery period in kids born from pregnancy toxaemia (PT) goats. This study involved 10 PT goats, in which a caesarean surgery was performed. Twenty-five kids were born after caesarean surgery of which 16 survived. A blood sample was collected from the jugular vein of the 10 goats and from the kids immediately after caesarean surgery (within 15 min). There were differences between the kids that survived and the kids that did not survive concerning the blood levels of pH (7.22 vs 7.00), base excess (− 9 vs − 18 mmol/L), pCO₂ (46 vs 62 mmHg) and L-lactate (5.6 vs 16 mmol/L). Maternal ketoacidosis due to PT has a negative impact on the survival rate of the offspring. This appears to be associated to a metabolic acidosis of the offspring. However, the only blood parameter in which there was a strong association between the maternal and newborn kids was blood urea nitrogen (r = 0.97).

Antibiotic susceptibility profile and synergistic effect of non-steroidal anti-inflammatory drugs on antibacterial activity of resistant antibiotics (Oxytetracycline and Gentamicin) against methicillin resistant Staphylococcus aureus (MRSA)

Non-steroidal anti-inflammatory drugs (NSAIDs) may exhibit antibacterial activity and have synergistic effects with antibiotics. One way to re-sensitize MRSA to resistant antibiotics is by combining with approved non-antibiotics. The study was intended to explore susceptibility of MRSA to various antibiotics and non-antibiotics (NSAIDs) by micro dilution broth method. MRSA isolates were confirmed by PCR (mecA gene) and in-vitro antibiotic susceptibility was determined by disc diffusion tests. Combinations of NSAIDs with resistant antibiotics were also evaluated in in-vivo trial in mice. In-vitro antibiotic susceptibility profile presented 100% resistance to Cefoxitin, 37.5% to Gentamicin and Amikacin, 25% to Oxytetracycline, 12.5% to Tylosin, Fusidic acid and Vancomycin, while Ciprofloxacin, Levofloxacin, Moxifloxacin, Trimethoprim + Sulfamethoxazole and Linezolid were found sensitive. Synergistic effect was observed when resistant antibiotics (Oxytetracycline/Gentamicin) were combined with sensitive antibiotics (Ciprofloxacin/Linezolid). Combination of Non-antibiotics (NSAIDs) with resistant antibiotics revealed that Meloxicam showed partial synergism with both Oxytetracycline and Gentamicin, while Flunixin Meglumine presented synergistic effect with Oxytetracycline and partial synergism with Gentamicin. Diclofenac Sodium revealed additive effect with Oxytetracycline while in case of Gentamicin indifferent effect was observed. In-vivo results showed that combinations of Oxytetracycline with Meloxicam/Flunixin Meglumine and Gentamicin with Meloxicam/Flunixin Meglumine were effective. The study concluded that the resistance against milk borne zoonotic MRSA infections can be successfully addressed by combining resistant antibiotics with NSAIDs. Flunixin Meglumine can be used in combination with oxytetracycline against MRSA infection.

Endometrial genome-wide DNA methylation patterns of Guanzhong dairy goats at days 5 and 15 of the gestation period

Uterine receptivity for the embryo is established and maintained through a series of precise cellular and molecular events, such as DNA methylation. There have been no studies to elucidate entire genome DNA methylation changes associated with embryo receptivity development of the endometrium (RE). In the present study, there was development of a complete genome-wide DNA methylome maps of the RE using whole-genome bisulphite sequencing and bioinformatics analysis. As many as 163.06 Gb of sequencing data averaging 81.53 Gb per sample were obtained for genome bisulphite sequencing of endometrium samples. There were distinct genome-wide DNA methylation patterns in pre-receptive endometrium (PE; Day 5 of gestation) and RE (Day 15 of gestation). There were as many as 16,467 differentially methylated regions (DMRs); 21,391 DMRs were less methylated in RE samples compared with PE samples (P-values ≤ 0.05 and |log2 (fold change)| ≥ 2). Compared with PE samples, methylation ratios of IGF2BP2, ACOX2, PTGDS, VEGFB and PTGDR2 genes were markedly less in RE samples (P-value ≤ 0.05 and |log2 (fold change)| ≥ 2). Conversely, in RE samples there was a markedly greater methylation ratio of IGFBP3 and IGF1R genes. The results of KEGG analysis indicated that these genes were involved in the signalling pathways for insulin, mitogen-activated protein kinase, gonadotropin-releasing hormone, vascular endothelial growth factor and progesterone-mediated oocyte maturation, which participated in differential regulation of goat endometrial development during receptive and prereceptive phases. The results of previous and the present study indicate resulting proteins of IGF2BP2, PTGDS, VEGFB, PGR, IGFBP3 and IGF1R gene expression may have important functions in regulating endometrial receptivity for the embryo.

