Effects of the level and source of dietary physically effective fiber on feed intake, nutrient utilization, heat energy, ruminal fermentation, and milk production by Alpine goats

Thirty-two primiparous and 31 multiparous Alpine goats were used to determine influences of diets varying in level and source of forage on performance in early to mid-lactation for 16 wk. Diets consisted of 40%, 50%, 60%, and 70% forage (designated as 40F, 50F, 60F, and 70F, respectively) with 60F and 70F containing coarsely ground grass hay (primarily orchardgrass) and 40F and 50F containing cottonseed hulls, alfalfa pellets, and coarsely ground wheat hay. Diets contained 15.9% to 16.3% crude protein and 37.8%, 42.1%, 53.5%, and 55.4% neutral detergent fiber (NDF) with 10.0%, 15.8%, 50.1%, and 55.5% particle retention on a 19-mm sieve, and 26.1%, 29.6%, 38.3%, and 40.0% physically effective NDF (peNDF) for 40F, 50F, 60F, and 70F, respectively. Dry matter intake (2.71, 2.75, 1.96, and 1.95 kg/d) and milk yield (2.82, 2.71, 2.23, and 2.10 kg/d for 40F, 50F, 60F, and 70F, respectively) were lower (P < 0.05) for the two diets highest in forage. Digestion of organic matter was similar among diets (P > 0.05), but digestibility of NDF was greater (P < 0.05) for 60F and 70F (57.5%, 58.4%, 68.9%, and 72.2% for 40F, 50F, 60F, and 70F, respectively). Diet affected (P < 0.05) milk fat (3.16%, 3.37%, 2.93%, and 2.97%) and protein concentrations (2.62%, 2.69%, 2.58%, and 2.52% for 40F, 50F, 60F, and 70F, respectively). Milk energy yield was greater (P < 0.05) for the two diets lowest in forage (7.51, 7.45, 5.68, and 5.34 MJ/d), although yield relative to dry matter intake was not affected (P > 0.05) by diet and was lower (P < 0.05) for primiparous vs. multiparous goats (2.71 and 3.09 MJ/kg). Ruminal pH and acetate proportion were greater for 60F and 70F than for the other diets and the proportion of butyrate was lower for the two diets highest in fiber. The mean lengths of time spent ruminating, eating, standing, and lying were not affected (P > 0.05) by diet or parity, but many interactions involving diet, period, hour, and parity were significant (P < 0.05). In conclusion, lactational performance of Alpine goats in early to mid-lactation will be constrained with diets high in forage of moderate quality, peNDF content, and large particle size, which appeared related to limited feed intake.

Alterations in Rumination, Eating, Drinking and Locomotion Behavior in Dairy Cows Affected by Subclinical Ketosis and Subclinical Acidosis

This study delves into the effects of subclinical ketosis (SCK) and subclinical acidosis (SCA) on various parameters related to dairy cow rumination, eating, drinking and locomotion behavior. The research hypothesized that these subclinical metabolic disorders could affect behaviors such as rumination, feeding, and locomotion. A total of 320 dairy cows, with a focus on those in their second or subsequent lactation, producing an average of 12,000 kg/year milk in their previous lactation, were examined. These cows were classified into three groups: those with SCK, those with SCA, and healthy cows. The health status of the cows was determined based on the milk fat-protein ratio, blood beta-hydroxybutyrate, and the results of clinical examinations performed by a veterinarian. The data collected during the study included parameters from the RumiWatch sensors. The results revealed significant differences between the cows affected by SCK and the healthy cows, with reductions observed in the rumination time (17.47%) and various eating and chewing behaviors. These changes indicated that SCK had a substantial impact on the cows' behavior. In the context of SCA, the study found significant reductions in Eating Time 2 (ET2) of 36.84% when compared to the healthy cows. Additionally, Eating Chews 2 (EC2) exhibited a significant reduction in the SCA group, with an average of 312.06 units (±17.93), compared to the healthy group's average of 504.20 units (±18.87). These findings emphasize that SCA influences feeding behaviors and chewing activity, which can have implications for nutrient intake and overall cow health. The study also highlights the considerable impact of SCK on locomotion parameters, as the cows with SCK exhibited a 27.36% reduction in the walking time levels. These cows also displayed reductions in the Walking Time (WT), Other Activity Time (OAT), and Activity Change (AC). In conclusion, this research underscores the critical need for advanced strategies to prevent and manage subclinical metabolic disorders within the dairy farming industry. The study findings have far-reaching implications for enhancing the well-being and performance of dairy cattle. Effective management practices and detection methods are essential to mitigate the impact of SCK and SCA on dairy cow health and productivity, ultimately benefiting the dairy farming sector.

