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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. Single pre‐ovulatory peaks of plasma LH, androgen and progesterone were observed which took 8, 8 and 12 h respectively, to increase and return to base‐line values. The concentration of plasma prolactin tended to be elevated between 6 h before and 6 h after the LH peak with the maximum values occurring after the peak.
3. The changes in the concentrations of plasma LH and progesterone were 3‐ and 7‐fold respectively while 2‐fold changes were observed in the concentrations of plasma androgen and prolactin.
4. The pre‐ovulatory concentration of plasma progesterone and prolactin began to decrease 4 and 6 h respectively, after the pre‐ovulatory peak of LH.
5. Ovulation and oviposition occurred 6 to 8 h and 36.10+ 0.57 h (SEM) ( n= 11) respectively after the pre‐ovulatory peak of LH.
6. In birds kept on 14 h light/d, pre‐ovulatory peaks of LH were initiated only during a 10 to 11‐h period starting within 2 h after the onset of darkness.
7. A comparison between these data and those from the fowl suggest that the egg is retained in the turkey's oviduct for about 3 to 4 h longer than in the fowl. 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. Preparations from leg weakness cases displayed neither accelerated muscle fatigue nor decreased nerve conduction velocities as compared with control preparations.
3. The muscles of the TA‐treated turkeys but not of those with naturally occurring leg weakness were hyperexcitable relative to those of controls.
4. Post‐tetanic potentiation of preparations from both naturally occurring and experimentally‐induced cases of leg weakness was less than that of control preparations, both before and after partial neuromuscular blockade, significantly so at the lower pulse frequencies used.
5. It is tentatively suggested that the last finding might be of significance in explaining the clinical signs of leg weakness and might be associated with a disordered calcium metabolism. 相似文献
2. This not only requires compensation for the reduced O2 partial pressure but, and of equal importance, recognition of the increased diffusivity of gases at altitude.
3. Equations are developed for predicting the required changes in O2, CO2 and water vapour composition of incubator gas at any altitude. 相似文献
2. Biotin deficiency decreased hepatic activity of pyruvate carboxylase [EG 6.4.1.1] but activity of acetyl‐CoA carboxylase [EG 6.4.1.2] was comparatively unaffected.
3. Increasing dietary protein increased the severity of biotin deficiency as assessed by skin lesions and decreased plasma biotin concentrations.
4. The severity of the skin lesions over all the treatments was most closely related to plasma biotin concentration. 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