نوع مقاله : مقاله پژوهشی
1 گروه علوم دامی، دانشکده علوم دامی و شیلات، دانشگاه علوم کشاورزی و منابع طبیعی ساری
2 دانشیار گروه علوم دامی، دانشکده علوم دامی و شیلات، دانشگاه علوم کشاورزی و منابع طبیعی ساری
3 شرکت شیر و گوشت مهدشت ساری
عنوان مقاله [English]
Background and objectives: Although nutrient imbalance does not play a role in the etiology of hypocalcemia and the existence of defects in physiological adaptations is the main cause of occurrences, the most common processes used to prevent the occurrences of hypocalcemia are nutritional and involve the use of some factors. Management in animal diets is close to calving. The aim if this study was to consider the effects of Anionic diets withdraw on metabolic response and productive and reproductive performance of Holstein cows during transition period.
Materials and methods: Holstein cows (n = 200) with averaged parity 3.0±1.0 and BCS 3.5±0.5 randomly selected according to previous milk yield and assigned into one of two treatments: 1) control deit (DCAD= +100 mEq/kg dietary DM) and 2) Anionis diets (DCAD= -100 mEq/kg dietary DM). Diets fed from 3 week before expecting calving. At calving, 6, 12, 24, 36 and 48 h after calving and at 7, 14, 44 and 74 DIM serum concentrations of Ca, P and Mg were measured. Blood metabolites and liver enzymes were assessed on d 7 and 14 after calving. Dry matter intake (DMI) was monitored within the first 24 h of calving. Milk yield was recorded daily through 23 DMI thereafter it was recorded monthly until 2 months of lactation.
Results: The yield of milk was greater in cows fed anionic diet compared to control group (40.39±0.73 vs. 39.27±0.55) within 3 weeks of lactation. Dry matter intake was lower in cows fed anionic diet compared to control group (12.10±0.12 vs. 12.90±0.13). Serum concentrations of P, Mg, beta-hydroxy butyric acid and non-esterified fatty acids were similar between groups. Mean concentrations of Ca in serum were not different between treatment groups at calving (0), 6 and 12 h after calving but were higher at 24 and 48 h after calving for cows that received anionic diets (P < 0.05). Incidence rates of dystocia, retained placenta and subclinical hypocalcaemia (P < 0.05) were less in cows received anionic diets. There were no differences between two groups in the incidence rate of clinical hypocalcaemia, endometritis and ovarian cysts (P > 0.05). Number of days to first service was shorter, the conception rate at first service was greater and open days was shorter in cows received anionic diets (P < 0.05). However, services per conception and Cows pregnant before 180 DIM were unchanged between two groups.
Conclusion: The results of the present study showed that the anionic diets increased milk production and first service conception rate via improve in health status of dairy cows.