Ever wonder how much weight is lost by calves when they're first put out on wheat pasture? USDA researchers in Oklahoma weaned calves in the fall and kept them in drylot for 14 days on hay and supplement. Calves were then turned out to graze wheat pasture and were weighed two and four weeks later. After two weeks on pasture, calves lost 15 lb. But during the next two weeks they gained 46 lb. It was concluded that calves placed on wheat pasture, after a two-week postweaning period in drylot, need two to three weeks on the new diet to begin gaining weight.
Monensin and Bloat
Monensin (Rumensin TM ) has been used for 25 years as a feed additive to increase weight gain (on pasture) and feed efficiency (in the feedyard). It has been observed that cattle on monensin seem to have less incidence of bloat, and a monensin-containing bolus is marketed in Australia for bloat control. But the mechanism of this effect has not been known.. Australian and Pennsylvania workers collaborated to study the effect of monensin on foams. Using a foaming solution created from an extract of red clover leaves, they determined that monensin definitely has anti-foaming properties. This may be the mode of action of monensin in reducing bloat.
Premium-Sale Premiums
The Texas A&M Extension Livestock Marketing group has analyzed results from one of the auctions holding preconditioned, commingled stocker-feeder sales, Jordan Livestock at San Saba. Included were 9 sales held from November, 1999, to March, 2001. Comparisons were made to traditional auctions held the same week around the state. Over the 9 Jordan sales, premiums averaged highest for cattle from 400 to 550 lb. As expected, #1 Muscle cattle brought more than #1-2, but premiums were higher for #1-2. During the period of the study cattle prices increased, but premiums tended to decrease. Premium buyers may be unwilling to pay more when cattle are high. It is not known what results would have been in a period of flat or declining prices. Additional information will be available on other factors influencing price at these sales, such as breedtype, sex, etc. It should be understood that extra value must be compared to the complete costs of preconditioning, including concentrate feed/supplement, pasture/hay, overhead, labor, interest, marketing, and opportunity cost.
Conception Rates With Sex-Sorted Semen
For a good while now we've been told that practical use of sex-sorted semen is just around the corner. But there may still be some problems. Colorado workers used semen as follows: frozen, unsorted control (standard sperm numbers/dose); frozen, unsorted low-dose (1/40 of standard dose); frozen, sex-sorted low-dose; and cooled, sex-sorted low-dose. Pregnancy percentages at day 60, in the same order, were 67, 49, 23, and 25. Fertility of sexed sperm was much higher with certain bulls. There may be an interaction between individual bull and ability of semen to withstand the stresses of sorting, particularly with low-dose insemination.
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