D.L. Rankins, Jr., S.E. Peacock and J.T. Eason

Each year, thousands of calves are purchased from sale bams during the fall and fed or grazed throughout the winter as stocker cattle to sell in the spring. Often these calves lose weight or make slow gains during the first month after purchase, but AAES research indicates that feeding them specially formulated diets can provide a boost in growth.

Most calves purchased at sales are newly weaned and have encountered numerous stressful events (shipping, vaccination, separation from mother, etc.) one to two weeks prior to purchase. Careful dietary management during the first 28 days is vital for reducing sickness and death. Several commercial receiving diets for young calves and several options for on-farm mixing are available to producers. A study was conducted at the Sand Mountain Substation in Crossville to evaluate four receiving diets for newly purchased calves.

Ninety-six calves (average weight 300 pounds) were purchased in November 1993 from local stockyards and transported to the substation that evening. Half of the calves were purchased on Nov. 1 and the other half on Nov. 8. Calves were assigned to one of four receiving diets: (1) commercial pellets, Master Mix Stressfighter 1; (2) 37% cracked corn, 30% ground alfalfa, 20% cottonseed hulls, 9% soybean meal and AS70OTM, Dyna-K, salt, and minerals; (3) diet 2 with 6% molasses added; and (4) diet 2 with 0.5 pound of Diamond V yeast culture added per head per day. The commercial pellets contained at least 12% crude protein, and the other three diets contained 14% protein. The diets were offered twice daily. For the first seven days each pen of calves also was offered 50 pounds of bermudagrass hay (approximately seven pounds per day), all of which was consumed.

All diets provided excellent results. Calves consumed from 8.6 to 9.1 pounds of dry matter per day during the first week, which is equivalent to approximately 3 % of body weight. No differences were detected between males and females. For the entire 28-day trial, the calves gained more than three pounds per day while consuming 10.7 to 11.1 pounds of feed. This resulted in 3.1 to 3.7 pounds of feed per pound of gain (see table).

Using fall 1993 feed prices, the cost per pound of gain was approximately 30 cents for the three on-farm diets and 40 cents for the commercial pellets. Animal performance was not significantly different on any of the diets. The only major difference was in cost per pound of gain and, if on-farm mixing is not available, the additional $45 per ton may be acceptable for having the convenience of a pelleted, bagged feed.

Of the 48 calves purchased on Nov. 1, six showed signs of "shipping fever" during the first week and received an injection of Naxcel. The second group of 48 calves exhibited more sickness, and all calves were given two injections of penicillin and vitamin B 12 the first week on test. In addition, 10 calves received Naxcel.

Newly purchased and transported calves usually consume only 0.5-1.5% of their body weight per day during the first one to two weeks on feed. In this trial, calves consumed more than 3% of body weight daily for the entire 28 days. This is probably attributable to good feed bunk management and immediate treatment of sick animals.

All four diets provided economical gains in these light-weight calves even though the diets cost $160 to $210 per ton. The reason is that this type of calf is very efficient at converting feed to body protein when sickness has been eliminated. Therefore, feeding diets designed specifically for receiving calves is well worth the extra feed cost. With a good dietary management and health program, newly received calves can gain rapidly during the first 28 days, rather than gaining slowly or losing weight.