Quality of the meat after the application of anabolic agents in young calves.

Abstract

Experiments were carried out to test the effect of implantation of Implix¿ (20 mg estradiol + 200 mg testosterone) or Revalor¿ (140 mg trienbolone acetate + 20 mg estradiol) on growth, feed conversion, slaughter quality, and residue levels in black Friesian bull calves at 4, 8, or 4 and 8 weeks before slaughtering. Weighings and calculations of feed conversion were carried out weekly. The control group of weight gain and feed conversion consisted of 22 calves; the chemical analyses of the control group was restricted to 8 animals. Implantation of the hormones at 4 or 8 weeks before slaughtering resulted in a significant beneficial effect on weight gain, feed conversion and carcass index over the control. This effect was improved (up to 15%) by implanting the hormones at 8 and 4 weeks before slaughter. The effects obtained with Revalor seemed to be superior to those obtained with Implix. In 75% of the treated animals, some remainder of implants was found. No effect was found on water binding capacity and colour of raw meat. Carcass quality was not significantly improved as judged from water, fat, ash, and protein content of the M. Longissimus Dorsi. The collagen content of the animals treated with Revalor was slightly, though not significantly, increased. There is a slight decrease in the relative bone content of the treated animals over the control resulting in higher meat percentages. Residues were determined in meat obtained from rib and neck by biological and chemical methods. Oestrogenic activity was found in only 7 samples from the neck; all samples from the rib were negative. Chemical examination indicates the presence of oestradiol in these samples. No residues of trienbolone could be detected in the meat samples. The Pars Dissiminata of the prostate was examined histologically on frozen and paraffin sections. Although the latter permitted a sharper interpretation, both methods indicated an increased activity of the prostates induced by hormone treatment. Compared to Implix, Revalor treatment provoked a more pronounced mucous activity. In recent years, the administration of estrogens in combination with testosterone or with trenbolone acetate (androst-4,9[10]-11-trien-3-one 17-acetate)2,3,4,17 has been shown to improve the growth rate and feed conversion5,14,17 in farm animals. However, there is a lack of information on carcass quality, which is of interest to the producer as well as to the consumer. Moreover, there are sample data14 about the residue levels remaining in the carcass following hormone implantation. These experiments were carried out to test the effect of the implantation of Implix¿ (20 mg estradiol + 200 mg testosterone) or Revalor¿ (140 mg trienbolone acetate + 20 mg estradiol) on growth, feed conversion, slaughter quality, and residue levels in black Friesian bull calves.