Comparisons of dairy breeds in the United States : Some fertility and longevity traits

ISBN-13: 9783639151411 / Angielski / Miękka / 2009 / 116 str.

Teresa Garcia-Peniche

Opis

Dairy breeds have been thoroughly studied withrespect to production and type traits, and theirperformance is acceptably well known. Besides, as aresult of genetic selection, production traits havegreatly increased through time. Contrastingly, scarceor even null improvement has occurred for otherimportant traits, sometimes called fitness traits,which include fertility and longevity. The dairyindustry is presently less concerned about productionand focusing more on improving, or at least,preserving, those traits. Fertility and Longevity arecomplex and low heritable and can be evaluated inseveral indirect ways. The general objective of theresearch was to compare the three most abundantbreeds in the United States for somefertility-related and longevity-related traits. Thiswork comprises two studies. The first one aimed toevaluate breed differences for heat-stressresistance, and the second one designed to compareand make inferences about survival-related traits,assessing breed by region interactions for sevenregions of the United States using linear andnonlinear models. This work should be of interest toanyone related to dairy science.

O autorze

Teresa B. Garcia-Peniche, PhD in Dairy Science: Studied at Virginia Polytechnic Institute and State University. Animal breeding scientist at National Institute of Agronomy, Forestry and Animal Science (INIFAP), Research Center La Posta, in Paso del Toro, VER. Mexico.