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Influence of Forage Inclusion Level on Growth Performance and Feeding Behavior in Finishing Steers
Forty-four steers (452 ± 4.6 kg) predominately of Angus and Simmental origin were used in a randomized block design to determine the effects of forage inclusion level on growth performance and feeding behavior in finishing steers. Steers were fed dry-rolled corn based diets which included a mixture of hay and corn silage as the forage source. Dietary treatments were 5%, 10%, 15%, or 20% forage. Diets were fed for 84 days. Feed intakes and feeding behavior were measured using the Insentec system. A visit was defined as each time the Insentec system detected a steer at a bunk. A meal was defined as eating periods which may include short breaks separated by intervals not longer than 7 min. Animals were weighed the first 2 days, then every 28 days after, and finally the last two days of the study. Steers were slaughtered with an average weight of 625 kg. There was a linear decrease (P ≤ 0.02) in DMI intake, ADG, and G:F as forage inclusion increased. Number of visits and meals per day and eating time per visit, per meal, and per day were not affected by forage inclusion. Feed DMI per visit did not differ between treatments but eating rate per meal decreased linearly (P < 0.001) with increasing forage inclusion. Eating rate (g/min) responded quadratically (P = 0.04) with the greatest eating rate observed in the 10% forage treatment. Hot carcass weight and dressing % decreased (P = 0.02) linearly as forage inclusion increased. These results indicate that a decrease in forage inclusion in a finishing diet will increase DMI, ADG, and G:F as well as increase DMI per meal.
Keywords:
forage, growth, behavior, finishing steers