Document Type : Research Paper
Authors
1 MSc students, Department of Animal and Poultry Nutrition, Faculty of Animal Science, Gorgan University of Agricultural Science and Natural Resources, Gorgan, Iran
2 Department of Animal and Poultry Nutrition, , Gorgan University of Agricultural Sciences and Natural Resources
3 Assistant Professor, Department of Animal and Poultry Nutrition, Faculty of Animal Science, Gorgan University of Agricultural Science and Natural Resources, Gorgan, Iran.
Abstract
Introduction: Minerals affect wool production in sheep by affecting feed intake, altering rumen function and affecting the flow of nutrients from the rumen or by directly disrupting the animal's metabolism. Wool has the highest concentration of sulfur, which indicates the higher need of wool-producing sheep for sulfur than other breeds. The purpose of this study was to investigate the effect of different levels of bentonite sulfur on yield, wool quality, blood minerals, liver enzymes and thyroid hormones of ewes.
Materials and Methods: An experiment was conducted to evaluate the use of different levels of bentonite sulfur in sheep. For this purpose, 18 Dalagh ewes (average weight 38 ± 3.5 kg) were kept individually for 42 days with three treatments and 6 repetitions. Experimental treatments included: 1) control (without bentonite sulfur), 2) treatment containing 0.15 percent of bentonite sulfur and 3) treatment containing 0.3 percent of bentonite sulfur(based on dry matter). At first, to ensure the health of all the ewes, they are subjected to a thorough and thorough examination. The bentonite sulfur used in this research contanied 90% sulfur and 10% bentonite. The diets used in this experiment were prepared and adjusted according to the tables of NRC and were given to the ewes in the morning and evening. Ewes were weighed at the beginning and the end of the period after 16 hours of starvation using a digital scale. In order to determine the quality of sheep's wool, in the initial test, the ewes were arranged uniformly on the 41st day of the experiment, and samples were taken from the left side of the ewes in a 10 x 10 cm format according to the common and standard instructions using a manual wool picker. For determination of blood parameters, on the last day of the experiment, three hours after morning feeding, blood samples were taken from the jugular vein of the ewes.
Results and discussion: The results obtained from this research showed that with the increase in the level of bentonite sulfur in the diet, the length of fibers, efficiency, strength, kemp and the coefficient of variation of fiber diameter increased (P<0.05). Also, increasing the level of bentonite sulfur increased the concentration of serum sulfur and triiodothyronine hormone (P<0.05). Bentonite sulfur supplementation had no significant effect on final weight, daily weight gain, dry matter intake and feed conversion ratio of ewes. Also, different levels of bentonite sulfur had no significant effect on Non-Medullated fibers, Medullated fibers, average diameter and fiber crude protein. copper gallate, calcium, selenium, phosphorus and serum molybdenum. Addition of bentonite sulfur had no significant effect on serum concentrations of copper, calcium, selenium, phosphorus, molybdenum as well as the concentration of liver enzymes of experimental ewes.
Conclusion: The results of this study indicated that the use of bentonite sulfur up to the level of 0.3% of dry matter, could improve the strength and efficiency of wool fibers and it can be used in feeding ewes without having negative effects on their health and performance.
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