Intake and daily gain of grazing Nellore bulls receiving concentrated supplementation with additives

Abstract Text: The objective of this study was to evaluate the effect of a commercial concentrate supplement with additives in the intake and daily gain of grazing bulls, during the dry/rainy transition season in Aquidauana-MS, Brazil. Twelve Nellore bulls (initial body weight of 370±15 kg) were randomly assigned to twelve Brachiaria decumbensStapf pastures (1.0 ha/pasture; one bull/pasture) on a completely randomized design. Treatments were: 1) concentrate supplement Lipomax® with homeopathic additives (Convert H®, Sodo 100®, Figotonus®) and Virginiamicina® (Lipomax treatment), and 2) concentrate supplement with a similar protein content (18% CP), and without additives (Control treatment). Animals were feed daily at rate of 0.5% of the animal’s body weight. The animals were weighed (shrunk body weight) at beginning of the experiment and 104 d after, to evaluate the weight gain. After 45 days, a trial for estimated intake was made using the enriched and purified lignin (LIPE®) as marker for fecal excretion estimation, and the indigestible neutral detergent fiber as internal marker. Forage nutritive value was estimated by hand-plucked sampling, and supplement intake was measured directly for each animal. A significance level of 5% was adopted. The forage (DMfor), supplement (DMsuppl), total dry matter, crude protein and TDN intakes showed no difference (P>0.05) between treatments (Table 1). However, DMsuppl intake was 50% higher when using additives (Lipomax treatment) with similar quantity reduction on DMfor. The lack of significance, in this case, could be explained by the high coefficient of variation of DMsuppl. The average daily gain was higher (P<0.05) when using concentrate supplement with additives. In conclusion, additives in concentrate supplement increased the efficiency of nutrient use for grazing animals.

 

_{Table 1. Intake and daily gain of Nellore bulls grazing brachiaria grass receiving concentrated supplementation with or without additives}

Item, kg/d	Treatment		CV (%)	P-value
	Control	Lipomax®
	kg/d
DMfor1	8.418	7.988	15.1	0.561
DMsuppl2	0.844	1.269	51.0	0.205
DMtot3	9.261	9.258	12.7	0.996
CPint4	0.848	0.835	22.0	0.797
TDN5	6.374	6.134	16.3	0.746
ADG	0.811	1.107	19.2	0.028

_{¹DMfor is dry matter intake of pasture. ²DMsuppl is dry matter intake of supplement. ³DMtot is the total dry matter intake. ⁴CPint is crude protein intake. ⁵TDN is total digestible nutrients intake.}

_{Keywords: grazing bulls, intake, performance}