Introduction1 Kermani sheep is one of the native dual purpose breeds that adapted with Kerman province’ s climate conditions. Body weight traits for sheep meat producers are very important, therefore precise evaluation of genetic factors for these traits have always been concern of breeders. Regarding to importance of meat production in economic benefit of sheep farming, this research was done with goal of genetic parameters estimation for daily gain and KLEIBER RATIOs in Kermani sheep. Materials and Methods This research was done by using pedigree information form 10988 Kermani sheep between 1983 to 2010 that was collected by Kermani sheep breeding station located in Shahr-e-Babak city of Kerman province, for genetic analysis of growth traits. Studied traits were average daily gain from birth to form weaning (ADG1), form weaning to 6 months (ADG2), form 6 months to 9 months (ADG3), form 9 months to 1 yearling (ADG4) and KLEIBER RATIOs corresponding to the respective daily weight gain (KR1, KR2, KR3 and KR4). For data prepaRATIOn and edition, pedigree analysis and genetic analysis of studied traits Excel, Fox Pro, CFC and Wombat Softwares were used respectively. Test of significance for the fixed effects on studied traits was done by GLM procedure of SAS 9. 2 Software and significant level of p<0. 05 was considered for fitting fixed effects in final model. Combined effect of HYS (23 herds), lamb sex and dam age at lambing was significant for all of studied traits. Genetic analysis of traits was performed of restricted maximum likelihood method by using of Wombat and most appropriate model according to Akaike’ s information criterion was selected. Results and Discussion In this research the records number of growth traits decreased by age due to culling of some of lambs or not registering of records in higher ages. The average daily gain of pre-weaning was calculated 231. 77 gr and this trait for post-weaning periods had down trend that was complied with reported results in similar studies. Average of ADG1 in this research rather than reported amounts by other researches was more that represented high capacity of growth in Kermani lambs. The Average of ADG2, ADG3, ADG4, KR1, KR2, KR3 and KR4 were estimated 109. 98, 40. 78, 38. 06, 19. 86, 13. 13, 7. 63 and 3. 30 gr respectively. The various climate conditions like raining content and environment temperature affects the quality and quantity of forage that resulted in significant changes at available nutrients amount of animal and supply of requirements and consequence of it the daily gain of lambs at different ages. Male lambs in all of traits compare with female lambs were more that showed that effect of sex on Kermani sheep lambs. The average of single lambs was more than twin lambs. The effect of dam age at lambing was significant on all of studied traits. The direct heritability for ADG1, ADG2, ADG3, ADG4, KR1, KR2, KR3 and KR4 were calculated 0. 14, 0. 15, 0. 16, 0. 16, 0. 17, 0. 19, 0. 20 and 0. 23 respectively. Although direct heritability of ADG1 was low, but by increasing of age the amount of direct heritability for traits increased that may be caused to the reducing effect of maternal effect on studied traits with increasing age. The total heritability for ADG1, ADG2, ADG3, ADG4, KR1, KR2, KR3 and KR4 were estimated 0. 19, 0. 20, 0. 19, 0. 16, 0. 21, 0. 19, 0. 23 and 0. 23 respectively. The covariance for ADG3 was estimated negative that shows negative presence of maternal genetic effects in this traits heritability and selection response. The genetic correlations between ADG1-KR1, ADG2-KR2, ADG3-KR3 and ADG4-KR4 were estimated 0. 57, 0. 74, 0. 68 and 0. 54 respectively. The phenotypic correlation between ADG1-KR1, ADG2-KR2, ADG3-KR3 and ADG4-KR4 were 0. 84, 0. 89, 0. 88 and 0. 98 respectively. It seems that selection for KLEIBER RATIO in each period resulted in increasing daily gain at that period too. Therefore, by selection according to KLEIBER RATIO, the average of food efficiency will increase. Between environmental correlation of studied traits with direct correlation of them showed that the difference among them was low in most of cases. Thus, regarding to available information it seems that the univariate model was more appropriate in genetic evaluation of studied traits. Conclusion The results of this research showed that selection according to KLEIBER RATIO in Kermani sheep can increase the efficiency of feed intake. More than this, the KLEIBER RATIO has this advantage that at calculating, starter and finisher weights of period which estimation of them are simple.

Introduction: Along with increase in genetic progress, maintaining genetic diversity in any population is very important to adapt with the economic and environmental changes in the future and ensure long-term response to selection for traits that are very important. Intensive use of a few breeding animals, where the selection intensity is high, could result in greater rates of inbreeding in the population. …

Feed efficiency is one of the most important traits in the meat producing animals including sheep.This trait can only be assessed through individual measurement of the feed consumption for each animal, which is very troblesome and costly. A measure which seems to be correlated with feed efficiency is KLEIBER RATIO, defind as the RATIO of average daily gain over metabolic body weigh at the end of the underlying period. This study examined KLEIBER RATIO as an indirect selection criterion in order to improve the feed efficiency for the Kurdish sheep. A fattenning trial, for 15 weeks and in individual boxes, was conducted on 65 Kurdish lambs. During the experimental period Growth traits (including: birth weight, weaning weight, initial and final weights) and feed consumption were recorded. The correlation between the KLEIBER RATIO with average daily gain and feed efficiency were 0.88 and 0.85 respectively, which are high enough to support the idea of including the Kliber RATIO in selection criteria. The phenotypic correlation between KLEIBER RATIO with birth weight, weaning weight and initial and final weights were -0.141, -0.143, -0.458 and 0.163, respectively, which are relatively low.

