As cow herd managers monitor the pasture conditions this spring and make decisions about rebuilding a depleted cow herd, some may wish to rethink the time of year that breeding and calving take place. New data from Tennessee on a fescue-based forage system gives us more information about the direct comparison between fall and spring calving.
In the April, 2013 edition the Professional Animal Scientist, they reported on nineteen years of data comparing fall and spring calving on an experiment station in that state. Over a span of 19 years, they had data from 478 spring-calving cows and 474 fall-calving cows. The fall calving cows weaned 193 more calves (over those 19 years ) than did the spring calving cows. The spring-born calves grew faster and had higher 205 weights, but the fall-calving herd had increased income because of greater number of calves and a reduced need for replacement heifers.
The endophyte-infected fescue may have been a factor in the summer breeding seasons that resulted in significantly fewer calves per cow over the 19 years. The wild type endophyte (Neotyphodium coenophialum) has been shown to reduce a cow"s ability to regulate body temperature which would be an important trait in summer breeding seasons. Source: A comparison of spring- and fall-calving beef herds grazing tall fescue. Campbell, et al., 2013. Prof. Anim. Sci. vol. 29, no. 2, pp 172-178.