University of Georgia, Athens 30606.
Wayne Farms LLC, 4110 Continental Drive, Oakwood, Georgia 30566.
Poult Sci. 2017 Aug 1;96(8):2641-2661. doi: 10.3382/ps/pex035.
The objective of this experiment was to evaluate the effects of raising broilers under sex separate and straight-run conditions for 2 broiler strains. Day-old Ross 308 and Ross 708 chicks (n = 1,344) were separated by sex and placed in 48 pens according to the rearing type: sex separate (28 males or 28 females) or straight-run (14 males + 14 females). There were 3 dietary phases: starter (zero to 17 d), grower (17 to 32 d), and finisher (32 to 48 d). Birds' individual BW and feed intakes were measured at 12, 17, 25, 32, 42, and 48 d to evaluate performance. At 33, 43, and 49 d, 4 birds per pen were sampled for carcass yield evaluation. Additionally, from 06:00 to 06:30, 13:00 to 13:30, and 22:00 to 22:30, video records were taken to assess behavior at 45 days. Data were analyzed as CRD with a 2 × 3 factorial arrangement of treatments over time. Throughout the experiment Ross 308 were heavier than the 708, and after 17 d, male pens had the heavier birds, followed by straight-run and then females. Straight-run pens had higher BW CV in comparison with sex separate pens. Sex separate male BW was negatively impacted from 17 to 32 days. On the other hand, females raised sex separate were heavier than females raised straight-run with lower CV from 25 to 41 days. Post 25 d, FCR was the lowest in male pens whereas feed intake was the highest for these pens after 17 days. Overall, males had total carcass cut-up weights higher than straight-run and females at the 3 processing times. The Ross 708 had higher white meat yields, whereas 308 had higher yields for dark meat. Feeding behavior results were not consistent over time. However, from 13:00 to 13:30, birds in female pens spent more time eating, followed by straight-run and then males. In conclusion, raising females in a straight-run system negatively impacted performance and CV, whereas males benefited from straight-run rearing, with the differences being possibly related to feeder space competition.
本实验的目的是评估在两种肉鸡品系下，采用公母分群和公母混养方式饲养肉鸡的效果。将 1344 只罗斯 308 和罗斯 708 一日龄雏鸡按公母分开（28 只公鸡或 28 只母鸡）或公母混养（14 只公鸡+14 只母鸡）方式，分 48 栏饲养。试验设 4 个饲养阶段：育雏期（0-17 日龄）、生长期（17-32 日龄）、育肥期（32-48 日龄）。在 12、17、25、32、42 和 48 日龄时，每个鸡只称重，以评估其生长性能。在 33、43 和 49 日龄时，每个栏随机选取 4 只鸡进行屠体产肉率评估。此外，在 45 日龄时，在 06:00-06:30、13:00-13:30 和 22:00-22:30 这 3 个时间段进行视频记录，以评估鸡的行为。试验数据采用完全随机设计（CRD），在不同时间设置 2×3 因子处理。在整个试验期间，罗斯 308 鸡体重均高于罗斯 708 鸡，且 17 日龄后公鸡体重最重，其次是公母混养组，然后是母鸡组。公母混养组的鸡只体重变异系数（CV）高于公母分群组。17-32 日龄时，公母分群组公鸡的体重显著下降。相反，25-41 日龄时，公母分群组母鸡体重高于公母混养组，且 CV 较低。25 日龄后，公鸡组的料重比最低，而公鸡组在 17 日龄后采食量最高。总体而言，公鸡组的屠体分割重量在 3 个屠宰时间均高于公母混养组和母鸡组。罗斯 708 鸡的白肉产量较高，而罗斯 308 鸡的黑肉产量较高。采食行为结果在不同时间不一致。然而，在 13:00-13:30 时，母鸡组的鸡采食时间最长，其次是公母混养组，然后是公鸡组。综上所述，在公母混养系统中饲养母鸡会对其性能和 CV 产生负面影响，而公鸡则受益于公母混养，这种差异可能与料位竞争有关。
