Veterinary World, EISSN: 2231-0916 RESEARCH ARTICLE Available at www.veterinaryworld.org/Vol.12/July-2019/31.pdf Open Access Retrospective study of the reproductive performance of Barb and Thoroughbred stallions in Algeria Nedjma Aouane1, Abdelkrim Nasri2, Mohamed Al Amine Bekara3, Ahmed Khireddine Metref4 and Rachid Kaidi4 1. High National Veterinary School of Algiers, Oued Smar, Algiers, Algeria; 2. National Stud farm of Chaouchaoua, Tiaret, Algeria; 3. Laboratory of Molecular Biology, Genomics and Bioinformatics, Department of Biology, Faculty of Nature and Life Sciences, University Hassiba Benbouali of Chlef, Algeria; 4. Laboratory of Biotechnology of reproduction, Veterinary Science Institute, University of Blida, Algeria. Corresponding author: Nedjma Aouane, e-mail: [email protected] Co-authors: AN: [email protected], MAB: [email protected], AKM: [email protected], RK: [email protected] Received: 21-01-2019, Accepted: 21-05-2019, Published online: 26-07-2019 doi: 10.14202/vetworld.2019.1132-1139 How to cite this article: Aouane N, Nasri A, Bekara MA, Metref AK, Kaidi R (2019) Retrospective study of the reproductive performance of Barb and Thoroughbred stallions in Algeria, Veterinary World, 12(7): 1132-1139. Abstract Background and Aim: The Barb horse occupies a prominent place in the history, culture, and equestrian traditions of the Maghreb (Algeria, Morocco, and Tunisia). Although many studies on the breed standard and morphometry have been published, there are no studies on its fertility and reproductive potential. Thus, this work aimed to study the fertility of Barb, Arabian Purebred, and Thoroughbred horses in Algeria. Materials and Methods: A total of 168 stallions and 1202 mares at the Chaouchaoua Stud farm in Tiaret, Algeria, were included in the study. The reproductive performance during 1592 cycles over 10 consecutive mating seasons (2003-2012) was evaluated. Multivariate analysis with logistic regression was used to analyze the reproductive parameters such as the number of cycles operated, number of pregnant mares, pregnancy rate per cycle, seasonal pregnancy rate, and embryonic mortality rate, and to determine the influence of breed, stallion’s age, and year of the study on reproduction. Results: Statistical analysis showed that stallion breed was a significant influencing factor for the number of pregnant barren mares (Odds ratio [OR]=1.72; p=0.03; 95% confidence interval [CI]=1.05, 2.84) seasonal pregnancy rate (OR=1.40; p<0.001; 95% CI=1.29, 1.53). Additionally, the reproductive performance of the Barb stallion was superior to that of the Thoroughbred stallion. With regard to the significant influence of stallion’s age of >5 years on the number of pregnant foaling mares and seasonal pregnancy rate, significant interactions were observed between the stallion’s breed and age, and the pregnancy rate per cycle: in the Barb breed, the pregnancy rate per cycle increased with the age of the stallion, while in the Thoroughbred, it decreased with age. Moreover, a significant effect of the year of the study on the pregnancy rate per cycle and number of pregnant foaling mares was observed. In contrast, the number of cycles and embryonic mortality rate were not influenced by the breed and age of the stallion, or the year of the study. Conclusion: The Algerian Barb horse attained a similar level of fertility compared with that of the Arabian Purebred and Thoroughbred stallions depending on its age and reproductive performance. Keywords: age, Barb, breeding performance, breed, stallion. Introduction sub-Saharan Africa (Madagascar, Mali, Senegal, and Barb horse is the representative breed of equines South Africa etc.) [3] Due to its excellent learning of North Africa (Algeria), and has an important place ability through characteristics of docile nature and in the history, culture, and tradition of the society. It highly developed faculties of assimilation and under- is generally used in the Fantasia (traditional exhibi- standing [4]. However, the Algerian Barb population tion of horseback riding in the Maghreb), as well as in amounts to 100.000 horses (10.000 Barb and 90.000 equestrian sports (endurance and jumping). In Algeria, Arab-Barb) [3,5]. the Barb is considered an autochthonous equine breed, To the best of our knowledge, several studies with genetical relationship to the Arabian horse [1,2]. focused on genetic characterization and morphome- Currently, the importance of the Barb horse extends try of Barb horses are reported in the literature [2,3], to other countries worldwide notably those in Europe but, unlike studies on the Arabian Purebred and (Spain, Italy, Malta, England, and France etc.) and Thoroughbred