&lt;b&gt;Efficiency of the use of ryegrass by heifers in response to the receival of supplement

Laila Arruda Ribeiro,Mônique Foggiato Da Silva,Anelise Pereira Hundertmarck,Marta Gomes Da Rocha,Luciana Pötter,Maria José De Oliveira Sichonany

doi:10.4025/actascianimsci.v39i1.33235

<b>Efficiency of the use of ryegrass by heifers in response to the receival of supplement

Laila Arruda Ribeiro, Mônique Foggiato Da Silva + Show 4 more

Open Access

https://doi.org/10.4025/actascianimsci.v39i1.33235

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Abstract

The intensity and frequency of defoliation of ryegrass (Lolium multiflorum Lam.) by beef heifers exclusively grazing or receiving corn grain or extruded commercial product with fat as supplement were evaluated. The grazing method was put-and-take stocking. The experimental design was completely randomized following a repeated measure arrangement, three treatments and two area replications. The phyllochron of ryegrass was 140.1 and 303.4°GD the leaf lifespan. The intensity (67.0 %) and the frequency of defoliation (6.4 days) were similar, regardless of supply or no of energetic supplement for grazing heifers. The defoliation frequency indicates that the heifers can return about 3.3 times to the same tiller during the leaf lifespan. Considering the different categories of leaf blades, the supply of extruded fat causes the heifers to remove higher proportion (66.5 %) of expanding leaf blades. On ryegrass pasture, the efficiency of forage use is not modified when heifers receive energetic supplement.

Highlights

The grazing management of forage plants has great impact on sward structure (Gastal & Lemaire, 2015) and it is the key structure of forage intake process
The frequency of defoliation is directly related to the stocking rate used (Lemaire, Silva, Agnusdei, Wade & Hodgson, 2009)
Forage harvest efficiency is related to leaf lifespan and defoliation frequency

Summary

Introduction

The grazing management of forage plants has great impact on sward structure (Gastal & Lemaire, 2015) and it is the key structure of forage intake process. It is required the maintenance of photosynthetically active leaf area and, at the same time, the opportunity for animals to harvest large quantities of high quality leaf tissue, in order to maximize the conversion efficiency of the forage produced. This understanding is essential when new variables, such as supplementation of the grazing animals, influence the choice of what and how to harvest. This study was conducted aiming to characterize the grazing efficiency of beef heifers exclusively on ryegrass pasture or grazing and receiving supplement (corn grain or extruded commercial supplement with added fat)

Material and methods

Results and discussion

Conclusion