ABSTRACT This study investigated the effect of calcium (Ca) and phytase interaction on growth performance and bone quality in 1-42-day-old broiler chickens. A total of 624 female one-day-old Ross 308 broilers were allotted to 13 treatments with four replicates and 12 birds per replicate. A 2 × 6 factorial experiment was designed to test the combinations of 0.50% and 1.00% Ca with 0, 500, 1,000, 2,500, 5,000, and 10,000 FTU/kg phytase in the basal diet (0.25% non-phytate phosphorus, NPP). The control diet contained adequate Ca and phosphorus (P). Dietary Ca, phytase, and their interaction affected growth performance and bone mineralization of broilers at 1-42 days of age (p<0.05). The broilers fed with 1.00% Ca had lower body weight gain (BWG) and feed intake (FI) compared with the birds fed with 0.50% Ca (p<0.05). The BWG, FI, leg bone weight, and ash weight of the broilers fed with 0.25% NPP were lower than those of birds fed with the control diet (p<0.05). The addition of 500-10,000 FTU/kg phytase improved growth rate and leg bone quality, especially at 1.00% Ca (p<0.05). No differences were observed in growth performance and bone quality of 42-day-old broilers fed with 1.00% Ca + 2,500-10,000 FTU/kg phytase and the control diet (p>0.05). These data indicated that high doses of phytase (2,500-10,000 FTU/kg) alleviate the negative effects of Ca and P imbalance (Ca-to-NPP ratio = 4.0) on growth performance and bone mineralization of broiler chickens.

ABSTRACT The objective of this study was to investigate the optimal zinc (Zn) requirement of broiler chickens based on Zn retention. On the day of hatch, 350 male Ross 308 broilers were randomly assigned to seven treatments with five replicates of ten birds each. Zinc was supplemented as ZnSO4·7H2O at 0, 20, 40, 60, 80, 100, or 120 mg/kg in the starter diet (fed from 1 to 21 d of age) and at 0, 16, 32, 48, 64, 80, or 96 mg/kg in the grower diet (fed from 22 to 42 d of age). The analyzed Zn levels were 34.98 and 27.57 mg/kg in the basal starter and grower diets, respectively. Supplemental Zn levels did not influence body weight gain, feed intake, feed conversion ratio, or liver Zn content of broilers at 21 and 42 d of age (p>0.05). Tibia ash Zn content of 21-d-old broilers increased when Zn supplementation level increased from 0 to 40 mg/kg Zn in (p<0.05). The highest breast muscle Zn content in 42-d-old broilers was observed when 100 and 80 mg Zn/kg was supplemented in the starter and grower diets, respectively. Fecal Zn content, Zn intake, Zn excretion, and Zn retention of 31- to 33-d-old broilers linearly increased with supplemental Zn levels (p<0.05). Zinc retention values, calculated as the difference between Zn intake and Zn excretion, were negative, about zero, and positive when starter/grower diets were supplemented with 0/0 and 20/16, 40/32, and 60/48 and 120/96 mg/kg, respectively. These results indicate that supplementing 40 and 32 mg Zn/kg in starter and grower diets, respectively, promote the growth performance of broiler chickens, while reduce Zn excretion in the environment.

ABSTRACT Fermented cottonseed meal (FCSM) is widely used in poultry diets in China. This study was conducted to investigate the effect of FCSM on lipid-related gene expression in broilers. Initially, 180 broiler chickens (21-days-old, equal number of males and females) were randomly divided into three groups, with six pens per group and 10 birds per pen. The chickens in the control group were fed a diet containing unfermented cottonseed meal, and those in the treatment groups were fed with diets including either CSM fermented by Candida tropicalis (Ct group) or CSM fermented by Candida tropicalis plus Saccharomyces cerevisae (Ct-Sc group) until 64 days old. The results revealed that, compared with the control group (p<0.05), the mRNA expression of peroxisome proliferator-activated receptor alpha (PPAR-a) and lipoprotein lipase (LPL) were upregulated in the livers of Ct-Sc males. The expression of PPAR-a was also upregulated in the livers of Ct females. The expression levels of acetyl CoA carboxylase (ACC) and LPL in the liver of males and the expression of PPAR-a in the liver of females were significantly different between the Ct and Ct-Sc groups (p<0.05). However, gene expressions of fatty acid synthase (FAS) and liver fatty acid-binding protein (L-FABP) in the liver were not altered when the broilers were fed FCSM-supplemented diets (p>0.05). Likewise, the expressions of peroxisome proliferator-activated receptor gamma (PPAR-g) and LPL in the abdominal fat were not altered by the FCSM-supplemented diets (p>0.05). The results in this study indicate that CSM fermented by Candida tropicalis and Saccharomyces cerevisiaeeffectively regulated the genes involved in fatty acid b-oxidation and triglyceride hydrolysis in male broiler chickens. Furthermore, the effects of the FCSM-supplemented diets were significantly different between bird sexes and between yeast strains used in the fermentation process.

