A group of spring-calving cows were supplemented a protein cube while grazing corn stalk residue and there was a group of cows grazing corn stalk residue that was not supplemented. After corn stalk grazing, cows were managed together. Pre-calving weight and body condition were statistically different between the two groups in favor of the supplemented group of cows. Precalving body condition score for cows grazing corn stalks and supplemented was 5.3 and that for non-supplemented cows was 5.2, although these numbers are statistically different, they are likely not different biologically, meaning it would be difficult to say that any performance difference between the two groups is a result of differences in body condition; nor would you expect any differences in performance due to differences in body condition of the two groups. There was no difference in calf birth or weaning weight. Calving date, percentage of the cows calving the first 21 days of the calving season, nor milk production was different. Subsequent pregnancy rate was high for both groups (97% for supplemented and 95% for non-supplemented cows).
We have other data (2008 NE Beef Report http://beef.unl.edu/beefreports/200805.shtml) that suggests small difference in body condition for cows that were either supplemented or not supplemented while grazing corn stalk residue. However, there was no difference in reproductive performance between the supplemented and non-supplemented groups. In this study, cows were in good body condition (greater than BCS 5.0) when they went to stalks.
To read the entire article, link here.