BACKGROUND: Estimation of genetic parameters of economic important traits are necessary for determining breeding goal and selection index. OBJECTIVES: In present study, the genetic parameters of average daily gain from birth to weaning (ADGa), from weaning to 6 month of age (ADGb) and from 6 to 9 month of age (ADGc) and KLEIBER RATIO at weaning (KRa), at 6 month of age (KRb) and at 9 month of age (KRc) were estimated. METHODS: The data set included 12701 records of rural flocks under supervision of Ghezel sheep breeding station located in Western Azerbaijan province and collected over the period from 1994 to 2009 were analysed by Restricted Maximum Likelihood (REML) procedure using WOMBAT software. RESULTS: Fixed effect of Herd - year of birth (HY) was significant on all traits. Effect of sex was significant on all traits except for KRa and effect of litter size was significant for all traits except for KRb. Effect of dam age was significant on ADGc, KRb, only. Model 1 (contains direct additive genetic effect) was the best model for ADGc and KRc and model 7 (contains direct additive genetic and maternal common environmental effects) was the best model for the other traits. Direct heritability of the ADGa, ADGb, ADGc, KRa, KRb and KRc based on the best model were 0.27, 0.18, 0.14, 0.22, 0.13 and 0.16, respectively. The proportion of maternal common environmental variance to phenotypic variance (c2) for ADGa, ADGb, KRa and KRb were 0.52, 0.16, 0.52 and 0.19, respectively. CONCLUSIONS: Direct heritability of Average Daily Gain and KLEIBER RATIO in studied rural flocks were moderate. Therefore selection specially based on KRa will be effective for these traits. Moreover, including maternal common environmental effect in animal models for accurate estimation of direct heritability in this breed is recommendable.

Objective: Estimation of genetic parameters for KLEIBER RATIO (KR) and genetic trends for pre-weaning weights of Arabi sheep has not been previously conducted.Methods: Data and pedigree information were collected at the Khuzestan Ramin Agricultural and Natural Resources University, Animal Science Research Station, located in southwest Iran, from 2001 to 2008. (Co)variance components and corresponding genetic parameters were estimated using the restricted maximum likelihood procedure by excluding or including maternal genetic or maternal permanent environmental effects. Six animal models were fitted to optimise the model KR from birth to weaning, which is defined as the RATIO of growth rate and metabolic rate and can be utilized as an indirect selection for feed conversion. Moreover, three-trait analyses were performed using the most appropriate models obtained in single-trait analyses on the basis of Akaike’s information criterion.Results: Direct heritability (h2d) estimate of 0.11 was obtained and maternal permanent environmental effects (pe2) contributed 10% of the total phenotypic variation for KR. Genetic trends for weight at birth and weaning were obtained by regression of average breeding values, on birth year. Direct genetic trends were positive and significant (p<0.05) for weight at birth and weaning (6 and 24 g per year, respectively). Genetic correlations among traits ranged from -0.52 to 0.89 and phenotypic correlations from -0.21 to 0. 0.71. Results showed the importance of inclusion of maternal permanent environmental effects in designing appropriate breeding programs to obtain accurate estimates of genetic parameters, and it is sounded that KR is a recommended option in selection program.

A pedigree file consisting of 5860 individuals, 167 sires and 1582 dams collected at Makooei sheep breeding station (MSBS) during a period of 24 years (1990 to 2013) was used to calculate the inbreeding coefficients to reveal any probable effects of inbreeding (F) on the studied traits. The studied traits were classified to the five main groups including body weight, KLEIBER RATIO, body measurements, greasy fleece weight and reproductive traits. The inbreeding coefficient among the individuals ranged from 0 to 25% with an average of 0.33%, and ranged from 0 to 25% among the ewes with an average of 0.21%. Fluctuations in individual and maternal inbreeding were observed in the period under study. The average geneRATIOn interval was calculated as 3.6 years. The effective population size of the flock was 51.8 animals. The rate of inbreeding was 0.08% per year and 0.53% per geneRATIOn. Six different models were applied and likelihood RATIO test (LRT) was used to select the appropriate model. Based on the LRT, model II was selected as appropriate model for growth, greasy fleece weight at 6 months of age and KLEIBER RATIO traits. The traits related to the live body weight were affected negatively (P<0.001) by the quadratic individual F. The linear individual regression coefficient of the KLEIBER RATIO was estimated significantly (P<0.01) as 0.001, as well the linear maternal inbreeding regression was estimated significantly (P<0.05) as 0.0002. In general, body measurements were affected negatively by the quadratic effects of inbreeding (both individual and maternal) and positively by the linear effects of inbreeding. The reproductive traits were studied based on ewe inbreeding coefficient. Among the reproductive traits, the quadratic regression coefficient of conception rate was estimated significantly (P<0.05) as -0.22. Quadratic regression coefficient of litter mean weight per lamb born were estimated significantly (P<0.01) as -0.63 per 0.01 change in the ewe inbreeding coefficient. Therefore, inbreeding should be avoided, except for purposes of genetic breeding whose main objective is the fixation of certain alleles in the population.

