Heat-No-Service: Reproductive lifetime performance of gilts inseminated on first versus second observed estrus in commercial piglet producing herds

Joab Malanda Osotsi,Péter Balogh,Gabriella Novotni Dankó

doi:10.34101/actaagrar/1/3731

Abstract

Heat No Service (HNS) is an increasing managerial decision made in commercial piglet producing herds. Performance of gilts has been shown to be influenced by initial decisions made on them at their introduction in the breeding herds. Lifetime Reproductive performance comprising of parity total born piglets and lifetime total born piglets of gilts initially bred on first observed estrus (0HNS) was compared with that of gilts bred on second observed estrus (1HNS). Stored data from Porcitec database consisted of 2.072 gilts bred on first observed estrus (0HNS) and 2.453 gilts bred on second observed estrus (1HNS) totaling to 4.525 gilts. Data was statistically analyzed using the GLM procedure of IBM SPSS version 25. The results showed a significance difference (p<0.001) in lifetime total born performance of gilts bred at 0HNS (mean 93.9) and 1HNS (mean 95.7). There was also a significant difference (p<0.001) of total born piglets in parity 1, 5 and 6 in the 2 groups. There was an observed increased parity total born and lifetime total born when first time insemination of gilts was delayed to second estrus. The findings in this study favor the 1HNS breeding with an overall increased lifetime total born. Gilts inseminated at 1HNS produce 1.57 more pigs for lifetime as compared with those inseminated at 0HNS when observation is made up to P6. Producers in piglet producing herds could re examine their decisions for increased productivity by promoting many gilts into 1HNS but still maintaining the balance between breed targets and production schedules to remain competitive and profitable in the current global swine industry.

Highlights

Gilts constitute a significant proportion of the breeding females (20%–25%) in most herds, and decisions made on gilts are likely to have a significant effect on overall herd performance and profitability (Sporke, 2005)
There is a notable decline in parity total born in both groups from P5–parity 6 (P6) (Table 2) for 0HNS, a finding that is supported by Tummaruk et al (2001) who observed a decline in parity total born from P5–P7
It is concluded that gilts that are inseminated at 1HNS tend to produce 1.57 more pigs for lifetime as compared with those inseminated at 0HNS when observation is made up to parity 6

Summary

Introduction

Gilts constitute a significant proportion of the breeding females (20%–25%) in most herds, and decisions made on gilts are likely to have a significant effect on overall herd performance and profitability (Sporke, 2005). Heat No Service (HNS) is a voluntary managerial decision by identification of pubertal estrus gilts without breeding and is influenced by (i) Physiological status of the gilt (age, body weight and backfat thickness at first service) (ii) Rate of sow replacement/culling in the herd and (iii) Production schedules. Pork producers are frequently advised to delay the breeding of gilts until they are 8 months old and have shown the first estrus (Field and Taylor, 2012). This is based on the fact that prolificacy is enhanced since ovulation rate increases to second estrus (Anderson and Einarsson, 1980; Brooks et al, 1980; Vinsky et al, 2006). Controlled experiment research demonstrated that gilts mated at first estrus produced fewer piglets than counterparts mated at third estrus (MacPherson et al, 1977; Young et al, 1990) in Young and King’s (1981) study, sows mated in first and third estrus were allowed to complete three parities and showed no substantial difference in total productivity

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