Soil arsenic contamination becomes a potential agricultural and environmental hazard worldwide, and has been a serious problem for safe food production. A field experiment on soil contamination was conducted on four wheat varieties (Jimai, Gaoyou, Weimai and Wennong) in Eastern China, using 50 or 100 mg arsenic/kg soil. Biomass production and yield components were determined and arsenic concentrations were measured in plant tissues. Differential arsenic effects on wheat varieties were determined at maturity. Results showed that addition of arsenic significantly (p<0.05) reduced root, stem and spike dry weight and yield components, which resulted in the decrease of grain yield per plant. Arsenic concentrations in plant tissues increased significantly (p<0.05) with treatments, and its uptake varied considerably among wheat varieties, plant tissues and arsenic treatments. Arsenic concentrations in plant tissues were as follows: roots > stems > leaves and rachises > grains > glumes > awns. In the arsenic treatments, arsenic concentrations in bran were about 2-3 times higher than those in flour. Most of the arsenic contaminated flour exceeded the Chinese tolerance limit. Arsenic contents of grain parts were dependent on variety and treatment level in polluted soils. Weimai and Wennong showed highest amounts of arsenic in flour than the other varieties at 50 or 100 mg/ kg soil treatment, respectively. Weimai possessed significantly lower (p<0.05) amount of arsenic in bran than any other wheat variety. Results showed significant variety differences in arsenic concentration in polluted areas; it is of outstanding importance that wheat with the lowest possible arsenic concentration is used for food or fodder production. The present results provide scientific basis for revising the standards of wastewater discharges.

La contaminación del suelo por arsénico es un peligro potencial agrícola y ambiental en el mundo, y ha habido serios problemas para una producción de alimentos saludable. Se condujo un experimento a campo sobre la contaminación del suelo con arsénico en cuatro variedades de trigo (Jimai, Gaoyou, Weimai, Wennong) en China Oriental usando 50 ó 100 mg de arsénico/kg de suelo. Se determinaron la producción de biomasa y los componentes del rendimiento, y se midió la concentración de arsénico en tejidos vegetales. Los efectos del arsénico sobre las variedades de trigo se determinaron a la madurez del cultivo. Los resultados mostraron que la adición de arsénico redujo significativamente (p<0,05) el peso seco de raíces, tallos y espigas, y los componentes del rendimiento, lo que determinó una disminución en el rendimiento de grano por planta. La concentración de arsénico en los tejidos vegetales se incrementó significativamente (p<0,05) con los tratamientos, y su absorción varió considerablemente entre las variedades de trigo, tejidos vegetales y tratamientos de arsénico. La concentración de arsénico en los tejidos vegetales fue como sigue: raíces > tallos > hojas y raquis > granos> glumas > aristas. En los tratamientos, las concentraciones de arsénico en salvado fueron 2-3 veces más altas que en la harina. La mayor parte de la harina contaminada por arsénico excedió el límite de tolerancia permitido en China. El contenido de arsénico de las partes del grano dependió de la variedad y el tratamiento en las áreas contaminadas. Weimai o Wennong mostraron mayores cantidades de arsénico en la harina que las otras variedades a 50 ó 100 mg de arsénico/kg de suelo, respectivamente. Weimai tuvo una menor (p<0,05) cantidad de arsénico en el salvado que las otras variedades. Los resultados mostraron diferencias significativas entre las variedades en la concentración de arsénico en lasáreas contaminadas; es de fundamental importancia que se utilice trigo con la menor concentración posible de arsénico en la producción de alimentos y forraje. Los resultados presentados proveen una base científica para revisar los estándares de la descarga de aguas residuales.