Founder representation and effective population size in old versus young breeds—genetic diversity of Finnish and Nordic Spitz

Finnish Spitz is 130‐year‐old breed and has been highly popular in Finland throughout its history. Nordic Spitz is very similar to Finnish Spitz by origin and use, but is a relatively recent breed with much smaller population size. To see how breed age and breeding history have influenced the current population, we performed comprehensive population genetic analysis using pedigree data of 28,119 Finnish and 9,009 Nordic Spitzes combined with genomewide single nucleotide polymorphism (SNP) data from 135 Finnish and 110 Nordic Spitzes. We found that the Finnish Spitz has undergone repeated male bottlenecks resulting in dramatic loss of genetic diversity, reflected by 20 effective founders (f_a) and mean heterozygosity (Hz) of 0.313. The realized effective population size in the breed based on pedigree analysis () is 168, whereas the genetic effective population size (N_eg) computed the decay of linkage disequilibrium (r²) is only 57 individuals. Nordic Spitz, although once been near extinction, has not been exposed to similar repeated bottlenecks than Finnish Spitz and had f_a of 27 individuals. However, due to the smaller total population size, the breed has also smaller effective population size than Finnish Spitz ( = 98 and N_eg = 49). Interestingly, the r² data show that the effective population size has contracted dramatically since the establishment of the breed, emphasizing the role of breed standards as constrains for the breeding population. Despite the small population size, Nordic Spitz still maintains SNP heterozygosity levels similar to mixed breed dogs (mean Hz = 0.409). Our study demonstrates that although pedigree analyses cannot provide estimates of the present diversity within a breed, the effective population sizes inferred from them correlate with the genotyping results. The genetic relationships of the northern Spitz breeds and the benefits of the open breed registry are discussed.     

Linkage disequilibrium and effective population size in Gir cattle selected for yearling weight

Linkage disequilibrium (LD) plays an important role in genomic selection and mapping of quantitative trait loci (QTL). This study investigated the pattern of LD and effective population size (N_e) in Gir cattle selected for yearling weight. For this purpose, 173 animals with imputed genotypes (from 18 animals genotyped with the Illumina BovineHD BeadChip and 155 animals genotyped with the Bovine LDv4 panel) were analysed. The LD was evaluated at distances of 25–50 kb, 50–100 kb, 100–500 kb and 0.5–1 Mb. The N_e was estimated based on 5 past generations. The r² values (a measure of LD) were, respectively, .35, .29, .18 and .032 for the distances evaluated. The LD estimates decreased with increasing distance of SNP pairs and LD persisted up to a distance of 100 kb (r² = .29). The N_e was greater in generations 4 and 5 (24 and 30 animals, respectively) and declined drastically after the last generation (12 animals). The results showed high levels of LD and low N_e, which were probably due to the loss of genetic variability as a consequence of the structure of the Gir population studied.     

Implementation of genetic evaluation and mating designs for the endangered local pig breed ‘Bunte Bentheimer’

A pedigree including 1538 individuals of the endangered pig breed ‘Bunte Bentheimer’ and 3008 records of the fertility traits ‘number of piglets born alive’ (NBA) and ‘number of piglets weaned’ (NW) were used to i) characterize the population structure, ii) to estimate genetic (co)variance components and estimated breeding values (EBVs) and iii) to use EBVs for the application of the concept of optimal genetic contributions. The average coefficient of inbreeding increased from F = 0.103 to F = 0.121 within the two recent cohorts. Average rate of inbreeding amounted to 1.66%, which resulted in an effective population size of N_e = 30 animals in the recent cohort. Average generation interval was 3.07 years considering the whole pedigree, and in total, only 612 sows and boars generated offspring. Estimated heritabilities for both traits NBA and NW were 0.12, and the estimated genetic correlation between both traits was 0.96. The variance component due to the service sire was higher than in commercial pig breeds, presumably due to the widespread use of natural service boars. The EBVs for NBA from 333 selection candidates (63 boars and 270 sows) were used to determine optimal genetic contributions. Based on selected animals and their optimal genetic contributions, specific mating designs were evaluated to minimize inbreeding in the next generation. Best results were achieved when using a simulated annealing algorithm and allowing artificial insemination.     