worldwide, studies on the reproductive performance of the Barb horses in Algeria are lacking. Copyright: Aouane, et al. Open Access. This article is distributed The influencing factors of the breeding performance under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/ of horses are generally categorized as explanatory by/4.0/), which permits unrestricted use, distribution, and variables related to the stallion, mare, and manage- reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the ment practices of animal husbandry [6]. Creative Commons license, and indicate if changes were made. In our study, we included the age and breed The Creative Commons Public Domain Dedication waiver (http:// creativecommons.org/publicdomain/zero/1.0/) applies to the data of the stallion and year of the study as variables in made available in this article, unless otherwise stated. the analysis of reproductive parameters such as the Veterinary World, EISSN: 2231-0916 1132 Available at www.veterinaryworld.org/Vol.12/July-2019/31.pdf number of operated cycles, number of pregnant mares total number of impregnated mares) was considered by category (barren, maidens, and foaling), con- as the most sensitive criterion for assessing the stal- ception rate per cycle, seasonal pregnancy rate, and lion’s fertility, which reflects the actual capacity to embryonic mortality rate. The study aimed to assess initiate gestation. In addition, the embryonic death the influence of and interaction(s) among the differ- rate (early or late) and seasonal pregnancy rate were ent factors that may affect the fertility of the Arabian evaluated according to the stallion breed: Barb (Barb Purebred, Thoroughbred, and Barb horses. and Arabian Barb) and others (Arabian Purebred and We conducted a multivariate analysis of the fer- Thoroughbred). tility data obtained in stallions during ten consecutive Statistical analysis mating seasons (2003-2012) at Chaouchaoua stud For data collected in this study, descriptive sta- farm, Tiaret, Algeria, the location considered as the tistical analysis was used, and continuous variables natural cradle of the Barb horse. were presented as mean and standard deviation, while Materials and Methods the categorical variables as absolute and percentage frequencies. Ethical approval This study was approved by the scientific council To study the impact of the characteristics of the of High National Veterinary School, Algiers, Algeria. stallion, including the breed (Barb vs. other breeds), age, and year of the study (from 2003 to 2012) on the Animals and place of study reproductive performance indicators of mares, a mul- A retrospective study was conducted with the tivariable generalized linear model was used. fertility records of the stallions at the Chaouchaoua To analyze reproductive performance in terms National stud farm of Tiaret (Algeria), during ten con- of the number of cycles operated, a linear regression secutive breeding seasons (2003-2012). In Algeria, the model was used Results of the model were reported as season of administrative mating begins on February 15 the mean difference in the number of cycles operated and ends on June 15 of each year. In our study, a total of with associated 95% Confidence Interval (CI) and 168 stallions of different breeds (Barb, Arabian Barb, p-value. Arabian Purebred, and Thoroughbred), aged between k yX=+αβ 4 and 30 years old, and who served a large number iK∑ k =1 iK i of mares of corresponding breed (1592 cycles) were ~,N 0 σ 2 included. Mares were categorized into three types i ( ) th according to their physiological status at the begin- Where for the i observation, γi is the number of ning of the season: Barren mares considered as prob- cycles operated, α is the intercept of the model, Xik is a lematic with pathological endometritis, embryonic vector of k covariates (breed, age, and year), βk is the mortality, or abortion; foaling mares, arrived at the associated coefficient, and ϵi is the error term. stud with a foal, and hence with reproductive history To assess the impact of the characteristics of known; maidens, never bred, young or sporty. the stallion (breed and age) and year of the study on the reproductive performance indicators including the Detection of heat and mating rate of gravid barren mares, pregnant foaling mares, In mares in estrus (heat), daily trans-rectal ultra- and gravid maiden mares, conception rate per cycle, sound examination was carried out to monitor the seasonal pregnancy rate, and early-embryonic death follicular growth, and thereby, determine the time rate, logistic regression models were used For each of closer to ovulation and minimize the use of stallions the indicators of reproductive