Identification of Factors That Cause Genotype by Environment Interaction Between Herds of Holstein Cattle in Seventeen Countries

Abstract

Currently, the International Bull Evaluation Service calculates international dairy sire evaluations using the multiple-trait across country evaluation procedure. This method depends implicitly on political boundaries between countries, because the input data are national evaluations from each participating country. Therefore, different countries are treated as different production environments. The goal of this study was to identify factors that describe the production system on each farm. Such factors could be used to group herds across countries for borderless genetic evaluations. First lactation milk records of Holstein cows calving between January 1, 1990 and December 31, 1997 in Australia, Austria, Belgium, Canada, Czech Republic, Estonia, Finland, Germany, Hungary, Ireland, Israel, Italy, The Netherlands, New Zealand, South Africa, Switzerland, and the USA were used in this study. Thirteen genetic, management, and climatic variables were considered as potential indicators of production environments: peak milk yield, persistency, herd size, age at first calving, seasonality of calving, standard deviation of milk yield, culling rate, days to peak yield, fat to protein ratio, sire PTA milk, percentage of North American Holstein genes, maximum monthly temperature, and annual rainfall. Herds were grouped into quintiles based on herd averages for each of these variables. Genetic correlations for lactation milk yield between quintiles were significantly less than one for maximum monthly temperature, sire PTA milk, percent North American Holstein genes, herd size, and peak milk yield. The variables can be used to group herds into similar production environments, regardless of country borders, for the purpose of accounting for genotype by environment interaction in international dairy sire evaluation.

Metabolic and hormonal acclimation to heat stress in domesticated ruminants

“…Carabano et al (1990) did not find a sire by region interaction for milk and fat yield and concluded that bulls with daughters in one region would not be expected to be significantly re-ranked on records of daughters in another region of the United States. Zwald et al (2003), exploring variables useful as an indicator of genotype by environment interaction, reported that bulls' daughters may perform differently in large v. small herds, or in herds with a hot climate v. herds with a cool climate. In a large study, reported that below a 72 THI, heritability for milk yield was 0.17 and additive variance for heat tolerance was 0.…”

Adaptation to climate change – exploring the potential of locally adapted breeds

“…Heat stress is an important factor in determining production environments already today (for dairy see Zwald et al, 2003). The high-output breeds that increasingly dominate global food production are usually not selected for heat stress resistance, but intensive systems are generally quite well able to protect animals from the local-scale effects of climate change; this may allow high-output breeds to be (2012) predict that due to competing demand, prices of food-feed crops are likely to increase more than the prices of livestock products, and land and water availability will become major constraints to the production of alternative ruminant feeds in intensive systems.…”

“…Heat stress is an important factor in determining production environments already today (for dairy see Zwald et al, 2003). The high-output breeds that increasingly dominate global food production are usually not selected for heat stress resistance, but intensive systems are generally quite well able to protect animals from the local-scale effects of climate change; this may allow high-output breeds to be retained.…”

“…Examples are provisions to alleviate the effects of high temperatures, including the use of cooling systems (shading or sprinkling to reduce excessive heat loads), adjusting the diet to reduce metabolic heat production, or modifications to diurnal practices such as night grazing (Gauly et al, 2013). Access to knowledge, technologies and to capital will determine the ability of producers to protect their herds from the physiological stress of climate change.Heat stress is an important factor in determining production environments already today (for dairy see Zwald et al, 2003). The high-output breeds that increasingly dominate global food production are usually not selected for heat stress resistance, but intensive systems are generally quite well able to protect animals from the local-scale effects of climate change; this may allow high-output breeds to be (2012) predict that due to competing demand, prices of food-feed crops are likely to increase more than the prices of livestock products, and land and water availability will become major constraints to the production of alternative ruminant feeds in intensive systems.…”

Efeitos do número de animais na matriz de parentesco sobre as estimativas de componentes de variância para produção de leite usando os métodos de Máxima Verossimilhança Restrita e Bayesiano

“…Entretanto, Weigel & Rekaya (2000), Jamrozik et al (2002) e Zwald et al (2003 estimaram valores de herdabilidade para produção de leite variando de 0,39 a 0,56. Segundo Zwald et al (2003), a superestimação da variância genética em rebanhos pequenos pode estar relacionada à falta de ajustamento da heterogeneidade da variância genética e leva a elevados valores de herdabilidade. Ressalta-se que neste trabalho os baixos valores de 2 p σ podem também ter inflacionado 2 a σ .…”