Estimates of phenotypic and genetic parameters for ewe productivity traits of Lohi sheep in Pakistan

Abstract

The aims of the study were to investigate the fixed effects which are considered to influence ewe productivity and to estimate the genetic parameters for ewe productivity traits of Lohi sheep. Genetic parameters were estimated by restricted maximum likelihood (REML) procedure using the GENSTAT program. The effects of year and age of ewe were significant for fertility, litter size at birth (LSB), litter size at weaning (LSW), litter weight at birth (LWB) and litter weight at weaning (LWW). The least squares means of fertility, LSB, LSW, LWB and LWW were 0.904, 1.422, 1.358, 6.689 kg and 41.577 kg, respectively. The means of total number of lambs born (TLB), total number of lambs weaned (TLW), total birth weight of lambs (TWB) and total weight of lambs weaned (TWW) per ewe over four lambing opportunities were 5.48, 5.25, 25.61 kg and 162.47 kg, respectively. Estimates of heritability for fertility, LSB, LSW, LWB and LWW were 0.0250, 0.0533, 0.0430, 0.0462 and 0.0255, respectively; and estimates of repeatability for these traits were 0.1242, 0.0787, 0.0772, 0.0882 and 0.0715, respectively. The low estimates of heritability and repeatability obtained in the current study for ewe productivity traits indicate that selection based on the ewe's own performance may result in slow genetic improvement.

Genetic analysis of reproductive characteristics in Iran-Black sheep

“…There was a slight tendency for the productivity of ewes to improve with aging, especially reaching a maximum between four and six years of age. The significant effect age on maternal effects, nursing and maternal behavior of ewe were discussed by Nouman and Abrar (2013) and reproductive efficiency of ewes from six years old onwards may tend to decrease. Decreasing reproductive performance after approximately 5 parities can be explained by an increase in twinning rate and conception rate with age (Fourie & Heydenrych, 1983).…”

Molecular detection of Babesia ovis and blood parameters’ investigation reveal haematological and biochemical alterations in babesiosis infected Lohi sheep in Multan, Pakistan

“…Pathological changes can only be better assessed when normal blood values are available for comparison ( Njidda et al , 2014 ). The current study focused on “Lohi,” which is the largest and most productive sheep breed in Pakistan ( Nouman and Abrar, 2014 ); however, published references for frequently measured hematological and biochemical parameters for this breed are limited. Although considerable information is available on normal blood parameters of domestic animals, it is difficult to be convinced that the use of such reference intervals is consistent across breeds of sheep ( Lepherd et al , 2009 ) given that many genetic and nongenetic parameters, including breed, genotype, management system, drugs, nutrition, and climate, influence the hematology and serum biochemistry ( Onasanya et al , 2015 ).…”