مرکز منطقه ای اطلاع رساني علوم و فناوري - استفاده از آب پنير به جاي آب و تاثير آن بر عملكرد گوساله هاي پرواري هلشتاين

چكيده لاتين :

The effect of feeding liquid whey on performance of 12 Holstein steers with mean body weight of 139±20 kg was studied in a completely randomized design with three dietary treatments and four replications for 98 days. The experimental treatments were; 1) free access to water (as control), 2) free access to whey and water, and 3) free access to whey. Alfalfa hay was given to steers at a level of 0.7 percent of BW. The same concentrate was used in all treatments. The concentrate, water and whey were fed ad lib. Water consumption by steers in treatment two reduced significantly in comparison with the respective value of the control treatment. In treatment two, 87.3% of the consumed liquid obtained through fresh whey. The total liquid consumption by steers in treatments one, two and three were 36.6, 50 and 48.5 kg per day respectively. The differences between treatments was significant (p<0.01). Ad lib. concentrate intake in treatments one, two and three were 4.99, 2.62 and 2.64 kg DM/d respectively. Free access to liquid whey led to significant reduction in ad lib, concentrate intake (about 50% in comparison with the control). The proportion of dry matter consumed in the form of liquid whey were 39 and 41.2 percent of the total dry matter intake in treatments two and three respectively. The NDF digestibility in treatments two and three were lower than the control value (p<0.05). Rumen ammonia nitrogen (NH3-N) content in the treatments containing liquid whey were significantly lower than the control value at the first sampling. Plasma urea nitrogen in treatments two and three was higher than the control mean in the set of data obtained at the first sampling (p<0.05). Total DM and alfalfa DM intake, daily weight gain, feed conversion ratio, DM, OM, CF and CP digesttbilities, rumen and blood pH and DM of feces were not affected by the treatments. It can be concluded that feeding liquid whey to steers can reduce concentrate intake without any adverse effect on daily weight gain and feed conversion ratio.