Effect of a low lignin hull, high oil groat oat on beef cattle growth, carcass quality and nutrient utilization

Abstract

A series of experiments were conducted to investigate the nutritional value of a new oat variety developed by the Crop Development Centre at the University of Saskatchewan. Trials 1 and 2 evaluated performance of steers fed a low lignin hull, high oil groat (LLH-HOG) oat as a replacement for barley or corn. In trial 1, 400 steers were fed one of two diets with barley or the LLH-HOG oat at 37.8% of the diet DM. Dry matter intake was lower (P=0.02) and gain to feed improved (P0.01) for steers fed the oat-based diet. In trial 2, 240 steers were finished diets with barley, corn or the LLH-HOG oat at 88.2% of the finishing diet (DM). During finishing, steers on the oat diet had lower (P0.01) ADG, body and carcass (P<0.01) weights than barley or corn-fed cattle reflecting lower (P0.01) DMI. In trial 3, 20 steers were fed one of seven diets consisting of barley silage and 0, 28, 56, or 84% LLH-HOG oat or barley grain (DM basis) to compare nutrient digestibility. Apparent DM, OM, ADF and NDF digestibility coefficients were lower (P<0.05) for LLH-HOG oat-based diets compared to barley-based diets. Apparent CP and EE digestibility coefficients were higher (P<0.05) for the LLH-HOG oat diets. Trial 4 was conducted to assess ruminal fermentation differences between LLH-HOG oat- or barley-based finishing diets using four rumen cannulated steers. No diet effects (P>0.05) were observed for total ruminal VFA concentration or molar proportions of individual VFA however mean ruminal pH was lower (P=0.01) for steers fed the LLH-HOG oat-finishing diet. Further, the extent of pH decline in oat-fed cattle was greater (P<0.01) than for barley-fed cattle. The results indicate that the energy value of the LLH-HOG oat is equivalent or superior to that of barley for growing cattle. However, further research is required to identify factors limiting feed intake of cattle fed this new oat type in finishing diets.