Breeding soundness evaluation and reproductive management in Baldras sport horses

Abstract

Morphometric characterization, breeding soundness evaluation and reproductive management of 33 sport horses (14 mares and 19 stallions) belonging to Palace Administration was carried out for 6 months from January to June/2014. Animals were also subjected to condition scoring, and detailed evaluation through ultrasonography, semen analysis and fertility test using AL The overall age, BCS and body weight were 15±5.7 years, 5.2±1.3 and 327.7±33.3 Kg, respectively. Stallions were significantly older than the mares while mares were heavier with relatively poorer BCS. Body weight was significantly correlated with girth both in mares (p<0.05; r=0.97) and stallions (p<0.05; r=0.68). Comparison of body morphometry among mares, studs and neutered stallions showed a significant difference (p<0.05) in loin length, front and hind leg height, and head length. BCS and scrotal circumference of the breeding stallions (n=12) were highly correlated (P<0.05; r=0.60). The length of estrous cycle and estrus in the breeding mares were 16.1±3.5 days and 7-12 days, respectively. There was a significant difference (P<0.05) in the total number of follicles among the mares. The mean (±SD) diameters of the first-largest and pre-ovulatory follicles were 24.3±9.23 mm and 29.4±9.19 mm, respectively. There was a significant difference (P<0.05) in the diameter of the preovulatory follicles among the breeding mares. Fresh semen was generally characterized by poor motility (<50%), small live percent (54.3%), high gel volume (>40%) and very poor freeze ability (<10% in total motility of frozen thawed semen) however, fertility of fresh semen was 50%. Poor performances are signs of inbreeding that also render the studs unfit for breeding. A proper reproductive management is required to mitigate further loss of performance and influence of inbreeding depression.

Keywords: breeding soundness, morphometry, semen analysis, sporting horses, ultrasonography