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Cattle Health: Keeping It Science Based
I have a good friend who likes to show up at government hearings wearing a button that says “Show Me The Science.” It’s a challenge to anyone trying to influence her opinion or choices to back their claims with proven facts.
Cow/calf producers, too, need to look for the science when they are sifting through all the information made available to them. Decisions grounded on solid information are especially critical when multiple alternatives are available, and when production costs can be significantly impacted. A perfect example of this is choosing a supplementation program. A multitude of products are available, offering tremendous variety in nutrient composition, ingredient selection, form, feeding method and cost. A compelling case can be made for self-fed liquid supplements, based on success stories, convenience, and low total costs. But beyond that, published research trials have documented the nutritional fit and positive performance responses to offering these products in forage-based production systems.
Liquid Supplementation of Grazing Cows and Calves.
A.V. Earley, B.F. Sowell, J.G.P. Bowman, Montana State University
PROCEDURE: Angus cow/calf pairs (average cow weight 1350 lb) were grazed on improved pastures (wheatgrass, bluegrass, timothy, alfalfa and clover) from July 28 to Oct.3, with half the cattle (50) having access to a 41% crude protein, 3% fat liquid supplement. Clipped samples of the pastures averaged about 7.5% protein; samples of the grass the cattle actually ate averaged 9.5% CP. A chemical marker was used to calculate forage intake, and supplement intake was monitored separately for calves and cows, using electronic ID. Milk intake was also estimated. Cattle were weighed periodically.
n Cows consumed 2/3 lb per day of liquid; calves consumed 1/4 lb per day.
n Forage intake by supplemented cows and calves was increased 64%.
n Milk intake by calves increased 67% (9 vs. 15 lb/hd/day)
A Molasses-based Liquid Supplement Program for Beef Cows Grazing Endophyte-Infected Tall Fescue.
D.G. Ely, D.K. Aaron, J.T. Johns, J.Wyles and L.A. Carver, University of Kentucky
PROCEDURE: At calving (March and April), beef cows and heifers were placed in Kentucky 31 tall fescue pastures, with or without a 32% commercial liquid supplement provided in lick-wheel feeders. Cows and calves were weighed in early May and late October, and cows were condition scored every 28 days. Representative blood samples were taken to monitor blood urea nitrogen levels. Control and liquid supplement groups were maintained as separate herds through the three year trial, with open cows replaced by bred heifers as necessary.
n Average weight gains for cows, calving to weaning, was 64 lb for control animals, and 84 lb for those receiving liquid supplement. Supplemented cows also had higher body condition scores at every evaluation point.
n Calves from the supplemented treatment weighed 15 pounds more at weaning, thanks to a statistically significant improvement in ADG.
Effect of Urea-Molasses Supplement on Forage Intake, Digestibility and Ruminal Turnover of Steers Grazing Bermudagrass.
R.A. Dawkins, Auburn University
PROCEDURE: Angus X Hereford steers grazed coastal Bermudagrass from late July into December, with or without a 35% liquid supplement offered in lick wheel feeders. Every three weeks there were 5-day complete fecal collections matched with two esophogeal samples. Passage rate and ammonia concentration were measured using a chemical marker. Liquid intake was measured, and forage intake, digestibility and passage rate calculated. Results were compared within and between periods when the grass was actively growing, maturing, and dormant.
n Liquid intake ranged from .8 to 1.9 lb/hd/day during the growing season, then increased to about 3 lb on dormant grass.
n When forage quality dropped to 5 - 7 % crude protein, liquid supplement increased forage intake 25% while maintaining digestibility.
n Rumen ammonia levels were not affected by treatment, indicating that the protein (including the NPN) was assimilated by the rumen microbes.
n Liquid supplement increased the liquid turnover rate 70% (which would be associated with improved efficiency of microbial protein production) and increased the particulate turnover rate 95%. Broken down by season, that led to a 3% increase in digestible dry matter intake when grass quality was high, and a greater than 100% increase in intake of TDN during the dormant season.
n Overall, liquid supplemented steers gained 114 pounds more from August through December, with most of the difference developing during the last half of the trial.
Effects of Supplement Type on Growth and Pregnancy Rate of Yearling Brahman-Crossbred Heifers.
J.D. Arthington, G.C. Lamb and F.M. Pate, University of Florida
PROCEDURE: Fall-born yearling heifers received one of two winter supplements: wheat-middlings based cubes, or a molasses/cottonseed meal slurry. Supplements were delivered each Monday, Wednesday and Friday during the trial. Both treatments provided equal amounts of energy and protein (3 ¼ lb TDN and 3/4 lb of CP per head per day). When pastures were limited, hay was provided free choice. Heifers were exposed to bulls for a 70-day breeding season.
n Supplement type did not affect heifer weight gains or frame growth. However, the heifers that received the molasses-based supplement had significantly higher pregnancy rates (76.3% vs 49.2%). The authors theorized that this improved response to supplementation may have been due to the fact the liquid was available to all animals over time, while all the cubes were consumed within an hour of delivery. It is possible the large pulse dose of nutrients from the cubes negatively impacted animal metabolism and hormonal function.
Source: Dr. Cathy Bandyk, Quality Liquid Feeds
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