Beef Steer Performance on Irrigated Monoculture Legume Pastures Compared with Grass- and Concentrate-Fed Steers

Pitcher, L.R.; MacAdam, J.W.; Ward, R.E.; Han, K.-J.; Griggs, T.C.; Dai, X.

Animals: An Open Access Journal from Mdpi 12(8)

2022


ISSN/ISBN: 2076-2615
PMID: 35454263
Accession: 079863476

Download citation:  
Text
  |  
BibTeX
  |  
RIS

Article/Abstract emailed within 1 workday
Payments are secure & encrypted
Powered by Stripe
Powered by PayPal

Abstract
Fall- or spring-born steers grazed monoculture irrigated birdsfoot trefoil (BFT; Lotus corniculatus L.) or cicer milkvetch (CMV; Astragalus cicer L.) pastures for approximately 12 weeks for 3 years and were compared with steers on concentrate diets. In the 3rd year, an irrigated meadow bromegrass (MBG; Bromus biebersteinii Roem. and Schult.) pasture treatment was added for further comparison. Steer average daily gain (ADG) was 1.31, 0.94, 0.83 and 0.69 kg d-1 on concentrate, 'Norcen' BFT, 'Oberhaunstadter' BFT, and 'Monarch' CMV diets, respectively; ADG on grass pastures was 0.43 kg d-1. The ADG on the concentrate diet was greater than ADG on legume or grass pastures, ADG was greater on BFT than CMV in every year (p < 0.03), and ADG on BFT was greater than ADG on grass (p < 0.03). The rate constant of gas production of an in vitro rumen fermentation demonstrated a slower rate of microbial digestion for CMV than for BFT. The elevated ADG on BFT pastures may be due to greater non-fiber carbohydrate (NFC) concentration and reduced neutral detergent fiber (NDF) concentration combined with condensed tannins that protect proteins in the rumen but do not impede protein digestion in the abomasum and intestines.