Feeding and Nutritional Factors That Affect Somatic Cell Counts in Milk of Sheep and Goats

The purpose of this quantitative review is to highlight the effects of feeding strategies using some mineral, vitamin, marine oil, and vegetable essential oil supplements and some agri-food by-products to reduce SCCs in the milk of sheep and goats. According to the results, only specific dietary factors at specific doses could reduce SCCs in the milk of dairy sheep and goats. The combination of Se and vitamin E in the diet was more effective in sheep than in goats, while the inclusion of polyphenols, which are also present in food matrices such as agro-industrial by-products, led to better results. Some essential oils can be conveniently used to modulate SCCs, although they can precipitate an off-flavoring problem. This work shows that SCCs are complex and cannot be determined using a single experimental factor, as intramammary inflammation, which is the main source of SC in milk, can manifest in a subclinical form without clinical signs. However, attention to mineral and vitamin supplementation, even in the most difficult cases, such as those of grazing animals, and the use of anti-inflammatory substances directly or through by-products, can improve the nutritional condition of animals and reduce their SCCs, offering undeniable benefits for the milk-processing sector as well.

Effects of sources and levels of dietary supplementary manganese on growing yak's in vitro rumen fermentation

Introduction

Manganese (Mn) is an essential trace element for livestock, but little is known about the optimal Mn source and level for yak.

Methods

To improve yak's feeding standards, a 48-h in vitro study was designed to examine the effect of supplementary Mn sources including Mn sulfate (MnSO₄), Mn chloride (MnCl₂), and Mn methionine (Met-Mn) at five Mn levels, namely 35 mg/kg, 40 mg/kg, 50 mg/kg, 60 mg/kg, and 70 mg/kg dry matter (includes Mn in substrates), on yak's rumen fermentation.

Results

Results showed that Met-Mn groups showed higher acetate (p < 0.05), propionate, total volatile fatty acids (p < 0.05) levels, ammonia nitrogen concentration (p < 0.05), dry matter digestibility (DMD), and amylase activities (p < 0.05) compared to MnSO4 and MnCl2 groups. DMD (p < 0.05), amylase activities, and trypsin activities (p < 0.05) all increased firstly and then decreased with the increase of Mn level and reached high values at 40-50 mg/kg Mn levels. Cellulase activities showed high values (p < 0.05) at 50-70 mg/kg Mn levels. Microbial protein contents (p < 0.05) and lipase activities of Mn-Met groups were higher than those of MnSO4 and MnCl2 groups at 40-50 mg/kg Mn levels.

Discussion

Therefore, Mn-met was the best Mn source, and 40 to 50 mg/kg was the best Mn level for rumen fermentation of yaks.

Effect of Source and Level of Dietary Supplementary Copper on In Vitro Rumen Fermentation in Growing Yaks

Copper (Cu) is essential for the health of livestock, however, the optimal source and level of dietary Cu for yaks are uncertain. To fill this important gap, we designed an in vitro study to examine the effects of three Cu sources, namely Cu methionine (Met-Cu), Cu chloride (CuCl2) and tribasic Cu chloride (TBCC), at five levels, namely 5, 10, 15, 20 and 25 mg/kg DM (includes Cu in substrate), on rumen fermentation in yaks. In vitro dry matter degradability (IVDMD) and amylase activity were greater (p < 0.05) with added Met-Cu than the other two Cu sources, and ammonia nitrogen (NH3-N), microbial protein (MCP) and propionate contents were greater with Met-Cu and CuCl2 than with TBCC. Total gas production and lipase activity were greater with Met-Cu and TBCC than CuCl2 (p < 0.05), which meant that the metabolizable energy yield was greater in the two former Cu sources than the latter, but CH4 production did not differ (p = 0.92) among Cu sources. IVDMD and lipase activity were greatest (p < 0.05) at 15 mg Cu/kg DM in the substrate and MCP, isobutyrate, butyrate and isovalerate contents, and amylase and trypsin activities were greatest or second greatest at 10 and 15 mg Cu/kg DM. It was concluded that Met-Cu was the best source of Cu and 10 to 15 mg Cu/kg DM was the optimal level for yaks, at least under in vitro conditions.

