نوع مقاله : مقاله پژوهشی
نویسندگان
1 گروه علوم دامی، دانشکده کشاورزی، دانشگاه زنجان، زنجان، ایران
2 گروه علوم دامی-دانشکده کشاورزی-دانشگاه زنجان-زنجان-ایران
3 گروه علوم دامی، دانشکده کشاورزی، دانشگاه شهرکرد، شهرکرد، ایران.
4 گروه علوم دامی، مرکز تحقیقات و آموزش کشاورزی و منابع طبیعی چهارمحال و بختیاری، سازمان تحقیقات، آموزش و ترویج کشاورزی، شهرکرد، ایران.
چکیده
کلیدواژهها
موضوعات
عنوان مقاله [English]
نویسندگان [English]
The aim of this study was to evaluate the effect of removing iron from mineral premix before calving on the productive performance and health status of Holstein dairy cows during transition period. The ninety multiparous Holstein cows entered the experiment -21 days before the expected calving and were randomly assigned to 3 experimental treatments. Treatments include: 1) control treatment: recipient of mineral supplement with iron (to supply iron requirement in the amount of 15 mg/kg; n = 30); 2) treatment without iron: recipient of mineral supplement without iron (n=30); 3) without supplemental iron treatment with cottonseed: recipient of mineral supplement without iron and 4.6% of cottonseed in the diet (n=30). Removing iron from mineral supplements with and without cottonseed had no significant effect (P < 0.05) on milk production, percentage and amount of milk fat, as well as the amount of milk protein. The somatic cell count (SCC) in control treatments without supplemental iron and without supplemental iron with cottonseed, were 471.48, 338.80 and 155.77 (103 per ml), respectively, which significantly decreased in the treatment without supplemental iron with cottonseed (P = 0.04). Body weight changes after calving were also affected by experimental treatments (P < 0.01). Also, in calves, 5.09 times more days of diarrhea were observed in the control treatment (P = 0.01) and the treatment without supplemental iron (P = 0.05) compared to cottonseed. Overall, the removal of supplemental iron along with cottonseed reduced the SCC and also improved the health status of cows and their calves
کلیدواژهها [English]