ABSTRACT
We hypothesised that adding a combination of fibrolytic and amylolytic enzymes to the diet of early-lactation dairy cows would improve rumen enzyme activity and bacterial diversity, promote energy metabolism, and benefit milk production in cows. Twenty multiparous early-lactation (90⯱â¯5â¯d) Holstein cows with similar body conditions were randomly allocated to control (CON, nâ¯=â¯10) and experimental (EXP, nâ¯=â¯10) groups in a completely randomised single-factor design. The CON was fed only a basal total mixed ration diet, and the diet of the EXP was supplemented with a combination of fibrolytic and amylolytic enzymes at 70â¯g/cow/d (cellulase 3â¯500â¯CU/g, xylanase 2â¯000â¯XU/g, ß-glucanase 17â¯500â¯GU/g, and amylase 37â¯000â¯AU/g). The experiment lasted 28â¯days, with 21â¯days for adaptation and 7â¯days for sampling. Enzyme addition increased the activity levels of α-amylase and xylanase, and the ammonia-N concentration (Pâ¯<â¯0.05) tended to increase the activity of ß-glucanase (Pâ¯=â¯0.08) in rumen fluid. However, there was no significant difference in the rumen bacterial richness and diversity, phylum (richnessâ¯>â¯0.1%) or genus (richnessâ¯>â¯1%) composition between the CON and EXP groups (Pâ¯>â¯0.05). A tendency of difference was found between CON and EXP (Râ¯=â¯0.22, Pâ¯=â¯0.098) in principal component analysis. Ten genera showed different abundances across the CON and EXP groups (linear discriminant analysis effect size, linear discriminant analysisâ¯>â¯2). EXP increased the ratio of albumin to globulin and the concentrations of total cholesterol and low-density lipoprotein cholesterol (Pâ¯<â¯0.05) and tended to increase triglycerides (Pâ¯=â¯0.09) in blood. Milk yield, 3.5% fat-corrected milk yield and energy-corrected milk yield increased with enzyme supplementation (Pâ¯<â¯0.05). The production levels of milk fat and lactose increased, but the percentage of solids, not fat and protein, decreased in EXP (Pâ¯<â¯0.05). Although the DM intake was not affected, the feed efficiency tended to increase (Pâ¯=â¯0.07) in EXP. In conclusion, dietary supplementation with a mixture of fibrolytic and amylolytic enzymes on multiparous early-lactation dairy cows increased α-amylase and xylanase activity levels in rumen fluid, enhanced milk performance and tended to improve the feed efficiency in cows.
Subject(s)
Milk , Rumen , Animal Feed/analysis , Animals , Cattle , Cholesterol/metabolism , Diet/veterinary , Dietary Supplements , Digestion , Female , Fermentation , Lactation , Milk/metabolism , Rumen/metabolism , alpha-Amylases/metabolismABSTRACT
This study aimed to investigate the effect of dietary supplementation with leucine and phenylalanine on pancreas development, enzyme activity, and related gene expression in male Holstein calves. Twenty male Holstein calves [1 d of age, 38 ± 3 kg of body weight (BW)] were randomly assigned to 1 of the following 4 treatment groups with 5 calves in each group: control, leucine supplementation (1.435 g/L of milk), phenylalanine supplementation (0.725 g/L of milk), and leucine and phenylalanine (1.435 + 0.725 g/L of milk). The diets were made isonitrogenous with the inclusion of alanine in each respective treatment. The feeding trial lasted for 8 wk, including 1 wk for adaption and 7 wk for the feeding experiment. Leucine tended to increase the concentration of total pancreatic protein (mg/kg of BW). Phenylalanine increased the concentrations of plasma insulin, cholecystokinin, and pancreatic DNA (mg/g) and the expression of trypsin gene but decreased the pancreatic protein:DNA ratio and tended to decrease the pancreas weight (g/kg of BW). No differences were observed in total pancreatic DNA (mg/pancreas and mg/kg of BW), pancreatic protein (mg/pancreas), or activities of α-amylase, trypsin, and lipase. The relative expression levels of the genes encoding α-amylase and lipase did not differ among the 4 groups. The supplementation of both leucine and phenylalanine showed an interaction on the pancreas weight (g and g/kg of BW) and a tendency of an interaction on the pancreatic protein concentration (mg/g of pancreas and mg/kg of BW) and the plasma glucose concentration. Leucine tended to increase the size of the pancreatic cells, whereas phenylalanine tended to increase the number of pancreatic cells. However, neither AA affected the activities of the pancreatic enzymes of the calves. These results indicate that leucine and phenylalanine supplementation in milk-fed Holstein calves differentially affect pancreatic growth and development.
Subject(s)
Cattle/genetics , Cattle/metabolism , Leucine/metabolism , Milk/metabolism , Pancreas/growth & development , Phenylalanine/metabolism , Animal Feed/analysis , Animals , Body Weight , Cattle/growth & development , Dietary Supplements/analysis , Female , Gene Expression , Male , Pancreas/enzymology , alpha-AmylasesABSTRACT
BACKGROUND: Earlier work from our laboratory highlighted the therapeutic potential of curcumin (turmeric), used as a dietary ingredient and as a natural anti-inflammatory agent in India and other Southeast Asian countries. This agent was shown to decrease the proliferative potential and induce the apoptosis potential of both androgen-dependent and androgen-independent prostate cancer cells in vitro, largely by modulating the apoptosis suppressor proteins and by interfering with the growth factor receptor signaling pathways as exemplified by the EGF-receptor. To extend these observations made in vitro and to study the efficacy of this potential anti-cancer agent in vivo, the growth of LNCaP cells as heterotopically implanted tumors in nude mice was followed. METHODS: The androgen-dependent LNCaP prostate cancer cells were grown, mixed with Matrigel and injected subcutaneously into nude mice. Experimental group received a synthetic diet containing 2% curcumin for up to 6 weeks. At the end point, sections taken from the excised tumors were evaluated for pathology, cell proliferation, apoptosis, and vascularity. RESULTS: Curcumin causes a marked decrease in the extent of cell proliferation as measured by the BrdU incorporation assay and a significant increase in the extent of apoptosis as measured by an in situ cell death assay. Moreover, a significant decrease in the microvessel density as measured by the CD31 antigen staining was also seen. CONCLUSIONS: Curcumin could be a potentially therapeutic anti-cancer agent, as it significantly inhibits prostate cancer growth, as exemplified by LNCaP in vivo, and has the potential to prevent the progression of this cancer to its hormone refractory state.