Performance, nutritional behavior, and carcass characteristics of feedlot lambs fed diets with non-forage fiber source or sodium bicarbonate.

Abstract

The study was carried out to evaluate the effect of sodium bicarbonate (SB) supplementation in diets and compare its chemical effect with the fiber effect of soybean hulls on performance, nutritional behavior, and carcass characteristics of feedlot lambs. Twenty-eight ram lambs (Dorper × Santa Inês), with an initial body weight of 30.2 ± 4.5kg and 94 ± 8.4days old, were used. They were assigned to a randomized complete block design, defined by initial age and body weight. Experimental diets were positive control, diet containing soybean hulls in 400g/kg dry matter (DM) (CONT), and three diets based on ground flint corn containing 10 (10SB), 20 (20SB), or 30 (30SB) g/kg DM of SB. Among the SB levels, the buffer supplementation quadratically increased dry matter intake, average daily gain, feed efficiency, as well as increased final and slaughter body weight, which led to higher hot and cold carcass weights, loin muscle area, leg compacity index, and weight of neck, shoulder, rib, and leg cuts, with higher values for the 20SB. Feeding SB linearly decreased the area and height of the papillae. None of the animals presented liver abscess; however, two animals from 30SB and one from CONT had F-rumen lesions. The use of SB provided a similar animal performance when compared to the treatment containing soybean hulls. This shows that the chemical effect of the buffer was efficient and provided greater safety for this type of diet without causing damages to the rumen health. Among the SB levels, the best results were observed in the 20g/kg level (20SB), which shows that the buffer can be used as a strategy for diets with high inclusion of corn and no fiber source.