An interspecies hybrid in deer

Abstract

Interspecies hybridisation between Père David's ('Elaphurus davidianus', PD) and red ('Cervus elaphus', red) deer, generating fertile F₁ offspring of both sexes, presents a unique opportunity for the evaluation of backcross hybrids in the New Zealand deer industry and for the investigation of the genetic control of quantitative traits. Backcross hybrids (¼ Père David's / ¾ red deer) were used for both comparative studies with reds and in the search for quantitative trait loci (QTL) in deer. Comparative aspects of growth and of physiology and the genetic control of gestation length, growth and seasonality traits were examined. Evolution, speciation and the classification of species with particular reference to the deer family (Cervidae) are reviewed. The ability of Père David's and red deer to hybridise is discussed with reference to their taxonomic classification and genetic divergence. The uses of several mammalian hybrids are discussed including in particular the interspecies mouse hybrids which have been used extensively in the development of genome mapping and in genetic linkage studies. Patterns of food intake, growth, carcass composition and seasonality in backcross hybrids and red deer were examined and compared. Feed intake patterns and growth of hybrids and reds (both sexes) were recorded in a controlled environment; all genotype/sex groups displayed a sinusoidal fluctuation in feed intake similar to that in other seasonal species of deer. Marked differences in patterns of voluntary food intake were evident between hybrids and red deer with the differences between genotypes being more evident in males than in females. Based on the published performance of the pure bred species on a high quality diet, the growth rate of hybrid genotypes was below expectation while the reds performed very well. In addition the reds performed well compared with growth rates on pasture.