Two experiments were conducted to investigate the relationship of laying hen body weight at 28 weeks to daily feed intake (DFI) and hen performance. Significant differences in the body weight of hens in the various body weight groups (BWG) were found at the beginning and end of the experiments. The differences in body weight were found to be related to DFI which increased in a linear fashion as body weight increased. It was found that 6.80 and 6.56 g more feed was consumed daily by each hen for each 100 g of body weight, in Experiments 1 and 2, respectively. Egg production did not differ significantly between BWG. Egg weight, egg mass, and feed efficiency were shown to be related to hen body weight. Egg weight and egg mass significantly increased as body weight increased. Feed efficiency, however, showed an inverse trend, decreasing in a linear fashion as body weight increased.(Key words: feed intake, laying hens, body weight)
Two experiments were conducted in which broiler breeders were fed either at 0800, 1300, 1600 hr, ad libitum, or at 1300 hr followed by a calcium-phosphorus (Ca-P) supplement 3 hr later. The Ca-P supplement was 10.6 g/bird/day of pellets containing 5.2% P and 21.0% Ca. Experiment 1 was conducted with 64-week-old hens from July 27 to August 23. Experiment 2 was conducted with 32-week-old hens from November 5 to January 27. The birds that were fed at 1300 hr followed by Ca-P pellets at 1600 hr and those fed at 1600 hr laid eggs with higher specific gravity than did the birds fed at 0800 hr, 1300 hr, or ad libitum. The ad libitum-fed birds laid eggs with the lowest specific gravity. There were no significant differences in fertility or hatchability of fertile eggs attributed to different feeding times, although ad libitum-fed birds had lower fertility and hatchability. However, egg production was significantly higher for hens fed at 1300 hr with Ca-P pellets at 1600 hr than for birds fed ad libitum in Experiment 1. In Experiment 2, ad libitum-fed birds had significantly higher egg production than birds fed at 1300 hr. However, there were no significant differences in egg production among birds fed at different times.
1. The relative sensitivities of broiler chicks, White Leghorn chicks, quail chicks, goslings and turkey poults to increasing dietary contents of aflatoxin from 1 to 21 d of age were determined. Aflatoxin was included in the diets at three concentrations (0.7, 1.4 and 2.1 mg aflatoxin B1 equivalents/kg). 2. Data were analysed for species differences in food consumption, body weight, food utilisation, mortality and liver pathology. 3. There were no significant effects of aflatoxin in broiler and Leghorn chicks. Aflatoxin at 0.7 mg/kg decreased the body weight of turkey poults but tended to increase the growth rate of goslings. At 1.4 mg aflatoxin/kg food consumption, body weight and weight gain of goslings were adversely affected. 4. Liver damage occurred in goslings and quail chicks at all inclusions of aflatoxin and was extensive at 2.1 mg/kg. 5. Poults and goslings appeared to be the most sensitive, quail were intermediate and domestic chicks were most resistant.
An experiment was conducted to determine whether increasing the moisture content of the litter would increase foot pad dermatitis in broilers, and to determine whether supplemental biotin or dried whey would affect this condition. Broilers grown on wet litter had significantly increased incidence of foot pad dermatitis. The addition of 3% of partially delactosed whey to the diet resulted in increasing the foot pad dermatis. The addition of biotin decreased foot pad dermatis. Examination of foot pad tissue indicated that the birds receiving the control diet were deficient in biotin.
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