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This study aimed to evaluate the influence of sodium monensin on the hepatic accumulation of copper in sheep. Twenty-four Santa Inês crossbred sheep were used and allocated in a 2 × 2 factorial experiment with six repetitions and considering the factors dietary copper (basal and high) and supplementation (with and without sodium monensin). Thus, four homogeneous groups were formed: control (basal diet); monensin (Mon), 30 ppm of monensin; copper (Cu), 10 10 mg/kg BW per day of copper; monensin + copper (MonCu). The experimental period lasted 14 weeks. Liver and bile samples were collected at the beginning and end of the experiment to determine mineral element concentrations, and weekly blood samples for biochemical, hematological, and mineral evaluation. Liver copper concentrations at the beginning of the experiment did not vary between groups, while mean liver copper concentrations at the end of the experiment were higher in the MonCu, Cu, and Mon groups when compared to the control. At the end of the study, hepatic copper concentration was influenced by copper (p = 0.0001) and monensin (p = 0.0003) supplementation. Copper-supplemented groups had reduced liver iron contents (p = 0.0287) and increased copper concentrations in bile. The biochemical evaluation showed increased serum GGT and AST activity (p 0.05) in the Cu and MonCu groups from the eleventh week on compared to the control and Mon groups. The increase in activity of these enzymes was influenced by copper supplementation (p = 0.0340). Monensin interferes positively with the hepatic accumulation of copper and the supplementation of this additive may predispose sheep to copper poisoning.

Background Acute ruminal lactic acidosis (ARLA) is a major nutritional and metabolic disorder usually characterized by excessive or non-adapted intake of diets rich in nonstructural carbohydrates. Feed additives that regulate the ruminal environment have been used to prevent ARLA, such as ionophores and, more recently, yeast culture. Thus, we aimed to compare the efficacy of a yeast-based culture (Saccharomyces cerevisiae) with that of monensin sodium in the prevention of ARLA in sheep. Eighteen male, crossbred, rumen-cannulated sheep were randomly distributed into three groups of six animals: control, yeast culture and monensin. Thirty days after the start of supplementation with yeast culture (4 × 109 cfu/animal/day of S. cerevisiae) and monensin (33 mg/kg of total dry matter intake), 15 g/kg BW of sucrose was administered directly into the rumen of the animals to induce ARLA. Samples of blood and ruminal fluid were collected at the following time points: at baseline (T0 h) immediately before the induction of ARLA; 6 h (T6 h); 12 h (T12 h); 18 h (T18 h); 24 h (T24 h); 36 h (T36 h); and 48 h (T48 h) after ARLA induction. Results Ruminal pH was higher in monensin group at T12 h and in yeast culture group at T36 h when compared to control group. Lower values of L-Lactate were found at yeast culture group at T24 h and T36 h. Monensin showed prophylactic effect by decreasing the rate of ruminal pH decline and occasionally reducing ruminal acidosis, whereas probiotics resulted in less accumulation of lactic acid in the rumen and a lower degree of systemic acidosis. Conclusion The use of yeast culture can be beneficial in the prevention and treatment of ARLA in sheep, because it can effectively reduce the accumulation of lactic acid, and thereby increase ruminal pH and reduce ruminal osmolarity. On the other hand, monensin showed prophylactic effect by decreasing the rate of ruminal pH decline and occasionally reducing ruminal acidosis, however, it did not directly prevent these conditions.

Background This study aimed to evaluate the clinical, haematological and biochemical responses to autologous blood transfusion and the feasibility of this practice in sheep. Thus, we used eight male, 8 months old sheep, weighing on average 30 kg, from which 15 mL/kg of whole blood was collected and stored in CPDA-1 bags. Blood samples were refrigerated for 8 days and subsequently re-infused. The clinical, haematological and biochemical parameters were evaluated before blood collection and reinfusion, after 10 minutes of collection and reinfusion, after 3, 6, 12, 24, 48, 96 and 192 hours after collection and reinfusion. Results With respect to clinical parameters, we observed a decrease in heart rate after 24, 48 and 196 hours from reinfusion compared to basal values (p p p p Conclusion Autologous transfusion in sheep slightly altered the physiological, biochemical and haematological responses of sheep, indicating that the technique proposed is safe and can be applied in the clinical practice of this species. The 8 d period was not sufficient for complete recovery of the haematological parameters after blood collection.