Group-training of rams at puberty for artificial vagina-mediated semen collection and its influence on semen quality and sexual behavior

There is a paucity of information with respect to group-training for artificial vagina and its influence on semen characteristics and sexual behavior of young untrained rams. A total of 18 healthy Najdi rams (with an initial body weight of 40-45 Kg and 7-8 month-old) were consequently used herein to test the usefulness of group-training for artificial vagina-mediated semen collection during the breeding season. Rams were randomly segregated into three groups (n = 6 rams per protocol), and the whole experiment was lasted for 10 weeks. The 1st group was subjected to a training protocol where one untrained ram was placed for 20 min with a teaser ewe, while the 2nd group were subjected to a protocol where one untrained ram was placed for 20 min with one trained ram and a teaser ewe, whereas the 3rd group were subjected to a protocol where three untrained rams were placed for 20 min with one trained ram and a teaser ewe. The obtained results clearly (P < 0.05) showed that training young rams in group has increased their sperm concentration and sexual stimulation, shortened the period of their training time, and descriptively had a complete training efficiency. The sexual stimulation of young untrained rams was intensified by the competition between rams in the co-presence of a trained ram. Collectively, these data may suggest that group-training of rams at puberty is a better protocol for AV-mediated semen collection compared to individual training. Some shortcomings were noted herein, but research dealing with this subject may very well improve the reproductive performance of young untrained rams.(AU)

DESEMPENHO E COMPORTAMENTO REPRODUTIVO DE OVINOS DESLANADOS

Na região Nordeste a criação de ovinos tem papel importantíssimo e fundamental no desenvolvimento da região, fortalecendo ainda mais a ovinocultura, que é atividade tradicional e marcante não só apenas nessa região, como também em todo território nacional.A eficiência reprodutiva é um dos principais pilares para o sucesso da ovinocultura, sendo responsável pelo crescimento populacional do plantel, pela propagação de genes de interesse zootécnico e respostas cada vez mais hábeis por parte dos animais.Obter todas as informações sobre a performance reprodutiva, assim como conhecer as ações inerentes ao comportamento sexual dos ovinos, são fatores importantíssimos para obtenção de bons índices zootécnicos e o próprio aumento da eficiência reprodutiva de um determinado plantel. Na reprodução, o comportamento reprodutivo das fêmeas e dos machos possuem importante papel, afetando tanto o sucesso do acasalamento, quanto a sobrevivência da prole. Portanto, o conhecimento dos padrões de comportamento das raças é necessário para a definição de um modelo de manejo mais adequado à sua exploração.Nesse sentido,objetivou-se avaliar o desempenho e comportamento reprodutivo de ovinos deslanados.O trabalho foi conduzido na Estação Experimental Benjamin Maranhão (6°S, 35°W, 188 m altitude). Foram utilizadas 35 fêmeas Dorper, 35 fêmeas Santa Inês e 6 reprodutores adultos, sendo 3 para cada genótipo, todos com experiência sexual previa. O desempenho reprodutivo foi avaliado por meio de índices zootécnicos. Os registros comportamentais foram realizados no período das 07:00 às 10:00 h e das 14:00 às 17:00 h, utilizando-se a amostragem do tipo animal focal. As médias da soma de escore das variáveis em cada tratamento foram comparadas pelo teste qui-quadrado de Friedman. Os índices reprodutivos foram expressos em forma de percentagem, por meio de análise descritiva. Observou-se uma taxa de prenhez de 97,1 e 85,7% para as ovelhas Dorper e Santa Inês, e o oposto para a taxa de fertilidade no parto de 85,2 e 96,7% para as ovelhas Santa Inês e Dorper, respectivamente. Os comportamentos sexuais mais evidenciados pelos animais do genótipo Santa Inês foram: cheirar região urogenital da fêmea, reflexo de Flehmen, urinar, cheirar urina, vocalização, exposição da língua, cortejo com patas, cabecear, perseguição e monta para a conduta sexual dos reprodutores, e reflexo de Flehmen, balançar a cauda, levantar a cauda e aceitar monta com cobrição para o comportamento reprodutivo das fêmeas, essas condutas comportamentais diferiram estatisticamente (P<0,05) em função do grupo genético. Fêmeas e os reprodutores da raça Santa Inês demonstraram maior atividade sexual em relação ao grupo Dorper. Em conclusão, os animais da raça Santa Inês demonstraram maior atividade sexual em relação aos animais do rebanho Dorper, sendo evidenciado pela expressividade das condutas comportamentais desse genótipo durante o regime de monta natural. Apesar do genótipo Santa Inês apresenta-se mais ativos sexualmente do que o rebanho Dorper, eles tiveram desempenho reprodutivo semelhante. Além de altos índices zootécnicos em ambos os genótipos

In the Northeast region, sheep farming plays an important and fundamental role in the development of the region, further strengthening sheep farming, which is a traditional and remarkable activity not only in this region, but also in the entire national region.Reproductive efficiency is one of the main pillars for the success of sheep farming, being responsible for the population growth of the herd, for the propagation of genes of zootechnical interest and increasingly skillful responses on the part of the animals.Obtaining all information about reproductive performance, as well as knowing the actions inherent to the sexual behavior of the sheep, are extremely important factors for obtaining good zootechnical indexes and the very increase in the reproductive efficiency of a given herd.In reproduction, the reproductive behavior of children and males plays an important role, affecting both the success of mating and the survival of the role. Therefore, knowledge of the behavior patterns of the breeds is necessary to define a management model more appropriate to their exploitation.In this sense,objective was to evaluate theperformance and reproductive behavior of ovines without wool. The work was carried out at the Experimental Station Benjamin Maranhão (6 ° S, 35 ° W, 188 m altitude). 35 Dorper females, 35 Santa Inês females and 6 adult breeders were used, 3 for each genotype, all with previous sexual experience. Reproductive performance was assessed using zootechnical indexes. Behavioral records were performed from 07:00 to 10:00 h and from 14:00 to 17:00 h, using focal animal sampling. The averages of the sum of the score of the variables in each treatment were compared using the Friedman's chi-square test. The reproductive indices were expressed as a percentage, through descriptive analysis. There was a pregnancy rate of 97.1 and 85.7% for the Dorper and Santa Inês ewes, and the opposite for the fertility rate at birth of 85.2 and 96.7% for the Santa Inês and Dorper ewes, respectively. The sexual behaviors most evidenced by the animals of the Santa Inês genotype were: sniffing the female's urogenital region, Flehmen's reflex, urinating, sniffing urine, vocalization, tongue exposure, courting with paws, heading, chasing and riding for the reproductive sexual conduct, and Flehmen's reflex, swinging the tail, lifting the tail and accepting breeding with the breeding behavior of females, these behavioral behaviors differed statistically (P <0.05) depending on the genetic group. Females and Santa Inês breeders showed greater sexual activity in relation to the Dorper group. In conclusion, the animals of the Santa Inês breed showed greater sexual activity in relation to the animals of the Dorper herd, being evidenced by the expressiveness of the behavioral behaviors of this genotype during the natural breeding regime. Despite the genotype Santa Inês is more sexually active than the Dorper herd, they had similar