Dairy goat producers' understanding, knowledge and attitudes towards biosecurity and Q-fever in Australia

The Australian dairy goat sector is an emerging animal industry undergoing rapid expansion. Limited information is available within this industry in relation to socio-demographic characteristics and biosecurity implementation. Q-Fever, caused by the bacterium Coxiella burnetii, is a zoonotic disease endemic in Australia, with a range of domestic and wild-animal reservoir species, including goats, with infected pregnant goats posing a significant public health risk. The aim of the current study was to investigate the socio-demographics of Australian dairy goat producers, their biosecurity implementation and levels of understanding, knowledge and attitudes towards Q-Fever. To achieve this aim, a cross-sectional study was conducted, using an online survey and follow-up semi-structured interviews among dairy goat producers. A total of 106 goat producers participated in the online survey (35.3% response rate) and 14 participated in the semi-structured interviews. Findings from this study suggest that most goat producers implement biosecurity practices related to direct animal husbandry, such as separating sick goats (86%), vaccinations (79%) and providing separate kidding space (75%); and, practices minimizing the risk of disease introduction, such as maintaining boundary fences (86%) and isolating incoming animals (67%). However, implementation of other biosecurity practices, such as keeping records of visitors and visitor biosecurity requirements, was inadequate. Furthermore, this study identifies a deficit of knowledge and understanding surrounding Q-Fever in the Australian dairy goat sector, and a disconnect between producers' perception of risk and implementation of known appropriate biosecurity measures. The research has identified that producers rely on 'trusted' community networks to provide advice on biosecurity implementation, due to a perceived absence of industry-specific, reputable information sources. Producers identified those outside of these networks as the 'other'. The creation of this other allows producers to deflect responsibility for individual biosecurity on to the other. A multifaceted approach is necessary to increase knowledge, understanding and perception of risk surrounding Q-fever, and promote positive uptake of biosecurity measures, for improved outcomes for animal and human health.

Carbon footprint of dairy goat production systems: A comparison of three contrasting grazing levels in the Sierra de Grazalema Natural Park (Southern Spain)

The main objective of this study was to analyze the carbon footprint (CF) of grazing dairy goat systems in a natural park according to their grazing level. A total of 16 representative grazing goat farms in southern Spain were selected and grouped into three farming systems: low productivity grazing farms (LPG), more intensified grazing farms (MIG) and high productivity grazing farms (HPG). Their CF was analyzed, including greenhouse gas emissions and soil C sequestration according to the farms' grazing level and milk productivity, taking into account different functional units (one kilogram of fat and protein corrected milk (FPCM) and one hectare) and milk correction. Results showed that all variables differed according to the milk correction applied as the values for cow's milk correction were 41% lower than for sheep's milk correction. Total emissions and contributions of soil carbon sequestration differed according to farming system group; LPG farms had higher total emissions than MIG and HPG farms, however total carbon sequestration was lower in the MIG farms than in the LPG and HPG farms. The CF values ranged from 2.36 to 1.76 kg CO₂e kg^-1 FPCM for sheep's milk correction and from 1.40 to 1.04 kg CO₂e kg^-1 FPCM for cow's milk correction. No differences were found between farming system groups in either of the two cases but when calculations took hectare of land as a functional unit, the contribution of MIG farms to the CF was 85% higher than LPG and HPG farms. Therefore it is important to take into account the functional unit used to calculate the CF by analyzing this indicator in a broader context, and including carbon sequestration by grazing livestock in the calculation. In order to reduce the CF of this type of system, it is advisable to make appropriate use of the natural resources and to reach an optimum level of milk productivity, high enough for pastoral livestock farming to be viable.

Chi-miR-3031 regulates beta-casein via the PI3K/AKT-mTOR signaling pathway in goat mammary epithelial cells (GMECs)

BACKGROUND

MicroRNAs can regulate gene expression at the posttranscriptional level through translational repression or target degradation. Our previous investigations examined the differential expression levels of chi-miR-3031 in caprine mammary gland tissues in colostrum and common milk stages.

