Impact of Oral Supplementation of Different Levels of Tamoxifen on Productive and Reproductive Efficiencies and Carcass Traits of Avian48 and Arbor Acres Broilers

Abstract

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.

Impacts of sex steroids and aromatase inhibitor on performances, carcass characteristics and gonadal histology of broiler chickens slaughtered at different ages

“…These results indicated that Tam10 might be used to improve griller broiler production Griller‐type chickens are broilers slaughtered between 27 and 29 days old, weighing 1.3 to 1.5 kg and sold as whole carcasses and feed conversion ratio of 1.5 kg of feed per 1 kg of meat (Olivo et al, 2001). Similar results were reported by Younis et al (2020); they investigated the effect of oral supplementation of Tam on productive and reproductive efficiencies and carcass characteristics of two broiler breeds.…”

“…These results supported the previous morphological modification in ovarian patterns (Cherici Camargo et al, 2009). Similar results were found in high‐dose TAM treatment in Avian48 (Younis et al, 2020). They found that the number of atretic mature follicles was significantly increased either in the early stage of atresia or the late atretic follicles.…”

“…Tam10 treatments did not statistically change the sex hormones of males or females from control treatments. Younis et al (2020) observed higher testosterone levels in males than females and the opposite for oestrogen; however, there were non‐significant differences between sex hormones of Tam10 and control treatments. Males in Bol treatment had substantially higher testosterone levels than males in control and Tam10 treatments, although their oestrogen level was not varied.…”

“…Examined samples of field veal calves that were positive for urine residues of 17β‐BOL. Findings have shown that the growth and degeneration of the germinal epithelium have been decreased by the testis (Younis et al, 2020) found that treatment of Avian 48 with Tam in different doses caused multi‐layered germinal epithelium and seminiferous tubules deformation with a significant increase in the interstitial tissue.…”

“…In contrast, the administration of high doses of Tam caused blockage of oestrogen receptors leading to a progressive decrease in the laying of eggs before their complete cessation (Rząsa et al, 2009). It has been used to induce sex shifting through in ova injection (Fazli et al, 2015; Trukhina et al, 2014) or to assess its impact on performance, the hormonal profile and reproductive system at young ages (Mirzaei et al, 2022; Younis et al, 2020). In aquaculture, it is used to produce all‐male tilapia fry; it can shift sex ratios towards males through binding to oestrogen, increasing androgen levels (Lichtenfels et al, 2017).…”