Comparison of camelina meal and DDGS in the diet of replacement beef heifers
The objective of this study was to evaluate the effect of supplementing beef heifers with either cold-pressed camelina meal or dried distillers grains with solubles (DDGS) for 75-d before breeding on weight gain and pregnancy rates. Heifers (n = 110) were blocked by weight (BW = 300 ± 1.1 kg) into 5 pens per treatment and assigned to 1 of 2 dietary treatments. Heifers fed camelina meal consumed an average of 5.3 kg/d millet hay, 0.7 kg/d camelina meal and 1.3 kg/d corn, whereas heifers fed DDGS consumed an average of 5.3 kg/d millet hay, 1.1 kg/d DDGS and 0.9 kg/d corn. Average nutrient composition of diets was 9.3% CP, 52.6% NDF and 29.5% ADF for the camelina diet and 9.6% CP, 54.7% NDF and 29.3% ADF for the DDGS diet. Supplements were placed in bunks each morning and millet hay fed after supplements had been consumed. Heifers were bred following a 5-day CO-Synch + CIDR® fixed time AI protocol and transported to pasture the next day. Fourteen days later, 3 clean-up bulls were placed in the pasture for 46 d. Pregnancy was determined by transrectal ultrasonography 96 d after AI. Weight and pregnancy data were analyzed using the GLM and GLIMMIX procedures of SAS, respectively. ADG (0.45 ± 0.08 kg/d; P = 0.2) and final BW (339 ± 1.26 kg; P = 0.97) did not differ between treatments during the 75-d treatment period. Similarly, no difference (P = 0.35) was detected for BCS (5.2 ± 0.04) at breeding between treatments. We noted no differences between treatments in conception to timed AI (P = 0.57) or in total pregnancy rate (P = 0.35). Our data suggests that camelina meal has the potential to serve as a feed resource for replacement heifers with no adverse effect on weight gain or pregnancy rates.
beef heifers, protein supplement, reproduction