【Objective】This study was conducted to investigate the effects of mannan oligosaccharides (MOS) supplementation to milk replacer on the development of gastrointestinal tract of 7-28 day-old Hu lambs. 【Method】 Thirty 7 day-old Hu male lambs were chosen and divided into 2 groups randomly, fifteen lambs in each group and each lamb as a repeat. Lambs were fed milk replacer with or without 0.2 % MOS, respectively. The test lasted for 21 days. Eight lambs were selected from each group randomly and slaughtered at 28 day-old. The weights of the compound stomach and the intestinal tract with and without content, and lengths of the intestinal tract were measured, and the relative quality and length were calculated. While the tissue samples from fundus gland region of the abomasum, the middle part of duodenum, jejunum and ileum were fixed in paraformaldehyde to analyse the histomorphology, and the apoptotic rate of intestinal epithelial cells as well. And the mRNA expression of claudin 1, zonula occludens-1 (ZO-1), and occludin protein of duodenum, jejunum and ileum mucosa were measured.【Result】The results showed that except relative length of jejunum (P=0.040), the relative weights (% body weight, % stomach weight, % intestinal tract weight, and % gastrointestinal tract weight), relative lengths (% intestinal tract length), content of stomach and intestinal tract (% body weight, % stomach content weight, % intestinal tract content weight, and % gastrointestinal tract content weight), the apoptotic rate of intestinal epithelial cells and mRNA expression of claudin 1 protein in intestinal tract of lambs were not affected by MOS (P＞0.05). However, MOS elongated the villus height and the muscular thickness, and decreased the villus width of lamb duodenum significantly (P=0.033, P=0.047, P=0.015). MOS also up-regulated the mRNA expression of ZO-1 protein of lamb jejunum significantly (P=0.028). And there was a tendency that MOS elongated villus height, width and crypt depth of ileum, muscular thickness of abomasum, and mRNA expression of occludin protein of ileum (P=0.075, P=0.078, P=0.085, P=0.084, P=0.052).【Conclusion】MOS almost did not affect the relative weights, lengths, and content distribution of gastrointestinal tract of 7-28 days old Hu lambs, but improved the histomorphology of duodenum and ileum, indicating it could maintain barrier function of intestinal tract and benefit to nutrients digestibility.
【Background】 The application of milk replacer powder has important significance for improving the health and survival rate of lambs. However, the effects of milk replacer feeding levels on immune function and intestinal barrier function of lambs were still unclear. The optimal level of milk replacer for development of immune function and intestinal health is still inconclusive. 【Objective】 The objective of this experiment was to analyze the effects of the milk replacer feeding level on the immune function and intestinal barrier function of lambs through the dynamic of hematological indicators, the morphology of ileum and colon, antioxidant index, immune index and expression of intestinal barrier function related genes.【Method】16 newborn lambs were randomly divided into two groups: the control group (CON, milk replacer feeding level was 2% of average body weight) and the intensive feeding group (H, milk replacer feeding level was 4% of their average body weight). All lambs were fed milk replacer from the 7th day of age and were slaughtered at 49 days of age. 【Result】The results showed that the milk replacer feeding level had no significant effects on leukocyte count, lymphocyte count, neutrophil count, red blood cell count and hemoglobin concentration (P＞0.05). The number of lymphocytes, red blood cells and hemoglobin in the 21-49d lambs increased gradually with age, significantly higher at 49 days of age (P＜0.05), while neutrophil lymphocytes were significantly lower than at 49 days (P＜0.05). The ileal villus height of the H group was significantly higher than that of the CON group (P＜0.05), the ileum and colon crypt depth was significantly lower than that of the CON group (P＜0.05), the ileal and colonic malondialdehyde (MDA) content and immunoglobulin A (The content of IgA) was significantly lower than that of CON group (P＜0.05). The expression of Claudin4 in colon was significantly lower than that in CON group (P＜0.05), and the expression of tumor necrosis factor (TNF-α) in ileum and colon was significantly lower than that in CON group (P＜0.05). 【Conclusion】The intensive milk replacer feeding could reduce intestinal oxidative damage, promote intestinal villus development, reduce intestinal physical barrier damage and reduce intestinal immune response. In the sheep production, an intensive milk replacer-feeding program benefits to the healthy intestinal development.
