Comparison between body condition scoring and subcutaneous fat thickness and its relation to reproductive efficiency in Mangalarga Marchador donor mares / ComparaÃÃo entre escore de condiÃÃo corporal e espessura de gordura subcutÃnea e sua relaÃÃo com a eficiÃncia reprodutiva de Ãguas doadoras Mangalarga Marchador

AUTOR(ES)
DATA DE PUBLICAÇÃO

2009

RESUMO

Body condition scoring (BCS) was compared to ultrasound subcutaneous fat thickness (SFT) determination and their relation to the reproductive efficiency of Mangalarga Marchador embryo donor mares. Fifty six barren mares were studied throughout the 2008/2009 breeding season (August through April). Body condition score, evaluated monthly, was obtained form the average of two evaluators on a 1-9 scale, from very thin to very obese. Tailhead and rib (between the 12nd and 13th ribs) SFT was evaluated monthly by ultra-sonography. SFT was captured through Image Pro-Plus 4.5. Mare weights were estimated monthly with a specific tape. Embryo recovery rates (ER) and 30, 60 and 90 day recipient mare (n=174) pregnancy rates (PR) were compared by chi square. Data were submitted to the mixed procedure (SASÂ) and lsmeans were used. Age, BCS and time effects on dominant follicular diameter were analyzed by the analyses of variance (GLM, SASÂ). Correlations were analyzed by the PROC CORR (SASÂ), and regression by PROC REG. BCS was higher in older mares (P=0.02) and increase with time in experiment (P=0.009), and there was a positive interaction between weight and time (P<0.0001). Weight was not associate with age, but increased throughout the experiment (P=0.03). Tail (P=0.04) and rib (P=0.03) BCS increased with age (P<0.0001), and decreased (P=0.02) with time. There was a positive correlation between BCS and tail and rib SFT (P<0.0001). Dominant follicle diameter increased along the estrous cycle (P<0.0001) and was smaller (P<0.05) for mares with BCS below 6.5. Time but not age influence dominant follicle diameter (P<0.01). Mean ovulatory follicle diameter was 38.43 Â 3.09. ER was not affected by age or BCS but was lower (41%, P=0.003) in mares that ovulated follicles smaller than 40mm compared to mares ovulating follicles greater than 40mm (59%). Donor age was not associated with recipient pregnancy rates. It is concluded that the embryo recovery rate and ovulatory dominant follicle diameter were associated to body fat deposition; moreover, body condition scoring was not a good predictor of subcutaneous fat depth under the present conditions, since it decreased with time in experiment, with increased physical activity. Thus, it seems that ultra-sonography may be essential for correct and reliable body condition scoring, especially for horses under marching exercise management.

ASSUNTO(S)

reproduction transferÃncia de embriÃes equine reproduÃÃo equino balanÃo energÃtico zootecnia embryo transfer energy balance

ACESSO AO ARTIGO

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