Effect of frequency of supplementation of a soyhulls and corn gluten feed blend on hay intake and performance of growing steers

Feeding supplements less frequently can reduce labor costs and increase profitability. However reducing the frequency of delivery of grain based supplements can negatively affect fiber digestion in the rumen because more grain must be fed per feeding potentially causing decreased ruminal pH and/or an insufficiency of ruminal nitrogen. Using supplements that have a moderate crude protein (CP) level, and that are low in starch, might alleviate negative effects on fiber digestion and therefore decrease negative effects associated with supplementing energy supplements less frequently. Corn gluten feed and soybean hulls are high in metabolizable energy but low in fat and starch, and corn gluten feed is also a good source of ruminally degradable CP. The objective of this study was to determine effects of reducing supplementation frequency during a weekly cycle on steer performance when supplementing medium quality hay with a blend of soybean hulls and corn gluten feed (SH/CGF). The 86d feeding experiment was replicated over 4 years. Each year, 40 steers (BW=263±2.5, 281±2.5, 271±2.9, 229±2.9kg for years 1–4, respectively) were stratified by body weight and assigned to 8 groups which were randomly assigned to treatment. During years 1 and 2, treatments consisted of ad libitum medium quality fescue hay (70–100g/kg CP and 340–410g/kg acid detergent fiber) that was either not supplemented (HAY), supplemented daily (7X) with 2.73kg/hd, or supplemented on Monday, Wednesday and Friday (3X) with 6.36kg/hd. During years 3 and 4, an additional treatment was added in which steers were supplemented on Monday and Thursday with 9.55kg/hd of SH/CGF (2X). Average daily gain was higher (P<0.01) in supplemented steers compared to non-supplemented steers, but did not differ due to supplementation frequency. Hay intake was reduced (P<0.01) by supplementation and was higher (P<0.05) for 7X compared to both 3X and 2X, but hay intake did not differ between 3X and 2X. The gain to feed ratio was increased by supplementation (P<0.01) and was further increased by less frequent supplementation (P≤0.02). Results suggest that when supplementing medium quality hay with a blend of soyhulls and corn gluten feed, steers can be supplemented as little as twice a week without reducing performance.