Longitudinal study of environmental effects for American Angus beef cattle over 30 years - INRAE - Institut national de recherche pour l’agriculture, l’alimentation et l’environnement Access content directly
Conference Papers Year : 2023

Longitudinal study of environmental effects for American Angus beef cattle over 30 years

B C D Cuyabano
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  • PersonId : 1321746
B O Makanjuola
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  • PersonId : 1151361
Cedric Gondro
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  • PersonId : 1016172

Abstract

Beef cattle production in the USA is mostly pasture-based, thus, animals spend most of their life outdoors. In such a vast country, herds are exposed to different degrees of climate variability across location, each potentially influencing animals’ performance differently. We analysed the trends of the American Angus population on birth weight (BW; ~6.7Mill records), weaning weight (WW; ~6.6Mill records), and post-weaning gain (PWG; ~3.4Mill records) over 30 years, and used historical records of climate variables to associate those trends with the climate variability in the locations of the herds. A single-step-multi-trait genetic evaluation was performed, with fixed contemporary group (CG) effect, maternal effect for BW and WW, and a permanent effect for WW. Using historical climate records from 1980-2020, we defined 5 classes of locations (LOC) in the USA, according to their frequency of higher than usual temperature-humidity-index (THI) during the breeding season. This classification of LOC was then assigned to the herds in our data through their GPS coordinates. From 1990, phenotypic and genetic trends were both decreasing for BW, and increasing for WW and PWG, with a smaller phenotypic slope observed after 2005 on WW and PWG. As for the effects obtained for CG (comprising climate+management), the trend was of decreasing effects over the years for all traits, while the variance of the CG increased during the same period. Interestingly, when studied per LOC, genetic trends were equivalent irrespective of LOC; phenotypic trends, although in the same direction for all LOC, presented lower values in LOC with more unusual THI events (LOC 4 and 5), and slopes of their trends were significantly different. CG effects were also consistently lower and with higher coefficient of variation in LOC 4 and 5 for all traits. From a population perspective, these results might suggest that, although genetic progress was equally achieved for herds in all LOC, in regions where unusually high THI events are becoming more frequent, management practices might not be sufficient to countervail the depressor effect of the climate on the animals’ performance.
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Dates and versions

hal-04331605 , version 1 (08-12-2023)

Identifiers

  • HAL Id : hal-04331605 , version 1

Cite

G. Rovere, B C D Cuyabano, B O Makanjuola, Cedric Gondro. Longitudinal study of environmental effects for American Angus beef cattle over 30 years. Book of Abstracts of the 74. Annual Meeting of the European Federation of Animal Science, EAAP, Aug 2023, Lyon, France. ⟨hal-04331605⟩
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