Abstract #W440

Section: Ruminant Nutrition
Session: Ruminant Nutrition: General III
Format: Poster
Day/Time: Wednesday 7:30 AM–9:30 AM
Location: Gatlin Ballroom

# W440
Nutrient intake of Nellore bulls in tropical pasture supplemented with crude glycerin and different sources of protein.
Antonio Jose Neto^*1, Joanis Tilemahos Zervoudakis², Pedro Veiga Rodrigues Paulino², Luciana Keiko Hatamoto-Zervoudakis², Renata Pereira da Silva-Marques², Luciano da Silva Cabral², Juliane Quenoizoré Soares², Everton Riva Donida², Felipe Cacite², ¹Department of Animal Science; São Paulo State University-UNESP, Jaboticabal, SP, Brazil, ²Department of Basic Sciences and Animal Production; Federal University of Mato Grosso-UFMT, Cuiabá, MT, Brazil.

This study was aimed to evaluate the effect of supplemental protein sources associated with glycerin on DM and nutrient intake of Nellore bulls in tropical pasture during the rainy season. Five Nellore bulls (448.2 ± 14.8 kg) were used in a 5 × 5 Latin square design (5 periods composed of 17 d and 5 treatments). The pastures were divided into 5 paddocks of 0.25 ha each, consisting of Brachiaria brizantha ‘Marandu’. All diets consisted of 15% of crude glycerin (DM) associated with protein sources: urea (GU), soybean meal (GS), cottonseed meal (GC), gluten (GG), and the control. Animals had a free access to mineral supplement. Animals were individually supplemented at the rate of 300 g·100 kg⁻¹ of BW, daily, at 1000 h. To estimate feed intake, chromium oxide was used as an external marker, and indigestible neutral detergent fiber (iNDF) was used as an internal marker to estimate forage intake. All data were analyzed using the MIXED procedure of SAS. Dry matter intake (% of BW) was higher (P < 0.01) when animals were supplemented with GU (Table 1). Forage intake was increased (P = 0.02) fed animals with GU supplements compared with other treatments. Supplement intake was similar (P = 0.89) among treatments. Feeding GU increased (P < 0.01) OM, CP, NDF and TDN intake of bulls. Crude protein intake were greater in bulls consuming supplements (P < 0.01) compared with control, which is logical due the lower content of CP in forage. Providing supplement with association of crude glycerin and urea for grazing cattle in the rainy season improved dry matter and nutrient intake. Crude glycerin can partially replace (15% of DM) energy source in ruminant diets. Table 1. Effect of supplemental nitrogen sources associated with glycerin on nutrients intake of Nellore bull in pasture

Item	Dietary treatments					SEM	P-value
Control	GU	GS	GC	GG
DM, intake
% of BW	1.68^c	2.24^a	1.98^b	2.01^b	1.94^b	0.08	<0.01
Forage, g/d	8,363^b	9,416^a	7,975^b	8,034^b	7,865^b	426.72	0.02
Supplement, g/d	0.00	1,832	1,862	1,858	1,854	15.73	0.89
OM, g/d	7,656^c	10,309^a	9,002^b	9,067^b	8,877^b	390.65	<0.01
NDF, g/d	5,565^b	6,870^a	5,872^b	5,861^b	5,830^b	283.91	<0.01
CP, g/d	754.4^c	1,402^a	1,292^b	1,293^b	1,268^b	38.51	<0.01
TDN, g/d	4,686^c	6,560^a	5,793^b	5,844^b	5,712^b	239.09	<0.01

Key Words: Brachiaria brizantha, glycerin, nutrient intake