Genotype-by-environment interaction with broiler genotypes differing in growth rate. 3. Growth rate and water consumption of broiler progeny from weight-selected versus nonselected parents under normal and high ambient temperatures
Genotype-by-environment interaction with broiler genotypes differing in growth rate. 3. Growth rate and water consumption of broiler progeny from weight-selected versus nonselected parents under normal and high ambient temperatures
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DOI：
10.1093/ps/81.3.293
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发表时间：
2002-03-01
期刊：
影响因子：
4.4
通讯作者：
Cahaner, A
中科院分区：
文献类型：
--
作者：
Deeb, N;Cahaner, A
对 BW 进行一轮高强度选择，以研究高环境温度 (AT) 下对性能的相关影响。从一大群商业父系中，35 日龄时体重最高的 3 只雄性和 15 只雌性进行交配，产生了一组 120 只体重精选的雏鸡。来自同一鸡群的 3 只平均体重雄性鸡和 15 只平均体重雌性鸡进行交配，产生 120 只雏鸡作为对照组。第 17 天，将两组均分在两个温控室中，并饲养在单独的笼子中。第一个室设置为正常 AT（NAT；恒定 22°C），第二个室设置为高 AT（HAT；恒定 32°C）。在 NAT 下，所选肉鸡相对于对照的相对优势从 17 天到 42 天的龄期没有变化，平均体重增加约 15%，饲料消耗约 9.7%。在 HAT 下，这些差异从第 17 天到第 28 天减半，并在 28 天到 42 天龄期间逆转，此时选定的肉鸡消耗的饲料明显少于对照组，体重增加也较少。在每次 AT 处理中测量水与饲料的比例。从 28 至 42 日龄，两组的平均值来看，HAT 下的鸡只消耗了 2.5 克水/克饲料，而 NAT 下的鸡只消耗了 1.5 克水/克饲料。HAT 下所选肉鸡的优势减弱，导致了基因型与环境之间的显着相互作用，涉及高 AT 和生长速度的库存遗传差异。看来，选择在最佳条件下快速生长的肉鸡在高 AT 下并未发挥其遗传潜力。因此，应将适应热量的具体指标（可能是耗水量或体温）添加到快速生长的商业选择中，以提高肉鸡在炎热气候下的生产性能。
One cycle of high-intensity selection on BW was conducted to study correlated effects on performance under high ambient temperature (AT). From a large flock of a commercial sire-line, 3 males and 15 females with the highest BW at 35 d of age were mated and produced a group of 120 BW-selected chicks. Three average-BW males and 15 average-BW females from the same flock were mated to produce a control group of 120 chicks. On Day 17, the two groups were equally divided between two temperature-controlled chambers and housed in individual cages. One chamber was set to a normal AT (NAT; constant 22 C) and the second chamber to high AT (HAT; constant 32 C).Under NAT, the relative advantage of the selected broilers over the controls did not change from 17 to 42 d of age, averaging about 15% for BW gain and 9.7% for feed consumption. These differences were halved under HAT from Days 17 to 28 and were reversed from 28 to 42 d of age, when the selected broilers consumed significantly less feed and gained less BW than the controls. Water-to-feed ratio was measured in each AT treatment. From 28 to 42 d of age, averaged over the two groups, birds under HAT consumed 2.5 g water/g of feed compared to only 1.5 g water/g feed under NAT.The diminished superiority of the selected broilers under HAT led to a substantial genotype-by-environment interaction involving high AT and within-stock genetic differences in growth rate. It appears that broilers selected for rapid growth under optimal conditions do not achieve their genetic potential under high AT. Thus, specific indicators of adaptation to heat, possibly water consumption or body temperature, should be added to commercial selection for rapid growth to improve broiler performance in hot climates.