Cool-season annual pastures with clovers to supplement wintering beef cows nursing calves

<p>Abstract</p> <p>In December of 3 years, 87 beef cows with nursing calves (594 ± 9.8 kg; calving season, September to November) at side were stratified by body condition score, body weight, cow age, and calf gender and divided randomly into 6 groups assigned to 1 of 6 cool-season annual pastures (0.45 ha/cow) that had been interseeded into a dormant common bermudagrass (<it>Cynodon dactylon</it> [L.] Pers.)/bahiagrass (<it>Paspalum notatum</it> Flugge) sod. Pastures contained 1 of the following 3 seeding mixtures (2 pastures/mixture): 1) wheat (<it>Triticum aestivum</it> L.) and ryegrass (<it>Lolium multiflorum</it> Lam., <b>WRG</b>), 2) wheat and ryegrass plus red clover (<it>Trifolium pretense</it> L., <b>WRR</b>), or 3) wheat and ryegrass plus white (<it>Trifolium repens</it> L.) and crimson clovers (<it>Trifolium incarnatum</it> L., <b>WRW</b>). All groups had <it>ad libitum</it> access to grass hay (12% crude protein; 58% total digestible nutrients). The second week in December, cow estrous cycles were synchronized and artificially inseminated. In late December, a bull was placed with each group for 60-d. Data were analyzed with an analysis of variance using a mixed model containing treatment as the fixed effect and year as the random effect. Body weight and condition scores did not differ (<it>P</it> ≥ 0.27) among cows between February and June. Calf birth weights or average daily gain did not differ (<it>P</it> ≥ 0.17) among treatments; however, calves grazing pastures with clovers did tend (<it>P</it> = 0.06) to weigh more than calves grazing grass only. Weaning weight per cow exposed to a bull was greater (<it>P</it> = 0.02) for WRR and WRW than WRG. Cows grazing winter-annual pastures containing clovers tended to wean more calf body weight per cow exposed to a bull than cows grazing the grass only pastures.</p