RESULTS

The present study detected the role of chi-miR-3031 in the lactation mechanisms of GMECs. High-throughput sequencing was used to analyze transcriptomic landscapes of GMECs transfected with chi-miR-3031 mimics (MC) and a mimic negative control (NC). In the MC and NC groups, we acquired 39,793,503 and 36,531,517 uniquely mapped reads, respectively, accounting for 85.85 and 81.66% of total reads. In the MC group, 180 differentially expressed unigenes were downregulated, whereas 157 unigenes were upregulated. KEGG pathway analyses showed that the prolactin, TNF and ErbB signaling pathways, including TGFα, PIK3R3, IGF2, ELF5, IGFBP5 and LHβ genes, played important roles in mammary development and milk secretion. Results from transcriptome sequencing, real-time PCR and western blotting showed that chi-miR-3031 suppressed the expression of IGFBP5 mRNA and protein. The expression levels of β-casein significantly increased in the MC and siRNA-IGFBP5 groups. We observed that the down-regulation of IGFBP5 activated mTOR at the Ser2448 site in GMECs transfected with MC and siRNA-IGFBP5. Previous findings and our results showed that chi-miR-3031 activated the PI3K-AKT-mTOR pathway and increased β-casein expression by down-regulating IGFBP5.

CONCLUSIONS

These findings will afford valuable information for improving milk quality and contribute the development of potential methods for amending lactation performance.

The prevalence of Coxiella burnetii shedding in dairy goats at the time of parturition in an endemically infected enterprise and associated milk yield losses

Background

This was a panel study of the prevalence of C. burnetii infection in does in an endemic dairy goat enterprise in Victoria, Australia. Our first objective was to determine the prevalence of does shedding C. burnetii at the time of parturition and to quantify the concentration of genome equivalents (GE) present in each C. burnetii positive sample. Our second objective was to determine the proportion of positive does that were persistent shedders. Our final objective was to quantify the association between C. burnetii qPCR status at the time of kidding and daily milk volumes produced during the subsequent lactation.

Results

Vaginal swabs (n= 490) were collected from does at the time of kidding and analysed using a quantitative polymerase chain reaction (qPCR) assay. Shedding of C. burnetii was detected in 15% (95% CI: 12% to 18%) of the sampled does. Does were classified as qPCR-negative, qPCR-positive low and qPCR-positive high based on the estimated concentration of GE from the qPCR. Persistent shedding at relatively low concentrations was detected in 20% (95% CI: 10% to35%) of shedding does sampled again at their subsequent parturition. After controlling for possible confounders and adjusting for variation in daily milk yields at the individual doe level, daily milk yields for qPCR-positive high does were reduced by 17% (95% CI: 3% to 32%) compared to qPCR-negative does (p= 0.02).

Conclusions

Shedding concentrations of C. burnetii were highly skewed, with a relatively small group of does shedding relatively high quantities of C. burnetii. Further, high shedding does had reduced milk yields compared to qPCR-negative does. Early detection and culling of high shedding does would result in increased farm profitability and reduce the risk of Q fever transmission.

Sodium butyrate improves antioxidant stability in sub-acute ruminal acidosis in dairy goats

Background

Currently, little is known about the effect of sodium butyrate (NaB) on oxidative stress following grain-induced sub-acute ruminal acidosis in dairy goats. In the present study, 18 lactating dairy goats implanted with a ruminal cannula and permanent indwelling catheters in the portal and hepatic veins were randomly allocated into 3 treatment groups over 20 weeks: low grain (LG, 40% grain; n = 6), high grain (HG, 60% grain; n = 6) and high grain with sodium butyrate (HG + NaB, 60% grain + NaB; n = 6).

Results

When added to the HG diet, NaB increased the mean ruminal pH and reduced the levels of ruminal, portal and hepatic LPS; Additionally, we observed an increase in SOD1, SOD2, SOD3, GPX1 and CAT mRNA expression, increased levels of TSOD and CAT enzyme activity as well as increased total antioxidant capacity (T-AOC) and decreased malondialdehyde (MDA) in both the liver and plasma, while GPx activity increased in the liver of goats fed the HG + NaB diet. The mRNA expression of UGT1A1, NQO1, MGST3, and Nrf2, as well as total Nrf2 protein levels were increased in goats fed the HG + NaB diet.

