ObjectiveIsoquinoline Alkaloids, derived from one plant (Macleaya cordata) can be an alternative when it is desired to increase performance in feedlot cattle. However, results on these nutritional additives in high energy diets in ruminants are still incipient in literature. In this context, the objective of this study was to evaluate performance and carcass traits of feedlot bulls supplemented with sanguinarine, the main alkaloid presents in Macleaya cordata in high energy density diets.MethodsThirty-two crossbred Angus-Nelore bulls with mean initial body weight of 365±10 kg and mean initial age of 11±3 months were used. The experiment lasted 119 days, with 14 days of adaptation and 105 experimental days. Experimental diet consisted of 85% whole corn grains and 15% protein-vitamin-mineral nucleus and supplied ad libitum. Treatments consisted of a control diet (CON) and a diet with sanguinarine supplementation (SAN) at a dosage of 4 g of product sufficient to provide 6 mg of sanguinarine/d. Experimental design was completely randomized.ResultsDry matter intake, average daily gain and feed conversion were similar (p>0.05) between treatments. However, SAN group animals had higher carcass yield (p = 0.045) and were more efficient in the transformation of dry matter consumed in carcass gain (p = 0.046) than CON. In addition, haptoglobin, increased throughout feedlot duration meaning high challenge for the animals due to the diet, but this behavior was similar (p>0.05) between treatments.ConclusionSanguinarine produced positive results in relation to carcass yield and could be used as an additive for bulls fed diets receiving high energy density diet.

No abstract

Feedlot cattle under a high-grain diet and supplemented with isoquinolone alkaloids had their gastro intestinal lesions evaluated. The rumen and reticulum of the treated group showed a significant reduction in the epithelial hydropic degeneration scores and lamina propria inflammation All non-keratinized tissues, except for ileum, had a significant decrease in the total counting of inflammatory cells.

Evaluation of alveolar macrophage functions of cattle is an important tool in order to assess whether measures taken during the cattle husbandry can decrease the respiratory tract defense. The aim of this study was to determine whether dexamethasone used at therapeutic dose can affect the oxidative metabolism of alveolar macrophages of cattle. This was evaluated by two tests, the fluorometric and colorimetric. The similarity of the results was studied, using alveolar macrophages of six healthy cattle, obtained from bronchoalveolar lavage on a basal and an immunosuppressant moment after the application of dexamethasone. For the fluorometric test, alveolar macrophages were incubated with Staphylococcus aureus and 2’-7’dichlorohidroflurescein, and analyzed by flow cytometer. For the colorimetric test, alveolar macrophages were incubated with Phorbol 12- miristate-13 acetate and nitroblue tetrazolium, dissolved and analyzed in a spectrophotometer. It was noted that dexamethasone therapeutic dose (0.05 mg/kg) reduced the functions of alveolar macrophages from healthy bovine. This result was observed by both tests with the difference that the flow cytometry assay was more informative for identifying which specific cellular function has been compromised.

To enhance the productivity of beef cattle, it has been used increasingly diets based on grains, which although they provide more energy, alter the pH and ruminal microflora, resulting in a condition called subacute ruminal acidosis syndrome (SARA). Early diagnosis of this disease through analysis of ruminal pH, allows it to be established management interventions, preventing or minimizing the clinical signs. The most recommended technique for this analysis is the rumenocentesis, widely applied in dairy cattle, but little described in beef cattle. Therefore, the objective of this study was to determine whether this technique can be applied repeatedly in bulls subjected to high grain diet. The rumenocentesis was performed by percutaneous puncture at caudo ventral sac of 32 young bulls ½ Angus blood of approximately 350 kg and 11 months of age, in two stages, M0 when it was provided diet composed of roughage and concentrate and M1 composed of 100% concentrate diet. Were analyzed the facility to obtain ruminal fluid, its characteristics and local changes. In M0 was not observed local changes in any of the animals, and all animals in M1 had reactions from small subcutaneous nodules to larger abscesses than 20 cm in diameter. It is believed that complications after rumenocentesis occurred due to animal temper, a higher accumulation of fat in the puncture area and/or due to ruminal fluid characteristics caused by diet, which showed that the rumenocentesis technique devised for cattle milk was not suited to beef cattle subjected to high grain diets.