1. Broilers and pullets were regularly handled or bled by wing vein puncture over periods of 5 and 31 weeks respectively. 2. Neither procedure had any effect on body weight, food consumption nor on egg production, egg weight, shell quality or the percentage of non-marketable eggs.

No abstract

Metabolizable energy assays using Australorp chickens were carried out on sorghum and maize hybrids grown in different regions in Queensland and harvested in different years. Relationships between metabolizable energy and the chemical composition of the grains were examined. Some comparisons also were made between the energy metabolized by different strains of chickens. The mean nitrogen-corrected metabolizable energy values and standard deviations for all maize and sorghum grains were 3770 � 154 (n = 48) and 3750 � 239 (n = 39) kcal per kg dry matter, respectively. There were significant differences in metabolizable energy values between locations and years of harvest for both grains. Significant differences were seen between sorghum hybrids, but not between maize hybrids. The interactions, hybrid x region and hybrid x year, also were significant for sorghum. Correlations between metabolizable energy and chemical composition of the grains were not sufficiently high to enable metabolizable energy to be predicted with the accuracy necessary for practical application. Chickens from a White Leghorn and two commercial broiler strains gave similar metabolizable energy values to those obtained with the Australorp chickens.

The performance of pullets either fed lysine deficient diets or restricted in total feed intake in their starter (0-6 weeks), grower (6-1 2 weeks) or developer (1 2-20 weeks) phases or throughout their rearing period (0-20 weeks) were compared in separate experiments. Two levels of severity of each type of restriction were examined. No restriction treatment significantly improved the efficiency of conversion of feed to egg either measured on a chronological basis (0-68 weeks) or a physiological age basis (40 weeks from first egg). Both types of restriction applied in the starter phase tended to reduce egg size. Severe restriction throughout rearing greatly increased rearing period mortality.

The intake of the pullet was controlled in both growing and laying periods by limiting time of access to feed. Experiments examined severity of restriction and the age of lifting growing period restriction. In the growing period, severity of restriction was of less importance than the age at which restriction was lifted. Although ending restriction at 18 weeks improved the efficiency of conversion of feed to eggs, delaying the lifting of restriction gave marked further improvements. Restricting the bird's intake during lay gave additional increases in efficiency over and above those produced by growing period restriction alone. Denying the bird's access to feed from 7.30 a.m. to 3.30 p.m. daily was the most effective of the laying period restrictions examined. The effects of treatments on carcase composition at point of lay were also examined.