Relationship between genealogical and microsatellite information characterizing losses of genetic variability: Empirical evidence from the rare Xalda sheep breed

Preservation of rare genetic stocks requires continual monitoring of populations to avoid losses of genetic variability. Genetic variability can be described using genealogical and molecular parameters characterizing variation in allelic frequencies over time and providing interesting information on differentiation that occurred after the foundation of a conservation program. Here we analyze the pedigree of the rare Xalda sheep breed (1851 individuals) and the polymorphism of 14 microsatellites in 239 Xalda individuals. Individuals were assigned to a base population (BP) or 4 different cohorts (from C1 to C4) according to their pedigree information. Genetic parameters were computed at a genealogical and molecular level, namely inbreeding (F), observed (H_o) and expected (H_e) heterozygosity, individual coancestry coefficients (f and f_m), average relatedness (AR), mean molecular kinship (Mk), average number of allele per locus (A), effective number of ancestors (f_a), effective population size (N_e and N_e(m)) and founder genome equivalents (N_g and N_g(m)). In general, the computed parameters increased with pedigree depth from BP to C4, especially for the genealogical information and molecular coancestry-based parameters (f_m, Mk and N_g(m)). However, H_o and H_e showed the highest values for C1 and the molecular heterozygote deficiency within population (F_IS(m)) showed the lowest value for C1, thus indicating that loss of genetic variability occurs very soon after the implementation of conservation strategies. Although no genealogical or molecular parameters are sufficient by themselves for monitoring populations at the beginning of a conservation program, our data suggests that coancestry-based parameters may be better criteria than those of inbreeding or homozygosity because of the rapid and strong correlation established between f and f_(m). However, the obtaining of molecular information in well-established conservation programs could not be justified, at least in economic terms.     

MC1R c.310G>‐ and c.871G > A determine the coat color of Kumamoto sub‐breed of Japanese Brown cattle

Coat color is one of the important factors characterizing breeds for domestic animals. Melanocortin 1 receptor (MC1R) is a representative responsible gene for this phenotype. Two single‐nucleotide polymorphisms (SNPs) in bovine MC1R gene, c.296T > C and c.310G>‐, have been well characterized, but these SNPs are not enough to explain cattle coat color. As far as we know, MC1R genotypes of Kumamoto sub‐breed of Japanese Brown cattle have not been analyzed. In the current study, genotyping for c.296T > C and c.310G>‐ was performed to elucidate the role of MC1R in determining the coat color of this sub‐breed. As a result, most animals were e/e genotype, suggesting the coat color of this sub‐breed is derived from the e allele of MC1R gene. However, we found six animals with E/e genotype, which coat color would be black theoretically. Subsequently, sequence comparison was performed with these animals to identify other polymorphisms affecting coat color, elucidating that these animals possessed the A allele of c.871G > A commonly. c.871G > A was a non‐synonymous mutation in the seventh transmembrane domain, suggesting alteration of the function and/or the structure of MC1R protein. Our data indicated that the A allele of c.871G > A might be a loss‐of‐function mutation.     

Serum Lipid Modification Related to Exercise and Polyunsaturated Fatty Acid Supplementation in Jumpers and Thoroughbred Horses

The importance of polyunsaturated fatty acids (PUFAs) within the different biological functions of animals has been widely recognized. In this study, exercise and PUFAs supplementation effects on serum triglycerides, total cholesterol, and nonesterified fatty acids (NEFAs) concentration were evaluated in athletic horses. Two sport horse types (10 Italian saddle jumpers and 10 Thoroughbreds) were equally divided into two groups. Jumpers and Thoroughbred experimental groups (A_J and A_T) received 4-week PUFAs supplementation and control groups (B_J and B_T) received no dietary supplement. Before starting the PUFAs supplementation (T0) and at the end of the experimental period (T4), horses were subjected to simulated events. From each subject, blood samples were collected every 7 days at rest, before and after the first test (T0_R and T0_PE), and before and after the second test (T4_R and T4_PE). Higher triglycerides and NEFA concentrations at T0_PE and T4_PE than T0_R and T4_R in both groups were found as a result of exercise (P < .005), but lower triglycerides and NEFA concentrations at T4_PE in group A_J than group B_J (P < .05) and in group A_T (P < .005) than group B_T were found as a result of PUFAs supplementation. Effects of PUFAs supplementation was highlighted by the statistically significant lower triglycerides and NEFA concentrations found at T4_PE than T0_PE in groups A_J (P < .05) and A_T (triglycerides: P < .05; NEFAs: P < .0001).     

