Breeding value evaluation in Polish fur animals: Estimates of direct heritability and portion of litter variation of fur coat and reproduction traits

The study presents estimates of heritability for fur coat and reproduction traits in arctic and silver foxes kept on Polish farms. The estimates of variance components were calculated using the DFREML and single-trait animal models. Due to a discrete character of fur coat traits, they were analysed twice: (1) without normalisation of their scores distribution, (2) after the normal probability scale transformation of their scores. Linear models included random additive genetic and common litter environment effects, and fixed effects of farm × year × birth season in the silver fox or year × birth season in the arctic fox as well as the fixed effect of female age when the reproduction traits were analysed. Moreover, the estimation of variance components for fur coat traits was done by a linear model with (Model 2) or without (Model 1) inbreeding coefficients included as linear covariable. In the arctic fox accounting for inbreeding and the data transformation did not markedly influence the estimates of heritability and the portion of litter variation calculated for the fur coat traits. An inbreeding effect was negligible (except for body size – BS) likely due to the low inbred level of the arctic fox population. In the silver fox the comparison of estimates derived using 2 different linear models and 2 data sets revealed more differences than it was found in the arctic fox. Accounting for inbreeding usually led to lower estimates of heritability, mainly when heritabilities were derived from the normal probability scale-transformed data. Most of the estimates of heritability of reproduction traits were found within the range reported by other authors. However, somewhat higher heritabilities were found for litter size at birth – LSB (0.205) and litter size at weaning – LSW (0.250).    

Download Full-text

Breeding value evaluation in Polish fur animals: Statistical description of fur coat and reproduction traits – relationship and inbreeding

Czech Journal of Animal Science ◽

10.17221/4266-cjas ◽

2011 ◽

Vol 49 (No. 1) ◽

pp. 16-27 ◽

Cited By ~ 2

Author(s):

H. Wierzbicki ◽

A. Filistowicz ◽

W. Jagusiak

Keyword(s):

Fixed Effects ◽

Breeding Value ◽

The Arctic ◽

Arctic Fox ◽

Data Sets ◽

Value Evaluation ◽

Inbreeding Coefficients ◽

Silver Fox ◽

Reproduction Traits ◽

As Relationship

Three data sets were available: records on conformation and coat traits for the arctic fox from one farm (5 540 observations, collected between 1983 and 1997), and the same traits for the silver fox from three farms (8 199 observations, collected between 1984 and 1999). The third set comprised 5 829 observations on reproductive performance of the arctic fox from one farm, collected between 1984 and 1999. The GLM procedure was used to test the significance of fixed effects on the analysed reproduction traits as well as differences between groups. Phenotypic trends as well as relationship and inbreeding across the studied years were computed. Most of the phenotypic trends were positive. Low relationship and inbreeding coefficients in the arctic and silver fox populations under study were estimated. The average relationship coefficients for the silver and arctic fox populations were 0.015 and 0.010, respectively, whereas the average inbreeding coefficients for the same species were 0.0039 and 0.0016, respectively. No inbreeding was found in the arctic fox breeding females.  

Download Full-text

Placental Scars and Estimation of Litter Size: An Experimental Test in the Arctic Fox

Journal of Mammalogy ◽

10.2307/1382615 ◽

1995 ◽

Vol 76 (4) ◽

pp. 1220-1225 ◽

Cited By ~ 15

Author(s):

O. Strand ◽

T. Skogland ◽

T. Kvam

Keyword(s):

Litter Size ◽

Experimental Test ◽

The Arctic ◽

Arctic Fox

Download Full-text

Complex therapy against toxascariosis of caged silver foxes

Russian Journal of Parasitology ◽

10.31016/1998-8435-2021-15-4-82-90 ◽

2021 ◽

Vol 15 (4) ◽

pp. 82-90

Author(s):

A. P. Konovalov ◽

I. I. Tsepilova ◽

F. I. Vasilevich

Keyword(s):

Live Weight ◽

Blood Parameters ◽

Food Supplement ◽

The Body ◽

The Arctic ◽

Arctic Fox ◽

Silver Fox ◽

Complex Therapy ◽

Before And After ◽

And Control

The purpose of the research is evaluating the efficacy of complex therapy using dironet, lactobifadol and keratin food supplement (DLK) against toxascariosis of the arctic fox.Materials and methods. To determine the helminth fauna in the conditions of Vyatka Fur Breeding Farm, 61 females silver fox and 55 females voilevoy arctic fox were used as study objects. To conduct complex therapy against toxascariosis, the study object was 24 females culled from the breeding herd, spontaneously infected with toxascariosis and being clinically healthy. The morphological and biochemical blood parameters in female foxes were determined before and after dehelminthization, and control weighing of animals from experimental groups was carried out before and after the experiment.Results and discussion. Of the studied 116 fur-bearing animals, 26 (22.4%) were infected with Toxascaris leonina. Infection rate of Toxascaris sp. in silver fox females aged 5–7 years was 42.6% when 7-9 eggs were found in one microscope field (magnification 7 × 9). Infection with Toxascaris sp. affects on the body weight of infected animals. The females silver fox from the second experimental group infected with Toxascaris sp., which were not treated, had an average live weight of 1.3 kg less (16.6%) as compared to the control. The complex therapy with the DLK treatment-and-prophylactic complex contributed to the improved metabolic processes and digestion. The applicability of the DLK treatment-and-prophylactic complex for therapy against toxascariosis was proved.

Download Full-text

Breeding value evaluation in Polish fur animals: Estimates of (co)variances due to direct and litter effects for fur coat and reproduction traits

Czech Journal of Animal Science ◽

10.17221/3907-cjas ◽

2011 ◽

Vol 51 (No. 1) ◽

pp. 39-46 ◽

Cited By ~ 11

Author(s):

H. Wierzbicki ◽

W. Jagusiak

Keyword(s):

Litter Size ◽

Genetic Correlations ◽

Reproductive Traits ◽

Original Data ◽

Breeding Value ◽

The Arctic ◽

Data Set ◽

Value Evaluation ◽

Reproduction Traits ◽

Fur Animals

5 540 records of the arctic fox fur coat and reproductive traits collected in 1983–1999 were studied. The analyzed traits were: body size (BS), colour type (CT), colour purity (CP), coat density (CD), hair length (HL), general appearance (GA), total score (TS), skin length (SL), litter size at birth (LSB), litter size at weaning (LSW), number of dead pups (NPD), pup weight at weaning (PW), and pregnancy length (PL). (Co)variance components were estimated using a derivative-free algorithm of REML and a multi-trait animal model. Random effects were direct additive, common litter environment and residual. The genetic parameters for the fur coat traits (discrete characters) were estimated twice: using the original data set, and the data set in which the distribution of fur coat scores was normalised using a probit link function. Direct heritability estimates obtained from the original data set ranged from 0.108 for SL to 0.276 for HL, and were somewhat lower than those estimated using the transformed data set (they ranged from 0.109 for GA to 0.315 for CT). Reproductive traits were lowly heritable with direct heritabilities ranging from 0.060 for PW to 0.174 for LSB. Estimates of the portion of litter variation calculated from the original and transformed data set were comparable ranging from 0.045 for GA to 0.156 for CP, and from 0.059 for GA to 0.185 for TS, respectively. Genetic correlations between fur coat traits ranged from high favourable (0.948 between SL and BS, original data) to strong negative ones between CP and GA (–0.405, transformed data). High positive genetic correlations were found between LSB and LSW (0.954), and between LSB and NPD (0.783), whereas PL was negatively correlated with all other reproductive traits.  

Download Full-text