Heifer development programs have changed over the years. In the 1990s, there were still many farmers that calved heifers at 3 years of age and nearly their mature weight. Since that time, most progressive cattlemen have moved to calving heifers at 2 years old, and 65% of their mature weight, which improves their lifetime productivity relative to calving 3 year olds when done properly.
Recently, the concept of “slow heifer development” has been introduced to cattlemen. The logic of this approach is that when you push heifers to a heavy weight (65% of mature weight), the feeding program is expensive and some heifers that need the supplement to grow enough to breed will “crash” at some point, due to their higher nutrient requirements.
Heifers that are developed more slowly (to about 58% of their mature weight at breeding) will typically not lose as much weight and condition as the heavier heifers after they calve and enter their second breeding season. Some heifers with very high nutritional requirements may not breed the first time in a slow development program, but those big, inefficient heifers are likely to drop out of the cow herd early anyway.
A slow development program means that it is possible to create forage systems where little if any supplementation is needed during development. A heifer that has a 205 day weight of 550 lbs needs to gain 200 lbs over the next 6 months to be adequately developed; an average daily gain of only about 1.21 lb per day. It is very possible to achieve that gain without supplement (unless the base forage happens to be toxic KY-31 tall fescue or bermudagrass).
Over the last two decades, North Carolina State University has done extensive research on developing heifers using tall fescue, with a focus on supplementation and the use of novel endophyte varieties. This work has shown that heifers on toxic tall fescue actually have gains comparable to novel endophyte tall fescue in stockpile systems after the toxin levels start to decline in early winter. When warm weather hits in late spring, the gains of heifers on toxic tall fescue are very low, while heifers grazing novel endophyte tall fescue outperform them by about 1 lb/day. In this work, heifers grazing novel endophyte tall fescue during both the winter and spring season ended up weighing over 100 lbs more than the heifers grazing the toxic tall fescue. Many of the problems with heifer development on toxic tall fescue can be overcome by feeding additional concentrates, but that is expensive and labor intensive compared to using novel endophyte tall fescue.~ Dr. Matt Poore, NCSU professor and president of the Alliance for Grassland Renewal
Learn more about adopting novel tall fescue varieties at the Alliance for Grassland Renewal’s workshops: February 23-35 (evenings) Virtually, or March 25 in Lexington. Learn more here
You must be logged in to post a comment.