A three-geneRATIOn resource population was developed by using two distinct Japanese quail strains, wild and white to map quantitative trait loci underlying KLEIBER RATIO, an indirect criterion of feed efficiency. Eight pairs of white (S) and wild (W) birds were crossed reciprocally and 34 F1 birds were produced. The F1 birds were intercrossed to generate 422 F2 offspring. All of the birds from three geneRATIOns (472 birds) were genotyped for eight microsatellite markers on chromosome 1. Liveweight data from hatch to 5 weeks of age were collected on the F2 birds. QTL analysis was conducted applying the line-cross model and the least-squares interval mapping approach. The results indicated QTL affecting KLEIBER RATIO for 1 to 2, 3 to 4, 4 to 5 and hatch to 5 weeks of age on chromosome 1. The F2 phenotypic variance explained by the detected QTL effects ranged from 0.8 to 3.7 for different traits.Modeling both additive and dominance QTL effects revealed QTL with significant additive mode of action. However, there was no evidence for imprinting (parent-of-origin) effects.

AbstractSix univariate animal models, including various combinations of the maternal effects, were used to estimate the (co)variance components and genetic parameters for growth rates from birth to weaning (GR1), weaning to six months of age (GR2) and weaning to 12 months of age (GR3), and the corresponding KLEIBER RATIOs (KR1, KR2, KR3), efficiencies of growth (EF1, EF2, EF3) and relative growth rates (RGR1, RGR2, RGR3) in Iran-Black sheep. The most appropriate model for each trait was identified by the Akaike Information Criterion (AIC). In addition, bivariate analyses were used to estimate the (co)variance components between traits. Estimated values of the direct heritability (±S.E.) were 0.08±0.03, 0.07±0.03 and 0.05±0.03 for GR1, GR2, and GR3; 0.25±0.07, 0.05±0.02, and 0.01±0.01 for KR1, KR2 and KR3; 0.05±0.03, 0.04±0.02 and 0.00±0.01 for EF1, EF2 and EF3; and 0.09±0.04, 0.05±0.02 and 0.00±0.01 for RGR1, RGR2 and RGR3, respectively. There was little additive genetic variation in growth rate and efficiency-related traits in Iran-Black sheep and therefore, a small genetic progress would be expected through selection. All the studied traits were affected by maternal effects. Estimates of the maternal heritability (m2) ranged from 0.02 (GR3) to 0.13 (EF1) and estimates of the RATIO of maternal permanent environmental variance to phenotypic variance (c2) ranged from 0.03 (GR2, GR3, KR2) to 0.09 (GR1, EF3). Genetic correlations between the studied traits varied from -0.63 (KR1 and EF3) to 0.99 (KR2 and EF3), and the phenotypic correlations ranged from -0.65 (GR1 and EF3) to 0.98 (EF2 and RGR2 and EF3 and RGR3). The study also showed the importance of inclusion of efficiency-related traits in selection programs to improve the biological characteristics of Iran-Black sheep.

Analysis of 2732 reproduction records in a baluchi flock in Yazd province revealed 60% apparent fertility (EP/EJ) and 40% weaning rate (LW/EJ). There was no incidence of twinning. Records of 1018 lambs on birth weight, weaning weight, average daily gain to weaning and KLEIBER RATIO were analysed by least square method for environmental effects, heritability estimates and phenotypic and genetic correlations. The effect of year and age of dam were significant on all traits (p<0.01) with the exception of the dam age on birth weight. Lambs born from 5 years old ewes had the highest weaning weight (27.20 kg), average daily gain to weaning (214.24 g), and KLEIBER RATIO (17.85 g/kg).Baluchi male lambs had significantly (p<0.01) higher birth and weaning weight, average daily gain to weaning, and rate of KLEIBER RATIOn than female lambs.Heritability for birth weight, weaning weight, average daily gain to weaning, and KLEIBER RATIO were estimated 0.08 (0.06), 0.15 (0.07), 0.15 (0.07) and 0.08 (0.06) respectively. Phenotypic and genetic correlations between birth weight and average daily gain to weaning, birth weight and weaning weight, birth weight and kleieber RATIO, average daily gain to weaning and weaning weight, average daily gain to weaning and KLEIBER RATIO and weaning weight and KLEIBER RATIO were 0.06 and 0.11 (0.42), 0.16 and 0.18 (0.24), 0.13 and 0.14 (0.57), 0.99 and 0.99 (0.002), 0.91 and 1.00).0.88 and 0.10 (0.79) respectively.