Reproductive response of crossbredBos taurus × Bos indicuscows to biostimulation by pre‐pubertal and pubertal teasers

Abstract

AbstractAlthough the beneficial effect of biostimulation on reproduction has been reported, the influence of selectivity and social factors on the response to biostimulation has not received sufficient research attention in bothBos indicusandBos indicusinfluenced cattle. Furthermore, ‘green and cheap’ strategies to improve cattle reproduction are currently in demand whileBos indicusinfluenced cattle with inferior reproductive performance, and farmers with economic limitations are common in tropical zones. Hence, to assess the reproductive response of crossbredtaurus × indicuscows to biostimulation by pre‐pubertal (PPM) or pubertal (PM) teasers males, two trials of 2 years each were conducted. Trial 1n = 187 cows (Year 1:85 cows exposed to PPM and Year 2:102 cows exposed to PM). Trial 2n = 196 cows (Year 1:101 cows exposed to PPM and Year 2:95 cows exposed to PM). The effect of exposing cows to PPM and PM on the intervals calving to first service (ICFS), calving to conception (ICC) and economic cost of days open (ECDO) was analysed using Kruskal–Wallis ANOVA and the effect of exposing cows to PPM and to PM on reproductive status at 90 days (RS90) and proportion of cows requiring hormonal protocols (PRH) was compared usingχ2analysis. Both ICFS and ICC were shorter (p < .0001) for PM‐exposed females (96.12 ± 4.1 and 110.93 ± 2.9 days; respectively) compared with those PPM‐exposed (134.41 ± 3.3 and 135.64 ± 2.4 days; respectively). With RS90, more (p < .0001) PM‐exposed cows (50.7%) were pregnant compared with PPM‐exposed cows (16.1%). The PRH was greater (p < .0001) in PPM‐exposed cows (79.0%) compared with PM‐exposed (27.9%). The ECDO was less (p < .0001) in PM‐exposed cows (US$ 142.9 ± 3.8) compared with PPM‐exposed (US$ 176.3 ± 2.9). In conclusion, cows exposed to PM had shorter ICFS and ICC compared with cows exposed to PPM. More cows exposed to PM were pregnant after 90 days, and PRH was less than cows exposed to PPM. Cows exposed to PM had a reduced ECDO than those exposed to PPM.