【Objective】The objective of this study was to evaluate the effects of deleting dietary lysine (Lys), methionine (Met) and threonine (Thr) on growth performance, and nutrients digestion and metabolism in 3-6 month-old Chinese Holstein heifers. It can provide not only the evidences for diagnosing the deficiency disease of amino acid of heifers in production, but also the guidance for determining amino acid requirements of heifers in the future.【Method】The experiment was conducted for 90 days with 72 Holstein heifers aged about 84 day-old fed in restricted amounts. Following a 7-day covariate period, heifers were allocated to 4 groups according to date of birth and body weight: 30% Lys reducing treatment (PC-Lys), 30% Met reducing treatment (PC-Met), 30% Thr reducing treatment (PC-Thr) and theoretical amino acid balanced treatment (PC). Body weight, body size and length of nipples were measured on 1, 30, 60 and 90 day. Six healthy calves were selected from each group at the ages of 132-138 and 173-179 day for twice and metabolism test. Feces, urine and feeds samples were collected to determine the apparent digestibility of nutrients and nitrogen metabolism. Dry matter intake was recorded daily throughout the whole trial period. 【Result】Compared with PC, the results showed that (1) Lys deficiency significantly decreased Gain/Feed (G/F) in 90 to 180 day-old heifers (P＜0.05). Average daily gain (ADG) of PC-Lys group was lowest among four groups in 90 to 180 day-old heifers (P＞0.05). ADG and G/F were not influenced by Met and Thr deficiency in 90 to 180 day-old heifers (P＞0.05); (2) No differences of diarrhea rate were found among four groups (P＞0.05), while diarrhea rate was highest in PC-Lys group (P＞0.05). However, Lys and Thr deficiency decreased fecal score (P＜0.05); (3) Lys, Met and Thr deficiency did not affect body size (P＞0.05), but the growth rate of nipples of PC-Lys group were lower than that of PC group (P＜0.05); (4) The apparent digestibility of nutrients were not influenced by different treatments. Retained N of intake N and biological value of N were significantly decreased in PC-Lys group (P＜0.05). 【Conclusion】On the basis of the theoretical amino acid balanced diet, reducing 30% dietary Lys had adverse effect on growth performance and nitrogen metabolism, and reducing 30% dietary Thr could deteriorate diarrhea, while reducing 30% dietary Met had no effects in heifers.
【Objective】 The purpose of this experiment was to study the slaughter characteristics and meat quality of Holstein bulls grain-fed under different dietary crude protein levels. To provide a reference for improving beef quality research.【Method】 Ninety Holstein bulls with body weight of about 197 kg and similar body condition were randomly divided into three groups with 30 calves in each group. Group I, II and III were fed diets with low, medium and high crude protein level, respectively. The dietary comprehensive net energy level in each group was the same, and the ratio of concentrate to roughage (dry matter basis) was 90﹕10. The pre-trial period lasted 10 d and the formal trial period lasted 193 d. 【Result】 The results showed as follows: (1) The longissimus muscle area in group III was significantly increased by 6.69% (P＞0.05) compared with group I, while there were no effects on dressing, meat-bone ratio, net meat percentage and carcass yield among the groups (P＞0.05). (2) The dehydration rates in group Ⅲ were significantly lower than those in group I by 9.01% (P＜0.05); with the increasing of dietary crude protein level, the shear stress and cooking loss decreased slightly, but the difference was not significant (P＞0.05), and there were no significant differences in meat pH, meat color, chroma and hue angle among groups (P＞0.05). (3) Dietary crude protein levels had no significant effect on conventional ingredients of longissimus muscle (P＞0.05). (4) The concentration of saturated fatty acid (SFA) of longissimus dorsi in group III was 14.58% (P＜0.01) and 9.68% (P＜0.05) lower than that in group I and group II, respectively, and the palmitic acid (C16:0) concentration in group III was significantly lower than that in group I (P＜0.05). Compared with groupⅠ, the concentration of monounsaturated fatty acid (MUFA) in group II and group III was increased by 14.16% and 17.42% (P＜0.01), respectively, and the oleic acid (C18:1n9c) concentration was increased by 28.89% and 30.19% (P＜0.01), respectively; the ratio of monounsaturated fatty acids to saturated fatty acids (M/S) in group II was significantly higher than that in groupⅠ(P＜0.05), and the M/S in group III was significantly higher than that in groupⅠ(P＜0.01).【Conclusion】In conclusion, under the experimental conditions, diets with high crude protein level could increase longissimus muscle area of Holstein bulls, increase MUFA content and decrease SFA content of longissimus dorsi, and improve meat quality in dairy bulls.
