Recently the use of antibiotic growth promoter (AGPs) in poultry feed is banned in China, leading to the increasing demand for AGPs substitutes. Probiotics have been considered as a potential substitute. The purpose of this study was to evaluate the effects of probiotic on serum biochemistry, and growth promotion of body weight and visceral organs and in Lohmann Brown chicks aged 0 to 9 weeks. Five hundred and forty 1-day-old male chicks were randomly divided into three groups, with six replicates and 30 chicks in each replicate. The experiment was carried out over 70 days. Dietary treatments were: (1) basal diet alone (control group); (2) basal diet containing 0.1% probiotics (probiotic group); and (3) basal diet containing 0.01% zinc bacitracin in the feed (antibiotic group). The body weight (BW) of probiotic group was significantly higher than that of the control group during the whole trial period (p<0.05). ADG (0~70 d) in the probiotic group and the antibiotic group was higher than that in the control group (p<0.05). The Oliver weight and serum total protein (TP) in the probiotic group was higher than that in the control group on the 63rd day (p<0.05). The length of the duodenum, the weight of the spleen, duodenum and Jejunum in both the probiotic and antibiotic groups were higher than those in the control group (p<0.05). The ileum weight in the probiotic group was significantly higher than those in the control group (p<0.05). The ileum length in the probiotic group was significantly longer than that in both the antibiotic and control groups (p<0.05). Probiotic mix with Bacillus subtilis and Pediococcus acidilactici play a similar role in promoting growth of body and visceral organs, and it is a promising growth promoter for Lohmann Brown chicks (0 to 9 weeks).

Formation of gallbladder stone is a process of nucleation from different substances, and the causing-stone gallbladder bile is a constantly supersaturated solution, and bile liquid crystal is a nucleation factor in the formation of gallbladder stones. The process of nucleation includes gathering, merging and phase-changing of bile liquid crystals. The process of gathering, merging of bile liquid crystal is the key to nucleation.

To investigate the molecular mechanism by which diets of different energy levels alter fat accumulation, 120 Black-Bone chickens were divided into 3 groups and fed diets with varying energy levels for six weeks (low: 3.02 Mcal/kg, moderate: 3.22 Mcal/kg, high: 3.42 Mcal/kg). The high-energy diet increased the concentration of blood lipids. Furthermore, high-energy intake inhibited the activities of several serum lipases. Histological sections showed over-synthesis of lipids in the livers of chickens fed high-energy diets. Data from western blotting and PCR analyses indicated that key factors for lipogenesis, regulatory transcription factors and fatty acid transporters, were up-regulated, while key factors for lipolysis were down-regulated. Chickens fed low-energy diets showed opposite results. In conclusion, varying energy levels of diets affect fat accumulation in Black-Bone chickens through changed expression of metabolic regulators.

Background: Cottonseed meal (CSM), a relatively rich source of protein and amino acids, is used as an inexpensive alternative to soybean meal (SBM) in poultry diets. Two experiments were conducted to investigate the effects of CSM on growth performance, liver redox status, and serum biochemical parameters in goslings. In experiment 1, 300 1-d-old male goslings were randomly divided into 5 groups (10 goslings/replicate, 6 replicates/group) and subjected to a 28-d experiment. In experiment 2, 240 28-d-old male goslings were randomly divided into 5 groups (8 goslings/replicate, 6 replicates/group) and subjected to a 35-d experiment. Five isonitrogenous and isoenergetic diets were formulated to produce diets in which 0% (control), 25% (CSM25), 50% (CSM50), 75% (CSM75), and 100% (CSM100) of protein from SBM was replaced by protein from CSM.Results: In experiment 1, dietary CSM was associated with linear decreases in body weight, average daily feed intake and average daily gain and linear increases in the feed-to-gain ratio and mortality from 1 to 28 d of age (P < 0.05). Increased dietary CSM was associated with linear decreases in the hydroxyl radical scavenging ability and superoxide dismutase, catalase and glutathione peroxidase activities in the liver (P < 0.05). Dietary CSM was associated with linear decreases in serum total protein, albumin, and globulin concentrations and linear increases in serum uric acid concentrations (P < 0.05). In experiment 2, the growth performance from 29 to 63 d, redox status indicators (except for malondialdehyde [MDA]) in the liver, and serum biochemical parameters at d 63 were not affected by dietary CSM concentrations (P > 0.05). The MDA content in the liver in the CSM100 group was lower than those in the other four groups (P < 0.05).Conclusion: CSM in gosling diets should not exceed 7.08% in the early growth stage (d 1 to 28), but it can be increased to 22.65% from d 29 to 63. A high concentration of CSM may reduce growth performance in 1- to 28-d-old goslings due to decreases in feed intake, liver metabolism and antioxidant capacity.