Effect of altering dietary cation-anion difference, energy and protein intake on the postparturient ovarian rebound

Document Type : Original Articles


The effect of nut1ition on the occurrence of reproductive disorders differs according to the plan of nutrition, type and sources of nutrients, as well as the managemental status of the animals. This investigation was carried out on 70 pregnant Holstein Frie­ sian cows aged 3-6 years old. The cows were divided into 2 groups. Group A. included 35 cows and were Jed a properl y formulated ration 28.00 Kg / head Iday for d ry preg­ nani cow with a red uced dietary cation- anion difference (DCAD). Group B, included 35 cows and were fed 26.00 Kg formulated ration/ head / day for a d ry pregnant cow wiih a slighil y elevated DCAD. The cows in both groups were observed until parturi­ tion and after parturition they were examined ultrasonographicall y twice weekly for 9 wee/cs to follow up uterine involution and ovarian find ings. Data concerning the post­ partum reproductive peiformance ( uterine involution, first estrus, open days, and con­ ception rate ) were recorded . Pregnancy diagnosis was done rectally 60 days post breeding using a proved fertile bull. Blood samples were taken twice weekly for 9 weeks, beginiing 7 days postpartum for progesterone assay . Serum progesterone level showed a significant rise in animals in group A ihan those in group B starting from the second week postpartum Animals in group A showed a significant (p < 0.01) red uction in days from calving to uterine involution ( 28.65±2.54 Vs. 37.67±4.65) as indicated by ultrasonographic exam­ ination, days tofirst estrus (58.87±6 .54 Vs. 87.98±9.82) . number of services per con­ ception (1.67±0.54 Vs. 3.21±0.87) and open days (87.76-9.75 Vs. 122.63±3.65). Group A showed a higher conceptuion rate than group B ( 80% Vs. 54.25% ).It could be concluded that careful adjustment of the rate of anionic salt supplemen­ tation in dry cow diets may support proper functioning of both Ca and energy regulato­ ry system so that optimal health is achieved in the peripartum period.


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