Dietary supplementation with selenium and vitamin E improves milk yield, composition and rheological properties of dairy Jonica goats.

The objective of this study was to evaluate the effect of dietary supplementation with selenium (Se) and vitamin E (VitE) on milk yield, composition and renneting parameters in dairy Jonica breed goats. Forty multiparous lactating goats fed the same basal diet were randomly allocated to 1 of 2 dietary treatments: for 135 days, the experimental period. Basal diet was composed by ad libitum mixed vetch-oat hay and a definite amount of a pelleted concentrate. Dietary treatments included: (1) the control diet containing background Se and VitE only, and (2) the experimental diet containing sodium selenite as the Se supplement in concentrate (0.20 mg/head per day of Na-selenite and 20 mg/day per head of VitE). During the trial, no significant differences (P>0.05) were registered in dry matter intake and body weight gain among groups. Goats fed Se-VitE diet showed the highest milk production (P<0.05), and fat (P<0.01) and protein (P<0.05) yields and percentages. Somatic cell count were significantly lower in Se-VitE diet compared with control group (P<0.05). Significant differences (P<0.05) were observed in milk renneting properties. Based on our results, it was concluded that dietary supplementation with SE and VitE led to an increase of milk production and quality in Jonica goat, with positively improvement in milk coagulation aptitude.