L. ANGELOW1, V. TSVETKOVA1 and G. JAHREIS2
1 Institute of Cryobiology and Food Technologies, BG-1407 Sofia, Bulgaria
2 Institute of Nutritional Sciences, 07743-Jena, Germany
ANGELOW, L., V. TSVETKOVA and G. JAHREIS, 2011. Influence of different selenium and iodine offer during the grazing period of sheep on the milk yield, milk performance and daily protein, fat and lactose secretion. Bulg. J. Agric. Sci., 17: 139-144
The large population size of different sheep breeds and their wide adaptability to forage quality, make sheep widely accepted and genetically of great potential for production of ewes milk and different milk products. However, the established imbalances of basic essential elements in the flora (Se, I)) in the investigated area (Rhodope Mountain - Village Borino) affected negatively the milk production during the pasture period. Through the milking periods (April-June) the control ewes were additionally supplemented “per os” with 0.25 mg selenium in the form of NaHSe03 and 0.15 mg iodine in the form of KI daily. The experiments were carried out with 16 ewes of Rhodope Tsygai breed, divided into two groups. The animals were fed according to ARC norms with different amounts of selenium and iodine during the experimental period. The milk samples were taken on the 30th and the 60th day after supplementation. Selenium and iodine deficiency in the ration reduced the milk yield during the whole period (60th days) by 44%. The Se-I-unsupplemented ewes produced daily 35% less fat and 41% less milk protein in comparison to the supplemented one.