The effect of breed and sex on sulfamethazine,enrofloxacin, fenbendazole and flunixin meglumine pharmacokinetic parameters in swine

Drug use in livestock has received increased attention due to welfare concerns and food safety. Characterizing heterogeneity in the way swine populations respond to drugs could allow for group‐specific dose or drug recommendations. Our objective was to determine whether drug clearance differs across genetic backgrounds and sex for sulfamethazine, enrofloxacin, fenbendazole and flunixin meglumine. Two sires from each of four breeds were mated to a common sow population. The nursery pigs generated (n = 114) were utilized in a random crossover design. Drugs were administered intravenously and blood collected a minimum of 10 times over 48 h. A non‐compartmental analysis of drug and metabolite plasma concentration vs. time profiles was performed. Within‐drug and metabolite analysis of pharmacokinetic parameters included fixed effects of drug administration date, sex and breed of sire. Breed differences existed for flunixin meglumine (P‐value<0.05; Cl, Vd_ss) and oxfendazole (P‐value<0.05, AUC_0→∞). Sex differences existed for oxfendazole (P‐value < 0.05; T_max) and sulfamethazine (P‐value < 0.05, Cl). Differences in drug clearance were seen, and future work will determine the degree of additive genetic variation utilizing a larger population.     

Improving production efficiency in the presence of genotype by environment interactions in pig genomic selection breeding programmes

We simulated a genomic selection pig breeding schemes containing nucleus and production herds to improve feed efficiency of production pigs that were cross‐breed. Elite nucleus herds had access to high‐quality feed, and production herds were fed low‐quality feed. Feed efficiency in the nucleus herds had a heritability of 0.3 and 0.25 in the production herds. It was assumed the genetic relationships between feed efficiency in the nucleus and production were low (r_g = 0.2), medium (r_g = 0.5) and high (r_g = 0.8). In our alternative breeding schemes, different proportion of production animals were recorded for feed efficiency and genotyped with high‐density panel of genetic markers. Genomic breeding value of the selection candidates for feed efficiency was estimated based on three different approaches. In one approach, genomic breeding value was estimated including nucleus animals in the reference population. In the second approach, the reference population was containing a mixture of nucleus and production animals. In the third approach, the reference population was only consisting of production herds. Using a mixture reference population, we generated 40–115% more genetic gain in the production environment as compared to only using nucleus reference population that were fed high‐quality feed sources when the production animals were offspring of the nucleus animals. When the production animals were grand offspring of the nucleus animals, 43–104% more genetic gain was generated. Similarly, a higher genetic gain generated in the production environment when mixed reference population was used as compared to only using production animals. This was up to 19 and 14% when the production animals were offspring and grand offspring of nucleus animals, respectively. Therefore, in genomic selection pig breeding programmes, feed efficiency traits could be improved by properly designing the reference population.     

Population genetic structure of Santa Inês sheep in Brazil

This study aimed to describe the population genetic structure and evaluate the state of conservation of the genetic variability of Santa Inês sheep in Brazil. We used pedigree data of the Santa Inês breed available in electronic processing of the Brazilian Association of Sheep Breeders. A file with 20,206 records, which enabled the calculation of the genetic conservation index (GCI), individual inbreeding coefficient (F), change in inbreeding (ΔF), effective population size (Ne), effective number of founders (?_e), effective number of ancestors (?_ɑ), generation interval (L), average relatedness coefficient of each individual (AR), and Wright’s F-statistics (F _IT, F _IS, and F _ST). For pedigree analysis and calculation of population parameters, the program ENDOG was used. The average inbreeding coefficient (\( \overline{F} \)) was 0.97% and the mean average relatedness (\( \overline{\mathrm{AR}} \)) 0.49%. The effective numbers of founders and ancestors were, respectively, 199 and 161. The average values of F and AR increased significantly over the years. The effective population size fluctuated over the years concurrently to oscillations in inbreeding rates, wherein N _e reached just 68 in the year 2012. The mean average generation interval was 5.3 years. The Santa Inês breed in Brazil is under genetic drift process, with loss of genetic variation. It requires the implementation of a genetic management plan in the herd, for conservation and improvement of the breed.     

