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.

Effects of Dietary Supplementation of Alpha-Ketoglutarate in a Low-Protein Diet on Fatty Acid Composition and Lipid Metabolism Related Gene Expression in Muscles of Growing Pigs.

The aim of the current study was to investigate whether dietary supplementation with alpha-ketoglutarate (AKG) in a reduced crude protein (CP) diet would affect fatty acid composition and lipid metabolism related gene expression in the muscles of growing pigs. A total of 27 Large White × Landrace growing pigs at 44 ± 1 d of age (11.96 ± 0.18 kg) were randomly allocated to three treatments (n = 9). Dietary treatments included: (1) normal protein diet with 20% crude protein (CP) (NP); (2) a low crude protein diet formulated to contain approximately 17% CP (LP); and (3) a low crude protein diet with 17% CP supplemented with 1% AKG at the expense of regular corn components (ALP). The experimental trial lasted 35 d. The results showed that compared with the NP and LP diets, supplementation with AKG in a low-protein diet increased the intramuscular fat (IMF), oleic acid (C18:1n-9), and monounsaturated fatty acid (MUFA) contents (p < 0.05), and tended to increase the percentage of palmitoleic acid (C16:1) and stearic acid (C18:0) (p < 0.10) in the biceps femoris and longissimus dorsi muscles of growing pigs. These effects may be associated with increased relative mRNA expression levels of fatty acid synthase (FAS), acetyl-CoA carboxylase (ACC), adipocyte determination and differentiation factor 1 (ADD1), fatty acid binding protein 4 (FABP4), and stearoyl-CoA desaturase (SCD) in skeletal muscle, indicating that AKG might be involved in the differential regulation of some key lipogenic genes in skeletal muscles of pigs.

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.

Alpha-Ketoglutarate in Low-Protein Diets for Growing Pigs: Effects on Cecal Microbial Communities and Parameters of Microbial Metabolism.

Alpha-ketoglutarate (AKG), a critical molecule in the tricarboxylic acid cycle, is beneficial to intestinal functions. However, its influence on intestinal microbiota and metabolism is not fully understood. We investigated the effects of a low-protein (LP) diet supplemented with AKG on cecal microbial communities and the parameters of microbial metabolism in growing pigs. Twenty-seven young pigs (Large White × Landrace) with an average initial body weight of 11.96 ± 0.18 kg were randomly allotted into three groups (n = 9): a normal protein (NP) diet containing 20% crude protein (CP); LP diet formulated with 17% CP (LP diet); or LP diet supplemented with 10 g kg-1 of AKG (ALP diet). After a 35-day trial period, the digesta of the cecum were collected to analyze the concentrations of ammonia and short-chain fatty acids (SCFAs). We also performed a microbial analysis. Although no significant differences were found in performance among the diet groups, pigs fed the ALP diet had greater average daily gain (ADG) when compared with those in the LP group. Experimental diet did not affect cecal bacterial richness or diversity, as determined by Chao1 and ACE species richness measures and Shannon and Simpson indices, respectively. The predominant phyla Firmicutes, Bacteroidetes, and Proteobacteria increased in relative abundances in the cecum of pigs fed ALP diet. At the genus level, compared to the LP diet, the ALP diet significantly increased the abundances of Lachnospiraceae UCG-005, Lachnospiraceae NK4A136 group, Phascolarctobacterium and Parabacteroides, while decreased Vibrio and Maritalea. Pigs fed the ALP diet increased Oribacterium and Lachnoclostridium when compared with the NP diet. Non-metric multidimensional scaling analysis revealed that the distribution of microbiota at each group was distinctly clustered separately along principal coordinate. In addition, quantitative PCR revealed that the ALP diet was also associated with increases in the amounts of Bacteroides, Bifidobacterium, and Lactobacillus, but a decrease in the level of Escherichia coli. Compared with the NP diet, the ALP diet enhanced the concentrations of valerate and propionate. This ALP diet also increased the concentrations of valerate and isobutyrate when compared with the LP diet. Moreover, the ALP diet was linked with a significant decline in the concentration of ammonia in the cecum. These results indicate that a LP diet supplemented with AKG can alter the balance in microbial communities, increasing the population of SCFA-producing bacteria and the amounts of Bacteroides and Bifidobacterium, while reducing the counts of Escherichia coli and the amount of ammonia in the cecum.