Optimizing the use of spineless cactus in the finishing diet of lambs: physicochemical properties and sensory characteristics of meat.

BACKGROUND: The use of spineless cactus in finishing diets for lambs improves the carcass quality. However, data about its influence on meat traits is very scarce. The effects of spineless cactus inclusion in the finishing diet of lambs at four levels (0, 150, 300 and 450 g kg-1 of dry matter, DM) in replacement of Tifton hay on the physicochemical and sensory properties of meat were studied. RESULTS: The spineless cactus modified the chemical composition increasing the protein (P < 0.001) and the fat (P < 0.01) contents of meat, presenting the greatest values in lambs fed diets with 150 and 300 g kg-1 (DM) replacing levels, respectively. However, the spineless cactus did not influence the growth performance from 23.7 to 37.3 kg of body weight (on average). In addition, colour parameters of the meat were not affected by the inclusion of spineless cactus in the finishing diet of lambs, resulting in mean values of 37.55, 14.96 and 8.49 for lightness, redness and yellowness, respectively. There were no statistical differences among treatments for cooking loss and shear force, with mean values of 34.8% and 14.8 N, respectively. Finally, the sensorial properties were not affected by the inclusion of spineless cactus in the finishing diet of lambs. CONCLUSION: Spineless cactus could be included up to the level of 300 g kg-1 DM in the finishing diets of lambs to increase the fat content of meat without compromising its sensorial properties. However, further studies about the fatty acid composition of meat from lambs fed diets containing spineless cactus are necessary. © 2019 Society of Chemical Industry.

Ruminal and morphometric parameters of the rumen and intestines of sheep fed with increasing levels of spineless cactus (Nopalea cochenillifera Salm-Dyck).

The objective of this study was to evaluate the ruminal parameters (pH, N-NH3, and microbial protein) and morphometry of the rumen and intestine of sheep fed with a diet containing four different levels of the spineless cactus variety, Baiana. The experiment was conducted at the National Semi-Arid Institute in Campina Grande, PB, Brazil. A total of 40 male sheep submitted to the confinement regime were used in a completely randomized design with four treatments (0, 15, 30, and 45% dry matter basis) and ten replicates, with an initial body weight of 23.7 ± 3.08 kg. Experimental diets were composed of ground corn, soybean meal, urea, mineral supplement, limestone, Tifton 85 hay, and spineless cactus of the Baiana variety. The pH, ammonia nitrogen, and microbial protein were evaluated in the ruminal fluid, alongside the morphometric characteristics of the rumen and intestine. While the addition of the spineless cactus did not affect N-NH3, it caused a linear reduction in the ruminal pH following 4 h of feeding, and also increased the microbial protein. In addition, it stimulated a reduction in the height of the papillae and the muscle layer of the rumen, and induced the mucosal height in the intestine to increase. The addition of up to 30% of spineless cactus in the diet of sheep without a defined breed did not alter the N-NH3, pH, and ruminal histology, but it did increase the production of microbial protein and intestinal mucosa.