The natural behavior of animals can be disrupted by the techniques and materials of research methodologies. This study aimed to evaluate the effect of the equipment used in the SF6 tracer technique to estimate enteric methane emissions on the behavior of lactating dairy cows. The cows (n = 24) were allocated to one of two diets: CONTROL and experimental diet (MIX). Behavior was assessed through video recordings between milking times during four phases: 3 days before fitting the cows with the SF6 equipment (PRE), first 2 days after the cows were fitted with the SF6 equipment (ADAP), 3 days during methane emission measurements (MEAS), and 2 days after the SF6 equipment removal (POST). The behaviors recorded included eating, ruminating or idling, resting, and others. Affiliative or agonistic and discomfort behaviors (scratching or pushing the equipment) were also recorded. Lying time was recorded over 14 days using dataloggers fitted to the cows' leg. Milk production and feed intake were recorded daily. MIX cows ruminated more than CONTROL cows (P = 0.05). The cows ruminated more at MEAS than in any other phase (P < 0.01). Time spent idling gradually decreased from PRE to MEAS for MIX cows (P < 0.01). The cows were lying down longer in MEAS than in ADAP and POST (P < 0.01). The time spent lying with the head down was shorter during PRE and ADAP than during POST (P < 0.05). No difference was observed in the occurrence of discomfort or agonistic behaviors (P > 0.05). Affiliative behaviors occurred more often in ADAP than in MEAS (P < 0.05). There was no difference between phases in daily lying time, number of lying bouts per day, or mean bout duration (P > 0.05). Milk production was not influenced by the SF6 equipment (P > 0.05). Dry matter intake was higher for CONTROL cows (P < 0.01), and it decreased from PRE to MEAS (P < 0.01). However, milk yield did not differ between cows wearing the SF6 equipment and those without it (P > 0.05). We conclude that the SF6 equipment had a minimal effect on dairy cow behavior.
Bibliographical noteFunding Information:
This study was funded by the National Commission for Scientific and Technological Research, CONICYT, Chile, through the Program FONDECYT, Grant Number 11160697, and the Program Support of International Networks for Researchers in Initial Stage 2017, Grant Number REDI170086. The authors thank the research funding agency Coordenação de Aperfeiçoamento de Pessoal de Nível Superior from Brazil (CAPES) for the post-graduate scholarships granted to FP. D-EH was sponsored by Rothamsted Research’s Institute Strategic Programme supported by the Biotechnology and Biological Sciences Research Council (BBS/E/C/000I0320).
© Copyright © 2021 Pereira, Teixeira, Boyle, Pinheiro Machado Filho, Williams and Enriquez-Hidalgo.
- cattle, enteric methane, milk production, lying duration, ruminating, habituation