اثر زمان‌بندی مصرف پروبیوتیک بر پایه باکتری‌های اسید لاکتیکی بر عملکرد و فعالیت ضد میکروبی سلول‌های خونی گوساله‌های نر نژاد کردی

The aim of this study was to examine the effect of Lactic acid bacteria based probiotic and its use schedule on Kurd male calves’ growth performance and white blood cell antimicrobial activity. The experimental period was 105 days after calves adapted to new environmental conditions. This study was carried out by 12 calves with an average body weight of 195 ± 10 kg and age of 240±10 days in a completely randomized design with three treatments and three replicate. Experimental groups included: 1) the control group was fed on a commercial basal diet (without probiotic). 2) was fed on basal diet and daily usage probiotic 3) was fed on basal diet and probiotic usage a day then skip 2 days and repeated. Growth performance and feed conversion rate were determined by measuring calves weight and feed intake on day 0, 52 and 105 of experiment after 14 h feed deprivation. For measurement of reactive oxygen species as anitimicrobial activity index in white Blood Cells, blood samples were taken from all of the calves at the end of experiment. Although body weight gain and feed conversion rate was not significantly different among any of the treatments 2 and 3  but increased and  decreased respectively compared to control group in end of experiment (p<0.05). Feed intake significantly increased in treatment 3 compared 2 (p=0.0424). No differences in reactive oxygen mean were observed in calves fed probiotic-supplemented diets and control group. According to this results dietary supplementation with probiotic did not affect white blood cell antimicrobial activity although improved Kurd calves growth performance and feed conversion rate, also daily usage of probiotic can be replaced by usage a day then skip 2 days and repeated schedule.