Supplementation of feedlot lambs with cactus cladodes as strategy to improve testicular function.

The aim of this study was to evaluate the effects of diets containing cactus cladodes genotypes on plasma testosterone levels, testicular histopathological and histomorphometric parameters, and oxidative stress markers in lambs. Thirty-six male, intact Santa Inês lambs (22.0 ± 2.9 kg initial body weight), were to feedlot for 86 days. A completely randomized design was used with three dietary treatments (control diet with Tifton-85 hay as the only roughage; and two more diets with Miúda or OEM cactus cladodes partially replacing hay) and twelve replicates. There was no influence of the diets on the testicular weight (P = 0.414) and gonadosomatic index (P = 0.384) of lambs. The testosterone serum concentrations were almost twice as higher in lambs fed Miúda cactus cladodes compared to control treatment. There was greater incidence and severity of lesions in the testicular parenchyma of animals that received control diet: loosening of germ cell epithelium, germ cell desquamation and vacuolization of Sertoli cells. The seminiferous tubule diameter and height of the seminiferous epithelium were higher in lambs fed OEM cactus cladodes (P = 0.003). The tubular volume and Leydig cells volume were higher in animals fed with cactus cladodes (P < 0.05). The levels of malondialdehyde were higher in the lambs of control group compared to OEM group (P = 0.039) and the testicular concentration of nitric oxide was higher in control group (P = 0.009). The diet containing OEM cactus cladodes increased the levels of superoxide dismutase. Our results indicate that diets containing cactus cladodes promote antioxidant protection to the testicular parenchyma and preserve the spermatogenic process of lambs.

Dwarf and tall elephant grass silages: intake, nutrient digestibility, nitrogen balance, ruminal fermentation, and ingestive behavior in sheep.

The objective of this study was to evaluate the exclusive supply of dwarf or tall elephant grass silages, harvested at 60 days of growth, without wilting or the use of additives, on intake, apparent digestibility, nitrogen balance, rumen parameters, and ingestive behavior of sheep. Eight castrated male crossbred sheep (57.6 ± 5.25 kg body weight), fistulated in the rumen, were distributed in two 4 × 4 Latin squares with four treatments and eight animals per treatment and four periods. The treatments consisted of four elephant grass genotype silages (Mott, Taiwan A-146 2.37, IRI-381, or Elephant B). There was no effect of silages (P > 0.05) on dry matter, neutral detergent fiber, and total digestible nutrient intake. The dwarf-sized elephant grass silages provided higher crude protein intake (P = 0.047) and N intake (P = 0.047), while the IRI-381 genotype silage provided higher non-fibrous carbohydrate intake compared to Mott (P = 0.042), without differing from Taiwan A-146 2.37 and Elephant B silages. There were no differences (P > 0.05) among the digestibility coefficients of the evaluated silages. It was observed that silages produced with Mott and IRI-381 genotypes caused a slight decrease in ruminal pH (P = 0.013), and the propionic acid concentration was higher in the rumen fluid of the animals fed with Mott silage (P = 0.021). Therefore, dwarf or tall elephant grass silages, produced with cut genotypes at 60 days of growth and without the use of additives or wilting process, can be used in sheep feeding.

Sugarcane yeast with urea in replace of soybean meal in the diet of Murrah buffaloes does not cause metabolic, endocrine, and mineral disorders.

The aim of this study was to evaluate the effect of the replacement of soybean meal by increasing levels of sugarcane yeast and urea on the energy, enzymatic, protein, mineral, and hormonal profiles of buffalo heifers. Twenty Murrah heifers with an average body weight of 168 ± 2.0 kg and 1 year old were used in a completely randomized design. The treatments consisted of the replacement of soybean meal by increasing levels of sugarcane yeast and urea (0, 33, 67, and 100% dry matter). The animals were weighed at the beginning and end of the experimental period, and blood was collected on the final day. The replacement of soybean meal with sugarcane yeast influenced the performance and metabolic dynamics, with total weight gain (P = 0.005) and average daily gain (P = 0.015), presenting, for both variables, a quadratic effect. Considering the biochemical profile, there was an influence on the serum concentration of triglycerides (P = 0.055), the serum activities of aspartate aminotransferase, gamma-glutamyl transferase, and alkaline phosphatase (P < 0.05), in addition to the serum concentration of phosphorus (P = 0.007) and potassium (P = 0.053), which showed positive linear effects. The hormonal profile was not influenced by diets (P > 0.05). The elements copper, iron, and zinc were able to be quantified at all levels of sugarcane yeast and urea in the diets offered. The use of sugarcane yeast with urea promotes adequate metabolic response of buffalo heifers and can replace up to 100% of soybean meal in the concentrate.

Serum concentrations of folic acid and cobalamin and energy metabolism of ewes as a function of the energy density of the diet, peripartum period, and pregnancy toxemia.

