Whole or ground millet grain provided in two supplementation frequencies for grazing beef cattle: nutritional parameters

Abstract

-The objective of this study was to evaluate the processing of millet grain provided at two supplementation frequencies for grazing beef cattle during the dry season on nutritional parameters. Five rumen-cannulated crossbred steers, with 24 to 26 months of age and average body weight of 428.6±26.06 kg, were assigned to a Latin square design (5 × 5) in a 2 × 2 + 1 factorial arrangement, as follows: two forms of millet grain (whole grains -or ground; WG -GG), two strategies of concentrate supplementation (daily distribution -7X; or three times a week -3X) and a control treatment (mineral mixture -MM). Animals were kept in five paddocks of 0.24 ha each with Marandu grass pastures. Concentrate supplements were supplied at 2.00 and 4.66 kg/animal/day for treatments 7X and 3X, respectively. The concentrate supplementation enhanced the intake of total dry matter (DM) and organic matter (OM) and nutrients compared with mineral supplementation. No differences were found between dry matter intake and forage organic matter intake. The values of digestibility coefficients of DM, OM, ether extract, total carbohydrates and non-fiber carbohydrates were increased by concentrate supplementation. Regarding concentrations of rumen ammonia nitrogen, the interactions among time × treatment × day and day × treatment had effects on the measurements of ruminal pH. Plasma urea nitrogen, urinary urea excretion and urinary urea N excretion differed only between MM treatment and the others, with no interference of grain physical form and supplementation frequency on those variables. The millet grain processing does not alter forage intake, but improves digestibility. Daily supplementation increases digestibility of dry matter and neutral detergent fiber.

Frequency of concentrate supplementation for grazing beef cattle

“…These results demonstrate the relationships between grazing time and pasture intake. In studies conducted in tropical conditions, authors also did not observe differences in the intake of pasture DM (MORAES et al, 2010, BENATTI et al, 2014MORAIS et al, 2014).…”

Supplementation strategies for grazing beef cattle during the rainy-dry transition period

“…The supply of concentrate supplements at a lower weekly frequency has resulted in similar nutrient digestibility to those found in animals supplemented daily (BENATTI et al, 2014;MORAES et al, 2010;PAULA et al, 2011;MORAIS et al, 2014).…”

“…Farmer et al (2004) suggested a few mechanisms that may play a role in lessening the impact of infrequent supplementation and minimize differences in performance of cattle. These mechanisms can maintain ruminal fermentation, especially the levels of rumen NH 3 , through an increase in N recycling in the gastrointestinal tract, thereby contributing to the maintenance of nutrient intake and digestion (BENATTI et al, 2014;MORAES et al, 2010;MORAIS et al, 2014) and animal performance (BENATTI et al, 2012;CANESIN et al, 2014;MORAIS et al, 2014).…”