Feed efficiency and enteric methane production of Nellore cattle in the feedlot and on pasture

Abstract

The objective of the present study was to assess the relationship between residual feed intake (RFI) evaluated in a feedlot-performance test and on pasture, and to determine the effect of feedlot RFI classification on enteric methane (CH4) production in the feedlot and on pasture. Seventy-three animals (25 with a low RFI, 24 with a medium RFI and 24 with a high RFI) classified in a feedlot performance test were subjected to performance testing on Brachiaria brizantha cv. Marandu pasture. Enteric CH4 was measured in a sample of these animals (n = 47, with high and low RFI) by the sulfur hexafluoride tracer-gas technique after the feedlot-performance test and during the performance test on pasture. In the feedlot-performance test, dry-matter intake (DMI) of low-RFI animals was 9.4% and 19.7% lower (P < 0.05) than that of medium- and high-RFI animals respectively. However, there was no difference in DMI and, consequently, in RFI on pasture among animals classified as low, medium and high RFI. Accordingly, there is evidence of re-ranking of animals for RFI performance tested in the feedlot after weaning and, subsequently, on pasture. During the period of enteric CH4 measurement in the feedlot and on pasture, the DMI, neutral detergent-fibre intake and gross-energy intake of low-RFI animals were lower than those of high-RFI animals, and low-RFI animals exhibited greater DM and neutral detergent fibre digestibility only in the feedlot. Enteric CH4 production did not differ between low- and high-RFI animals either in the feedlot (101 and 107 g CH4/day) or on pasture (101 and 95.9 g CH4/day). A significant difference in CH4 yield (CH4/kg DMI) was observed on pasture between animals with low and high RFI (17.6 and 13.7 g CH4/kg DMI respectively). The results did not support the hypothesis that an increase in feed efficiency, evaluated in growing animals in feedlot-performance tests, decreases enteric CH4 production (g/day) proportionally to the lower DMI.

Methane and Carbon Dioxide Emission of Beef Heifers in Relation with Growth and Feed Efficiency

“…In the review of Richardson and Herd [41], digestibility was assumed to account for 10% of the variation in RFI on average in beef cattle, while Lovendahl et al [42], in their review of dairy cattle, concluded that between-cow variation in digestibility alone was too small to explain the observed variation in feed efficiency. Nonetheless, higher digestibility of DM or NDF was found in low-RFI as compared to high-RFI cattle in the studies of McDonnell et al [15] and Oliveira et al [17] with beef cattle and Olijhoek et al [43] with dairy Holstein cows. On the other hand, no significant difference was observed in the studies of Nkrumah et al [7], Fitzsimons et al [12] and Fitzsimons et al [44] with beef cattle and Olijhoek et al [43] with dairy Jersey cows and Fischer et al [45] with dairy Holstein cows.…”

“…However, the methane yield was significantly higher [p < 0.001] in the low-RFI (25.1 g/kg DMI) compared to the high-RFI (22.8 g/kg DMI) group. In a second study with Nellore cattle, Oliveira et al [17] observed no difference in the CH 4 measured with the SF6 technic between 25 low-RFI and 22 high-RFI animals selected among 159 male and female yearling Nellore animals when tested in a feedlot then at pasture. Methane yield, when measured in feedlot, was not different between low-and high-RFI animals.…”

“…On the other hand, no significant difference was observed in the studies of Nkrumah et al [7], Fitzsimons et al [12] and Fitzsimons et al [44] with beef cattle and Olijhoek et al [43] with dairy Jersey cows and Fischer et al [45] with dairy Holstein cows. Interestingly, a higher digestibility and a higher methane yield were observed in low-RFI beef heifers tested with three different diets by McDonnell et al [15] and in low-RFI beef Nellore tested in feedlot by Oliveira et al [17].…”

“…Based on first results [7,8], Waghorn and Hegarthy [9] and Basarab et al [10] stated that selecting individuals with a low residual feed intake (RFI) would reduce methane production as a direct consequence of a reduction of feed intake. The results on the reduction of methane yield are more conflicting [11][12][13][14][15][16][17]. There is a need of new experiments to verify if low RFI beef cattle are actually low methane emitters before implementing breeding programs.…”

Review: Biological determinants of between-animal variation in feed efficiency of growing beef cattle

“…Most of the aforementioned research involved cattle in confinement, usually offered energy-dense diets, where individual animal intake and associated behaviour was relatively easily determined using automated feeding systems coupled with electronic animal identification sensors. In contrast, there is comparatively little published information pertaining to feed efficiency in grazing beef cattle despite the fact that the majority of beef production systems worldwide are largely based on pasture (Lawrence et al, 2012;Manafiazar et al, 2015;Oliveira et al, 2016). This is not surprising considering how challenging it is to accurately obtain equivalent measurements with individual animals grazing pasture (Lawrence et al, 2012).…”