Cactus cladodes cause intestinal damage, but improve sheep performance.

The objective of this study was to evaluate the effect of three varieties of cactus cladodes resistant to carmine cochineal on the animal performance and histology of the large intestine of sheep. Forty lambs (21.0 ± 2.0 kg body weight) were distributed in a completely randomized design, with four treatments and ten repetitions. The experimental treatments consisted of a control diet and three more diets in which part (750 g/kg) of the elephant grass hay, and all the corn were replaced by Miúda cactus cladodes, IPA-Sertânia cactus cladodes, or Orelha de Elefante Mexicana (O.E.M.) cactus cladodes. On the 60th day after the introduction of the tested diets, blood samples were collected to quantify serum magnesium (Mg2+) levels. After 63 days of experiment, the animals were slaughtered and fragments of the cecum and colon were collected for histopathological analysis. The inclusion of the Miúda and O.E.M. cactus cladodes in the diet caused inflammatory lesions in the cecum (100% of the animals) and in the colon (71.43% of the animals) of the sheep. The inflammation in the cecum caused by Miúda and O.E.M. cactus cladodes was considered accentuated (P = 0.009). Less voluntary water intake was observed for animals submitted to diets with cactus cladodes (P < 0.001), as well as higher water content in the feces (P < 0.001). The cactus cladodes, especially the Miúda and O.E.M. varieties, cause lesions in the tissue morphology of the cecum and colon of sheep, but improve productive performance.

Histomorphometric changes of the fore-stomach of lambs fed with diets containing spineless cactus genotypes resistant to Dactylopius sp.

The histomorphometric parameters of the fore-stomach epithelium of lambs fed with spineless cactus genotypes resistant to Dactylopius sp. were evaluated. Thirty-two lambs (23.0 ± 2.06 kg body weight) were distributed in a completely randomized design with four treatments and eight replications. The treatments consisted of the base diet and diets in which part of the elephant grass hay and all ground corn was replaced by the Miúda, IPA-Sertânia, or Orelha de Elefante Mexicana (OEM) spineless cacti. The keratin layers of the ruminal epithelium of the animals consuming the spineless cacti Miúda and OEM presented greater thickening relative to the control diet: 47.31, 41.30, and 25.81 µm, respectively. The heights of the ruminal papillae were higher in the animals that were fed with the OEM spineless cactus. The Miúda spineless cactus caused an enlargement in the keratinized layer of the reticulum epithelium, as well as a decrease in the thickness of the non-keratinized layers. The diet containing OEM spineless cactus resulted in greater thickening of the keratin layer of the omasal epithelium and decreased thickness of the non-keratinized layers. The spineless cacti Miúda and OEM changed the morphology of the fore-stomach epithelium and increased the dry matter intake and weight gain of lambs.