Birth Intervals in Cattle Raised for Meat: Belief and Fact

by Viktor and Annie Reinhardt

It is commonly believed that calves must be artificially weaned so thatthe cow gives birth at the most frequent possible intervals. We had theunique opportunity to question the justification of this belief by comparingthe reproductive performance of 18 cows who were allowed to raise theircalves beyond the age of natural weaning with the reproductive performanceof 96 other cows who were subjected to the traditional forced weaning managementsystem. Both categories of cows lived on the same ranch, in herds of approximately50 animals including two mature bulls per herd.

The calves of the "managed" cows were taken away from theirmothers at the age of about eight months and raised in separate groups.Shortly thereafter, the mothers were also removed from the original herdand re-grouped in other herds. These artificial disruptions of social relationshipswere extremely disturbing for the animals, and it took several days oreven weeks until they calmed down again and established new relationshipswith the members of the new groups.

The calves of the "semi-wild" cows were naturally weaned bytheir mothers: female calves at the age 7-12 months, male calves at theage of 9-14 months. The weaning did not impair in any way the affectionatebond between mother and calf. In fact, the mother-calf bond was the foundationof the herd's cohesive social structure (see photo).

The performance of cattle is usually assessed by calculating the timelapse between two births. This so-called calving interval averaged 388days in the semi-wild cows, versus 494 days in the managed cows.

The difference of 106 days was statistically significant, indicatingthat the performance was enhanced when the calves were allowed to staywith their mother rather than when they were artificially weaned by beingtaken away from the maternal herd.

The better performance of the semi-wild cows could not be attributedto different climatic or nutritional conditions. In contrast to the managedcows, however, the semi-wild cows lived in a stable social environment.It was probably this stability of the social environment that accountedfor the animals' better reproductive performance. Artificially breakingnot only the bond between mothers and their still nursing calves but alsofriendship relationships between the mothers and other herd members, apparently,constituted a severe stress situation for the managed cows which resultedin a depression of their reproduction.

The affectionate mother-calf bond
is the foundation of a cattle herd's
cohesive social structure. A study
by Viktor and Annie Reinhardt
suggests that the bond lasts for
life under natural conditions.
Here, cow Dora grooms her
eight-year old daughter Riese
while grandson Rick is taking
a nap. Photo by Viktor Reinhardt.

Our observations challenge the inertia of tradition, demonstrating thatreproduction of beef cattle is enhanced rather than reduced whencows are allowed to wean their calves at the biologically determined age.Interfering in biological processes may satisfy man's ambition to havecontrol over them, but this is bound to have unforeseen repercussions ifthe biological process is not properly understood. Interfering in the naturalweaning process of cattle not only inflicts avoidable emotional pain butit also unnecessarily diminishes the animal's natural reproductive potential.

AWI Quarterly Spring/Summer 1997, Volume 46, Numbers 2 &3