Dietary Fiber Level Improve Growth Performance, Nutrient Digestibility, Immune and Intestinal Morphology of Broilers from Day 22 to 42.

There are few systematic studies on the dietary fiber requirements of broilers in the late feeding stage, and there are not enough data to support this hypothesis. This experiment was conducted to examine the effects of dietary fiber level on growth performance, nutrient digestibility, immune function and intestinal morphology of broilers from day 22 to 42. A total of 480 one-day-old Arbor Acres broilers with half male and half female were randomly allocated into four groups, with eight replicates in each group and fifteen chickens in each replicate. The experimental period was 42 days. All broilers were fed a basal diet from 1 to 21 days. During the 22-42 day period, the four experimental groups were fed diets with soybean hulls as the fiber source, and crude fiber (CF) levels were 2%, 5%, 8% and 11%, respectively. The results showed that during the 29-42 day period, the average daily feed intake (ADFI) of broilers was higher in the 5% CF and 8% CF groups (p < 0.05), and during the 29-35 day period, the average daily gain (ADG) of broilers was higher and the ratio of feed and gain (F/G) of broilers was lower in the 5% CF and 8% CF groups (p < 0.05). The digestibility of crude protein (CP), ether extract (EE), CF, acid detergent fiber (ADF) and neutral detergent fiber (NDF) was higher in broilers of the 8% CF group (p < 0.05). The immunoglobulin A (IgA), immunoglobulin G (IgG) and immunoglobulin M (IgM) content of the plasma of broilers was higher in the 8% CF group (p < 0.05). The villus height (VH) of the duodenum, jejunum and ileum of broilers was higher, and the crypt depth (CD) was lower in the 8% CF group than that in the 2% CF group (p < 0.05). The ratio of VH and CD (V/C) of the duodenum and jejunum of broilers in the 8% CF group was higher than that in the 2% CF group (p < 0.05). The quadratic regression analysis showed that the optimum dietary CF level was 7-9%. In conclusion, under the conditions of this experiment, a diet of 7-9% CF may promote growth performance by improving the nutrient digestibility, immunity and intestinal morphology of broilers from day 22 to 42.

Estimation of genetic parameters of eggshell translucency and production traits in different genotypes of laying hens.

The translucency of eggshells is a ubiquitous appearance problem caused by moisture translocation and the accumulation of egg contents into the eggshell ultrastructure. Previous studies have mainly investigated the causes of eggshell translucency from nutritional and environmental perspectives. However, little is known of the effect of genetics the causes of eggshell translucency on hen production performance. To evaluate the genetic parameters of eggshell translucency and other production performance indicators, we performed an experiment on 3 pure hen lines: 624 Dwarf Layer-White, 1,612 Rhode Island Red, and 813 Rhode Island Red-White. We collected eggs from each hen over 5 d and measured eggshell translucent level (TL) using the grading method. Additionally we measured indicators of each hen during the laying period, including age at laying of the first egg (AFE), body weight at laying of the first egg (BWFE), weight of the first egg (FEW), body weight at 40 wk (BW40), egg weight at 40 wk (EW40), egg production up to 40 wk of age (EN), and calculated the genetic parameters among the indicators. The results showed that the estimated heritability of TL in the 3 genotypes were 0.30, 0.24, and 0.20, respectively, suggesting a low or moderate level of heritability. We found a positive correlation between TL and AFE, with genetic correlation coefficients 0.19 to 0.41, and negative genetic correlation between TL and EN, with correlation coefficient -0.36 to -0.19. Additionally, we observed positive correlation exists between AFE and FEW, BWFE and FEW, and BW40 and EW40; and negative correlation between AFE and EN in the 3 pure lines. These results enriched the research on heritability of eggshell translucency in different hen breeds and demonstrated moderate or low heritability of the indicator. Furthermore, eggshell translucency was negatively affected by AFE and EN. Our results provide a valuable reference for predicting selection response of eggshell translucency and production performance in brood hens, and locating the genes regulating eggshell translucency.

Distribution and Photochemistry of Polycyclic Aromatic Hydrocarbons in the Baotou Section of the Yellow River During Winter.

In this study, ice and water samples were collected from seven sites along the Baotou section of the Yellow River during winter 2013. Total polycyclic aromatic hydrocarbon (PAH) concentrations in the ice and in the water under the ice ranged from 21.3 to 59.4 ng L(-1), and from 38.3 to 222.4 ng L(-1), respectively. The average concentration in water under the ice was approximately 2.5 times greater than the average concentration in the ice phase. Four-ring PAHs dominated and accounted for 68.2 and 76.0 % of the total PAHs in ice and water, respectively. PAH concentrations were highest at sampling site S2 and were also relatively high at sites S4 and S5. PAH sources in ice and in water under the ice were similar. Three components were selected to represent the coal-combustion sources of PAHs. Because it was the main pollutant, and its concentrations were the highest, we examined the photodegradation behavior of fluoranthene and investigated the effects of light-sensitive materials (H2O2, acetone, and sediment) on fluoranthene photodegradation in the ice phase. Results showed that low H2O2 concentrations promoted photoconversion in the initial stage of the reaction and that degradation rates decreased later in the reaction. Likewise, high H2O2 concentrations promoted photoconversion. As acetone concentrations increased, the rates of fluoranthene-degradation decreased. Sediments may also have decreased the degradation rate of fluoranthene.

[Study on the risk factors of schistosomiasis transmission and control strategy in the Three Gorges Reservoir Areas].

OBJECTIVE: To understand the risk factors of schistosomiasis transmission in the Three Gorges Reservoir Area (TGRA) and to provide evidence for the development of control strategy. METHODS: Approaches including epidemiology, immunology and field survey were applied to investigate the potential risk factors which would involve the importation of infectious resources live mobile and migrant population, and livestock in the reservoir area. Meanwhile, observation on survival and reproductive status of snail under simulation habitats was also carried out, using ecological methods on snails. Strategy in preventing the spread of snail as infectious resources was also provided. RESULTS: 175 mobile people from schistosomaisis endemic area of were tested and one person showed immunology tests positive with indirect hemagglutination test (IHA) and circumoral precipitin test (COPT), with a positive rate of 0.57%. Through the two-year period under observation, data showed that the snails with ribbon/smooth shells could survive and reproduce under habitats of simulation. CONCLUSIONS: Once the infectious resource of schistosomiasis was introduced into the TGRA, the area became a new schistosomiasis epidemic area in TGRA which called for countermeasures to be taken.