Advanced search
Start date
(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Beef cattle responses to pre-grazing sward height and low level of energy supplementation on tropical pastures

Full text
Dorea, Joao R. R. [1, 2] ; Gouvea, Vinicius N. [1, 3] ; Agostinho Neto, Luiz Roberto D. [1] ; Da Silva, Sila C. [1] ; Brink, Geoffrey E. [4] ; Pires, V, Alexandre ; Santos, Flavio A. P. [5]
Total Authors: 7
[1] Univ Sao Paulo, Luiz De Queiroz Coll Agr, Dept Anim Sci, BR-13418900 Piracicaba, SP - Brazil
[2] Univ Wisconsin, Dept Anim & Dairy Sci, Madison, WI 53706 - USA
[3] New Mexico State Univ, Clayton Livestock Res Ctr, Dept Anim & Range Sci, Clayton, NM 88415 - USA
[4] US Dairy Forage Res Ctr, Madison, WI 53706 - USA
[5] Pires, Alexandre, V, Univ Sao Paulo, Luiz de Queiroz Coll Agr, Dept Anim Sci, BR-13418900 Piracicaba, SP - Brazil
Total Affiliations: 5
Document type: Journal article
Source: JOURNAL OF ANIMAL SCIENCE; v. 98, n. 6 JUN 2020.
Web of Science Citations: 0

The objective of this study was to investigate the effects of energy supplementation and pre-grazing sward height on grazing behavior, nutrient intake, digestion, and metabolism of cattle in tropical pastures managed as a rotational grazing system. Eight rumen-cannulated Nellore steers (24 mo of age; 300 +/- 6.0 kg body weight {[}BW]) were used in a replicated 4 x 4 Latin square design. Treatments consisted of two levels of energy supplementation (0% {[}none] or 0.3% of BW of ground corn on an as-fed basis) and two pre-grazing sward heights (25 cm {[}defined by 95% light interception (LI)] or 35 cm {[}defined by >= 97.5% LI]) constituting four treatments. Steers grazed Marandu Palisadegrass {[}Brachiaria brizantha Stapf. cv. Marandu] and post-grazing sward height was 15 cm for all treatments. Forage dry matter intake (DMI) was increased (P = 0.01) when sward height was 25 cm (1.86% vs. 1.32% BW) and decreased (P = 0.04) when 0.3% BW supplement was fed (1.79% vs. 1.38% BW). Total and digestible DMI were not affected by energy supplementation (P = 0.57) but were increased when sward height was 25 cm (P = 0.01). Steers grazing the 25-cm sward height treatment spent less time grazing and more time resting, took fewer steps between feeding stations, and had a greater bite rate compared with 35-cm height treatment (P < 0.05). Energy supplementation reduced grazing time (P = 0.02) but did not affect any other grazing behavior parameter (P = 0.11). Energy supplementation increased (P < 0.01) diet dry matter digestibility but had no effect on crude protein and neutral detergent fiber digestibilities (P = 0.13). Compared with 35-cm pre-grazing sward height, steers at 25 cm presented lower rumen pH (6.39 vs. 6.52) and greater rumen ammonia nitrogen (11.22 vs. 9.77 mg/dL) and N retention (49.7% vs. 20.8%, P < 0.05). The pre-grazing sward height of 25 cm improved harvesting efficiency and energy intake by cattle, while feeding 0.3% of BW energy supplement did not increase the energy intake of cattle on tropical pasture under rotational grazing. (AU)

FAPESP's process: 11/13369-7 - Energy supplementation for beef steers grazing tropical grass (Brachiaria brizantha, cv Marandu) managed under rotational system with different initial sward heights
Grantee:João Ricardo Rebouças Dórea
Support type: Scholarships in Brazil - Doctorate