Conclusions

Our study indicates that sodium butyrate could improve the oxidative status in sub-acute ruminal acidosis through the partial activation of Nrf2-dependent genes.

Coxiella burnetii in dairy goats with a history of reproductive disorders in Brazil

Coxiella burnetii, an intracellular bacterium, is the agent of Q fever/coxiellosis, a worldwide zoonosis. Dairy animals are the primary reservoirs of C. burnetii, and although the disease is usually asymptomatic or subclinical, abortion is a serious clinical outcome among small ruminants. This study was conducted to investigate C. burnetii seroprevalence and infection In a flock of dairy goats in Brazil. Serum samples from 312 goats collected from a dairy goat flock with a history of reproductive failure were tested by a commercial ELISA (LSIVet Ruminant Q Fever - Serum/Milk; Thermo Fisher Scientific, Lissieu, France) for anti-C. burnetii IgG antibodies. Samples of cotyledons from 23 placentas were analyzed by nested PCR for the presence of the bacterial DNA. ELISA seroreactivity was found in 55.1% (172/312; 95% CI = 49.4%-60.7%) of the serum samples analyzed. C. burnetii DNA was detected in 8.7% (2/23) of the placental samples tested, where both animals were also seropositive. This study reports the first description of C. burnetii infection in an abortion outbreak in goats in Brazil. The results point out to the importance of including this disease in animal and public health surveillance programs as well as into the list of abortive diseases in goats in Brazil.

First genotyping of Blastocystis sp. in dairy, meat, and cashmere goats in northwestern China

Blastocystis is one of the most common parasites inhabiting in small intestines of human and animals. Although its pathogenicity has been remaining controversial, the possibility of zoonotic transmission between human and animals was recognized. The goat was one of the most important economic animals supplying people with cashmere, meat, and dairy products. However, few studies were to investigate Blastocystis infection in goats. A total of 789 faecal specimens of goats (including 362 of dairy, 193 of meat and 234 of cashmere goats) were collected from multiple regions of Shaanxi province in northwestern China to investigate the colonization frequency and subtypes of Blastocystis, and to assess the zoonotic potential of these goats. The respective colonization frequencies of Blastocystis in dairy, meat and cashmere goats were 54.1% (196/362), 40.4% (78/193) and 78.6% (184/234). The prevalence of Blastocystis in pre-weaned (0-2-month) goats was significantly lower than that in goats of other age groups, and the highest colonization was observed in goats of 7-11-month age group. Sequence analysis of Blastocystis positive samples indicated the presence of seven subtypes in these goats, including six known subtypes (STs1, 3, 4, 5, 10, 14) and one possible novel subtype (isolate Sd26), with the subtype 10 as the predominant one. Additionally, zoonotic subtypes were found in dairy (ST1, ST3 and ST5) and cashmere (ST4 and ST5) goats, but not detected in meat goats. These results showed that Blastocystis is highly prevalent, widely distributed and genetically diverse in goats in Shaanxi province, northwestern China, and zoonotic potential of dairy and cashmere goats to transmit Blastocystis.

Constraints affecting dairy goats milk production in Kenya

In Kenya, the population of dairy goats is about 200,000 and 80% of these are reared in Mount Kenya region. They provide a quick source of milk for consumption or sale, which has an immense value especially to poor households. The small land sizes required for their rearing are especially useful in these highly populated areas. Although much research has been done on problems faced by dairy cattle farmers, limited information is available on problems faced by dairy goat farmers. Therefore, the objective of this study was to determine the constraints affecting dairy goat production in Mount Kenya region. In a cross-sectional survey, 157 farmers were interviewed on major constraints using a semi-structured questionnaire. The results from the questionnaires showed that the main problems experienced by these farmers were as follows: lack of market of milk and goats 45% (71/157), diseases 33% (52/157), high cost of concentrates 25% (38/157), lack of feed 19% (30/157), problems of unreliable buck rotation program 16.5% (26/157), and insecurity 1.8% (3/157). The study revealed that dairy goat farmers in the region faced by a number of challenges and therefore, our recommendation is there is a need for farmers to be trained on innovative ways of value chain addition and other strategies to market their milk. Additionally, the government should put resources to salvage the milk plant and association members should put firm measures to improve management. Creation of farmer awareness, treatment, and disease control measures should be instituted to improve productivity.

