Effect of protein supplementation on yield and milk composition of F1 Holstein x Zebu cows kept in deferred pasture of brachiaria grass

Abstract

The objective of this study was to evaluate different supplementation strategies concentrated to F1Holstein x Zebu lactating cows managed in deferred signal grass pasture on the yield and composition ofmilk and body weight gain. Thirty six F1 Holstein x Zebu cows with an average lactation period of 267 ±10 days, mean body weight of 548 ± 19kg were used following a completely randomized design in a 4 x 5factorial scheme, being four feeding strategies and five days under evaluation. The treatments consistedof four nutritional strategies: deferred pasture as a source of roughage without supplementation (PDSS);deferred pasture as a source of roughage with protein supplement offer (PDCS); deferred pasturesupplemented with 15 kilos of corn silage (natural base) + 1,200 grams of protein supplement (PDSP) andcorn silage (ad libitum) + 700 grams of protein supplement (SMP). There was no interaction (P> 0.05)between the nutritional plans and days under evaluation for any of the variables. It was found that cowsfed SMP showed milk production 26.06% higher than the other nutritional plans (mean of 11.46kg/day).F1 Holstein/Zebu cows handled in deferred pasture in a traditional way supplemented with proteinmaintains milk yield.