Effects of Inbreeding on Production and Survival in Jerseys

Abstract

Responses of registered Jersey cows to various levels of inbreeding were examined with pedigree data supplied by the American Jersey Cattle Association and test-day production data from 1970 through 1998 obtained from the Animal Breeding Center at Cornell University. Rate of increase in level of inbreeding is accelerating with time, making it more difficult for producers to make matings that avoid the potentially deleterious effects of inbreeding. Production losses caused by inbreeding were significant and curvilinear for all traits studied except somatic cell linear score, with the greatest losses at higher levels of inbreeding. Inbreeding was found to have the greatest effect on production at early ages and early in lactation. Early onset of the deleterious effects of inbreeding resulted in larger net present value losses than if effects of inbreeding occurred later in the life of an animal. Losses were probably enhanced because of the need to freshen animals as early as possible to maximize net present value returns. Survival decreased as level of inbreeding increased and was likely to have a greater negative impact on the financial health of the dairy enterprise than production losses.

Reproductive performance of Jersey and Fleckvieh × Jersey heifers and cows maintained on a pasture-based feeding system

“…A decreased survival rate of Jerseys has been observed as the level of inbreeding increased. Survival is likely to have a greater negative impact on the financial health of the dairy enterprise than production losses (Thompson et al, 2000).…”

Population genetic analysis of White Park Cattle in Germany

“…Certainly it can be supposed that the mean inbreeding as well as the mean relationship of them are much higher than indicated by means of only three generations of ancestors. To what extent inbreeding results in depression and threatens a population, is the topic of investigations mostly concerning foreign cattle populations (THOMPSON et al 2000a, b, BIFFANI et al 2002, CARAVIELLO et al 2003, CASSEL et al 2003a, b, UZMAY and AKBAS 2003. It was shown that inbreeding causes depression in all traits which are important for dairy breeding, such as constitution, fertility, and duration of use, which are the traits characterized by a low heritability.…”

Efecto de la edad al primer parto sobre parámetros productivos en vacas Jersey de Costa Rica.

“…Este resultado, es distinto de lo que menciona Thompson et al (2000), quienes reportan que altos índices de endogamia producen un deterioro marcado del rendimiento productivo, de alrededor de 0,5 y 1,5 kg menos de leche por día.…”