263 Improvest Improves Gilt Performance

Abstract

Abstract Improvest (Zoetis, Parsippany NJ) is approved in the U.S for temporary suppression of estrus in gilts. Estrus suppression has secondary performance benefits, including increased average daily feed intake (ADFI), which leads to greater average daily gain (ADG), greater final body weight (FW), and improved group uniformity. Based on 4 recent (2016 to 2021) peer-reviewed articles (Brazil, Belgium, and Spain) and 5 Zoetis studies (USA and Canada), this summary quantifies the arithmetic mean (average) percent increase and the 95% confidence interval for ADFI, ADG, FW and hot carcass weight (HCW) of Improvest-treated gilts compared with untreated control gilts. The confidence interval (CI) was calculated in Microsoft Excel based on the average, standard deviation of the population, and the number of data points (measurements) for each parameter. Results showed that Improvest-treated gilts had a 3.2% (CI: 2.78% - 3.71%) increase in FW and 3.1% (CI: 2.49% - 3.91%) increase in HCW compared with controls. Overall ADG was increased by 4.4% (CI: 3.53% - 5.31%), with an 11.7% (CI: 68.7% - 14.66%) increase after the second dose. Similarly, Improvest-treated gilts showed an increase in overall ADFI of 6.1% (CI: 4.59% - 7.53%), and 12.8% (CI: 11.41% - 14.13%) increase after the second dose. There were no significant differences in overall feed efficiency (FE) in any of the studies. The rapid increase in ADFI occurs 7-10 d after the 2nd Improvest dose. Feed supplies must be managed carefully during this period to avoid out-of-feed events and capitalize on the increased ADG. This summary provides producers with solid estimates of the performance benefits associated with estrus suppression in gilts. Improvest clearly demonstrated an increase in HCW in gilts across all studies. Strategic use of Improvest has the potential to mitigate slow growth and reduced ADFI that is seen in the summer heat. TU-07020