ARS | Publication request: Prepubertal Scoring of Scale Activity in Gilts and Its Potential Relationship to Subsequent Fertility and Reproductive Performance in Landrace-Duroc-Yorkshire Cross Females

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: March 31, 2009
Publication Date: June 20, 2009
Citation: Rempel, L.A., Rohrer, G.A., Brown-Brandl, T. 2009. Prepubertal Scoring of Scale Activity in Gilts and Its Potential Relationship to Subsequent Fertility and Reproductive Performance in Landrace-Duroc-Yorkshire Cross Females [abstract]. Proceedings of VIIIth International Conference on Pig Reproduction, Banff, Alberta, Canada, p. 177.

Technical Abstract: A majority of animals culled due to reproductive failure are skewed towards younger parities (1 or less), decreasing the economic potential of the herd, thereby leading to an overall reduction in the herd’s sow lifetime productivity. The ability to identify young females with superior reproductive potential would have a large economic impact on commercial swine production. Therefore it was our objective to monitor temperament in prepubertal females and determine if a relationship existed between behavior and reproductive and production performances. One thousand two hundred thirty-two Landrace-Duroc-Yorkshire females were scored for behavioral tendencies at approximately 154 days of age during a scheduled weighing. Animals were scored from 1 to 5 at 0.5 increments while being weighed. A description of rated scale activity is as follows: 1) remains calm with little or no movement; 2) walks forward and backward at a slow pace; 3) continuously moves forward or backward at a rapid pace; 4) continuously moves forward or backward at a rapid pace with vocalization; and 5) continuously moves forward or backward at a rapid pace with vocalization and attempts to escape. Subsets of scored animals were also monitored for age at puberty (AP) measured as first detected estrus; day 35 post-breeding pregnancy diagnosis; farrowing rate; and production parameters including total number born (TNB), number born alive (NBA), and number weaned by dam (WND_DAM); ovulation rate (OR); and weaning-to-estrus interval (WEI). Data were collected on animals through parity 2. Animals that were scored 3 or greater had a decreased (230.0 ± 2.18 d; P = 0.0048) AP in contrast to animals that were scored between 1 and 2.5 (236.9 ± 1.13 d). Scale activity scores were related to pregnancy diagnosis at 35 days post-breeding as well as farrowing rate where animals with greater activity scores were more often diagnosed pregnant (P = 0.0264) and farrowed (P = 0.0278), respectively. Regression analysis indicated that a one-degree increase in scale activity score increased pregnancy rate by approximately 3.3% (P = 0.0173) and farrowing rate by 3% (P = 0.0345). However no significant correlations were detected between AP and early pregnancy diagnosis or farrowing rate (P = 0.1537 and P = 0.2063, respectively). None of the measured production traits (TNB, NBA, WND_DAM) were affected by the early activity score (P > 0.05). Likewise, WEI and OR were not impacted by the scale activity score (P > 0.05). These results indicate that prepubertal behavior may be useful as an indicator for females that have an increased fertility as measured by AP, pregnancy rate, and farrowing rate. Furthermore, since animals with greater scale activity scores at 154 days of age had no negative impacts on litter production performance, it may be plausible that earlier selection for these active animals will not detrimentally affect herd production, but rather increase it as a function of improved fertility.