Influence of housing conditions and calving distance on blood metabolites in water buffalo cows

The aim of this study was to evaluate whether housing conditions allowing the animals to lie in the mud and perform more physical exercise can negatively affect reserve mobilization and milk production. In addition, the effect of calving distance on blood metabolites was assessed. The experiment was conducted on twenty-eight lactating buffalo cows, equally allocated to two treatments. Fourteen cows were group-housed in a loose open-sided barn with a concrete floor and equipped with self-locking stanchions, where they received 10 m2/head of space allowance, as in intensive systems (Group IS). Fourteen others were group-housed in a similar barn but they also had the benefit of an outdoor yard with 500 m2/head as space allowance, including spontaneous vegetation and potholes for bathing and wallowing, as in traditional systems (Group TS). Animals were included in the experimental groups 5 days after calving. Daily milk yield, and milk fat, protein and somatic cell content were determined 4 weeks after grouping (about 35 days after calving) and then at monthly intervals (5 recordings). Blood samples were collected from the jugular vein in vacuum tubes 10 days after grouping (i.e. 15 days after calving) and then at 10 day intervals (17 collections). After centrifugation, plasma and serum aliquots were frozen stored until metabolite determinations (glucose, cholesterol, triglycerides, NEFA, urea, creatinine, albumins, total proteins, calcium, phosphorus, bilirubin, alkaline phosphatase, aspartate aminotransferase, alanine aminotransferase, lactate dehydrogenase and γglutamyl transferase). Treatment did not affect daily milk yield and milk fat, protein or somatic cell count content. Blood metabolite levels were not affected by treatment and interaction treatment x time. Conversely, as expected, calving distance had an influence on most of these variables (P<0.05÷0.001). In particular, in the first two months after parturition, glucose concentration decreased, whereas NEFA and cholesterol increased as a consequence of the high energetic requirements of animals in the first stage of lactation. The systems that allow the expression of some basic natural behaviour did not have any detrimental effect on buffalo metabolism and production, thus they should be encouraged.