Effects of dietary supplementation of Lycium barbarum polysaccharides on growth performance, immune status, antioxidant capacity and selected microbial populations of weaned piglets.

Lycium barbarum polysaccharides (LBPs) are a complex mixture of highly branched and partially characterised polysaccharides and proteoglycans extracted from the goji berry. This mixture has great potential as a novel feed supplement for pigs. Two trials were conducted to evaluate the effects of supplementation with LBPs on the growth performance, immune status, antioxidant capacity and selected intestinal microbial populations in weaned piglets. In trial 1, a total of 400 weaned piglets [(Yorkshire × Landrace) × Duroc] with an average body weight (BW) of 6.34 ± 0.16 kg (21 days of age) were divided into five groups and fed a basal diet (control group) or a basal diet containing 1,000, 2,000, 4,000 or 6,000 mg/kg LBPs (supplemented at the expense of corn). Supplementation with 4,000 or 6,000 mg/kg LBPs for 2 weeks significantly increased the average daily gain (ADG) and average daily feed intake (ADFI) of the pigs compared with the control group (p < .05). In trial 2, thirty-two 21-days-old weaned piglets (BW: 6.33 ± 0.11 kg) were allotted to a control group (fed with a basal diet) or an experimental group (basal diet containing 4,000 mg/kg LBPs). The experiment lasted for 14 days. Pigs fed LBP diets exhibited an increased ADG and ADFI, and a decreased diarrhoeal incidence compared with those fed the basal diets (p < .05). Supplementation with LBPs increased the serum IgG and IgM levels (p < .05). Dietary LBPs effectively promoted antioxidant defence properties through enhancing the activities of serum, liver superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GSH-Px), in addition to decreasing the malondialdehyde (MDA) content (p < .05). The addition of LBPs increased the amounts of Bacteroidetes in the ileum and caecum and the caecal contents of Lactobacillus spp. and Bifidobacterium spp. (p < .05), while decreased the populations of Escherichia coli and Firmicutes in the ileum and caecum (p < .05) compared with the control group. Our results suggest that dietary supplementation with LBPs can enhance growth performance, immune status and antioxidant capacity, and improve the intestinal microbial populations of weaned piglets.

Effect of Dietary Niacin Supplementation on Growth Performance, Nutrient Digestibility, Hematology, and Lipoprotein Concentrations of Young Turkeys, Meleagris gallopavo.

The growth performance, nutrient digestibility, hematology, serum chemistry, and lipoprotein concentrations of turkey (Meleagris gallopavo) poults fed diets supplemented with high or recommended concentrations of niacin were investigated in this study. A total of 120 four-week-old turkey poults were randomly divided into three treatment groups with five replicates of eight birds in each group. The poult diets were supplemented with 0.0, 60, and 180 mg/kg niacin in the three treatments, termed control, recommended niacin supplementation (RNS), and high niacin supplementation (HNS), respectively. The study lasted for four weeks. The results showed that the HNS treatment reduced the feed intake and increased the body weight gain of poults. The apparent, nitrogen-corrected, and true metabolizable energy contents were the highest in the HNS-group turkey poults (P<0.05). The red and white blood cell counts and hemoglobin concentration of the turkeys improved with increasing niacin supplementation (P<0.01). The serum constituents, including the serum protein and globulin, were significantly increased (P<0.05), while the uric acid and creatinine contents were significantly reduced in the HNS-group turkeys. Similarly, the HNS-group turkeys exhibited significantly reduced alanine aminotransferase (ALT) and alkaline phosphatase (ALP) contents, while the RNS-group turkeys had the least aspartate aminotransferase (AST) content. In addition, the HNS-group turkeys had the least serum low-density lipoprotein (LDL), triglyceride, and total cholesterol concentrations and the highest serum high-density lipoprotein (HDL) (P<0.01) concentrations. In conclusion, the supplementation of 180 mg/kg niacin in the diet reduced the feed intake and serum ALT, ALP, LDL, triglyceride, and cholesterol contents and increased the body weight gain, metabolizable energy, and HDL concentration in turkeys. This study showed that niacin supplementation could reduce the fat content without compromising the body weight gain and increase stress resistance in turkey poults.

