Pedigree data of the Border Collie dog breed were collected in Hungary to examine genetic diversity within the breed and its different lines. The database was based on available herd books dating from the development of the breed (in the late 1800s) to the present day. The constructed pedigree file consisted of 13,339 individuals, of which 1566 dogs (born between 2010 and 2016) composed the alive reference population which was active from breeding perspective. The breed is subdivided by phenotype, showing a thicker coat, harmonic movement, a wide skull, and heavier bones for the show type, and a thinner or sometimes short coat and smaller body for the working line, while the mixed line is quite heterogeneous (a combination of the above). Thus, the reference population was dissected according to the existing lines. The number of founders was 894, but eight individuals were responsible for contributing 50% of the genetic variability. The reference population had a pedigree completeness of 99.6% up to 15 generations and an inbreeding coefficient of 9.86%. Due to the changing breed standards and the requirements of the potential buyers, the effective population size substantially decreased between 2010 and 2016. Generation intervals varied between 4.09 and 4.71 years, where the sire paths were longer due to the later initial age of breeding in males compared to females. Genetic differences among the existing lines calculated by fixation indices are not significant; nonetheless ancestral inbreeding coefficients are able to show contrasts.
Pedigree data of 13,339 border collie dog was collected along with canine hip dysplasia (CHD) and canine elbow dysplasia (CED) records (1352 CHD and 524 CED), and an inbreeding–purging (IP) model was created. Ancestral inbreeding coefficients were calculated by using a gene dropping simulation method with GRain 2.2 software. Cumulative logit models (CLM) for CHD and CED were fitted using a logit-link Poisson distribution and the classical (F_W), and ancestral inbreeding (F_BAL, F_KAL, and F_KAL_NEW) coefficients as linear regression coefficients. The effective population size was calculated from F_W and decreased in the examined period along with an increase of F_W; however, slight differences were found as a consequence of breeding dog imports. CHD values were lowered by the expansion of F_BAL, as the alleles had been inbred in the past. For CHD, signs of purging were obtained. There was a positive trend regarding the breeding activity (both sire and dam of the future litters should be screened and certified free from CHD and CED), as years of selection increased the frequency of alleles with favorable hip and elbow conformation. Division of the ancestral inbreeding coefficient showed that alleles that had been identical by descent (IBD) for the first time (F_KAL_NEW) had a negative effect on both traits, while F_KAL has shown favorable results for alleles IBD in past generations. Some authors had proven this phenomenon in captive populations or experimental conditions; however, no evidence of inbreeding purge has ever been described in dog populations. Despite the various breeding practices, it seems that alleles of these polygenic disorders could be successfully purged out of the population with long-term selection.
From 2016 to 2020, an investigation was carried out to identify the rate of Angiostrongylus spp. infections in European badgers in Hungary. During the study, the hearts and lungs of 50 animals were dissected in order to collect adult worms, the morphometrical characteristics of which were used for species identification. PCR amplification and an 18S rDNA-sequencing analysis were also carried out. Global and local spatial autocorrelation methods were used to detect high-rated and low-rated infected animal clusters. We conducted a binary logistic regression analysis along with hierarchical agglomerative clustering to determine the relation between selected biotic and abiotic variables, and the prevalence of an A. daskalovi infection. We found a high prevalence (72%) and moderate mean intensity (14.1) of Angiostrongylus sp. infection. Morphology and sequencing revealed that all animals were infected by A. daskalovi. The results of both spatial autocorrelations suggested that the spatial distribution of infected badgers was more spatially clustered than random. The results of an analysis of the correlation between habitat characteristics and infection showed that the infected animals could be associated with dry and open landscape habitats without extended and connected canopy. It is suggested that the territorial behaviour of badgers and the landscape-directed aggregation of potential intermediate hosts might be the drivers of an A. daskalovi infection.
