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A 3x4 factorial arrangement with three Metabolizable Energy (ME) levels (12.13, 12.55, 12.97 MJ/kg) and four Crude Protein (CP) levels (20.0, 21.0, 22.0 and 23.0%), respectively, was undertaken to investigate the influence of varying levels of dietary energy and protein on broiler performance and carcass quality from 1-21 d aysof age. Six hundred 1 day old broiler chicks were randomly divided into 12 treatments, each of which had five replicates of 10 birds. BW of 21 days of age was significantly increased with an increase in dietary ME (p 0.05). Both ME and CP significantly improved feed efficiency (P

This experiment was conducted to compare carcass characteristics of native quality chicken white Lueyang (WL), modern commercial broiler strain Arbor Acres breeder (AA) and their respective F cross when 1 achieve a common live body weight. A total of 300 day-old chicks were allotted to three groups and reared under the same conditions until they reached market weight (1800±20 g) respectively, then ten of individual male birds from each group were killed for measuring. There were significant differences in carcass and meat characteristics for breeds at a common market weight. WL had a large age to market weight, lower abdominal fat weight, lower breast meat yield, higher leg meat yield (P

This study was conducted to determine the effect of supplemental dietary vitamin C (VC) and vitamin E (VE) on improving semen quality and antioxidative status in breeder roosters challenged with dexamethasone (DEX). 120 45-week-old Lveyang black-boned breeder roosters were divided into 5 experimental treatments, including negative group, positive group, and three trial groups, which were fed basal diet supplemented with 300mg/kg VC, 200mg/kg VE, or 300mg/kg VC and 200mg/kg VE (VC+VE). At 49 weeks of age, the positive control and trial groups were subcutaneously injected 3 times every other day with DEX 4 mg/kg body weight, the negative control group was sham injected with saline. At 50 weeks of age, average daily feed intake of birds challenged with DEX significantly increased (P

Three experiments were carried out to determine optimal feed input and excreta collection time in bioassay of feedstuff true metabolizable energy for ducks. In experiment 1, 20 drakes had been food withdrawn and were allocated to 4 groups, each of which contained 5 birds. Birds of each group were force- fed 50 g complete feed, approximately 48 h after food withdrawal. The excreta voided during the exact 56 h following feeding were collected. In experiment 2, 28 drakes were force-fed 50 g complete feed, approximately 48 h after food withdrawal. 4 birds were killed by an intravenous dose of sodiu m pentobarbitone 4 h, 8 h, 14 h, 24 h, 32 h, 38 h and 48 h after feeding. The residues in alimentary canal were collected and dried in an oven at 65 C. In experiment 3, 70 mature drakes were allocated to 7 groups. The o treatments comprised an unfed negative control and five levels of feed input (30, 50, 70, 90, 110 and 150 g complete feed). The birds were force-fed at approximately 48 h after food withdrawal. The excreta voided during the exact 36 h following feeding were collected. The results indicated that the time prior to force - feeding and excreta collection period should be 32-36 h when evaluating feed metabolizable energy and 50- 70 g feed per bird is feasible for evaluating feed metabolizable energy.

This study was conducted to evaluate the effect of paprika extract (PE) on egg performance and egg quality of laying hens. A total of 960 fifty-three wk-old laying hens were randomly allotted into five groups and each of six replicates with 32 birds. The birds were fed wheat-soybean meal-based diets supplemented with 0, 0.1%, 0.2%, 0.4% and 0.8% PE respectively. The experiment lasted 4 weeks. RFC value linearly increased with an increase in dietary PE (P < 0.01) and achieved 9.9 when dietary PE added by 0.8%. L* value of egg yolk decreased with increase in dietary PE (P < 0.05), The a* value linearly increased with an increase in dietary PE (P < 0.01), while b* value unaffected (P

An experiment was undertaken to evaluate the effect of dietary selenium (Se) levels on growth performance and immune competence of broilers under heat stress. Birds were raised in either a thermoneutral (TN, 23.9 degrees C constant) or heat stress conditions (HS, 23.9 degrees C to 38 degrees C cycling) and were fed a corn-soybean meal basal diet supplemented with Se at 0, 0.2 and 0.4 mg/kg. A total of 240 one-day-old male broiler chicks were randomly assigned to six groups; each group had four replicates of 10 birds. Body weight and feed intake were not influenced by dietary Se, while feed conversion was significantly improved by a Se-supplementation of 0.2 mg/kg. HS significantly reduced body weight, feed intake and feed conversion. Numbers of abdominal exudate cells (AEC), percentage of macrophages in AEC, phagocytic macrophages, internalized opsonised and unopsonised sheep red blood cells (SRBC) were significantly increased by dietary Se. Both primary and secondary antibody responses were characterised by increasing titres of antibody to SRBC by dietary Se when birds were exposed to HS (p < 0.05). Lymphoid organ weights, antibody responses, incidence of macrophages in AEC, and phagocytic ability of macrophages were also significantly reduced under HS. These results indicated that HS severely reduced growth performance and immunocompetence of broilers, whereas the immune response of broilers improved by dietary Se supplementation under HS.