Efeito da adição de soro de leite sobre a digestibilidade aparente e os parâmetros sanguíneos de vacas secas

Abstract

The effect of liquid whey addition in the diet on blood parameters and on the apparent digestibility of dry matter (ADDM), crude protein (ADCP), neutral detergent fiber (ADNDF), and acid detergent fiber (ADADF) was evaluated in 12 dry Gir cows, receiving coastcross (Cynodon dactylon) hay supplemented with protein salt and zero (control), 15, 30, or 45 liters of whey per day. The inclusion of the whey in the diet affected the ADDM and ADCP (P<0.01) and had no effect on ADNDF and ADADF. As high the volume of whey inclusion, higher the ADDM and ADCP values. The average values of glucose in blood plasma - 59.3, 64.0, 66.6, and 69.2mg/dL - varied (P<0.01) among treatments, adjusting themselves to positive linear dL regressions. The whey inclusion diminished (P<0.01) blood urea values - 22.83, 20.17, 17.5, and 15.67. The whey improved the efficiency of utilization of nitrogen compounds in the rumen and can be used to complement protein supplements with high levels of urea.