【Objective】 The objective of this study was to determine the effects of different neutral detergent fiber (NDF) levels of starter on growth performance, blood biochemical and antioxidant indices of calves.【Method】Sixty new born dairy calves (24 females and 36 males) with body weight (42 ± 2.5) kg were randomly assigned to four treatment groups (10N, 15N, 20N and 25N) with nine male calves and six female calves each. Each group was fed one of the four starters which had different NDF levels (10%,15%, 20% and 25%, respectively). Starter intake was measured daily, and body weight of calves was measured every two weeks. The body sizes of calves were measured at 35 and 112 days of age, respectively. The concentrations of serum biochemical and antioxidant indices were determined at 35, 70, 90 and 112 days of age prior to morning feeding.【Result】 (1) At the age of 70-112 days, the starter intake of calve in 10N group was significantly lower than that in 25N group (P＜0.5). At the age of 42-70 days, the NDF intake of calf in 20N and 25N groups were significantly higher than that of the 10N and 15N groups (P＜0.05). The NDF intake of calve increased significantly with the dietary NDF level increasing during the 70-112 days (P＜0.05). (2) At the age of 70-112 days and 15-112 days, the body weight gain was increased by 12.67%, 43.56%, 30.17% and 6.16%, 18.09%, 15.16%, respectively in group II than that in group 10N, 20N and 25N (P＜0.05). The wither height was significantly higher in group 15N than that in group 20N and 25N (P＜0.05). The body length and heart girth were significantly higher in group 15N than in group 25N (P＜0.05). (3) At 90 days of age, serum globulin content of group 15N was significantly higher than that of the other three groups, and ALB/GLB value was significantly lower than that of the other three groups (P＜0.05). At 112 days of age, serum glutamic-pyruvic transaminase, glutamic oxalacetic transaminase and alkaline phosphatase were significantly decreased with improved NDF level (P＜0.05). (4) At 35, 70 and 112 days of calf age, the activities of superoxide dismutase of serum in group 15N, 20N and 25N were significantly higher than that in group 10N (P＜0.05), and the content of malondialdehyde in serum of group15N, 20N and 25N were significantly lower than that of group 10N (P＜0.05).【Conclusion】The content of NDF in starter diets had a direct influence on intake and body weight gain of calf, and the optimum level of NDF in starter of calves aged15-112 days was 15%.
【Objective】 The study was conducted to evaluate the effects of Resveratrol and Bacillus licheniformis on growth performance, nutrient digestibility and serological parameters in lambs.【Method】A total of 120 neonatal Hu lambs ((3.82±0.46) kg of BW) randomly divided into four groups, including CON group (lambs were conventional weaned at 49 days of age), EW group (lambs were early weaned at 21 days of age), RSV group (lambs were supplemented with 10 mg·kg -1 BW Resveratrol and early weaned) and BL group (lambs were supplemented with 60 mg·kg -1 BW Bacillus licheniformis with ≥4.0×10 9 CFU/g live bacteria and early weaned). Each group had 3 replicates with 10 lambs in each replicate. The digestion trial was carried out during day 56-63, and serum parameters were determined on day 63. The experiment lasted 63 d.【Result】There were no differences in body weight (BW) at day 21, average daily gain (ADG ) and solid feed intake during day 1 to day 21 between the groups (P＞0.05). The BW of day 21 and day 49 were significantly lower (P＜0.01) but solid feed intake of day 21-49 were significantly higher (P＜0.01) in EW, RSV and BL groups than that in CON group. During the whole experiment, the ADG of ER, RSV, and BL groups were significantly lower than that of CON group (P＜0.01), which were relatively decreased by 18.5%, 15.1% and 20.5%, respectively. The digestibility of dry matter (DM) and organic matter (OM) were significantly higher in CON and EW group than that in RSV group (P＜0.05), and the OM digestibility was significantly higher in EW group than that in RSV group (P＜0.05). The apparent digestibility of CP, EE, Ca and P were not significantly different among the groups (P＞0.05). The digestibility of NDF and ADF were significantly higher in EW group than that in RSV group (P＜0.05), but there was no significant difference between the other groups (P＞0.05). There were no significant differences in serum anti-oxidation, immunity and inflammation parameters of lambs between groups (P＞0.05).【Conclusion】 The results showed that weaning at 21 days of age and directly switching them to solid feed had negative effects on lambs’ growth performance with the BW reducing by about 15% at 63 days of age. The supplementation of Resveratrol and Bacillus licheniformis seemed no influence on growth performance, nutrient digestibility, serum antioxidants and immunity parameters in Hu lambs.
