Search Results (253)

Under grazing conditions, it is difficult for lactating Yili mares to meet their nutritional requirements and those of their suckling foals solely through the consumption of natural pasture. Furthermore, seasonal variations and rainfall significantly influence the quality and nutrient content of forage, which severely constrains the healthy breeding of Yili horses and the industrial development of mare milk resources. Therefore, this study aimed to investigate the effects of concentrate supplementation on lactation performance and milk concentrations of amino acids, fatty acids, and mineral elements in Yili horses under grazing conditions. Twenty-two healthy Yili mares in early lactation, with similar ages (3–4 years), foaling dates, and body weights (391.5 ± 13.74 kg), were randomly assigned to either a grazing group (G, n = 11) or a grazing + supplementation group (GS, n = 11). Mares in group G grazed naturally on pasture, while those in group GS received 1 kg of concentrate supplement twice daily (totaling 2 kg/day) in addition to grazing. The experimental period lasted for 100 days, including a 10-day adaptation period and a 90-day formal experimental period. The results showed that: (1) In terms of lactation performance, the GS group exhibited highly significant increases in milk yield and lactose yield (p < 0.01), as well as significant increases in milk protein and milk fat yields (p < 0.05), with an extended duration of the peak lactation period. (2) Regarding the amino acid profile, the concentrations of threonine (Thr), serine (Ser), glycine (Gly), and alanine (Ala) in the milk of the GS group were significantly higher than those in the G group (p < 0.05), whereas the proline (Pro) content was significantly lower (p < 0.01); supplementation improved the uptake of certain functional amino acids by the mammary gland. (3) Concerning the fatty acid profile, the concentrations of polyunsaturated fatty acids (PUFA) and alpha-linolenic acid in the milk of the G group were significantly or highly significantly higher than those in the GS group (p < 0.05 or p < 0.01). (4) For mineral elements, concentrate supplementation highly significantly decreased the potassium (K) content and the K/Na ratio in horse milk (p < 0.01), highly significantly increased the levels of iron (Fe) and cobalt (Co) (p < 0.01), and significantly enhanced the chromium (Cr) content (p < 0.05). In conclusion, concentrate supplementation during grazing improved lactation performance in Yili mares, primarily by increasing milk yield and extending the peak lactation period. However, grazing alone was more favorable for maintaining higher PUFA and α-linolenic acid proportions in milk. Therefore, concentrate supplementation should be regarded as a nutritional strategy that increases milk output and modifies amino acid and mineral element composition, but may involve a trade-off with some beneficial fatty acids. Full article

Nutrient restriction (NR) increases small-for-gestational-age (SGA) offspring; however, some NR ewes deliver Non-SGA lambs. We evaluated whether fetal biometry and Doppler indices could distinguish divergent fetal growth trajectories. Ninety-five single-pregnant Corriedale ewes were assigned to NR grazing (n = 72) or supplemented Controls (n = 23) from gestational day (GD) 70 to 140. Fetal biparietal diameter (BPD), femur length (FL), thoracic height (TH), umbilical cord diameter (UCD), and resistance (RI) and pulsatility (PI) indices in umbilical (UA), cotyledonary (CA), and uterine (UtA) arteries were assessed at several GDs. Offspring within NR group was stratified by birth weight (BW) quartiles as SGA (n = 18) or Non-SGA (n = 18). At birth, BW differed (p < 0.05) among Control (4.95 ± 0.10 kg), Non-SGA (5.33 ± 0.06 kg), and SGA (3.79 ± 0.11 kg), with reduced BPD and FL in SGA lambs. Prenatal biometry did not differ. UA-RI at GD125 was higher in SGA (p < 0.005) and associated with BW (R² = 0.15; p < 0.001). UtA indices were lower in SGA at GD110 and GD125 (p < 0.05) but weakly associated with BW (R² ≤ 0.08). Doppler differences were detected before measurable growth divergence but have modest predictive value. Full article

