Study on Population Dynamics and Effects of Inbreeding on Performance Traits in Indian Murrah Buffalo

Abstract

Background: A population is continuously facing the changing environment and its directly influencing the production of animal so to adopt these changes population must be flexible and have sufficient variability to overcome the adverse affects of environment. The evaluation of animals in terms of production performance traits along with impact of inbreeding coefficient is essential to formulate breeding and selection strategies for higher genetic improvement. Methods: Genealogy data of 6429 animals maintained at ICAR-NDRI, Karnal, India was analyzed by web-based POPREP application tool (http:// poprep.tzv.fal.de) and ENDOG V5.8 used to study the population structure and genetic diversity and regression model to study the effect of inbreeding on first lactation productive traits in Murrah buffaloes. Result: The result indicated that 91.91% of the individuals had known pedigree. The maximum generation traced was 13 with mean, full and equivalent complete generation as 5.93, 1.67 and 3.25 respectively. The average generation interval was 8.28 years and longer for the sire-son pathway and 2.16% was average inbreeding in whole population. The average genetic diversity loss was 2.10% indicated that the population has been stable with sufficient diversity. The study also revealed non significant effect of inbreeding on all first lactation traits. The low inbreeding was firstly due to introduction of new genetic variant and culling of animals avoiding mating of related ones and secondly due to incompleteness of pedigree in earlier years. This can be used as a base line information of phenomic needs to be generated before applying genomics tools in particular herd to be used as reference population in future for genomic selection.

Comparative assessment of the effective population size and linkage disequilibrium of Karan Fries cattle revealed viable population dynamics

“…Considering the generation interval of 5 years, they originated 16 to 18 generations ago. A similar drop of N e for KF was found around 5 to 7 generations ago, which corre-sponded to earlier reports of the development of KF cattle 6 generations ago through genealogical analysis [4]. Martinez et al [42] was also able to determine the time over which different strains of Salmon were established, which corresponded to the most likely generation when the breeding program was started.…”

“…The breed has since been maintained at this level of exotic inheritance by selective breeding. Presently, the sixth generation of KF cattle has been maintained in the Livestock Research Complex of ICAR-National Dairy Research Institute, Karnal, India [4].…”

“…The decline in genetic variation poses a significant threat to the sustainability of these cattle breeds [6]. An earlier genealogical study utilizing pedigree data of KF cattle has shown few alarming results, with the individual cow having a high inbreeding coefficient of 31.25% in the herd [4]. This situation necessitated a thorough study for robust analysis of the population diversity in KF cattle using high-throughput genomic data.…”