Benefits of a prepartum anionic diet on the health of dairy cows in the transition period: prevented subclinical hypocalcemia and minimizing oxidative stress
Albani, Kassio DuanSilva, Aleksandro Schafer daMachado, GustavoBottari, Nathieli BottariAlves, Mariana SauzenCampigotto, GabrielaFritzen, AlexandroSchetinger, Maria Rosa ChitolinaMorsch, Vera MariaZaboot, RobertoLopes, Leandro Samia
Background: There are many metabolic diseases that affect dairy cows during the transition period, among them, the postparturient hypocalcemia, also known as milk fever, puerperal paresis syndrome, or fallen cow. This disease may affect animals 72 h after calving due to a nutritional imbalance in the calcium metabolism, which occurs after a sudden demand of this mineral at the beginning of lactation. This problem is more common in animals with high milk production, and usually after the second lactation. Therefore, this study evaluated whether the anionic diet on the prepartum phase would be beneficial for dairy cows in the transition period. Materials, Methods & Results: Eight Holstein cows on their second and third pregnancy with body condition score between 3.5 and 4 were used. During the experiment, the animals remained in paddock with grazing Tifton 85 (Cynodon spp.) and water ad libitum. Two groups of four animals each were used: the group A (control) received a dietary cation-anion difference (DCAD) diet of 2.57 mEq kg-1, and the second group, called the group B (treatment), received a DCAD diet of -112.2 mEq kg-1. To evaluate animal health, we performed gynecological examinations, in addition to blood samplings on days 20, 10 and 5 prepartum and 3, 7, 12 and 20 postpartum to assess seric levels of calcium (Ca), total protein, albumin, globulin, cholesterol, triglyceride, urea, and hepatic function (AST, ALT and GGT). It was also measured the production of free radicals (ROS) and lipid peroxidation (TBARS) in the transition period of the cows. No statistical differences were observed between groups regarding body condition score, uterine tone, dominant follicle diameter, size and presence of the corpus luteum and the presence of genital discharge up to 30 days postpartum. However, the anionic diet prevented a dramatic reduction in calcium levels, unlike what occurred in the control cows (the group A) where a subclinical hypocalcemia was observed.[...](AU)
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