To examine the importance of albumen as a protein source during embryonic development on the posthatch performance of laying hens, 3 mL of the albumen was removed. At hatch, no difference in BW could be observed. Chicks from the albumen-deprived group had a lower residual yolk weight due to higher yolk utilization. During the rearing phase (hatch to 17 wk of age), the BW of the albumen-deprived pullets was lower compared with the control and sham pullets. The feed intake of the albumen-deprived pullets was also lower than the control pullets. However, during the laying phase (18 to 55 wk of age) these hens exceeded the control and sham hens in BW, although this was not accompanied by a higher feed intake. The albumen-deprived hens exhibited a lower egg production capacity as demonstrated by the reduced egg weight, laying rate, and egg mass and increased number of second grade eggs. In addition, the eggs laid by the albumen-deprived hens had a higher proportional yolk and lower proportional albumen weight. In conclusion, prenatal protein deprivation by albumen removal caused a long-lasting programming effect, possibly by differences in energy allocation, in favor of growth and maintenance and impairing reproductive performance.
When added to the feed of broiler breeder hens, dietary polyunsaturated fatty acids (FA) can be incorporated into the yolk and therefore become available to the progeny during their early development. The mechanism involved in lipid metabolism and deposition in the egg may be influenced by breeder age. Before the effect of an elevated concentration of certain polyunsaturated FA on the embryo can be investigated, the effect at breeder level and egg quality must be further assessed. The aim of the present experiment was to evaluate the effects of dietary n-6/n-3 ratios and dietary eicosapentaenoic acid (EPA, 20:5 n-3) and docosahexaenoic acid (DHA, 22:6 n-3) ratios, provided to broiler breeder hens, in terms of their zoo technical performance, egg quality, and yolk FA composition. Starting at 6 wk of age, 640 Ross-308 broiler breeder hens were fed 1 of 4 different diets. The control diet was a basal diet, rich in n-6 FA. The 3 other diets were enriched in n-3 FA, formulated to obtain a different EPA/DHA ratio of 1/1 (EPA = DHA), 1/2 (DHA), or 2/1 (EPA). In fact, after analysis the EPA/DHA ratio was 0.8, 0.4, or 2.1, respectively. Dietary EPA and DHA addition did not affect the performance of the breeder hens, except for egg weight. Egg weight was lower (P < 0.001) for all n-3 treatments. Dietary EPA improved number of eggs laid in the first 2 wk of the production cycle (P = 0.029). The absolute and relative yolk weight of eggs laid by EPA = DHA fed hens was lowest (P = 0.004 and P = 0.025, respectively). The EPA and DHA concentrations in the yolk were highly dependent on dietary EPA and DHA concentrations with a regression coefficient equal to 0.89. It can be concluded that dietary EPA and DHA can be incorporated in the breeder egg yolk to become available for the developing embryo, without compromising the performance and egg quality of the flock.
Patients presenting with ADHF and volume overload have increased global left ventricular-but not psoas muscle-T2-values, which decrease with successful decongestion. Relief of myocardial oedema correlates with haemodynamic unloading.
It is not rare that newly hatched chicks remain without feed for about 24 to 48 h before they are placed on farms due to a series of logistic operations. Furthermore, the spread in hatching time can also mount up to 30 to 48 h for late v. early hatchers. In other words, the practice is a complex combination of spread of hatch and delayed feed access. The present study was aimed to investigate the combined effects of hatching time with a delay in feed access of 48 h, starting from their hatch-time (biological age). When chicks had access to feed immediately after hatch, late hatchers had a higher feed intake and relative growth rate up to day 5 compared with their early hatched counterparts. Feed deprivation during the first 48 h resulted in retarded early growth rate, which was further aggravated by an impaired feed intake after refeeding. In addition, the differential effects of hatching time on relative growth rate and feed intake observed in immediately fed chicks were eliminated by the 48 h feed delay. The yolk utilization after hatch was faster for the late hatchers up to biological day 2 regardless of the feeding treatments. Hatching muscle glycogen content was higher in the late hatchers compared with that of their early counterparts at hatch and at biological day 2 independent of feeding treatment. Moreover, the liver glycogen content of the late hatchers was also higher at hatch. For the immediately fed chicks, the proportional breast muscle weight of the late hatchers was higher at biological day 2 and 5. For the starved chicks, on the other hand, this effect was only observed after they had access to feed (biological day 5). The different plasma T 3 levels at hatch may have contributed to the different post hatch performance. It is concluded that the spread of hatch influenced post hatch performance, especially appetite and growth at least until day 5. Moreover, the delay in feed access interacted with the hatching time and caused adverse effects on the post hatch performance.
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