This experiment was conducted to investigate the effects of 1alpha-hydroxycholecalciferol (1alpha-OH D3) on the growth performance, tibia and plasma parameters, nutrient utilization, meat quality of the breast and thigh, and type IIb sodium phosphate cotranspoter gene expression of broilers. A total of 96 males of 1-d-old Arbor Acres broilers were randomly assigned to 8 cages of 12 birds each. Two dietary treatments were applied to 4 cages each. Diet 1 was prepared as the basal diet (nonphytate phosphorus, 0.21%), whereas diet 2 was the basal diet supplemented with 5 microg/kg of 1alpha-OH D3. Results showed that supplementation of the basal diet with 1alpha-OH D3 increased growth performance, tibia ash and strength, plasma inorganic phosphate concentration, utilization of total phosphorus and nonphytate phosphorus, lightness and yellowness of the breast and thigh meat, and intestinal type IIb sodium phosphate cotranspoter mRNA expression, whereas it decreased the shear force and water-holding capacity of the thigh meat. These data suggest that the addition of 1alpha-OH D3 might improve growth performance, tibia development, and meat quality in 1- to 21-d-old broilers by increasing the absorption and retention of phosphorus.

A b s t r a c tSoybean meal is the main vegetable protein source in animal feed. Soybean meal contains several anti-nutritional factors, which directly affect digestion and absorption of soy protein, thereby reducing growth performance and value in animals. Fermented soybean meal is rich in probiotics and functional metabolites, which facilitates soybean protein digestion, absorption and utilization in piglets. However, the mixed solid-state fermentation (SSF) conditions of soybean meal remain to be optimized. In this study, we investigated the optimal parameters for SSF of soybean meal by Lactobacillus species and Clostridium butyricum. The results showed that two days of fermentation was sufficient to increase the viable count of bacteria, lactic acid levels and degradation of soybean protein in fermented soybean meal at the initial moisture content of 50%. The pH value, lowering sugar content and oligosaccharides in fermented soybean meal, was significantly reduced at the initial moisture content of 50% after two days of fermentation. Furthermore, the exogenous proteases used in combination with probiotics supplementation were further able to enhance the viable count of bacteria, degradation of soybean protein and lactic acid level in the fermented soybean meal. In addition, the pH value and sugar content in fermented soybean meal were considerably reduced in the presence of both proteases and probiotics. Furthermore, the fermented soybean meal also showed antibacterial activity against Staphy lococcus aureus and Escherichia coli. These results together suggest that supplementation of both proteases and probiotics in SSF improves the nutritional value of fermented soybean meal and this is suitable as a protein source in animal feed.

Bacillus species are commonly used as probiotics in the poultry feed industry for preventing infectious diseases and improving productivity by altering gastrointestinal microbiota. The growth parameters of Bacillus subtilis for surfactin production in fermentation and the benefits of surfactin on broiler chickens remain unclear. In this study, we examined the growth parameters of B. subtilis in fermentation and evaluated the effects of surfactin from B. subtilis-fermented products on Clostridium perfringens-induced necrotic enteritis and growth performance in broilers. Results showed that the highest viable biomass of B. subtilis was observed at 10% molasses and 2% yeast supplementation during fermentation. The 4- and 6-day fermented B. subtilis products were heat-, acid- and bile-resistant. Furthermore, the 4-day fermented B. subtilis products with the highest surfactin concentration showed the maximal antimicrobial activity against pathogens, including Escherichia coli, Staphylococcus aureus, Salmonella typhimurium and C. perfringens. Dietary B. subtilis-fermented product supplementation in broilers significantly improved intestinal morphology and necrotic lesions under C. perfringens challenge. Bacillus subtilis treatments could enhance broiler productivity, as well as promote bone quality and intestinal morphology. These results together indicate that B. subtilis-fermented products containing surfactin have potential for the development as feed additives and use as possible substitutes for antibiotics to treat C. perfringens in the poultry industry.

