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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. 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. An insemination programme to produce high fertility and hatchability with semen which had been deep frozen for 2 months was devised.
3. Over 90% fertile eggs with a 90% hatch of all eggs set was obtained with frozen and thawed semen over a period from the 2nd to the 12th day after the first of four inseminations. The persistency of fertility was also tested and 93, 86.6 and 30.7% of the eggs were fertile during days 2 to 6, 2 to 8 and 9 to 15 after the last insemination.
4. Corresponding with the high fertility rate, chicks were produced by every hen that was inseminated and from every male whose semen was frozen and stored. The implications for future breeding practices of this successful result are discussed. 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