Abstract
A 2-yr study was conducted using a randomized complete block design to determine the effects of grazing AC Yellowhead alfalfa (ALF) and AC Mountainview sainfoin (SF) in binary mixtures with either Tom Russian wildrye or AC Success hybrid bromegrass (HBG) in late summer at Lanigan and Swift Current, SK. Forty-eight Angus steers (404 + 18 kg in yr 1; 400 + 16 kg in yr 2) at Swift Current SK and 64 Angus heifers (364 + 51 kg in yr 1) and 48 Angus steers (338 + 23 kg in yr 2) at Lanigan SK were randomly allocated to 1 of 4 replicated (n=4) pasture mixtures, (i) ALF-RWR; (ii) ALF-HBG; (iii) SF-RWR; and (iv) SF-HBG. Data were analyzed using Proc Mixed model of SAS. Average daily gain (ADG) of steers at Swift Current were similar (P = 0.19) for all pasture mixtures. At Lanigan, heifer ADG were similar (P = 0.09) for all pasture mixtures in yr 1 ranging 0.47 to 0.66 kg d-1. In yr 2, Lanigan steers grazing SF-RWR pasture had higher (P = 0.02) ADG (1.1 kg d-1) compared to ALF-HBG steers (0.64 kg d-1). Animal grazing days (AGD) (P = 0.26) and total beef production (TBP) (P = 0.59) at Lanigan were similar in both years, for all pasture mixtures ranging from 78 to 116 AU ha-1 AGD and 58 to 78 kg ha-1 TBP, respectively. However, at Swift Current in yr 2, AGD and TBP did differ (P = 0.01) with steers grazing ALF-HBG mixtures having greater AGD (121 vs. 74 AU ha-1) and TBP (120 vs. 67 kg ha-1) compared to steers grazing SF-RWR (74 AU ha-1) pasture. These results suggest that novel legume-grass pasture mixtures are suitable for late summer grazing to improve grazing beef cattle performance.
Keywords: beef cattle, grass-legume mixtures, summer grazing