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One alpha-hydroxycholecalciferol (1α-OH D 3 ), an analog of cholecalciferol (vitamin D 3 ), improves growth performance and phosphorus retention in broilers. In the present study, we investigate the effects of dietary calcium (Ca) levels on the efficacy of 1α-OH D 3 in the phosphorus (P)-deficient corn-soybean meal diets of 1-to 21-d-old broilers. Four hundred female Ross 308 broilers, 1-d-old, were randomly allotted to 10 treatments with 4 cages of 10 birds each. A 5×2 factorial experiment was designed to test 0.40, 0.60, 0.80, 1.00, and 1.20% Ca combined with 0 and 5 μg/kg of 1α-OH D 3 in a basal diet (0.25% non-phytate phosphorus (NPP), 0.48% total phosphorus (tP)) without vitamin D 3 . The lowest levels of body weight gain (BWG), feed intake (FI), feed efficiency (FE), tibia quality (except of ash and P), as well as the highest value of mortality, were observed at 0.40% Ca. Additional Ca corrected the Ca deficiency and eventually 1.2% Ca caused a P deficiency. The addition of 1α-OH D 3 improved BWG, FI, FE, serum inorganic phosphate concentration, tP retention, tibia weight, length, breaking-strength, and content of ash, Ca, and P, and decreased mortality. However, 1α-OH D 3 efficacy responded negatively to dietary Ca level. These results indicate that 1α-OH D 3 exerts the highest activities at lower concentration of dietary Ca.

-A 7 × 2 factorial experiment was designed to test the effects of calcium (Ca) to non-phytate phosphorus (NPP) ratio (1.14, 1.43, 1.71, 2.00, 2.29, 2.57, and 2.86) and different sources of vitamin D (1α-hydroxycholecalciferol (1α-OH-D 3 ) and 25-hydroxycholecalciferol (25-OH-D 3 )) on growth performance and bone mineralization in 1-to 42-d-old broiler chickens. On the day of hatch, 700 female Ross 308 broilers were weighed and randomly assigned to 14 treatments with five stainless steel cages of 10 birds each. Dietary Ca levels were 4.0, 5.0, 6.0, 7.0, 8.0, 9.0, and 10.0 g kg −1 and the NPP content was 3.5 g kg −1 . The dose of 1α-OH-D 3 or 25-OH-D 3 was 5 µg kg −1 . Diets were not supplemented with cholecalciferol (vitamin D 3 ). Results showed that the Ca to NPP ratio, vitamin D source, and their interaction affected body weight gain (BWG), feed intake (FI), feed efficiency (FE), and carcass and breast yields, as well as tibia weight and length and ash weight in broiler chickens from 1 to 42 d of age. Broilers fed 1α-OH-D 3 had higher BWG and FI as well as tibia breaking strength, weight, length, diameter, and ash weight than birds fed 25-OH-D 3 at 42 d of age. The Ca to NPP ratio had a quadratic effect on BWG, FI, mortality, as well as tibia breaking strength, weight, length, ash weight, and ash and P contents in 42-d-old broilers. Broiler chickens at 42 d of age obtain optimal growth performance and bone mineralization at the Ca to NPP ratio of 2.32 when 1α-OH-D 3 or 25-OH-D 3 are used as the vitamin D source.

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A trial was conducted to study the influence of different levels of a commercial enzyme complex on performance, nutrient availability, blood parameters, digestive tract measurements, amylase and trypsin activity of the digestive tract and gut morphology in broilers fed the typical diets in north China. There were four treatments: the control diet and the other three enzyme complex supplemented diets which were 180 mg/kg, 360 mg/kg and 720 mg/kg enzyme complex supplemented to the control diet, respectively. The birds fed the diets supplemented with 180 mg/kg and 360 mg/kg enzyme complex had better performance and nutrient availability, the activities of amylase and trypsin in the digestive tract in the two treatments were improved, the villus height and surface area of villus in the small intestine increased and the crypt depth and epithelial thickness of small intestine decreased. Relative weights of pancreas and relative weights and lengths of small intestine decreased. However, the addition of 720 mg/kg enzyme complex had no effects on these parameters and increased crypt depth and epithelial thickness of the small intestine. The data suggested that suitable supplementation of enzyme complex was beneficial for the birds, while excess enzyme complex inhibited secretion of endogenous enzyme and destroyed the structure of the small intestine.