Uso de análise multivariada para determinar a associação do desempenho reprodutivo de machos suinos com as caracteristicas seminais / Use of multivariate analyses to determine the association of boar fertility with semen traits

AUTOR(ES)
FONTE

IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia

DATA DE PUBLICAÇÃO

2012

RESUMO

The application of new approaches that measure certain sperm motion characteristics and their association with boar fertility has shown a recent increase. Computer-assisted semen analysis (CASA) offers standardized assessment of multiple sperm motion parameters and it is plausible that the combination of these parameters with morphological sperm defects may indicate the fertility potential of boars. The fertility outcome (farrowing rate - FR and number of total piglets born - TB) of 14 boars was obtained from a field trial conducted in a commercial farm using multiparous sows through single sire mating with two billion motile sperm cells per AI dose. Sows (n=948) bred were equally distributed among boars according to parity, mean lifetime number of piglets born, body condition score, weaning-to-estrus interval, lactation length and number of weaned piglets during 10 weeks of breeding period. Sperm motion parameters evaluated with CASA system in natura and in semen stored at 17°C for 240h in addition to morphological sperm defects, measured at the collection day, were included in the analysis to determine which semen traits were important to discriminate the fertility potential of ejaculates from these boars. The data underwent multivariate statistical analysis, including cluster, canonical and discriminant analyses. Among the 14 evaluated boars four clusters were formed based on fertility outcome. One boar, with the lowest FR and TB values (89.7% and 11.98), and two boars, with the highest FR and TB values (97.8% and 14.16), were placed in different clusters. The others boars were separated in two new distinct clusters (4 and 7 boars), including boars with intermediate TB (12.64 and 13.22) but divergent values of FR (95.9% vs. 91.8%). Canonical analysis was able to separate the individual ejaculates into the previously clustered boars and a better separation was shown between the lowest fertility group and the others. Semen traits which had higher discriminatory power included total motility, progressive motility, amplitude of lateral head displacement, analyzed during semen storage, and sperm morphological defects such as cytoplasmatic droplets. The multivariate discriminant analysis showed that more than 80% of the 140 ejaculates were correctly classified into their own group. The multivariate analysis can be an efficient statistical tool to improve the discrimination of potential fertility of boars.

ASSUNTO(S)

reproducao animal : suinos casa análise multivariada fertility fertilidade animal sperm defects motilidade espermática sperm motility boar desempenho reprodutivo : suínos

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