Background: Mannan oligosaccharides (MOS) are a promising feed additive in animal husbandry due to mainly improving animal health status. The purpose of this study was to investigate the effects of MOS on growth performance, nutrient digestibility, ruminal fermentation, and twelve hematological parameters in sheep. Methods: Ninety-six healthy Hu rams with similar body weights were chosen and divided into four treatment groups (twenty-four rams in each group), in which four different doses of MOS were tested: 0%, 0.8%, 1.6% and 2.4% of the basal diet (on an as-fed basis). Results: The results showed that supplementation dietary MOS did not affect feed intake, body weight, average daily weight gain, or ruminal short-chain fatty acids (SCFAs) concentration; the ratio of individual fatty acids to total SCFAs, the C2/C3 ratio, and the hematological parameters in the sheep were also unaltered (P > 0.05). Conversely, supplementation dietary MOS increased the dry matter, organic matter, crude protein, neutral detergent fiber, acid detergent fiber, and ash apparent digestibility (P < 0.05), and decreased the ruminal ammonia concentration in the sheep (P < 0.05), especially at a dose of 1.6%. Conclusions: This indicates that supplementation dietary MOS improved nutrient utilization by the sheep and nitrogen metabolism in the rumen; however, the effects are too slight to interfere with the basal metabolism in the sheep.

This study investigated the effects of mannan oligosaccharides (MOS) on in vitro and in vivo gas emission, utilization of crude protein (CP) and energy, and relative parameters of sheep under fasting metabolism conditions. In vitro gas productions were evaluated over 12 h in sheep diets containing different amounts of MOS (from 0% to 6.0%/kg, the increment was 0.5%). A control experiment was used to assess the gas emission, utilization of CP and energy, and fasting metabolism in control sheep and sheep treated with 2.0% MOS over 24 days (d). The results showed that 2.0% MOS supplementation led to the lowest in vitro CO₂ production and less CH₄ production, while also leading to decrease in vivo nutrients intake, CP and energy excretion, digested and retained CP, and energy released as CH₄ (p < 0.05). Furthermore, 2.0% MOS supplementation appeared to decrease in vivo O₂ consumption and CH₄ production per metabolic body weight (BW^0.75), and increase the CP retention rate of sheep (p < 0.074). MOS did not affect other parameters, along with the same parameters of sheep under fasting metabolism conditions (p > 0.05). The findings indicate MOS has only slight effects on the gas emission and nutrients and energy metabolism of sheep.

The purpose of this study was to investigate the optimum proportion of sorghum straw and ammoniated wheat straw in vitro and in vivo to apply in ruminant diets. One-factor and two-factor experimental designs were used in the in vitro tests, with different ratios of sorghum straw to ammoniated wheat straw (S:AWS) of 2:8, 3:7, 4:6, 5:5, 6:4, 7:3, and 8:2 to measure the in vitro total gas production, CH₄ production, in vitro dry matter degradability (IVDMD), in vitro organic matter degradability (IVOMD) and in vitro fermentation parameters. Additionally, the nylon bag technique was used to determine the dynamic degradation of these different ratios of mixed feedstuffs for incubating in sheep rumen for 6 h, 12 h, 24 h, and 48 h. The results show that IVDMD, IVOMD, and the molar ratio of propionate were the highest when the ratio of S:AWS was 8:2 (p < 0.05) in vitro; however, this ratio released much more CH₄ (p < 0.05). In addition, the degradability of DM, OM, CP, and ash and the effective degradability of DM and CP were the highest when the ratio of S:AWS was 8:2 cultured in sheep rumen for 48 h (p < 0.05). In the in vitro and in situ nylon bag tests, IVDMD, IVOMD, rumen nutrient degradability, and effective degradability of DM and CP increased with the increase in the sorghum straw proportion. In conclusion, the higher the proportion of sorghum straw, the higher the nutrient degradability in vivo and in vitro, but also the higher the emissions of CH₄. Therefore, when the ratio of S:AWS is 8:2, ruminants can effectively utilize nutrients in feed.

The effect of mannan oligosaccharides (MOS) on health, growth performance, fatty acids deposition, serum, and urine metabolites, as well as the correlation between differential metabolites and other indexes, were investigated in Hu lambs. In total, 30 seven-day-old Hu male lambs were fed a milk replacer with or without 0.2% MOS (15 lambs in each). The lambs were placed on this diet until they were 28 days old. MOS significantly increased the apparent digestibility of organic matter (OM), crude protein (CP), ether extract (EE), calcium (Ca) and phosphorus (P), and unsaturated fatty acid (UFA) proportion, and decreased the diarrhea rate and saturated fatty acid (SFA) proportion in lambs (p < 0.05). MOS upregulated 20 metabolites in serum and 1 in urine and downregulated 11 metabolites in serum and 2 in urine (p < 0.05). Most of these metabolites comprised glycerophosphoethanolamines and glycerophosphocholines, which are significantly correlated with nutrient digestibility and fatty acid composition (p < 0.05). Overall, our results suggest that MOS benefited the health, nutrient utilization, and fatty acid profiles in Hu lambs via glycerolipid and glycerophospholipid metabolism pathways.

Maternal melatonin (MT) readily crosses the placental barrier to enter the fetal circulation, and it holds the potential to enhance hair follicle (HF) development, possibly augmented through nutritional interventions during pregnancy. However, the specific impact of maternal MT treatment on fetal HF development remains largely unexplored. In this study, we implanted pregnant rabbits with 10 mg of MT-containing and non-MT-containing silica gel microcapsules. We then assessed HF density and the extent of HF cell apoptosis in the neonatal rabbits. Our findings revealed that maternal MT implantation significantly reduced HF cell apoptosis and promoted an increased HF density in the neonates. Mechanistically, this process involved MT downregulating the expression of JUN/FOS and AP-1, while concurrently upregulating equol expression and reducing norepinephrine levels. Analysis of key protein expression within the MAPK pathway indicated that maternal MT activated this pathway. These results suggest that maternal MT treatment promotes beneficial HF development in offspring. Notably, the transcriptional regulation of JUN/FOS members of the AP-1 complex emerges as a pivotal factor mediating the beneficial effects of MT on neonatal hair follicle development.

The aim of this experiment was to study the sustained effects of early supplementation with a starter on the performance of lambs during the pre-weaning, post-weaning, and fattening periods. Sixty male Hu lambs (3.59 ± 0.05 kg) were randomly assigned to two (30 lambs per group) treatments. The lambs were fed milk replacer from three days of age. The early supplementation (ES) group was supplemented with a starter ration at seven days of age, the control (CON) group was supplemented at 21 days of age, and lambs in both groups were weaned from milk replacer at 28 days of age. Eight lambs from each group were randomly slaughtered at 98 days of age, and the remaining lambs were fed the same nutrient level of a fattening ration until slaughter at 200 days of age. The results showed that early supplementation with starter significantly improved average daily feed intake (ADFI) and average daily weight gain (ADG) in the pre-weaning period (7–28 days of age), and ADFI and slaughter performance (live weight before slaughter, carcass weight and dressing percentage) in the post-weaning period (29–98 days of age, p < 0.05). In addition, early supplementation with the starter had no significant effect (p > 0.05) on ADFI, ADG, and slaughter performance, but significantly decreased (p < 0.05) the feed-to-gain ratio (F/G) of lambs during the fattening period (99–200 days of age). In addition, early supplementation with starter increased the ratio of rumen and reticulum weight to total stomach weight in lambs (p < 0.05). In conclusion, early supplementation with starter can reduce feed costs and improve the performance of lambs, while the growth advantage produced by early supplementation had initially disappeared by 154 days of age.