The developmental transcriptome landscape of receptive endometrium during embryo implantation in dairy goats

Under natural conditions, some embryos cannot implant successfully because of the dysfunction of receptive endometrium (RE). Thus, it is imperative for us to study the molecular mechanisms involved in the formation of the RE from pre-receptive endometrium (PE). In this study, the endometrium from gestational day 5 (D5, PE) and gestational day 15 (D15, RE) dairy goats were selected to systematically analyze the transcriptome using strand-specific Ribo-Zero RNA-Seq, >120 million high-quality paired-end reads were generated and 47,616 transcripts were identified in the endometrium of dairy goats. A total of 810 mRNAs were differentially expressed genes (DEGs) between the RE and PE meeting the criteria of P-values<0.05. Bioinformatics analysis of the DEGs revealed that a number of biological processes and pathways were potentially involved in the establishment of the RE, notably energy metabolism and amino acid metabolism. Furthermore, we speculated that CXCL14, IGFBP3, and LGALS15 potentially participated in the development of endometrium. What's more, putative SNPs, InDels and AS events were identified and analyzed in the endometrium. In a word, this resulting view of the transcriptome greatly enhances the comprehensive transcript catalog and uncovers the global trends in gene expression during the formation of receptive endometrium in dairy goats.

Histological differences in the adrenal glands and cortisol levels of suckling dairy goat kids in enriched and non-enriched environments

Intensive production systems can negatively affect the welfare of goats. Environmental enrichment techniques can be used to reduce stress. The aim of this study was analyze the effect of environmental enrichment on the histological characteristics of adrenal glands, cortisol levels and weekly weight gain of suckling Alpine French male kids under confinement. A randomised design was used to test the effect of the treatment. The animals (n=20) were randomly assigned to two treatments (enriched and non-enriched) with two replicates each. Enrichment elements included elevated sacks of henequen, trunks, tires and coconuts. The cortisol levels were measured weekly. Male kids were euthanized when their weight reached 10kg, and immediately after euthanasia, samples of the adrenal glands were collected. The adrenal glands were weighed and measured, and histological sections were taken and fixed. Four hundred cells were measured from each animal, with two blind measurements taken from each sample. There were no significant differences between experimental groups (P>0.05) in the weigh, size, the area of cells from the glomerulosa and fasciculata areas of the adrenal glands, the cortisol levels and weekly weight gain. However, there were histological differences between the glomerular and fascicular zones of the left and right adrenal glands of the different groups (P<0.05). These findings suggest that adrenal glands of animals in non-enriched environment, contained histological changes, suggestive of increased activity. We suggest testing adrenal histology as an indicator of stress and recommend the use of environmental enrichment as a means to reduce stress.

Detection and comparison of microRNAs in the caprine mammary gland tissues of colostrum and common milk stages

Background

MicroRNAs (miRNAs) have a great influence on various physiological functions. A lot of high-throughput sequencing (HTS) research on miRNAs has been executed in the caprine mammary gland at different lactation periods (common milk lactation and dry period), but little is known about differentially expressed miRNAs in the caprine mammary gland of colostrum and peak lactation periods.

Result

This study identified 131 differentially expressed miRNAs (P < 0.05 and log₂ colostrum normalized expression (NE)/peak lactation NE > 1 or log₂ colostrum NE/peak lactation NE < −1), including 57 known miRNAs and 74 potential novel miRNAs in the colostrum and peak lactation libraries. In addition, compared with differentially expressed miRNAs in the peak lactation period, 45 miRNAs in the colostrum lactation period were remarkably upregulated, whereas 86 miRNAs were markedly downregulated (P < 0.05 and log₂ colostrum NE/peak lactation NE > 1 or log₂ colostrum NE/peak lactation NE < −1). The expressions of 10 randomly selected miRNAs was analyzed through stem-loop real-time quantitative PCR (RT-qPCR). Their expression patterns were the same with Solexa sequencing results. Pathway analysis suggested that oestrogen, endocrine, adipocytokine, oxytocin and MAPK signalling pathways act on the development of mammary gland and milk secretion importantly. In addition, the miRNA-target-network showed that the bta-miR-574 could influence the development of mammary gland and lactation by leptin receptor (LEPR), which was in the adipocytokine signalling pathway. Chr5_3880_mature regulated mammary gland development and lactation through Serine/threonine-protein phosphatase (PPP1CA), which was in the oxytocin signalling pathway.

