Supplementation level increasing dry matter intake of beef cattle grazing low herbage height

Autor(es)

Barbero, Rondineli Pavezzi ^[1] ; Malheiros, Euclides Braga ^[2] ; Maria Aguilar, Natalia ^[3] ; Romanzini, Elieder Prates ^[4] ; Ferrari, Adriana Cristina ^[4] ; Nave, Renata La Guardia ^[5] ; Mullinks, John Travis ^[6] ; Reis, Ricardo Andrade ^[4]

Afiliação do(s) autor(es)

^[1] UFRRJ, Inst Zootecnia, Dept Prod Anim, BR-23897000 Seropedica, RJ - Brazil

^[2] Univ Estadual Paulista, UNESP, Fac Ciencias Agr & Vet, Dept Ciencias Exatas, Campus Jaboticabal, Jaboticabal - Brazil

^[3] INTA, Estn Expt Agr Colonia Benitez, Chaco - Argentina

^[4] Univ Estadual Paulista, UNESP, Fac Ciencias Agr & Vet, Dept Zootecnia, Campus Jaboticabal, Jaboticabal - Brazil

^[5] Univ Tennessee, Dept Plant Sci, Knoxville, TN - USA

^[6] Univ Nebraska, West Cent Res & Extens Ctr, North Platte, NE - USA

• Tipo de documento: Artigo Científico
• Fonte: JOURNAL OF APPLIED ANIMAL RESEARCH; v. 48, n. 1, p. 28-33, JAN 1 2020.
• Citações Web of Science: 0

Resumo

To evaluate the foraging behaviour of yearling bulls grazing on Marandu grass, we conducted two experiments. In the first experiment (Exp. 1), three grazing heights of 15, 25, and 35 cm were evaluated, with bulls receiving 0.3% of body weight (BW) of supplement (161 g kg(-1) crude protein (CP) and 20.1 MJ kg(-1) gross energy (GE)); in the second experiment (Exp. 2), supplementation levels were decreased as grazing height increased: (1) low height (15 cm) and high supplementation (0.6% BW: 142 g kg(-1) CP and 18.9 MJ kg(-1) GE (LH-HS)); (2) moderate height (25 cm) and moderate supplementation (0.3% BW: 161 g kg(-1) CP and 20.1 MJ kg(-1) GE (MH-MS)) or (3) high height (35 cm) without supplementation (HH-WS). Ingestive behaviour was evaluated by direct visual observations, and intake using markers. It was used 9 paddocks each experiment. The experimental design was completely randomized, analysing effects by polynomial orthogonal contrasts (Exp. 1) and Tukey test (Exp. 2). In Exp. 1, a linear decreasing response to daily grazing time (P < 0.01) was observed, whereas a linear increasing response to herbage intake (P < 0.01) was observed with increased grazing height. In Exp. 2, LH-HS bulls had lower herbage intake (P < 0.01) than their counterparts. Bulls from both experiments showed increased grazing activity after 12 PM (P < 0.05). The herbage intake substitution effect of supplements can be explored as a production strategy, as the adjustment of supplementation levels can promote high dry matter intake as well as performance in beef cattle, in conditions of low grazing height or low forage allowance, even with a high stocking rate. (AU)

• Processo FAPESP: 12/20264-0 - Impactos produtivos, ambientais e econômicos de estratégias de suplementação da dieta de bovinos de corte sob alturas de pastejo e estratégias de terminação
• Beneficiário: Ricardo Andrade Reis
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 12/14956-6 - Impactos produtivos, ambientais e econômicos de estratégias de suplementação da dieta de bovinos de corte sob alturas de pastejo e estratégias de terminação
• Beneficiário: Rondineli Pavezzi Barbero
• Modalidade de apoio: Bolsas no Brasil - Doutorado