The Influence of Feed Energy Density and a Formulated Additive on Rumen and Rectal Temperature in Hanwoo Steers

Abstract

The present study investigated the optimum blending condition of protected fat, choline and yeast culture for lowering of rumen temperature. The Box Benken experimental design, a fractional factorial arrangement, and response surface methodology were employed. The optimum blending condition was determined using the rumen simulated in vitro fermentation. An additive formulated on the optimum condition contained 50% of protected fat, 25% of yeast culture, 5% of choline, 7% of organic zinc, 6.5% of cinnamon, and 6.5% of stevioside. The feed additive was supplemented at a rate of 0.1% of diet (orchard grass:concentrate, 3:7) and compared with a control which had no additive. The treatment resulted in lower volatile fatty acid (VFA) concentration and biogas than the control. To investigate the effect of the optimized additive and feed energy levels on rumen and rectal temperatures, four rumen cannulated Hanwoo (Korean native beef breed) steers were in a 4×4 Latin square design. Energy levels were varied to low and high by altering the ratio of forage to concentrate in diet: low energy (6:4) and high energy (4:6). The additive was added at a rate of 0.1% of the diet. The following parameters were measured; feed intake, rumen and rectal temperatures, ruminal pH and VFA concentration. This study was conducted in an environmentally controlled house with temperature set at 30°C and relative humidity levels of 70%. Steers were housed individually in raised crates to facilitate collection of urine and feces. The adaptation period was for 14 days, 2 days for sampling and 7 days for resting the animals. The additive significantly reduced both rumen (p<0.01) and rectal temperatures (p<0.001) without depressed feed intake. There were interactions (p<0.01) between energy level and additive on ruminal temperature. Neither additive nor energy level had an effect on total VFA concentration. The additive however, significantly increased (p<0.01) propionate and subsequently had lower acetate:propionate (A/P) ratios than non-additive supplementation. High concentrate diets had significantly lower pH. Interactions between energy and additive were observed (p<0.01) in ammonia nitrogen production. Supplementation of diets with the additive resulted in lower rumen and rectal temperatures, hence the additive showed promise in alleviating undesirable effects of heat stress in cattle.

A hot lunch for herbivores: physiological effects of elevated temperatures on mammalian feeding ecology

“…High-fibre diets favour the production of acetate over propionate. Inefficient ATP production using acetate as a substrate is now thought, in part, to cause the high DIT measured in ruminants (Cho et al, 2014). As testament to the thermogenic effects of acetate, this substrate is preferentially oxidised when an animal is cold-challenged, leaving larger amounts of amino acids relative to glucose available for growth and reproduction than would be available at thermoneutrality (Baumgard & Rhoads, 2012).…”

The Effect of Live Yeast Supplementation on Beef Cattle Performance: A Systematic Review and Meta-Analysis

“…Gaughan, Mader, Holt, Hahn and Young (2002) reported that animals in thermal stress reduced the DMI as a way to regulate their body temperature. Nevertheless, using yeast in the cattle diet reduces the ruminal and rectal temperature (Cho et al, 2014), and increases the DMI. Our results highlighted that crossbred animals supplemented with yeast showed a greater ADG than the control group.…”

Do microbiotas warm their hosts?

“…Certain food additives decreased the temperature of the rumen of steers by optimizing microbial fermentation to produce more propionate and less acetate. 15 Based on these data and the fact that diet influences human gut microbiota composition, 16 we suggest that foods can have warming or cooling properties depending on what changes they bring about in the microbiota. Could this help explain the traditional Chinese medicine concept of heating and cooling foods?…”