Dry mater intake, milk yield, and heat stress indicators of dairy cows fed diets with cashew nut

A study was carried out to evaluate dry matter intake, milk yield, and heat stress parameters in Brown Swiss cows fed diets with cashew nut. Animals were raised in the semi-arid region of the Brazilian Northeast. Twelve cows were subjected to a switch back experimental design, with four treatments: 0, 8, 16, and 24% of cashew nut in the concentrate. Each cow received 7kg of concentrate per day and had free access to sugar cane. Dry matter (DM) intake and milk yield were daily taken as well as measurements of rectal and milk temperature,, and cardiac and respiratory rates. The highest intake of forage (sugar cane) was obtained when the concentrate had no cashew nut (7.7kgDM/day). This value was not different when the concentrate contained 8% of cashew nut (7-59kgDM/day) but greater than dry matter intake of cows receiving diets with 16% of cashew nut (7.35kgDH/day; P < 0.05). The diet with 24% of cashew nut in the concentrate resulted in the lowest consumption of forage (7.05kgDM/day), which was significantly different from all other treatments (P < 0.05). Variations in milk yield (from 14.76 to 15.31 kg/day) were not related to changes in the content of cashew nut in the concentrate (P > 0.05). Such low variability, in daily milk yield could be associated with the higher energy density of diets containing more cashew nut. Finally, indicators of heat stress were not influenced by changes in the diets, given the air temperatures and environment where all cows were raised.