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Conference papers
Differences in digestibility between cows contribute to explain differences in feed efficiency
Abstract : Residual Feed Intake (RFI) is a feed efficiency (FE) trait phenotypically independent of body weight and level of production. It reflects inherent between-animal variations in biological determinants of FE. Among these determinants, differences in digestion have been suggested but it may rely on the type of diets used. We tested the hypothesis of a higher digestibility in more efficient cows (low RFI) regardless of the type of diets. The objective of this study was to determine the apparent digestibility of dry matter (DMd) of high (NDF=62%) and low fibre (NDF=39%) diets in simultaneously 2 RFI divergent groups of 8 non-pregnant non-lactating Charolais cows (RFI-: -0.73±0.59, 705±96 kg and RFI+: 1.02±0.34, 711±78 kg). RFI was measured when cows were heifers (21 months old) during 12 weeks on herb silage (cultivated fescue) diet distributed ad libitum. Four periods (P) of digestion trials were carried out successively using either high (100% hay, P1 and P2) or low fibre diet (maize silage/concentrate, 67/33, P3 and P4). Each period lasted 2-3 weeks ad libitum followed by 7 days of total faeces collection at 95% ad libitum. DMd was calculated using dry matter intake (DMI) and feacal dry matter excretion. The intra period individual range of variation of DMI and DMd were closed to 4 kg/d and 6 to 8 g/100 g for both diets respectively. Differences between RFI groups were significant for DMd (P=0.024) and not for DMI (P=0.27). RFI-cows presented higher DMd than RFI+ cows for diets (61.0±1.81% vs 60.0±2.1% for high-fibre diet and 69.6±1.96% vs 68.3±1.82% for low-fibre diet). This study showed that on average feed efficient cows (RFI-) had higher digestive efficiency than non-efficient cows (RFI+) regardless of the type of diets used.
https://hal.inrae.fr/hal-02744137
Contributor : Migration Prodinra Connect in order to contact the contributor
Submitted on : Wednesday, June 3, 2020 - 7:04:51 AM
Last modification on : Wednesday, January 26, 2022 - 11:22:09 AM
Contributor : Migration Prodinra Connect in order to contact the contributor
Submitted on : Wednesday, June 3, 2020 - 7:04:51 AM
Last modification on : Wednesday, January 26, 2022 - 11:22:09 AM
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