This research was aimed at estimating the effect of oral supplementation of Tamoxifen on productive efficiency, carcass characteristics, hormonal profile and gonadal structure of two broiler breeds. One hundred and eighty chicks of each breed of Avian48 and Arbor Acres were divided into three groups: control group; TAM10 group, supplied with 10 mg Tamoxifen/kg of body weight at 3, 5, 7 and 9 days of life; and TAM20 group, supplied at the same intervals with 20 mg Tamoxifen/kg of body weight. Both levels of Tamoxifen improved productive performance at early ages, but Arbor Acres produced better results with TAM20 levels than TAM10, while Avian48 breeds reacted adversely. On the contrary, Tamoxifen supplementation significantly decreased feed intake and feed conversion (after the first two weeks of life) compared to control with a higher level of decrease reported for TAM20 treatments than TAM10 and for Arbor Acres compared to Avian48 breed. Carcass traits were not affected significantly with Tamoxifen supplementation compared to control although Arbor Acres responded better to TAM20 and Avian48 for TAM10. With regard to the effect of Tamoxifen (TAM) on sex hormones, it could be concluded that TAM10 treatments showed a stimulating effect on the level of such hormones as compared with the TAM20 group with the most favourable results being clearly detectable in 42-day-old birds although both concentrations of Tamoxifen did not differ significantly from control. However, treatment of broiler chickens with Tamoxifen in different doses caused a gradual decrease in follicle production rate and eventually led to an increase of the atretic follicles in different stages of atresia. Finally, we can conclude that Tamoxifen supplementation can improve performance and carcass efficiency of broilers without changing the hormonal profile, however much research is required to estimate the best concentration required for each breed.

中文翻译：

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口服补充不同水平的他莫昔芬对 Avian48 和 Arbor Acres 肉鸡的生产和繁殖效率以及胴体性状的影响。


本研究旨在评估口服补充他莫昔芬对两个肉鸡品种的生产效率、胴体特性、激素分布和性腺结构的影响。将Avian48和Arbor Acres各品种180只雏鸡分为三组：对照组； TAM10组，在生后3、5、7和9天时给予10mg他莫昔芬/kg体重； TAM20组，以相同的时间间隔给予20mg他莫昔芬/kg体重。两种水平的他莫昔芬都提高了早期的生产性能，但 Arbor Acres 在 TAM20 水平下产生的结果比 TAM10 更好，而 Avian48 品种的反应则相反。相反，与对照相比，他莫昔芬补充剂显着降低了采食量和饲料转化率（出生后前两周），据报道，TAM20 处理的降低水平高于 TAM10，Arbor Acres 处理的降低水平高于 Avian48 品种。与对照相比，添加他莫昔芬后胴体性状并未受到显着影响，尽管 Arbor Acres 对 TAM20 和 Avian48 对 TAM10 的反应更好。关于他莫昔芬 (TAM) 对性激素的影响，可以得出结论，与 TAM20 组相比，TAM10 治疗显示出对此类激素水平的刺激作用，在 42 天中可以清楚地检测到最有利的结果。老鸟，尽管他莫昔芬的两种浓度与对照没有显着差异。然而，不同剂量他莫昔芬对肉鸡的处理导致卵泡生成率逐渐下降，最终导致闭锁不同阶段的闭锁卵泡增多。 最后，我们可以得出结论，补充他莫昔芬可以在不改变激素分布的情况下提高肉鸡的生产性能和胴体效率，但需要大量研究来估计每个品种所需的最佳浓度。