Effects of Solid-State Fermentation Pretreatment with Single or Dual Culture White Rot Fungi on White Tea Residue Nutrients and In Vitro Rumen Fermentation Parameters

Fermentation of agricultural by-products by white rot fungi is a research hotspot in the development of ruminant feed resources. The aim of this study was to investigate the potential of the nutritional value and rumen fermentation properties of white tea residue fermented at different times, using single and dual culture white rot fungal species. Phanerochaete chrysosporium, Pleurotus ostreatus, and Phanerochaete chrysosporium + Pleurotus ostreatus (dual culture) solid-state fermented white tea residue was used for 4 weeks, respectively. The crude protein content increased significantly in all treatment groups after 4 weeks. Total extractable tannin content was significantly decreased in all treatment groups (p < 0.01). P. chrysosporium and dual culture significantly reduced lignin content at 1 week. The content of NH3-N increased in each treatment group (p < 0.05). P. chrysosporium treatment can reduce the ratio of acetic to propionic and improve digestibility. Solid state fermentation of white tea residue for 1 week using P. chrysosporium was the most desirable.

Dietary forage to concentrate ratios impact on yak ruminal microbiota and metabolites

To improve the rumen fermentation function and growth performance of yaks (Bos grunniens), better understanding of the effect of different dietary forage to concentrate ratios on rumen microbiota and metabolites is needed. In the present study, three diets with different dietary forage to concentrate ratios (50:50, 65:35, and 80:20) were fed to 36 housed male yaks. The changes in the distribution of rumen microorganisms and metabolites and the interactions between them were studied by 16S rRNA gene sequencing and liquid chromatography-mass spectrometry (LC–MS). The diversity and richness of microorganisms in the rumen varied according to diet. The most abundant phyla were Firmicutes and Bacteroidetes. Firmicutes was the most abundant in the C50 group, and the relative abundance of Bacteroidetes was significantly lower in the C65 group than in the C80 group (p < 0.05). The Christensenellaceae_R-7_group, Rikenellaceae_RC9_gut_group, and Methanobrevibacter had the highest relative abundances at the genus level. Among them, Christensenellace_R-7_group had the highest relative abundance in the C50 group. The Rikenellaceae_RC9_gut_group was significantly abundant in the C80 group compared with the C50 group. The Methanobrevibacter content was higher in the C65 group than in the other two groups. Both the concentration and metabolic pathways of rumen metabolites were influenced by the dietary concentrate ratio; lipids, lipid-like molecules, organic acid metabolites, and organic oxide-related metabolites differed between the groups. Significant changes were found for six metabolic pathways, including arginine and proline metabolism; glycine, serine, and threonine metabolism; glyoxylate and dicarboxylate metabolism; arginine biosynthesis; glycerophospholipid metabolism; glycerolipid metabolism; and nitrogen metabolism.

Rumen Bacterial Community of Grazing Lactating Yaks (Poephagus grunniens) Supplemented with Concentrate Feed and/or Rumen-Protected Lysine and Methionine

Simple Summary

Ruminal microorganisms, especially bacteria, play a vital role in utilizing fibrous material in ruminants. The yak is a bovid on the Qinghai-Tibet Plateau that traditionally only grazes natural pasture all year. During lactation, energy intake of yaks is often well below requirements, and yaks lose body weight. Today, to mitigate body weight losses during lactation, suckling yaks are often offered supplementary feed. This study examined the effect of dietary supplements on rumen bacteria in lactating yak. The yaks were offered supplementary concentrate feed (C), rumen-protected Lys and Met (RPA), or both (RPA+C). The ratio of the relative abundance of Firmicutes to Bacteroidetes in RPA+C was greater than in the RPA group, while there was no difference between C and RPA+C. The intakes of supplements resulted in a number of alterations in the abundances of bacteria at the genus level. When supplemented with C, yaks increased the concentration of ruminal total volatile fatty acids (VFAs), acetate, and butyrate. These results demonstrate that supplementary feed: (1) alters the composition of rumen microbiota and VFAs of lactating yaks; and (2) can be used to manipulate the composition of rumen microbiota.