Conclusions

Our finding suggested that the profiles of miRNAs were related to the physiological functions of mammary gland in the colostrum and peak lactation periods. The biological features of these miRNAs may help to clarify the molecular mechanisms of lactation and the development of caprine mammary gland.

Electronic supplementary material

The online version of this article (doi:10.1186/s12863-017-0498-2) contains supplementary material, which is available to authorized users.

paratuberculosis fecal shedding in dairy goats and dairy sheep using latent class Bayesian modeling

Background

The study’s objective was to evaluate the ability of fecal culture (FCUL) and fecal PCR (FPCR) to identify dairy goat and dairy sheep shedding Mycobacterium avium ssp. paratuberculosis. A cross-sectional study of the small ruminant populations was performed in Ontario, Canada between October 2010 and August 2011. Twenty-nine dairy goat herds and 21 dairy sheep flocks were visited, and 20 lactating females > two years of age were randomly selected from each farm resulting in 580 goats and 397 sheep participating in the study. Feces were collected per rectum and cultured using the BD BACTEC™ MGIT™ 960 system using a standard (49 days) and an extended (240 days) incubation time, and underwent RT-PCR based on the hsp-X gene (Tetracore®). Statistical analysis was performed using a 2-test latent class Bayesian hierarchical model for each species fitted in WinBUGS.

Results

Extending the fecal culture incubation time statistically improved FCUL sensitivity from 23.1 % (95 % PI: 15.9-34.1) to 42.7 % (95 % PI: 33.0-54.5) in dairy goats and from 5.8 % (95 % PI: 2.3-12.4) to 19.0 % (95 % PI: 11.9-28.9) in dairy sheep. FPCR demonstrated statistically higher sensitivity than FCUL (49 day incubation) with a sensitivity of 31.9 % (95 % PI: 22.4-43.1) in goats and 42.6 % (95 % PI: 28.8-63.3) in sheep.

Conclusions

Fecal culture demonstrates such low sensitivity at the standard incubation time it cannot be recommended as a screening test to detect shedding of MAP in either goats or sheep. Extending the incubation time resulted in improved sensitivity; however, it is still disappointingly low for screening purposes. Fecal PCR should be the screening test of choice in both species; however, it is important to recognize that control programs should not be based on testing alone when they demonstrate such low sensitivity.

Electronic supplementary material

The online version of this article (doi:10.1186/s12917-016-0814-5) contains supplementary material, which is available to authorized users.

Lactation curve and milk quality of goats experimentally infected with Trypanosoma vivax

The present study aimed to evaluate the effects of Trypanosoma vivax infection on the shape of the lactation curve and the milk quality of dairy goats experimentally infected with T. vivax. In total, twenty Saanen goats, aged 26-30 months and the same number of calving (two calvings), were divided into two experimental groups: an infected group, consisting of ten goats intravenously infected with 0.5 ml of blood containing approximately 1.25 × 10(5) trypomastigotes of T. vivax and ten uninfected animals as the control group. Clinical tests and hematocrit, parasitemia, and serum biochemistry evaluations were performed on all of the goats. Milk production was measured daily for 152 days by hand milking the goats and weighing the milk. Every seven days, physiochemical analyses were performed to evaluate the milk. Wood's nonlinear model was used to analyze the lactation curve parameters. The infected goats had high levels of parasitemia and hyperthermia, significantly reduced hematocrit, serum total protein, albumin, and glucose levels and increased cholesterol and urea concentrations. Wood's model indicated that the milk production of goats in the infected group declined sharply over a short period of time and produced a flattened yield curve and significant difference (P < 0.05) in the rate of increase of peak milk production, rate of decrease of milk production after the peak, day of peak milk production, and maximum peak milk production compared with that of the control group. Trypanosomiasis also affected the persistency of lactation, which was significantly reduced in goats in the infected group. In addition, the physico-chemical properties of the milk, including the fat content, defatted dry extracts (DDE) and protein content, decreased significantly (P < 0.05) in the goats in the infected group compared with those in the control group. The T. vivax-infected goats showed reduction in milk production, persistence of lactation, and fat levels, the defatted dry extract (DDE) content, and protein, changing the quality of milk.