|DEL CURTO, TIM|
Submitted to: Journal of Animal Science Supplement
Publication Type: Abstract Only
Publication Acceptance Date: 5/23/1995
Publication Date: N/A
Interpretive Summary: Cattle grazing lush vegetation in spring are sometimes limited by inadequate dry matter content in the forage. They cannot consume enough forage to obtain the energy they need to gain at their full potential. Other research has found potential for low levels of energy supplementation to enhance performance. This study was conducted to determine whether low levels of a high energy supplement would enhance animal performance in lat spring. Yearling heifers and steers were fed 0 0.5, 0.75, and 1.0 kg of cracked corn per head per day over a 72 day period. Diet samples were collected, intake was estimated, and animals were weighed biweekly. Results indicate that it is not economically feasible to feed corn to cattle during the late spring period. Performance was not improved by supplementation. This knowledge will save livestock operators from the unnecessary expense of feeding corn during this period. Analysis of forage eindicates that the window of time when supplementation may be beneficial i only during very early growth in spring.
Technical Abstract: Two experiments evaluated the effects of energy supplementation on diets and performance of cattle grazing native flood meadows. In experiment 1, eighty-four heifers (avg. beginning wt 272 kg) were blocked by weight and randomly allotted to the following corn supplementation treatments: 1) Control (no supplement, CON); 2) .5 kg/h/d (LOW); 3) .75 kg/h/d (MED); 4) 1.0 kg/h/d (HI). In experiment 2, 10 ruminaly cannulated steers were blocked by weight and randomly allotted to CON or MED treatments of experiment 1. Digestive kinetics and intake were determined by a pulse dose particulate phase marker. In experiment 1, heifers showed no treatment effect and gained approximately 1 kg/d during the 72 d trial. In experiment 2, supplementation had no effect (P>.10) on forage intake of steers or in vitro digestibility. Rate of forage DM or NDF disappearance (%/h) was similar in both groups. Particulate passage rate, ruminal retention time, and gastrointestinal fill were altered by supplementation (P<.05). Supplementation increased particulate passage rate from 2.70 to 3.33 %/h, decreased ruminal retention time to 35.9h and reduced gastrointestinal fill. Some changes in digestive kinetics were noted, however, supplementation did not increase performance of animals.