British Poultry Science

Gilbert, A. B.; Blair, R.

doi: 10.1080/00071667508416227pmid: N/A

1. Hens fed on a diet containing 0–05% calcium virtually ceased egg laying (production <4%) whereas those fed on a diet containing 0–5% Ca maintained production at between 20 and 30%. 2. After a return to a normal diet (3% Ca) egg weight, shell weight, ovarian characteristics and oviduct size were of a similar nature in the two groups, though the differences in egg weight, shell weight and shell calcium were significant at the 1 % level. 3. Bone weight and bone ash did not differ significantly between the groups but after a return to normal rations, bone weight and bone ash became higher in the group that had received the 0.05% Ca diet. 4. There were no clinical signs of bone demineralisation during the experiments.

Levinger, I. M.

doi: 10.1080/00071667508416228pmid: N/A

1. The effects of anaesthesia, temperature, pH, scalding agents and bleeding on the connection of the feather to the skin were studied. 2. Anaesthetics and increasing the temperature tend to loosen the feather; low temperatures and scalding agents tighten the connection, and bleeding is without effect while the effect of pH is variable depending upon the substance used. 3. In all local applications of drugs, no significant changes were found between living and slaughtered birds.

Payne, C. G.

doi: 10.1080/00071667508416229pmid: N/A

1. The effects of lighting pattern on production to 399 d in caged, female, meat‐strain chickens was investigated. Energy intake was controlled from 56 to 399 d. 2. Four different rearing treatments with a subsequent constant 16‐h photoperiod during laying were used. 3. A 15‐h rearing photoperiod resulted in delayed sexual maturity, increased mature body weight and decreases in both total egg numbers and the proportion of smaller eggs, compared with a 6‐h photoperiod. 4. Continuous light to 56 d, although associated with a high incidence of subsequent blindness, resulted in satisfactory egg production. 5. Abrupt reduction in the photoperiod from 15 to 6 h for the 112 to 167 d period resulted in unsatisfactory subsequent performance, especially when the day‐length was only slowly increased to 16 h during laying. 6. In the two laying treatments, in which the photoperiod was increased gradually from 6 to 16 h during the 168 to 238‐d period, a decrease in the number of smaller eggs occurred, compared with the treatments in which a single abrupt increase in photoperiod was used.

Pearce, J.

doi: 10.1080/00071667508416230pmid: 1192232

1. Diets high in wheat and low in protein (18%) produced 5 to 6% mortality from fatty liver and kidney syndrome (FLKS) in broiler chicks whereas there were no deaths from FLKS in birds fed on a maize/barley diet containing 20% protein. 2. Supplementation of the wheat‐based diets with choline or inositol (2.5 g additive/kg diet) did not affect the incidence of FLKS or liver lipid metabolism. 3. The wheat‐based diet did not significantly affect the activities of hepatic lipogenic enzymes suggesting that hepatic lipid biosynthesis is not a cause of the syndrome. 4. The biotin contents of the wheat and maize/barley diets were little different, which may suggest that factors other than this are implicated in FLKS.

Manwatkar, S. G.; Netke, S. P.; Sathe, B. S.

doi: 10.1080/00071667508416231pmid: N/A

1. The nutritive value of Niger oil cake (Guizotia abyssinica, Cass.) as a protein supplement for layers’ diets has been assessed. 2. Replacing groundnut oil cake (GNC) by Niger oil cake (NC) on an isonitrogenous basis, did not affect egg production, egg weight or the amount of food required per dozen eggs. 3. The percentage retention of nitrogen from diets containing 30% GNC or 30% NC was similar. 4. The ME value of NC used was 3025 kcal/kg. 5. It is concluded that NC can replace GNC in layers’ diets.

Martindale, L.

doi: 10.1080/00071667508416232pmid: 1192233

1. One‐day‐old male broiler chicks were fed on diets containing 3.8% or 2.7% added NaCl in two experiments lasting 22 and 42 d respectively. 2. Sodium clearance was increased in treated birds in both experiments. No other changes in renal function were observed but an increase in plasma urate in treated birds of the first experiment may indicate some loss of proximal tubular function. 3. Renal function, relative to body weight, diminished slowly with age in control and treated birds but these changes could not be related to the fact that at about 3 weeks of age testicular cysts no longer develop.

Long, P. L.; Rowell, J. G.

doi: 10.1080/00071667508416233pmid: 1192234

1. A method of sampling the surface litter of commercial broiler houses for laboratory estimation of numbers of coccidial oocysts is described. 2. The resulting estimates can be regarded as indices of the total number of oocysts present in the house at the time of sampling. 3. Using material from a variety of sources it was shown that reliable estimates for many practical purposes can be achieved with few samples, unless the birds are less than 3 weeks old. 4. Oocyst numbers usually reached a peak 4 to 5 weeks after introduction of the birds and then rapidly declined in the next few weeks.

Gupta, N. D.; Johar, K. S.

doi: 10.1080/00071667508416234pmid: 1192235

1. The means, standard errors and coefficients of variation for body weight at fortnightly intervals from day 1 to day 90 of five indigenous strains of White Leghorn were estimated. 2. The differences between the strain and body weight were significant at all ages while the differences between sex were significant from day 45. 3. Phenotypic correlations between body weight at day 1 with that of day 30, 60 and 90 were 0–237, —0–007 and —0–07. 4. The heritability by paternal half‐sib method ranged from 0.32 to 0.54 for body weights from day 1 to day 90.

Washburn, K. W.; Potts, P. L.

doi: 10.1080/00071667508416235pmid: N/A

1. The relationships between oviposition time and specific gravity, shell thickeness, deformation and breaking strength of eggs from six commercial layer strains were examined after 6 and 12 months of production. 2. Shell strength, assessed by any of the methods, was relatively low in eggs collected at 10.00 h and was generally successively greater in those collected at 12.00, 14.00 or 16.00 h. Over the same period egg weight decreased. 3. These time‐related changes in shell strength were similar for the two production ages despite the difference in shell quality due to age. 4. No consistent significant differences were observed between strains in time of oviposition.

D'mello, J. P. F.

doi: 10.1080/00071667508416236pmid: 1192236

1. The leucine, isoleucine and valine requirements of the 3‐week‐old turkey were determined in a factorial experiment and were found to be 1.42, 0.84 and 1.21% respectively in semi‐purified diets containing 12.5 MJ ME/kg. 2. It is suggested that the efficiency with which turkeys and chicks utilise isoleucine and valine is similar, and that a daily intake of about 325 mg of valine would sustain a rate of growth of about 23 g/d in both species.