The objective of this study was to assess the contribution of oat (Avena sativa L.) and common vetch (Vicia sativa) hay supplementation as a forage-based strategy to improve the environmental and productive performance of grazing systems in the high Andean zone through its effects on enteric methane (CH₄) emissions and live weight gain. Twenty heifers grazed native grasses, and only half of the group received the supplement. The experiment was conducted as a crossover design. Methane emissions were quantified through sulfur hexafluoride methodology. Native pastures were characterized by low protein content, while lignin was lower in the oat hay plus common vetch hay than in the native grass mixture. On average, heifers consumed 7 kg dry matter per day (p ≥ 0.05) and ingested 24% more crude protein when supplemented (p = 0.0001). Digestible and metabolizable energy intakes were also significantly higher in supplemented animals (p ≤ 0.05). Live weight change was positive for supplemented animals (245 g/d). Net CH₄ production ranged from 179.6 to 196.3 g/d (p = 0.183). However, when CH₄ emissions were expressed relative to crude protein or acid detergent lignin intake, supplemented diets were found to emit less than native grass-based diets (p ≤ 0.05). These results suggest that supplementation with oat hay plus vetch is a feeding alternative for heifers during the dry season in the Peruvian Andean region to increase animal productivity without affecting CH₄ emissions. Full article

Rumen microbial fermentation plays a central role in nutrient utilization and milk production in dairy cows. This study evaluated the effects of supplementation with exogenous fibrolytic enzymes, alone or in combination with live yeast on rumen microbiota, fermentation characteristics, nitrogen-related metabolites, and production performance during the transition from outdoor grazing to indoor housing. Thirty Lithuanian Red dairy cows were assigned to control (CTR), enzyme (E), or enzyme plus yeast (YE) treatments across outdoor (OD) and transit (T) periods, while nine cows (three per group) were selected for rumen and microbiota analysis. Rumen bacterial communities were characterized using 16S rRNA gene sequencing, and functional parameters were evaluated using linear mixed-effects models. Supplementation resulted in selective changes in several bacterial genera, including Blautia spp., WPS-2, Ruminococcus spp., Erysipelotrichaceae UCG-009, Sharpea spp., uncultured Bacteroidales, and Prevotellaceae UCG-003, and was associated with alterations in fermentation patterns, particularly propionate concentration, and in nitrogen metabolism, including putrescine dynamics. The transition period significantly influenced microbial diversity and total bacterial abundance across treatments. Cows in the YE group maintained higher milk yield during the transition period. Overall, dietary supplementation modulated specific rumen metabolic responses and contributed to production stability without causing large-scale changes in overall microbial structure. Full article

Parasitic infections constitute a common concern for livestock breeders, since they induce animals with various physiological, behavioral, and neurological alterations. Consequently, they negatively affect their health, productivity, and welfare, leading to reduced productivity and increased mortality, and causing severe economic losses to livestock breeders. In the context of recent interest in the development of functional animal feeds and/or feed supplements with potent antiparasitic activity, we exploited the chemical contents and bioactivities of 21 wild and cultivated Fabaceae plant species against Haemonchus contortus and Trichostrongylus colubriformis, two widely prevalent gastrointestinal nematode parasites of small ruminants. The respective results revealed that four wildly grown plants exhibit potent antiparasitic activity, with Lathyrus laxiflorus exerting the most significant protective effect against both parasites tested. This plant was also found to display the highest antioxidant potency and the richest phenolic and tannin contents, with rutin molecules being the most abundant. Moreover, the extracts of 11 cultivated species were found to display potent antiparasitic activity, while Trifolium repens, Medicago sativa, and Lathyrus sativus species were determined to provide higher extraction yields and display the most potent antiparasitic activities. Results herein are indicative of Fabaceae plants’ potential to act against parasitic infections, either as grazing plants in pasture-based systems, or as bioactive dietary supplements in intensive farming systems, eventually contributing to reductions in antiparasitic drug utilization. Full article