Whole-genome sequence analysis reveals candidate genomic footprints and genes associated with reproductive traits in Thoroughbred horse

The primary objective of most horse breeding operations was to maximize reproductive efficiency and minimize the cost of producing live foals. Here, we compared individual horses from the Thoroughbred population (n = 17), known as a horse breed with poor reproductive performance, with other six horse populations (n = 28), to detect genomic signatures of positive selection underlying of reproductive traits. A number of protein-coding genes with significant (p-value <.01) higher F_ST values (616 genes) and a lower value for nucleotide diversity (π) (310 genes) were identified. The results of our study revealed some candidate genes such as IGFBP2, IGFBP5, GDF9, BRINP3 and GRID1 are possibly associated with functions influencing reproductive traits. These genes may have been under selection due to their essential roles in reproduction performance in horses. The candidate selected genes identified in this work should be of great interest for future research into genetic architecture of traits relevant to horse breeding programmes.     

Monitoring of genetic diversity in the Japanese Black cattle population by the use of pedigree information

The gene pool of the Japanese Black cattle has been completely closed to foreign breeds during the last 100 years. Genetic diversity of the Japanese Black cattle from 1960 to 2000 was monitored with three estimates of effective number of ancestors. Founder genome equivalent (N_ge) accounts for all the causes of reduction of diversity. Effective number of founders (N_ef) and non‐founders (N_enf) explain reduced diversity because of unequal genetic contributions of founders and random genetic drift in non‐founders, respectively. Further examination using gene dropping simulation was conducted to obtain information on survival of founder alleles. Unique founder alleles were dropped down along the actual pedigree with Monte Carlo procedure following Mendelian segregation rules, and generated genotypes of all the current live animals (612 959 heads). Pedigree records consisted of 2 075 188 animals was used for these analysis. The estimates of three effective numbers (N_ef, N_ge, and N_enf) decreased from 418.6 to 50.3, 86.6 to 7.3, and 109.2 to 8.5, respectively, during the period 1960–2000. The increasing differences between two kinds of genetic diversity indices derived from N_ge and N_ef showed that large part of the reduced diversity from 1980 was attributed to genetic drift caused by the intensive use of particular limited number of sires. In gene dropping analysis, probabilities of extinction of founder alleles were derived from their distributions of frequency in the current animals. Several founders showed low probabilities of allele extinction, irrespective of their relatively low genetic contributions. This suggests that these founders have lineages through which their alleles are surely transmitted to the current breed. The use of these founders as a strategy for recovering the genetic diversity was discussed.     

Breed-related plasma disposition of ivermectin following subcutaneous administration in Kilis and Damascus goats

Many factors related with drug and animals affect the plasma disposition of endectocides including ivermectin (IVM). The aim of the present study was to investigate the breed differences in pharmacokinetics of IVM in goats following subcutaneous administration. Two different goat breeds (Kilis and Damascus goats) were allocated into two treatment groups with respect to breed. The injectable formulation of IVM was administered subcutaneously at a dose rate of 0.2 mg/kg bodyweight. Blood samples were collected before treatment and at various times between 1 h and 40 days after treatment and the plasma samples were analysed by high performance liquid chromatography (HPLC) using fluorescence detection. The results indicated that the plasma disposition of IVM was substantially affected by breed differences following subcutaneous administration in goats. The last detectable plasma concentration (t_last) of IVM was significantly later in Kilis goats (38.33 days) compared with Damascus goats (22.50 days). Although, there were no significant differences on C_max (10.83 ng/ml vs. 10.15 ng/ml) and t_max (2.75 days vs. 2.33 days) values; the area under the concentration–time curve-AUC (110.26 ng.d/ml vs. 73.38 ng.d/ml) the terminal half-life-t_1/2λz (5.65 days vs. 3.81 days) and the mean plasma residence time-MRT (9.31 days vs. 6.35 days) were significantly different in Kilis goats compared with Damascus goats, respectively. The breed-related difference observed on the plasma disposition of IVM between Kilis and Damascus goats could be attributable to different excretion pattern or specific anatomical and/or physiological characteristics such as body fat composition of each breed.     

