|Endecott, Rachel - MONTANA STATE U. EXT|
Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: April 12, 2008
Publication Date: July 1, 2008
Citation: Endecott, R.L., Waterman, R.C. 2008. Use Of A Self-Fed, Small-Package Protein Supplement For Beef Cows Post-Weaning. Journal of Animal Science 86(E-Suppl. 3):136. Abstract #26. Interpretive Summary: Abstract only
Technical Abstract: A 60-d supplementation study conducted at Miles City, MT from mid-October to mid-December 2007 evaluated responses of beef cows (n = 141; avg BW = 535 kg) grazing dormant native range (7.7% CP, 57% NDF, 74% IVDMD) to two different supplementation strategies. Cows were stratified by age and weight at weaning and then assigned to one of two supplements: 1) self-fed loose mineral mix (MIN) or 2) self-fed mineral plus high-bypass protein sources (MIN+PRO; 50% mineral mix, 25% feather meal, 25% fish meal). Target intakes were 70 g/d for MIN and 140 g/d for MIN+PRO. Cows were weighed and hip height and girth measurements were taken at the beginning and end of the study. Weight-to-height and weight-to-girth ratio changes were calculated. Data were analyzed with cow age, supplement and their interaction in the model. Cows fed MIN consumed 28 g/d and MIN+PRO cows consumed 93 g/d, which was lower than the expected target amount for both supplements. Cow age × supplement interactions were not observed (P >= 0.22). Weight change, weight-to-height ratio change, and weight-to-girth ratio change were similar regardless of cow age (P >= 0.79). Cows lost similar (P = 0.62) amounts of weight during the study regardless of supplement treatment (-28 and -30 ± 4 kg for MIN and MIN+PRO, respectively). Likewise, weight-to-height ratio change (-0.31 and -0.32 ± 0.03) and weight-to-girth ratio change (-0.13 and -0.15 ± 0.02) were similar (P >= 0.62) for MIN and MIN+PRO cows, respectively. Protein supplementation at this level did not impact cow performance. However, target intakes were not achieved, which may have contributed to the lack of response to supplementation with the mineral-protein mix.