Yushu yaks face nutritional deficiency and poor production performance in the cold season on the Qinghai–Tibet Plateau, yet their metabolic responses to different feeding modes remain unclear. This study investigated the effects of traditional grazing, grazing with concentrate supplementation, and TMR stall-feeding on 90 four-year-old Yushu yaks (30 per group) during a 180-day cold-season trial, by determining body weight changes, serum biochemical parameters and plasma metabolic profiles. Stall-fed yaks had the highest average daily gain (259.05 ± 61.56 g/d), while grazing yaks showed negative gain (−279.50 ± 44.45 g/d) and supplementary-fed yaks had intermediate performance; grazing yaks had stronger antioxidant enzyme activity, and supplemented/stall-fed yaks had higher serum mineral and albumin levels. Metabolomic analysis identified 2024 plasma metabolites, with grazing yaks enriched in plateau adaptation and antioxidant pathways, stall-fed yaks in energy metabolism pathways, and supplementary-fed yaks in both growth and antioxidant pathways. Our findings confirm that gradient nutritional interventions regulate the balance between yak growth and plateau adaptability, with concentrate supplementation as the optimal cold-season feeding mode for local herders and stall-feeding suitable for intensive breeding to maximize growth efficiency. Full article

In the context of climate change and increased frequency of droughts, summer supplementation of grazing cattle may improve productivity and resilience of pastoral systems. However, the provision of supplements may increase the risk of heat stress in cattle. This study aimed to evaluate the productive and physiological response of grazing steers supplemented during summer. Three independent studies were conducted over three summers (2020–2023). In each experiment, steers grazing native grasslands with access to shade were allotted to one of two treatments: control (CONT) and supplementation (SUPPL), in a completely randomized block design. SUPPL steers were group-fed in the morning three days per week with an energy–protein ration at a level of 1.98% body weight (BW) on days of feeding. Pasture attributes, animal performance, respiration rate (RR), and body temperature (BT) were analyzed using a mixed model. According to the temperature–humidity index, cattle were exposed to heat stress 32% of the time. Summer supplementation increased average daily gain and final body weight of steers. Although supplementation temporarily increased BT (morning) and RR (afternoon), daily average RR and BT were similar for both treatments. These findings show that summer supplementation improves animal performance of grazing steers without increased risk of severe heat stress. These results are aligned with the concept of sustainable livestock intensification, which aims to enhance animal source foods to feed a growing population without causing collateral animal welfare issues. Full article

This study was conducted to investigate the effect of different concentrate-to-roughage ratios on the lipid composition of camel milk. Thirty-six Qiangar Bactrian camels were randomly allocated to three groups: the control group (C, grazing plus roughage only), the low-concentrate group (L, grazing plus roughage with 2 kg/d concentrate supplementation), and the high-concentrate group (H, grazing plus roughage with 4 kg/d concentrate supplementation). The trial comprised an 18-day adaptation period followed by a 42-day feeding period (60 days total). A systematic lipidomics approach revealed significant differences in milk lipid profiles among the three dietary treatments. High-concentrate diets markedly remodeled the milk lipidome (especially in positive-ion mode mass spectrometry), with the most pronounced differences detected between the C and H groups. Multivariate analyses (PCA and PLS-DA) confirmed that varying concentrate levels significantly affected milk lipid composition, and the separation between H and C was greater than that between L and C. KEGG annotation and enrichment analysis indicated that lipid-related pathways, notably glycerophospholipid metabolism, were significantly affected by dietary concentrate levels. These findings provide theoretical support for optimizing camel feeding strategies to improve milk nutritional quality and offer scientific guidance for camel husbandry and dairy product development. Full article