Evaluation of genetic diversity in Japanese Brown cattle population by pedigree analysis

The Japanese Brown is the second most common domestic beef breed in Japan. However, nowadays this breed is facing reduction in numbers because of pressure from a profitable domestic breed. This breed is uniformly characterized by its brown coat colour, but is comprised of two isolated sub‐breeds, Kumamoto and Kouchi, each possessing a different gene pool. Pedigree analyses were carried out for the two sub‐breeds using the pedigree records of animals born from 1970 to 2000. The effective population size has been found to be consistently reducing during the last three decades in both sub‐breeds. The current effective sizes were estimated to be 25.5 and 6.0 for the Kumamoto and Kouchi sub‐breeds, respectively. The estimate of the effective number of founders (N_ef) in the Kumamoto sub‐breed decreased from 152.1 to 74.4; that of non‐founders (N_enf), from 41.7 to 5.3; and that of founder genome equivalents (N_ge), from 32.7 to 4.9. The corresponding changes in the Kouchi sub‐breed were from 108.2 to 79.4, 16.2 to 4.1, and 14.1 to 3.9. Increasing differences between the two genetic diversity indices in the sub‐breeds indicate that the greater part of the reduction of genetic diversity can be attributed to genetic drift that accumulated in the non‐founder generations. A comparison with published estimates for several cattle breeds suggests the extremely limited genetic diversity of Japanese Brown. In addition to the avoidance of further reduction of genetic diversity, it will be important to counteract the process of breed decline by establishing a production system to efficiently utilize the unique characteristics of this breed and by developing links between the breed and products with market value.     

Genetic variability of three Italian cattle breeds determined by parameters based on probabilities of gene origin

In this study, we have investigated the genetic variability of three Italian cattle breeds, autochthonous of the Tuscany region (Chianina, Maremmana and Mucca Pisana), using the parameters based on probabilities of gene origin: f _e, f _a and N _g. Compared with Chianina (N _g=53.9) and Maremmana (N _g=79.6), Mucca Pisana was found to be the genetically smaller (N _g=10.1) and less diverse population. The genetic variability in Chianina population was lower than in Maremmana probably because of bottlenecks in its pedigree and genetic drift. However, the values found in these breeds were higher than those found in dairy cattle breeds, but lower than those found in beef cattle breeds.     

500 years of breeding in the Carthusian Strain of Pura Raza Español horse: An evolutional analysis using genealogical and genomic data

The Carthusian horse is a Pura Raza Español (PRE) strain (CS), bred as a closed population since its creation more than 500 years ago. The aim of this study was to analyse for the first time its population structure and situation of variability combining both genealogical (GEL) and genomic (GEN) data. The GEL data comprised 348,429 pedigree records (56,105 CS horses), while the GEN analysis included the high-density genotypes (670,804 SNPs) of 287 horses. Pedigree completeness demonstrated its accuracy, showing a good correlation of GEL (F) and GEN (F_ROH) inbreeding coefficient in the case of PRE subpopulations partially related and non-related to Carthusian strain (0.68) but a lower value in the 100% Carthusian horses (0.42), due to the high weight of founders not detected by GEL analysis. GEN (PCA, AMOVA, and Admixture) and GEL analysis showed a good differentiation of subpopulations, but also a high level of introgression of the CS in the breed during past decades. A recent change in this trend was noteworthy, with a considerable reduction in CS variability and a genetic bottleneck (effective population sizes of 31.57 and 30.20 in GEL and GEN analysis, respectively, in last generation). The PRE has maintained its variability, and a considerable difference in estimated N_e by GEL (60.77) and GEN (188.0) data was observed. Using two sources of complementary information, it was found the existence of an ancient PRE strain with a unique genetic landmark, practically free from the influence of other equine populations.     

