EFFECT OF SUPPLEMENTAL ZINC AND VITAMIN A ON PERFORMANCE OF LACTATING COWS. | ||
| Journal of Animal and Poultry Production | ||
| Article 1, Volume 25, Issue 5, May 2000, Pages 2533-2544 PDF (776.63 K) | ||
| Document Type: Original Article | ||
| DOI: 10.21608/jappmu.2000.258945 | ||
| Author | ||
| A. A. Zaki, | ||
| Animal Production Research Institute, Agriculture Research Center, Ministry of Agriculture, Egypt. | ||
| Abstract | ||
| This study was carried out to study the effect of zinc or zinc plus vitamin A supplementation on nutrients digestibility of adult rams (61 kg in average) and on milk production of seven lactating Friesian crossbred cows (447 kg in average) using “Swing Over” method to evaluate the following experimental rations: Control ration (C) : Concentrate feed mixture (C.F.M.) + Rice straw (R. S.). 1st tested ration (T1) : C.F.M. + 50 mg Zn/kg DM (as zinc sulphate) + R. S. 2nd tested ration (T2): C.F.M. + 50 mg Zn/kg DM + 10000 IU vitamin A/100 kg body weight + R.S. The main results showed that the DM and OM digestibility of sheep fed ration (T2) were significantly (P<0.05) higher than rations (T1) and control (C). Also, the previous items of T1 ration were significantly (P<0.05) higher than ration C. The total digestible nutrients (TDN) and starch equivalent (SE) of the three tested rations were responded simillary as that of DM and OM digestibility. The differences in daily DM intake of cows fed C, T1 and T2 rations were not significant. The daily milk yield as fat corrected milk (FCM) was higher by 10.08 and 15.57% in cows fed T1 and T2 than the control ration. Also, fat yield was higher by 11.23 and 16.05 % in cows fed T1 and T2 than C ration. Total solid and lactose of milk of lactating cows fed ration T1 and T2 were significantly (P<0.05) higher than control ration. Additionally, feed efficiencies (as kg TDN and SE/kg FCM) were better (P<0.05) of cows fed ration T2 than others. The economical efficiencies and return/kg FCM were the best for cows fed the rations supplemented zinc with or without vitamin A. | ||
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