Gastrointestinal nematodes (GINs) remain a significant challenge to productivity and sustainability in beef cattle systems in the United States, contributing to subclinical reductions in growth, reproductive performance, and overall herd health across production stages. Control programs have historically relied on routine anthelmintic use; however, increasing reports of anthelmintic resistance highlight the need for alternative management strategies. This narrative review synthesizes peer-reviewed literature identified through targeted searches of major scientific databases spanning approximately seven decades, with articles selected for relevance to GIN epidemiology, diagnostics, and control in beef cattle. Particular emphasis is placed on life stage-specific susceptibility, host immune development, and the role of diagnostic tools in guiding evidence-based interventions. The review further examines non-anthelmintic strategies such as grazing management, nutritional supplementation, selective breeding, and integrated parasite management practices adapted from small ruminant systems. Across studies, young and immunologically developing cattle experience the greatest productivity losses, while mature animals contribute disproportionately to pasture contamination, reinforcing the importance of targeted control measures. Overall, the literature supports a transition toward integrated, diagnostics-driven parasite control programs that sustain productivity and animal well-being while preserving long-term anthelmintic efficacy. Full article

High-altitude grazing animals are continuously exposed to strong wind and low temperature, which challenge physiological homeostasis and energy metabolism. Improving living conditions and nutritional supplementation are two commonly used strategies. In this study, sixty 7-month-old Gangba sheep (initial body weight (BW) 21.00 ± 1.90 kg) were allocated to a 42-day trial with four groups (open-air sheepfold, mobile sheepfold, open-air sheepfold + supplementary feeding, mobile sheepfold + supplementary feeding) to investigate their effects on growth performance, serum parameters and gut microbiota in naturally grazing Gangba sheep. Mobile sheepfolds increased the temperature–humidity index (THI) and reducing the wind chill index (WCI) (p < 0.05). The sheep with mobile sheepfold showed higher serum total antioxidant capacity and lower levels of heat shock proteins HSP70 and HSP90 (p < 0.05), indicating alleviated stress. Supplementary feeding markedly increased final BW and average daily gain (p < 0.05). The interaction between sheepfold type and feeding supplementation showed increasing IgA levels in the open-air sheepfold with supplementary feeding group and increasing IL-4 levels in the mobile sheepfold with supplementary feeding group, while TNF-α concentrations were reduced in all three treatment groups (p < 0.05). Meanwhile, KB and FFAs were increased in the open-air sheepfold with supplementary feeding group but decreased in the mobile sheepfold with supplementary feeding group (p < 0.05). The mobile sheepfold also increased the Bacillota-to-Bacteroidota ratio, suggesting improved microbial community structure. Functional predictions showed enrichment of reductive acetogenesis and reduction in aerobic chemoheterotrophy and sulfur-related respiration pathways (p < 0.05). Moreover, key microbial genera were significantly correlated with THI and WCI (p < 0.05). Collectively, these results demonstrated that mobile sheepfold together with feeding supplementation improve stress responses, serum immune and lipid metabolic indicators, and potentially altered gut microbial composition and function, providing insights into host–microbiota interaction in extreme high-altitude environments. Full article

The objective of this research was to investigate how injectable trace minerals and vitamins influence the mineral and vitamin status, hematological parameters, antioxidant capacity, metabolic profile, and performance of Nellore calves during the pre-weaning phase. A total of 38 grazing Nellore male calves with access to creep feeding were randomly assigned to two treatments: injectable supplementation of saline solution (saline; n = 19) or injectable supplementation of trace minerals (copper, manganese, zinc, and selenium) and vitamins (A and E) (ITMV; n = 19), administered on days 75 and 150 of the calves’ age. The injectable supplementation did not affect (p > 0.05) body weight, average daily gain, body measurements, or carcass measurements throughout the experimental period from 75 to 218 days (7 days before weaning) of age. However, ITMV-treated calves showed higher (p ≤ 0.05) liver concentrations of Cu and Se on day 195 than saline calves. Higher plasma concentrations of Cu (days 195 and 218) and Se (days 135, 195, and 218) were observed for ITMV calves compared to the saline group. Furthermore, the ITMV group showed greater (p ≤ 0.05) glutathione peroxidase activity, higher red blood cell count, hemoglobin, and hematocrit levels, and a lower neutrophil/lymphocyte ratio (p = 0.04). In the metabolic profile, only a day effect was observed (p ≤ 0.05). In conclusion, the injectable supplementation of trace minerals and vitamins in suckling Nellore calves improved copper and selenium status and optimized antioxidant capacity and hematological parameters, in addition to modulating the immune response towards a less inflammatory state, although it did not affect performance or the metabolic profile. Full article