Genome‐wide linkage disequilibrium in the Blonde d'Aquitaine cattle breed

We present here the first genome‐wide characterization of linkage disequilibrium (LD) in the French Blonde d'Aquitaine (BLA) breed, a well‐muscled breed renowned for producing high‐yielding beef carcasses. To assess the pattern and extent of LD, we used a sample of 30 unrelated bulls and 36 923 single nucleotide polymorphisms (SNPs) covering all cattle autosomes. The squared correlation of the alleles at two loci (r²) was used as a measure of LD. The analysis of adjacent marker pairs revealed that the level of LD decreases rapidly with physical distance between SNPs. Overall mean r² was 0.205 (±0.262). Strong LD (r² > 0.8) and useful LD (measured as r² > 0.2) were observed within genomic regions of up to 720 and 724 kb, respectively. We analysed the genetic structure of the BLA population and found stratification. The observed genetic sub‐structuring is consistent with the known recent demographic history that occurred during BLA breed formation. Our results indicate that LD mapping of phenotypic traits in the BLA population is feasible; however, because of this sub‐structuring, special care is needed to reduce the likelihood of false‐positive associations between marker loci and traits of interest.     

Fit of Wood's function to daily milk records and estimation of environmental and additive and non-additive genetic effects on lactation curve and lactation parameters of crossbred dual purpose cattle

The objectives of this study were to estimate the environmental and additive and non-additive genetic effects on lactation curve and lactation parameters of crosses of Holstein (H), Brahman (B) and Brown Swiss (BS) in Olancho region in Honduras. The data consisted of 54,517 milk yield records from 192 dual-purpose crossbred cows lactating from 2000 to 2005 at the Universidad Nacional de Agricultura de Honduras (UNA). The lactation curve and lactation parameters of interest were the scaling factor to represent yield at the beginning of lactation (a), the factor associated with the inclining (b) and declining (c) slopes of the lactation curves, and the milk yield at initial day of lactation (MY₂₀), peak milk yield (MY_max), day at peak milk yield (t_max), and the total milk yield (TM) per lactation, respectively. The incomplete gamma function (Wood function) was used to estimate lactation curve and lactation parameters from daily milk records of H × B, H × BS and BS × B crossbred cows. The environmental, additive and non-additive genetic effects on lactation curve and lactation parameters were estimated using Dickerson and Kinghorn models. The coefficients of determination of fitness of Wood's function (R²) ranged from 80% to 97% with an average of 93%. The lactation curve of the crossbred cows was similar to those reported for dairy cows grazing in the tropics. Lactation parameters such as MY_max, t_max and TM were significantly (P < 0.05) influenced by environmental sources of variation suggesting the necessity of differential management strategies. The moderate to large positive phenotypic correlation of MY_max and TM indicate that one of the milk yield parameters could be used as a selection criterion to improve either one or both traits. Despite the fact that both genetic models showed similar patterns, the absolute value of the parameters varied. For both models, individual additive genetic breed effect for H breed were significant (P < 0.05) and contributed more to TM than the BS breed. In the Dickerson model, highly positive significant (P < 0.01) effect on TM for H×BS and BS×B crosses was found. The Kinghorn model did not show significant effects of dominance on this parameter. The estimate of recombination effect for all crosses involving B breed were negative and significant (P < 0.05) for positive correlated lactation curve parameters. Although the inclusion of non-additive effects on crossbreeding genetic effects were not all significant for lactation curve and lactation parameters, non-additive effects should be taken into account to improve the Honduran dairy cattle production management.     

