Reproductive response to parenteral copper supplementation in anoestrous and cows with hypocupraemia

Abstract

The study was carried out for six months in a herd of 5817 cows with hypocupraemia (<10.0 µmol/L copper in blood serum) in anoestrus. The animals were distributed into four groups: Group I (n=2984): Oestrus was induced with the application of progesterone and oestradiol benzoate following the administration scheme of progesterone in doses of 60, 90 and 90 mg via IM at 48 h intervals followed by 1 mg of oestradiol benzoate 48 hs later and inseminated at 48 and 56 h after treatment; Group II (n=1314), treated as Group I. but supplemented with a subcutaneous injection of copper (50 mg); Group III (n=1070), only received the copper supplement; Group IV: (n=449), control, without hormonal treatment or copper supplement. The groups supplemented with copper presented normal levels of the mineral at the end of the study, likewise, they presented pregnancy rates of 24.5% (Group II) and 37.4% (Group III), significantly higher than the rate of 19.5% in Group I and 19.0% in Group IV (p<0.05). It is concluded that copper supplementation in cows with hypocupraemia can contribute to reducing the percentage of anoestrus with and without the administration of hormonal therapy under the conditions of the study.