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

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 ± 4.5 kg and 94 ± 8.4 days 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 400 g/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 20 g/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.

Different physiological stages and breeding systems related to the variability of meat quality of indigenous Pantaneiro sheep.

This study configures a first report regarding the variability of meat quality of locally adapted Pantaneiro sheep depending on different physiological stages and breeding systems. Pantaneiro sheep are raised in Brazil under a tropical wetland ecosystem denominated Pantanal. Twenty-nine Pantaneiro sheep from different sex and physiological stages were sorted into three groups, simulating three of the most representative ovine meat products commercialized by South American industries: a) non castrated male lambs (n = 11); b) wethers (n = 9); c) cull ewes (n = 9). Animals from each physiological stage were submitted to different breeding systems, resembling farming strategies adopted in several developing countries of South America. The effect of physiological stages on the quality of meat was accessed using 16 variables measured in the longissimus thoracis et lumborum (LM) and the semimembranosus (SM) muscles. The variables were related to brightness, color, physical aspects, soluble and total collagen as well as chemical traits. The physiological stage was defined as a classification variable in order to proceed ANOVA tests and comparison of means (P<0.05). Multivariate analysis was used to identify patterns of similarity and differentiation between samples of different physiological stages (a, b, c). The results revealed that meat quality varies according to different physiological stages, especially between lambs (a) and cull ewes (c). As a consequence, the physiological stage at slaughter should be taken into consideration to cote the quality of meat from indigenous sheep raised in tropical regions. The results contribute towards sensorial evaluation and the characterization of potential food products derived from indigenous sheep bred under tropical climate in developing countries.