May 17, 2016
Beef bounces back
by Derrell S. Peel, Oklahoma State University Extension livestock marketing specialist
Beef and cattle prices bounced back sharply in the past ten days. Choice boxed beef ended last week at $218.56/cwt., up $14.82cwt. from the recent low on May 6. Wholesale prices were generally higher last week for end meats (round and chuck) as well as middle meats (rib and loin). Five-market fed cattle prices ended the week of May 13 at $132.64/cwt., up $14.61/cwt. from the May 4 low. Auction prices for feeder cattle in Oklahoma were mostly up four to six percent in the past one to two weeks.
Price improvement has occurred despite continuing year over year increases in beef production. For the week ending May 14, estimated beef production was up 6.1 percent year over year, contributing to a ten week average increase of 5.3 percent compared to the same period last year. Cattle slaughter was estimated at 601 thousand head last week, up 5.8 percent year over year. Average cattle slaughter has been 4.1 percent higher than last year for the last ten weeks. Carcass weights are still up year over year but have decreased dramatically in recent weeks. Average steer carcass weights were 868 pounds last week, down 26 pounds from early March and just 3 pounds heavier than the same period last year.
The recent rally in cattle and beef prices provides a new base for seasonal price movements through the summer and the remainder of the year. Beef production is expected to increase seasonally through June but this will be tempered both by the recent acceleration in cattle marketings that is pulling cattle ahead of the seasonal peak combined with smaller year over year increases in carcass weights. Beef production will likely trend higher in the second half of the year but carcass weights may partially offset increased cattle slaughter. The recent seasonal decline in carcass weights may not be done yet and carcass weight may drop below year earlier levels for much of the second half of the year. Steer carcass weights have declined 62 pounds from the October peak last fall. This compares to an average fall to spring seasonal decrease of 41 pounds the past five years. A typical seasonal increase in carcass weights this fall from current levels would leave steer carcass weights ten to 20 pounds below the record carcass weights from the fall of 2015. This will depend on whether feedlots continue to market cattle aggressively and maintain a faster turnover rate.
 
Percentage of mature weight at puberty in heifers
by Glenn Selk, Oklahoma State University Emeritus Extension animal scientist
For years, the accepted target weight for yearling replacement beef heifers at breeding was 65 percent of their mature weight. Recently that target has been questioned.
Oklahoma State University reproductive physiologists have studied the weight that beef heifers reach puberty in relationship to their eventual mature weight. A total of 34 crossbred heifers (in 3 different years) were studied at puberty and again when they had reached maturity at 5 to 7 years of age. The heifers were at least ¾ Angus and ¼ or less Hereford.
Shrunk weights were obtained when concentrations of progesterone in the plasma indicated that cycling activity had begun. Please remember that “average” is the point at which approximately half of the heifers reached puberty. The average weights at puberty were statistically similar (695 lb, 695 lb, and 737 lb) for the three years. Mature weights were obtained in mid-gestation, adjusted to a body condition score of 5. Mature average body weights were also similar (1269 lb, 1256 lb, and 1280 lb) for cows born in all three years. The mean, or average, weight at which heifers reached puberty was 56 percent of the mature weight. Figure 1 below shows the percentage of heifers reaching puberty at the incremental increases in percentage of mature weight.

Only 12 percent of the heifers reached puberty at 50 percent of mature weight or less. Only forty-seven (47%) percent of the heifers reached puberty at 55 percent of mature weight or less. Ninety-one (91%) percent of the heifers reached puberty at 60 percent of mature weight and 97 percent had reached puberty by the time they weighed 65 percent of the mature weight.
Producers wanting to be certain that a high percentage (90% or more) of their replacement heifers have reached puberty before the start of the breeding season, need to have heifers weigh at least 60 percent of the mature weight.
For example, if a producer goes to the expense and effort of estrous synchronization and AI, getting the most heifers bred artificially is probably the goal. In this scenario, making certain that all of the heifers weighed 60 percent or more of the mature weight makes sense. Other producers may wish to place maximum selection pressure on early puberty and high reproductive soundness. They may choose to turn bulls in with heifers at 55 percent of mature weight and cull any open heifers after a relatively short (45 to 60 day) breeding season. Source:  Davis and Wettemann. 2009 Oklahoma State University Animal Science Research Report.
Cow-Calf Corner is a weekly electronic newsletter by the Oklahoma Cooperative Extension Agency.