Grazing yaks often face protein deficiency due to low-quality pasture, which limits milk production. This study aimed to investigate the effects of varying protein levels in concentrate supplementation on lactational performance, immune function, and rumen microbial and metabolites in grazing lactating yaks. Thirty-six lactating Qinghai Plateau yaks (172.78 ± 11.70 kg) were assigned to four treatments for 70 d (10 d adaptation + 60 d trial): grazing only (CON) or grazing plus 1.50 kg/d concentrate containing 15.09% (CP15), 17.00% (CP17), or 18.98% CP (CP19). Concentrate supplementation significantly increased average daily gain (ADG; 0.22 vs. 0.72–0.90 kg/d; p < 0.001) and milk yield (622.18 vs. 1094.25–1385.73 g/d; p < 0.001), and milk yield showed a linear increase with higher dietary protein levels (p < 0.001). Milk protein yield (29.99 vs. 56.00–68.60 g/d; p < 0.001) and milk lactose yield (40.71 vs. 79.85–93.53 g/d; p < 0.001) were also increased. Milk composition, including fat, protein, and lactose, also improved across supplementation groups, with the greatest enhancement observed at the CP17 group (p < 0.05). Rumen pH and volatile fatty acids did not differ between treatments, while microbial protein increased with supplementation (10.88 vs. 12.72–15.00 mg/dL; p = 0.041) and showed a linear response to dietary CP level (p = 0.033). Concentrate supplementation significantly altered the rumen microbial structure (ANOSIM, p = 0.036), enriching Succinivibrionaceae_UCG-002, Fibrobacter, Ruminobacter, and Succinimonas and reducing Saccharofermentans in CP17 yaks (p < 0.05). Untargeted metabolomics further indicated a marked shift in the ruminal metabolite profile. Compared with CON, CP17 yaks exhibited higher levels of calcium propionate, 2-nitrofuran, curvulalide, and 2,5-dihydroxybenzoic acid, but lower levels of 4-pyridoxic acid, L-carnitine, bitocholic acid, and taurodehydrocholic acid. Pathway enrichment analysis identified vitamin B6 metabolism as significantly enriched. Collectively, these findings suggest that moderate protein concentrate supplementation (CP17) may enhance lactation performance by modulating rumen microbiota and metabolism in lactating yaks. Full article

To elucidate the driving factors and regulatory mechanisms of epilithic algal communities in subtropical rural rivers, we investigated the water physicochemical parameters, sediment characteristics, phytoplankton, macroinvertebrates, and epilithic algal communities in the Shilipu and Xiabu Rivers during the summer period (June and August 2023). A total of 131 epilithic algal species belonging to five phyla were identified, with Cyanobacteria, Chlorophyta, and Bacillariophyta constituting the dominant groups. Core dominant species included Lyngbya sp. C. Agardh, 1824, Oscillatoria sp. Vauch., 1803, and Gomphonema sp. Agardh, 1824. Epilithic algal communities exhibited significant monthly differences, with both biomass and abundance being significantly higher (p < 0.05) in August than in June. Environmental factors, encompassing both abiotic and biotic parameters, collectively explained 56.76% and 56.99% of the variation in epilithic algal abundance and biomass, respectively. Water physicochemical parameters and phytoplankton biomass emerged as the core driving factors. Both showed highly significant positive correlations with epilithic algal abundance (R = 0.26, p < 0.001; R = 0.27, p < 0.001) and biomass (R = 0.21, p < 0.001; R = 0.27, p < 0.001). Sediment factors exerted a mild regulatory effect (abundance: R = 0.13, p < 0.05; biomass: R = 0.17, p < 0.01) by releasing nutrients to supplement the water column. The impact of macroinvertebrates was weak and biomass-dependent, showing only a weakly significant positive correlation with epilithic algal biomass (R = 0.12, p < 0.05). This study reveals the synergistic regulatory effects of abiotic and biotic factors on epilithic algal communities in subtropical rural rivers, where elevated external nutrient input attenuates the competitive effects of phytoplankton and the grazing pressure of macroinvertebrates. This provides a scientific basis for the ecological monitoring and restoration of similar river systems. Full article

