Red propolis extract as a natural ionophore for confined sheep: performance and morphological and histopathological changes.

This study aimed to evaluate the effect of increasing levels of red propolis extract (RPE) in the diet of confined sheep on performance and histomorphometric parameters of rumen and intestine and histopathological parameters of liver and kidney. Thirty-five male sheep (17.08 ± 2.36 kg) were used, distributed in a completely randomized design, with five treatments (0, 7, 14, 21, and 28 mL day-1 RPE) and seven replications, submitted to 68 days of experiment. At the end of the experimental period, the animals were euthanized, and samples of rumen, intestine, liver, and kidney were collected to histomorphometry and histopathology analyzes. Higher RPE inclusions (21 and 28 mL day-1) maintained dry matter intake and increased total weight (5.78 x 6.14 and 6.95 kg, respectively) gain up to 20.24%. In the rumen, the inclusion of RPE led to an increase in the thickness of the epithelium and the highest level also increased the thickness of the keratinized portion of this epithelium (21.71 x 32.15 µm). The level of 21 mL day-1 provided larger ruminal papillae (1620.68 x 1641.70 µm) and greater ruminal absorption area (561791.43 x 698288.50 µm2). In intestine 21 and 28 mL-1 of RPE provided greater mucosal thickness (468.54 x 556.20 and 534.64 µm), higher goblet cell index (23.32 x 25.82 and 25.64) and higher hepatic glycogen index (1.47 x 1.64 and 1.62), supporting higher nutrients absortion and glicogenolise and intestinal health, corroborating the weight gain indices. The inclusion of RPE did not cause renal histopathological lesions. Therefore, levels of 21 and 28 mL day-1 of RPE can be used in sheep diets, promoting greater final weight gain, causing positive histomorphological changes in the rumen, intestine and liver, without causing kidney or liver damage.

Intake, digestibility, ruminal parameters, and performance in lamb fed with increasing levels of red propolis extract.

The objective of this study was to examine the effect of increasing levels of red propolis extract (RPE) on the intake, digestibility, feeding behavior, rumen parameters, metabolic parameters, and performance of feedlot lambs. Thirty-five uncastrated male Santa Inês lambs with an initial weight of 17.08 ± 2.36 kg were used in a completely randomized design with five treatments (0, 7, 14, 21, or 28 mL RPE/animal/day). The animals were confined for 68 days. Red propolis extract induced a negative quadratic response (P < 0.05) in the intakes of dry matter, organic matter, crude protein, ether extract, neutral detergent fiber, non-fibrous carbohydrates, and metabolizable energy. The apparent digestibility coefficients of dry matter, organic matter, and neutral detergent fiber, as well as the rumen concentration of NH3-N, also responded quadratically (P < 0.05) to RPE. Feeding efficiency increased linearly (P < 0.05) with the inclusion of RPE, whereas rumination efficiency was maximum (P < 0.05) at the RPE level of 16 mL/day. Red propolis extract induced a linear response (P < 0.05) in serum total protein, albumin, creatinine, and gamma-glutamyl transpeptidase. There was a quadratic effect on final body weight and average daily gain with minimum values for inclusion of RPE of 12.89 mL/day and 10.93 mL/day respectively. Feed efficiency rose linearly (P < 0.05) with the increasing concentrations of RPE in the diet. The inclusion of 21 mL RPE/day (8.5 mg total flavonoids/mL) in the diet of feedlot lambs is recommended to reduce the rumen NH3-N production and increase the animals' performance.

Can roughage: concentrate ratio affect the action of red propolis extract on sheep metabolism?

The aim of the present study was to evaluate whether the addition of red propolis extract (RPE), in different roughage: concentrate (R:C) ratios, influences the intake, digestibility, ruminal parameters, and serum biochemistry of sheep. We used eight Santa Inês sheep with an average body weight of 29.45 ± 1.58 kg, housed in metabolism cages for 60 days, and distributed in two simultaneous Latin square designs in a 2 × 2 factorial scheme. The factors consisted of two R:C ratios (70:30 and 30:70) with or without the addition of 15 mL/day of RPE. No interactions were found (P > 0.05) between R:C ratios and with or without RPE. Sheep fed 30:70 ratio showed higher (P < 0.05) intake and dry matter (DM) digestibility and non-fibrous carbohydrates and lower (P < 0.05) intake and neutral detergent fiber (NDF) digestibility. The addition of RPE did not influence (P > 0.05) the intake or nutrients digestibility, but the sheep that received RPE had a higher (P < 0.05) ruminal pH and longer (P < 0.05) time of rumination (min/kg DM) compared to the group without propolis. The ruminal ammonia concentration was higher for sheep fed 70:30 ratio, but the concentrations of total protein and albumin did not differ between R:C ratios. The addition of 15 mL of RPE does not influence the intake, digestibility, ingestive behavior, and rumen ammonical nitrogen of sheep. There is no association between the R:C ratio and the addition of 15 mL/day of RPE for sheep.