Abstract

Traditionally, yaks graze only natural pasture all year round without supplements. Forage intake of lactating yaks is below energy and protein requirements, even in the summer, and suckling yaks lose a substantial amount of significant body weight. Today, to mitigate the loss in body weight, supplementary feed is being offered to lactating yaks. However, the effects of supplementary feed on ruminal bacterial communities in lactating yaks is unknown. In the current study, we examined the effect of supplementary feed on ruminal microbiota, using 16S rRNA sequencing, and on volatile fatty acids (VFAs). Twenty-four lactating yaks of similar body weight (218 ± 19.5 kg) and grazing natural pasture were divided randomly into four groups and received different supplements: (1) rumen-protected amino acids (RPA); (2) concentrate feed (C); (3) RPA plus C (RPA+C); and (4) no supplements (control-CON). The concentrations of total VFAs, acetate, and butyrate were greater (p < 0.05) when supplemented with concentrate feed (C and RPA+C) than without concentrate feed (CON and RPA). Bacteroidetes (B) and Firmicutes (F) were the dominant ruminal bacterial phyla in all groups. The ratio of relative abundance of F:B in RPA+C was greater than in the RPA group, while there was no difference between CON and RPC (interaction, p = 0.026). At the genus level, the relative abundances of Absconditabacteriales_SR1, Bacteroidales-RF16-group, Bacteroidales_BS11_gut_group, Prevotellaceae, and Rikenellaceae_RC9_gut_group were lesser (p < 0.05) with supplementary concentrate feed (C and RPA+C) than without concentrate feed (CON and RPA), whereas Butyrivibrio_2 and Pseudobutyrivibrio were greater (p < 0.05) with supplementary rumen-protected amino acids (RPA and RPA+C) than without rumen-protected amino acids (CON and C). These results demonstrate that supplementary feed: (1) alters the composition of rumen microbiota and concentrations of ruminal VFAs in lactating yaks; and (2) can be used to manipulate the composition of rumen microbiota.

Sodium Butyrate Mitigates iE-DAP Induced Inflammation Caused by High-Concentrate Feeding in Liver of Dairy Goats

The aim of this study is to explore the impact of sodium butyrate on d-glutamyl- meso-diaminopimelic acid (iE-DAP)-induced liver inflammation in dairy goats during subacute ruminal acidosis (SARA) caused by high-concentrate feed. To achieve this aim, 12 lactating dairy goats were randomly divided into two groups: a high-concentrate feed group ( n = 6, concentrate/forage = 6:4) as the control group and a sodium butyrate (SB) with high-concentrate feed group ( n = 6, concentrate/forage = 6:4, with 1% SB by wt.) as the treatment group. A rumen pH below 5.6 lasted for at least 4 h/d due to long-term HC feeding. The concentration of iE-DAP was significantly lower (11.67 ± 3.85 μg/mL, and 7.74 ± 1.46 μg/mL, at the fourth h and sixth h of feeding, respectively) in the SB-treated group than that in the HC group (51.45 ± 5.71 μg/mL, and 18.31 ± 3.83 μg/mL, at the fourth h and sixth h of feeding, respectively). Meanwhile, SB significantly suppressed the mRNA expression of inflammatory genes (NOD1, RIPK2, TAK1, NF-κB/p65, ERK, JNK2, p38, IL-1β, TNF-α, CCL5, CCL20, CXCL12, FOS, β-defensin/LAP). Moreover, the protein expression of NOD1, p-IκBα, p-NF-κB/p-p65, p-ERK1/2, p-JNK, p-p38, and HDAC3 was significantly downregulated in the HC+SB group. In conclusion, iE-DAP-induced inflammation and liver disruption generated by the HC diet was mitigated by SB treatment.

