1. Compensatory growth and the onset of lay were studied in White Rock broiler females severely restricted in food intake from day of hatching.
2. When changed to feeding ad libitum the restricted birds gained weight rapidly, but stabilised at a mean body weight 500 to 700 g less than that of controls fed ad libitum. Egg production was similar to that of controls.
3. Birds maintained at low mean body weight (2 224 g at 42 weeks) by continued restriction did not come into lay. In groups maintained at somewhat higher mean body weights (2 300 to 2 700 g) for periods of up to a year, some birds came into lay.
4. Birds fed ad libitum showed accelerated development of comb, ovary and oviduct and weighed 2 300 to 2 700 g between 14 and 15 weeks of age, but did not come into lay until 20.5 weeks of age.
5. These results suggest that a minimum body weight and age may be required for the onset of lay in this strain. 相似文献
Posthatched naive or inoculated male broiler chicks were kept in separate rooms. An inoculum was prepared from intestines of stunting-syndrome affected broiler chicks. Tap water was supplied from 2 L cups, 1 cup per pen. In the Ist experiment, the naive chicks were provided with tap water only and the inoculated ones had free access to tap water or to an electrolyte solution. In the 2nd experiment, the naive and inoculated birds had free access to water in addition to an electrolyte solution. Supplementation was provided up to 3 weeks of age; thereafter all chicks had access to tap water only. Water or electrolyte consumption and body weight (BW) were determined. Total water intake of inoculated chicks was higher than that of naive counterparts (P<0.001). Electrolyte supplementation increased drinking (P<0.001) in inoculated birds more than in naive ones. At 1 week old the weight of the inoculated birds was about 64% of the weight of naive ones; at the age of 4 and 6 weeks it was about 74% and 86% respectively. Compensatory growth was most apparent in the inoculated chicks provided with electrolyte solution. At the age of 6 weeks, the latter exceeded the BW of the exclusively water supplied counterparts by 327 g. Electrolyte supplementation up to the age of 3 weeks had no effect on the naive counterparts. Osmolality was reduced slightly, but very significantly by inoculation; electrolyte supply had no effect on this variable. Sodium concentration in the plasma was higher in the inoculated birds. Plasma albumin was markedly reduced by inoculation on weeks 1 and 2. Whereas the inoculated chicks supplied with electrolytes resumed the level plasma albumin level of the naive chicks on week 3, an over-compensation occurred in the inoculated-water-supplied (IW) group, and they surpassed the naive chicks significantly. Blood hematocrit increased significantly with age; inoculation, age and/or electrolyte supplementation had no effect on this variable. Sodium-dependent glucose transport rates were enhanced in vesicles obtained from inoculated chicks as compared to naive ones. While electrolyte supplementation had no effect on glucose active transport in naive chicks, electrolyte supplementation decreased rates of glucose active transport in inoculated ones. These data demonstrate that electrolyte supplementation during the early age may be used to enhance the tolerance of broiler chicks to stunting-syndrome by improving food and water consumption, and subsequently growth rate during and after cessation of electrolyte supply. 相似文献
1. Two‐week old male chicks of a light‐bodied strain were either fed ad libitum or given one (1M) or two (2M) 2‐h meals per day. A fourth group was pair‐fed (P1M) the amount of food which had been consumed by the 1M group on the preceding day.
2. Compared with ad libitum‐fed counterparts, a marked increase in the relative weight of the storage organs (crop and gizzard) was observed in the meal‐fed birds. The relative weight of the intestine was not affected by meal feeding but the ileal wall became thinner.
3. After food deprivation for 14 or 22 h, respectively, for the ad libitum and the meal‐fed chicks, the weights of contents in the gastrointestinal tract (GIT) segments did not differ between treatments except for those of the gizzard and caecum. Food restoration resulted in an increase in the contents of the GIT of meal‐fed chicks. The increments in the crop and gizzard contents were related to the severity of food restriction. The contents of the intestinal segments were quite similar in all treatments.
4. The activities of the digestive enzymes in the pancreas, expressed as units/g pancreas or units/kg body weight, were not significantly affected by feeding regime. In the small intestine of the meal‐fed birds, marked increases in specific (units/g content) and relative (units/kg body weight) activities were observed of amylase and chymo‐trypsin when compared with their ad libitum‐fed counterparts. The effect of meal feeding on trypsin activities was less pronounced. 相似文献
1. Male broilers selected for high (HF) or low (LF) abdominal fat were fed from 8 to 53 d of age on diets containing different concentrations of protein: according to N.R.C. (1984) recommendations (IP), 14% lower (LP) or 14% higher (HP). 2. The growth of LF birds fed on the LP diet was depressed until 35 d of age, but did not differ from the other groups later on. 3. The HF birds had heavier adipose tissues (AT) (g/kg body weight) than the LF birds. Significant line by diet interactions indicated a difference in magnitude of the response of the lines to dietary protein content. 4. Fat concentration of the AT and skin was higher, and in the tibia lower in the HF than in the LF birds. The fat concentration in liver and in breast muscle was not affected by line or by diet. 5. The ratio of saturated plus monoenoic fatty acids to polyenoic fatty acids, considered as an index of fat synthesis, was higher in the abdominal adipose tissue (AAT) of HF compared with LF birds. In AAT, liver and in breast muscle, this ratio was inversely related to dietary protein content. 相似文献
Abstract: This article explores the ways by which special dishes prepared for the Chinese community festivals in the Vietnamese town of Hoi An negotiate and expand the notions of ethnic identity and place of origin of migrant groups. Although the festivals stress specific regional identities in (Imperial) China, the food consumed in the communal feasts defines much wider scopes of ethnicity and territory. By discussing these alternative scopes and comparing the feasts in two festivals, the article suggests that a new transnational ‘greater‐Chinese’ identity is celebrated in contemporary Chinese‐Vietnamese community festivals. The scope and importance of this new identity is analysed in relation to an imagined ‘greater‐China’ as a dominant player in the forthcoming ‘Pacific Century’. The position of the culinary sphere as a privileged arena for sociocultural negotiation, especially in post‐socialist authoritarian regimes, is also discussed.相似文献
Chromatin plays roles in processes governed by different time scales. To assay the dynamic behavior of chromatin in living cells, we used genomic tiling arrays to measure histone H3 turnover in G1-arrested Saccharomyces cerevisiae at single-nucleosome resolution over 4% of the genome, and at lower (approximately 265 base pair) resolution over the entire genome. We find that nucleosomes at promoters are replaced more rapidly than at coding regions and that replacement rates over coding regions correlate with polymerase density. In addition, rapid histone turnover is found at known chromatin boundary elements. These results suggest that rapid histone turnover serves to functionally separate chromatin domains and prevent spread of histone states. 相似文献