Molecular genetic diversity and genetic structure of Vietnamese indigenous pig populations

The study characterized genetic diversity and genetic structure of five indigenous pig populations (Ha Lang, Muong Te, Mong Cai, Lung and Lung Pu), two wild pig populations (Vietnamese and Thai wild pigs) and an exotic pig breed (Yorkshire) using FAO/ISAG recommended 16 microsatellite markers in 236 samples. All estimated loci were very polymorphic indicated by high values of polymorphism information content (from 0.76 in S0225 to 0.92 in Sw2410). Indigenous populations had very high level of genetic diversity (mean He = 0.75); of all indigenous breeds, Lung Pu showed highest mean number of alleles (MNA = 10.1), gene diversity (He = 0.82), allele richness (5.33) and number of private alleles (10). Thirteen percentage of the total genetic variation observed was due to differences among populations. The neighbour‐joining dendrogram obtained from Nei's standard genetic distance differentiated eight populations into four groups including Yorkshire, two wild populations, Mong Cai population and a group of four other indigenous populations. The Bayesian clustering with the admixture model implemented in Structure 2.1 indicated seven possible homogenous clusters among eight populations. From 79% (Ha Lang) to 98% (Mong Cai). individuals in indigenous pigs were assigned to their own populations. The results confirmed high level of genetic diversity and shed a new light on genetic structure of Vietnam indigenous pig populations.     

Pharmacokinetic, metabolism and withdrawal time of orphenadrine in camels (Camelus dromedarius) after intravenous administration

The pharmacokinetics of orphenadrine (ORPH) following a single intravenous (i.v.) dose was investigated in six camels (Camelus dormedarius). Orphenadrine was extracted from the plasma using a simple sensitive liquid–liquid extraction method and determined by gas chromatography/mass spectrometry (GC/MS). Following i.v. administration plasma concentrations of ORPH decline bi-exponentially with distribution half-life (t_1/2α) of 0.50 ± 0.07 h, elimination half-life (t_1/2β) of 3.57 ± 0.55 h, area under the time concentration curve (AUC) of 1.03 ± 0.10 g/h l⁻¹. The volume of distribution at steady state (Vd_ss) 1.92 ± 0.22 l kg⁻¹, volume of the central compartment of the two compartment pharmacokinetic model (V_c) 0.87 ± 0.09 l kg⁻¹, and total body clearance (Cl_T) of 0.60 ± 0.09 l/h kg⁻¹. Three orphenadrine metabolites were identified in urine samples of camels. The first metabolite N-desmethyl-orphenadrine resulted from N-dealkylation of ORPH with molecular ion m/z 255. The second N,N-didesmethyl-orphenadrine, resulted from N-didesmethylation with molecular ion m/z 241. The third metabolite, hydroxyl-orphenadrine, resulted from the hydroxylation of ORPH with molecular ion m/z 285. ORPH and its metabolites in camel were extensively eliminated in conjugated form. ORPH remains detectable in camel urine for three days after i.v. administration of a single dose of 350 mg orphenadrine aspartate.     

Microsatellite-based diversity analysis and genetic relationships of three Indian sheep breeds

The genetic structure of three Indian sheep breeds from two different geographical locations (Nali, Chokla from north‐western arid and semi‐arid region; Garole from eastern saline marshy region) of India was investigated by means of 11 ovine‐specific microsatellite markers as proposed in FAOs MoDAD programme. Microsatellite analysis revealed high allelic and gene diversity in all the three breeds. Nali sheep showed higher mean number of alleles and gene diversity (6.27 and 0.65) than Chokla (5.63 and 0.64) and Garole (5.63 and 0.59). High within population inbreeding estimates observed in the three breeds (F_IS, Chokla = 0.286, Nali = 0.284, Garole = 0.227) reflected deficit of heterozygotes. The overall estimates for F‐statistics were significantly (p < 0.05) different from zero. High values of F_ST (0.183) across all the loci revealed substantial degree of breed differentiation. Based on pair wise F_ST and N_m between different breeds, Nali and Chokla (F_ST = 6.62% and N_m = 4.80) were observed to be the closest followed by Garole and Nali (F_ST = 20.9% and N_m = 1.80), and Garole and Chokla (F_ST = 21.4% and N_m = 1.71). In addition, genetic distance estimates, phylogeny analysis and individual assignment test used to evaluate interbreed genetic proximity and population structure also revealed substantial genetic differentiation between Garole and the other two Rajasthani (Nali and Chokla) sheep. This divergent status of Garole sheep indicated genetic uniqueness of this breed suggesting higher priority for its conservation.