Redox potential: An intrinsic parameter of the rumen environment

The ruminal ecosystem is a fermentative milieu which is interesting to discuss in terms of its redox status as a reflection of an intense bacterial activity. The objective of this systematic literature review is to quantitatively analyze data collected on redox potential (Eh) in the rumen and to explore relationship between ruminal Eh, nature of the diet fed to ruminants, and ruminal fermentation parameters. Data obtained from 15 studies comprising 24 different diets was used in the analysis. Studies included in the data file were selected based on the criteria of: (i) the nature of the reference electrode was specified, (ii) the ruminal Eh was recorded simultaneously to pH, (iii) animal body weight (BW) and dry matter intake (DMI) were reported and (iv) the composition of the diet was precisely described. Results showed a high variability in ruminal Eh values. However, all recorded values are markedly negative reflecting the absence of oxygen and the strong reducing power of the rumen environment. The main factors contributing to the variation were the method of Eh measurement and the nature of the diet fed to ruminants. Redox potential was positively correlated with DMI and proportion of concentrate in the diet, and tended to be positively correlated with soluble carbohydrates content. In contrast, it was negatively correlated with neutral detergent fibre from forages. The hierarchical ascendant classification discriminated two groups of diets leading to significant change in ruminal Eh level. Ruminal Eh was negatively correlated with pH, total volatile fatty acids produced and proportion of acetate, and positively correlated with proportion of propionate. This review revealed Eh to be dependent on the diet composition and DMI, at least within the range of diets included in the database.

Review: Use of human-edible animal feeds by ruminant livestock

The drive to increase the output of animal product in some sectors of ruminant livestock production has led to greater use of feeds such as cereal grains and soyabean meal that are potentially human-edible. This trend has caused concern since, by so doing, ruminants compete not only with monogastric livestock but also with the human population for a limited global area of cultivatable land on which to produce grain crops. Reasons for using potentially human-edible feeds in ruminant diets include increased total daily energy intake, greater supply of essential amino acids and improved ruminal balance between fermentable energy and degradable protein. Soyabean meal, produced on land that has been in arable cultivation for many years can fulfil a useful role as a supplier of undegraded dietary protein in diets for high-yielding dairy cows. However, in the context of sustaining the production of high-quality foods from livestock to meet the demands of a growing human population, the use of potentially human-edible feed resources by livestock should be restricted to livestock with the highest daily nutrient requirements; that is, potentially human-edible feed inputs should be constrained to meeting requirements for energy and protein and to rectifying imbalances in nutrient supply from pastures and forage crops such as high concentrations of nitrogen (N). There is therefore a role for human-edible feeds in milk production because forage-only systems are associated with relatively low output per head and also low N use efficiency compared with systems with greater reliance on human-edible feeds. Profitability on farm is driven by control of input costs as well as product value and examples are given of low-cost bovine milk and meat production with little or no reliance on potentially human-edible feeds. In beef production, the forage-only systems currently under detailed real-time life-cycle analysis at the North Wyke Farm Platform, can sustain high levels of animal growth at low feed cost. The potential of all-forage diets should be demonstrated for a wide range of ruminant milk and meat production systems. The challenge for the future development of ruminant systems is to ensure that potentially human-edible feeds, or preferably human-inedible by-products if available locally, are used to complement pastures and forage crops strategically rather than replace them.

Changes in milk performance and hepatic metabolism in mid-lactating dairy goats after being fed a high concentrate diet for 10 weeks

Feeding a high concentrate (HC) diet is a widely used strategy for supporting high milk yields, yet it may cause certain metabolic disorders. This study aimed to investigate the changes in milk production and hepatic metabolism in goats fed different proportions of concentrate in the diet for 10 weeks. In total, 12 mid-lactating goats were randomly assigned to an HC diet (65% concentrate of dry matter, n=6) or a low concentrate (LC) diet (35% concentrate of dry matter, n=6). Compared with LC, HC goats produced greater amounts of volatile fatty acids and produced more milk and milk lactose, fat and protein (P<0.01). HC goats showed a greater concentration of ATP, NAD, plasma non-esterified fatty acids and hepatic triglycerides than LC goats (P<0.05). Real-time PCR results showed that messenger RNA (mRNA) expression of gluconeogenic genes, namely, glucose-6-phosphatase, pyruvate carboxylase and phosphoenolpyruvate carboxykinase were significantly up-regulated and accompanied greater gluconeogenic enzyme activities in the liver of HC goats. Moreover, the expression of hepatic lipogenic genes including sterol regulatory element-binding protein 1c, fatty acid synthase and diacylglycerol acyltransferase mRNA was also up-regulated by the HC diet (P<0.05). HC goats had greater hepatic phosphorylation of AMP-activated protein kinase than LC (P<0.05). Furthermore, histone-3-lysine-27-acetylation contributed to this elevation of gluconeogenic gene expression. These results indicate that lactating goats fed an HC diet for 10 weeks produced more milk, which was associated with up-regulated gene expression and enzyme activities involved in hepatic gluconeogenesis and lipogenesis.