oh look what I found..
In this new era of elevated feed costs (both grain and hay), developing heifers from weaning to breeding involves a substantial investment. And, if heifers developed this winter fail to re-breed after their first calf next summer, much of the cost associated with developing them will not be recovered.
To avoid non-pregnant 2- and 3-year old cows at the end of the breeding season, producers are considering altering the nutritional development of heifers between weaning and first breeding. One of the quickest ways to maximize reproductive performance is to provide more nutrients. However, based on recently-reported data, this is probably not the most economical solution.
A New Approach
Historically, heifers have been developed to weigh approximately 60-65% of their mature body weight at breeding time (about 13-14 months old), in an effort to increase pregnancy rate. This practice has been based largely on evidence that: 1) increased energy intake during development improves heifer pregnancy rate, and 2) heifers developed to a body weight less than 65% take longer to re-breed after calving as a 2-year old. Yet, some argue that increasing the amount of feed provided (which increases costs substantially) in order to increase pregnancy rate leads to a long-term cycle of elevating costs and declining profitability on a cattle operation.
Several researchers have begun to explore the possibility of developing heifers at a slower rate, which ultimately leads to weights at first breeding that are lighter than historical averages. Nebraska research led by Dr. Rick Funston compared the long-term reproductive performance of two groups of crossbred heifers developed to 53% (low gain) and 58% (high gain) of mature body weight. The heifers were developed on identical rations (hay, wheat middlings, corn, and supplement), except for a difference in corn to reflect the increased gain in the "high gain" heifers. Interestingly, there was no difference between the two groups for pregnancy rates through the fourth breeding season (Table 1).
An economic evaluation was conducted by University of Nebraska researchers to follow-up on the reduced gain concept. The above data were used, in addition to data from an experiment by Creighton (also in Nebraska) where two development systems were compared: low gain (to 50% of mature weight, prior to breeding for 60 days) vs. high gain (to 55% of mature weight, prior to breeding for 45 days). Similarly, the low gain heifers had a pregnancy rate of 87% in a 60-day season compared to a pregnancy rate of 89% in a 45-day breeding season in the high gain heifers.
Using estimated feed costs and cattle prices over an 11-year period, the "low gain" heifers cost $27 per bred heifer less than the "high gain" heifers (Table 2), when data were averaged over the 11-year period. Average calf birth date, weight, difficulty, and loss were similar for both treatments, as well as calf gain and weaning weight. It should be noted that this analysis was conducted prior to the recent hike in grain and hay prices. Thus, it's possible that cost savings could be even larger today.
Looks like 50 - 55% target weight.. I was RIGHT ON.. These are LOW weight heifers. I'm sure it would be even more difference if they used low weight 50% vs. an average 65% weight.
Looks like maybe the teacher needs to go back to school. :nod:
$$$$$ in your pocket for the entire life of that cow.
BOOOOOOOOMMMMMMM!!!!!!!!!! goes the dynamite..
