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2. Body‐weight gain and carcass fat and water content increased and fertility decreased with increasing energy allowance. Maximum egg production occurred at an energy intake of 1.73 MJ AME/bird d.
3. Differences in egg weight and hatchability were related to differences in both energy and protein intake. The highest egg weight occurred at the highest allowance of energy and protein. Hatchability was depressed where the daily allowances of protein and energy were in a ratio of more than 15 g protein: 1 MJ AME.
4. Apart from egg size no significant effects on reproductive performance were observed when dietary protein intake was varied from 27 to 19.5 g/bird d.
5. Requirements of broiler breeder hens for protein during lay may be lower than previously thought. For the strain used a protein intake of 19.5 g/bird d appeared adequate provided essential amino acid concentrations were maintained.
6. The close relationships between body weight and energy allowance and the latter and egg production make body‐weight gain a useful guide to management. A body‐weight gain of about 1.1 kg from 21 to 36 weeks of age was associated with optimum performance in this study. 相似文献
2. At regular intervals birds in both groups were stimulated orally with solutions of acetic acid, quinine hydrochloride and sodium chloride and the number of beak and tongue movements counted.
3. By the end of the experiment the vitamin A‐deficient birds showed a significant decrease in their response to the oral stimulants compared with the control birds. 相似文献
2. Restricted birds were lighter throughout the experiment.
3. Relative adrenal weight tended to be greater in restricted birds but the difference decreased with time.
4. There was no depletion of adrenal cholesterol: from week 5 there was a significantly greater amount in the adrenals of restricted birds.
5. After 1 week of restriction plasma corticosterone concentration was 73% greater than in controls. It decreased progressively, falling within the normal range at 5 weeks.
6. Restricted birds were hypoglycaemic from weeks 2 to 7 and hyper‐lipacidaemic throughout. A negative correlation between plasma glucose and free fatty acids was found. 相似文献
2. After hatching, the relative amount of STE in the liver tissue decreased considerably while that of TG increased. The proportion of phospholipids (PHL) remained essentially constant.
3. The fatty acid composition of the liver lipids changed significantly, but specifically for each individual class during postnatal growth. Striking differences were the higher values of long‐chain polyunsaturated acids (20 :4 ω6, 22 :4 ω6 and 22: 6 ω3) in PHL, TG and free fatty acids (FFA) and the higher proportion of oleic acid in the STE at hatching compared with those at older ages.
4. The predominant alterations in the relative composition of the liver lipids (lipid classes and fatty acids) occurred in the first week after hatching and may be accounted for by the decreasing yolk utilisation and adaptation to ingested food. The change within the diet itself from cropmilk to grain (starting around the 4th day) influenced the development of the lipid and fatty acid content only in a minor way.
5. The large weight decrease of the pigeon liver after the 19th day was accompanied by a decrease in absolute PHL content while TG stores were unaltered. 相似文献
2. Growth rate, food intake, food utilisation and proportion of dietary nitrogen retained were much poorer in chicks receiving salseed meal.
3. The chicks receiving salseed meal developed pathological lesions in liver and kidney.
4. The red blood cell count, white blood cell count, haemoglobin concentration and packed cell volume of the chicks receiving salseed meal were lower than those of chicks receiving maize.
5. The apparent metabolisable energy value of salseed meal was determined as 6.83 MJ/kg. 相似文献