Purpose: This study investigated the effects of dietary bamboo leaf extract (BLE) on milk parameters and intestinal microbiota in lactating Yili mares. Methods: Twenty-four Yili mares of similar age (10 ± 2 years), weight (360.62 ± 15.23 kg) and body condition were selected for this study and randomly divided into four groups of six mares each: an untreated control group (CG) and three experimental groups (EG1, EG2, EG3) were fed a basal diet supplemented with 0, 10, 20, or 30 g/day of BLE, respectively, for 60 days. Then, horse milk composition, antioxidant activity, and immunoglobulin levels along with the relative abundance of fecal microbiota were measured. Results: Compared with the control group, supplementation with BLE for 60 days significantly improved milk yield and composition. The protein content in the EG1 was significantly higher than that in the CG, the milk yield and fat content in the EG2 was significantly higher than that in the CG, and the lactose content in the EG3 was significantly higher than that in the CG. BLE also significantly increased the milk’s antioxidant capacity, vitamin C, IgG, IgM, and IgA levels, with the antioxidant and immune properties in the EG2 being significantly higher than those in the CG. Furthermore, BLE feeding promoted communities of beneficial intestinal microbes. Bacteria associated with energy metabolism and organic matter decomposition increased significantly in BLE-fed groups, especially the EG2, which had elevated abundance of UCG-002 and the NK4A214_group. BLE also significantly reduced the abundance of Euryarchaeota, Verrucomicrobiota, Methanobacteriaceae, and Methanobrevibacter. Conclusions: Dietary supplementation with bamboo leaf extract is a safe and inexpensive way to enhance milk yield and quality and to promote the growth of beneficial intestinal microbes in Yili horses. Full article

Dual-purpose livestock farming in the Colombian low tropics faces nutritional limitations that affect productivity and increase enteric methane (CH₄) emissions. Therefore, it is necessary to evaluate supplementation strategies that optimize the use of nutrients and reduce environmental impacts. The objective of this study was to evaluate the effects of three types of dietary supplementation—mineralized salt (MS), proteinized salt (PS), and concentrated feed (CO)—on milk production, efficiency in the deposition of dairy nutrients, and enteric CH₄ emissions in dual-purpose grazing cows in the Colombian Amazon. Twenty-four F1 Holstein × Gyr cows were used in a completely randomized block design. Nutrient intake, digestibility, composition, and efficiency in the milk deposition of Ca, P, K, and N were measured; additionally, CH₄ emissions were assessed using a portable electronic spirometry mask. The results indicated that the treatments did not modify the total intake of dry matter or the production and composition of milk. CO and MS supplementation improved the efficiency of Ca and P (p < 0.03) deposition in milk, while no differences were observed for N and K. CH₄ emissions (196 ± 17.9 g/cow/day) were not affected by the supplements and were within the ranges reported for dual-purpose tropical systems. However, with the supplementation with CO was a lower losses of gross energy intake as CH₄ (Y_m) (p < 0.05). In conclusion, supplementation with the evaluated products did not impact milk production or CH₄ emissions, although with CO was lower energy losses as CH₄ and, CO and MS improved the use of Ca and P, which highlights the importance of adjusting supplementation to optimize nutritional efficiency without increasing greenhouse gas emissions. Full article