Effects of Supplemental Energy on Beef Female Performance
ABSTRACT McCullough, Sara A. M.S., Purdue University, December 2015. Effects of Supplemental Energy on Beef Female Performance. Major Professor: Ronald P. Lemenager. The effect of supplemental energy on beef female performance and reproductive parameters was investigated through two separate studies. In the first study, Angus-Simmental yearling replacement heifers were allocated and placed on one of three treatments; 1) a control diet with no added dietary fat, 2) a low fat diet, and 3) a high fat diet. The heifers on the added fat treatments were fed a supplemental ground flaxseed 28d prior to initiation of the breeding season. Concentrations of plasma progesterone were used to determine cyclicity status, and the number of heifers exhibiting estrous was not different among treatments. All heifers were bred following estrus detection and remained on the dietary treatments for 30d after initiation of the breeding season. There were no differences in initial or final body weights or BCS among treatments, and all heifers performed adequately on the dietary treatments, and attained an estimated 66% of their mature equivalent weight prior to breeding. There were no differences in either artificial insemination or overall breeding season pregnancy rates. In the second study; mature, early lactation, fall-calving beef cows were utilized to evaluate the metabolic and reproductive effects of feeding distiller’s grains with solubles (DDGS) prior to breeding. Cows were assigned to one of three diets; 1) control with no added DDGS, 2) DDGS 30d prior to breeding, or 3) DDGS 60d prior to breeding. No differences were seen in BW or BCS at the start or end of the feeding trial. Likewise, no differences were seen in the change of BW or BCS throughout the experiment. The number of cows cyclic at the beginning of the breeding season did not differ. Artificial insemination and final end-of-season pregnancy rates did not differ among treatments. Collectively, these experiments illustrate that a flax-based supplement and DDGS can be utilized in the beef female with no detrimental effects on animal or reproductive performance.
Lemenager, Purdue University.
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