Supplementation with α-ketoglutarate to a low-protein diet enhances amino acid synthesis in tissues and improves protein metabolism in the skeletal muscle of growing pigs.

α-Ketoglutarate (AKG) is a crucial intermediate in the tricarboxylic acid (TCA) cycle and can be used for the production of ATP and amino acids in animal tissues. However, the effect of AKG on the expression patterns of genes involved in muscle protein metabolism is largely unknown, and the underlying mechanism remains to be elucidated. Therefore, we used young pigs to investigate the effects of a low crude protein (CP) diet and a low CP diet supplemented with AKG on protein accretion in their skeletal muscle. A total of 27 growing pigs with an initial body weight of 11.96 ± 0.18 kg were assigned randomly to one of the three diets: control (normal recommended 20% CP, NP), low CP (17% CP, LP), or low CP supplemented with 1% AKG (ALP). The pigs were fed their respective diets for 35 days. Free amino acid (AA) profile and hormone levels in the serum, and the expression of genes implicated in protein metabolism in skeletal muscle were examined. Results showed that compared with the control group or LP group, low-protein diets supplemented with AKG enhanced serum and intramuscular free AA concentrations, the mRNA abundances of AA transporters, and serum concentrations of insulin-like growth factor-1 (IGF-1), activated the mammalian target of rapamycin (mTOR) pathway, and decreased serum urea concentration and the mRNA levels for genes related to muscle protein degradation (P < 0.05). In conclusion, these results indicated that addition of AKG to a low-protein diet promotes amino acid synthesis in tissues and improves protein metabolism in skeletal muscle.

Effects of natural dietary supplementation with Macleaya cordata extract containing sanguinarine on growth performance and gut health of early-weaned piglets.

This study was conducted to investigate the effects of dietary supplementation with Sangrovit® (SAG; minimum of 1.5% sanguinarine, a quaternary benzo[c]phenanthridine alkaloid extracted from Macleaya cordata) on growth performance, intestinal morphology, intestinal microflora and its metabolites of early-weaned piglets. A total of 20 healthy weaned piglets (Duroc× [Large White×Landrace]), weaned at 21 days of age with an average body weight (BW) of 6.52 ± 0.23 kg, were randomly assigned to receive either a corn-soybean meal basal diet (CTR) or a basal diet supplemented with 50 mg/kg SAG (SAG). During the 21-days trial, we collected and analysed intestinal tissues and the luminal digesta for their morphology and populations of gut microbiota, as well as for measuring the concentrations of short-chain fatty acids (SCFAs) and ammonia. Compared with the CTR group, supplementation with SAG improved average daily gains (p = 0.011) and average daily feed intake (p = 0.037). Piglets fed the SAG diet had an average lower value for crypt depth of the jejunum (p = 0.011) and greater values for villus height in the ileum (p = 0.015) and ratios of villus height to crypt depth in the jejunum (p < 0.01) and in the ileum (p = 0.027) than did animals receiving the CTR diet. The addition of SAG increased the amounts of Lactobacillus in the ileum (p = 0.033) and caecum (p < 0.01), and tended to increase the amounts of Bifidobacterium (p = 0.058) in the caecum, while decreasing the amounts of Escherichia coli (p = 0.046) and Salmonella spp. (p = 0.035) in the ileum, as well as Salmonella spp. (p = 0.029) in the caecum. Dietary supplementation with SAG enhanced (p < 0.05) the concentrations of acetate, propionate, butyrate and total SCFAs, and also tended to increase the level of valerate (p = 0.055 and p = 0.052) in the ileal and caecal contents when compared with the CTR group. Concentrations of ammonia also declined in the caecal (p = 0.037) and ileal (p = 0.046) digesta in response to SAG. These results indicate that feeding early-weaned piglets a SAG-supplemented diet can potentially improve their growth performance and intestinal morphology, and can modify the intestinal luminal environment in a beneficial manner.