In ovo administration of DL-methionine and post-hatch Hydrogel® supplements were tested to examine the impact of early feeding on performance and immune-related traits in a commercial broiler stock. One thousand one hundred and twenty Ross 308 eggs were incubated and assigned to seven treatment groups: intact (no in ovo administration) and immediate feed access (C1), in ovo saline treatment and immediate feed access (C2), intact and delayed feeding (ID), in ovo saline treatment and delayed feeding (IoS), in ovo DL-Methionine treatment and delayed feeding (IoM), intact and delayed access to feed, but immediate access to commercial Hydrogel® without (Hyd) or with 5mg/kg (HydM) DL-methionine post-hatch. The results showed, that the in-ovo methionine may have positive effects on the weight gain of the birds (p < 0.001) compared to the commercial Hydrogel® however, it cannot compete with the immediate feeding. The number of heterophils decreased significantly (p < 0.001) by day 21 in ID and IoS compared to the immediately fed control (C1). The number of lymphocytes, monocytes, and eosinophils, increased in treatments supplemented with methionine (p < 0.05) (IoM,HydM) indicating enhanced immune protection. There were no differences in the total antioxidant capacity (FRAP) and malonaldehyde concentration (MDA) (p = 0.07) in the examined groups. The Cytochrome P450 H1 (CYP2H1) gene was downregulated in all treatment groups (on days 21 and 35) indicating a slower metabolism, particularly in the ID group compared to C1 and C2 (p < 0.001). The HydM treatment could upregulate the IL2 expression as the immediate feeding, while only IoM treatment resulted in significant downregulation by day 35 (p < 0.001). IL6 was upregulated in all treatment groups (p < 0.001) except for HydM, where the gene expression did not differ from the housekeeping gene. Early administration of dietary methionine has a positive effect on performance and the immune system, however, none of the early feeding methods can compete with immediate feed access. The possible positive effects of early nutrition and its epigenetic impact should be examined in further studies.
15 February 2018 in Italian Journal of Animal Science
Genetic parameters for 21-d litter weight (LW21) and thigh muscle volume (TMV) were estimated, and based on these traits a two-trait selection index was created with the purpose of increasing the efficiency of the Pannon White rabbits’ breeding programme. Litter weight at 21 d of age (LW21, n = 22,002) and thigh muscle volume (TMV, n = 8124) measurements (based on computed tomography – CT) were analysed that were recorded between 1992 and 2016. The evaluated animals were reared in 4178 litters and the total number of rabbits involved in the pedigree file was 14,124. LW21 and TMV records were analysed jointly in a two-trait animal model. The estimated heritability for LW21 and TMV were 0.10 ± 0.01 and 0.21 ± 0.02, respectively, and the estimated genetic correlation between these traits was −0.24 ± 0.07. The common environmental effect had the same magnitude (0.10 ± 0.01) as the additive genetic effect. The created selection index constructed to have 50 and 50% contribution of the measured traits. Application possibility of the created index was tested on a given kindling batch. In this case, the first step of the selection procedure was performed either according to the current breeding programme (based on the LW21 breeding values) or based on the two trait selection index. The second step of selection was not changed (based on the TMV breeding values). The consequences of using index scores instead of the regular procedure were obtaining 27.8% higher average breeding value for TMV and 11.4% lower average breeding value for LW21. These results suggest that introduction of the index may improve economic efficiency.
Pedigree data of 13 339 border collie dog was collected along with hip and elbow dysplasia records (1352 CHD and 524 CED), and an inbreeding-purging (IP) model was created to detect possible purging. Ancestral inbreeding coefficients were calculated by gene dropping simulation method (Ballou, 1997; Kalinowski, 2000) with GRain 2.0 (Baumung et al., 2015) software. GLMM models were created to the examined traits fitted with a log-link Poisson distribution, added to the estimated values of classical inbreeding coefficient (F_W), and the ancestral inbreeding (F_BAL, F_KAL, F_KAL_NEW) as covariates. The effective population size decreased in the examined period along with the increase of F_W however, slight differences were found as a consequence of breeding dog imports. CHD values were getting lower by the expansion of F_BAL as the alleles were inbred in the past. For CHD signs of purging were obtained. There was a positive trend regarding the breeding activity (both sire and dam of the future litters should be screened and certified free from CHD and CED), as years of selection increased the frequency of alleles with favorable hip and elbow conformation. Division of the ancestral inbreeding coefficient shows that alleles IBD for the first time (F_KAL_NEW) had a negative effect on both traits, while F_KAL shows favorable results for alleles IBD in the past generations. Some authors had proven this phenomenon in captive populations or experimental conditions however, no evidence of inbreeding purge has ever been described in dog populations. Despite the various breeding practices, it seems, that alleles of these polygenic disorders could be successfully purged out of the population with long term selection.