The aim of this study was to determine the serum levels of folic acid, cobalamin, and indicators of energy metabolism during the peripartum period of ewes submitted to different diets and with or without pregnancy toxemia. Forty Santa Inês ewes were divided into three groups, a group of 20 animals fed only roughage-diet with low energy density (G1), a group of 10 ewes submitted to diet containing roughage and concentrate-diet with high energy density (G2), and a group of 10 ewes with diagnosis of pregnancy toxemia (PT) (G3). In the ewes of groups G1 and G2, blood samples were collected -30, -15, -7 days pre-partum, on the day of partum, and 7, 15, and 30 days postpartum; blood samples from G3 animals were collected during the veterinary clinic care. Significant variations were observed in the plasma concentration of glucose and serum folic acid, cobalamin, fructosamine, NEFA, and ß-hydroxybutyrate in the groups fed diets with different energy levels, with and without PT (P < 0.05). A positive correlation of folic acid and cobalamin was observed with plasma glucose and serum NEFA concentrations, in addition to negative correlation of glucose with NEFA and ß-hydroxybutyrate and positive correlation between the latter biomarkers of energy metabolism. The ewes diagnosed with PT showed higher levels of folic acid, NEFA, and ß-hydroxybutyrate (P < 0.05). Ewes fed diet containing roughage and concentrate present higher serum levels of folic acid, cobalamin, and glucose, in the pre-partum period and in the lactation period. The results obtained contribute to better understanding of the application of blood concentration tests for folic acid and cobalamin in the energy metabolism and in PT in ewes.

Kidney changes in lambs fed cactus pear varieties resistant to Dactylopius opuntiae as the only roughage.

This study aimed to evaluate the effects of four varieties of cactus pear resistant to carmine cochineal as exclusive roughage for lambs on the biochemical, histopathological, and histomorphometric parameters of kidneys. Twenty-four castrated male crossbred lambs at eight months of age and an initial body weight of 21.0 ± 0.5 kg were distributed in a completely randomized design, with four treatments and six repetitions. The experimental treatments consisted of four diets containing Miúda cactus pear, IPA-Sertânia cactus pear, IPA-F21 cactus pear, or Orelha de Elefante Mexicana (OEM) cactus pear as the only roughage. Blood samples were collected every two weeks (14 d, 28 d, 42 d, and 56 d) to quantify serum urea and creatinine levels. After 72 days of the introduction of the tested diets, the animals were slaughtered and fragments of the kidneys were collected for histological analysis. The serum urea level was higher in animals fed a diet based on the Miúda variety (49.38 mg dL-1), and the serum creatinine levels were lower in the last two collections (P = 0.009). The most frequent histopathological findings in the kidneys were calcification, congestion, glomerular atrophy, presence of luminal cellular debris, and nephrosis, regardless of the cactus pear variety. The Miúda cactus pear and OEM cactus pear varieties caused more severe damage to the nephron components, while the varieties IPA F-21 and IPA-Sertânia caused less significant injuries. The use of IPA-Sertânia and IPA F-21 cactus pear varieties is suggested in lamb's diets, due to the lower impact on the renal parenchyma. However, there was no expressive impairment of renal function, and there was no difference between the cactus pear varieties tested in this study on the weight gain of the animals, and they can all be used to feed feedlot sheep.

Diets containing cactus cladodes on serum and liver levels of microminerals in sheep and goats.

Two experiments were performed to evaluate the effects of partial replacement of Tifton hay by Miúda cactus cladodes (Nopalea) or Orelha de Elefante Mexicana (O.E.M.) cactus cladodes (Opuntia) on serum and liver concentrations of iron (Fe), copper (Cu), zinc (Zn), and manganese (Mn) in feedlot small ruminants. The experiment 1 (Exp. 1) lasted 86 days, and thirty-six male Santa Inês lambs (22.0 ± 2.9 kg initial body weight-IBW) were used. In experiment 2 (Exp. 2), lasting 100 days, thirty-six male goats of undefined breed (19.0 ± 2.8 kg IBW) were used. In both studies, the animals were distributed in a completely randomized design, with three treatments (diet control-without cactus; and diets with hay partially replaced by Miúda or O.E.M. cactus cladodes) and twelve replicates. Blood samples were collected to quantify serum micromineral levels, and at the end of the feedlot periods, sheep and goats were slaughtered and liver fragments were collected for micromineral dosage. In Exp. 1, lambs fed Nopalea cactus cladodes diet showed greater hepatic Cu accumulation (441.87 mg/kg DM; P = 0.027). The diets containing cactus cladodes tended to increase serum levels of Cu (P = 0.075) and Zn (P = 0.058). In Exp. 2, goats fed diet containing Opuntia cactus cladodes presented higher serum levels of Fe (P = 0.024) and Cu (P = 0.012). In conclusion, the partial replacement of Tifton hay by cactus cladodes increases hepatic concentrations of Cu in lambs and serum levels of Fe and Cu in goats.

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.