Swine Resources - Breeding/Reproduction

October 2020

ABSTRACT:

Objective

This study’s objective was to assess the relationship between visually assigned prepubertal vulva score and subsequent sow productivity in a commercial production system.

Materials and Methods

The study was conducted at a genetic nucleus herd, where farm personnel visually classified prepubertal gilts into categories: vulva score 1 (VS1; below average size), VS2 (average vulva size), and VS3 (above average vulva size), at approximately 15 wk of age. Reproductive performance from gilts incorporated into the breeding herd were tracked through 2 parities of production.

Results and Discussion

Age at parity 1 (P1) was greatest (P ≤ 0.01) in gilts assigned a VS1 score compared with those receiving a VS2 or VS3 score. The P1 total pigs born for gilts categorized as VS2, VS3, and VS2/3 (VS2 and VS3 combined into one group) was greater (P ≤ 0.05) compared with gilts receiving a score of VS1. The number of pigs born alive was also lower (P ≤ 0.05) for gilts assigned a VS1 compared with those assigned VS2 or VS3 and the combined group (VS2/3). Second parity litter performance was not affected (P > 0.18) by prepubertal vulva score assignment, although total pigs born and pigs born alive through 2 parities combined tended to be greater (P ≤ 0.08) for gilts in the combined VS2/VS3 group compared with those assigned a score of VS1.

Implications and Applications

These data suggest visually assessing prepubertal vulva development may identify females more likely to farrow at a younger age with improved P1 litter performance.

Matthew R. Romoser, Tom Gall, Lance H. Baumgard, Aileen F. Keating, Kenneth J. Stalder PAS, Jason W. Ross
https://doi.org/10.15232/aas.2020-02034

April 2020

Post-cervical artificial insemination doses took less time than cervical doses to reach the desired temperature, but sperm quality was similar for CAI- and PCAI-doses during storage.

November 2019

In a series of articles, swine reproduction and insemination specialist, Javier Gil Pascual, addresses the key aspects of oestrus stimulation and detection, and insemination.

Achieving a good return to oestrus, both in weaned sows and gilts, improving fertility and obtaining the maximum prolificacy of the genetics we are using, continue to be a challenge on most farms.

All management practices related to gilts coming into heat and estrous detection, along with insemination, are determining factors in the reproductive success of a farm. We will logically start this article series from the beginning and address oestrus stimulation in this first article.

July 2019

The fact that the major phenotypic characteristic of boar spermatozoa, motility, is constrained by time of cryostorage should be considered when building cryobanks of pig semen.

September 2018

L-proline supplementation during early-pregnancy improves litter size and birth weight in sows with negative energy balance.

September 2018

A novel gel formulation was selected for intravaginal delivery of the GnRH agonist (triptorelin) for synchronizing ovulation in pigs. Studies with gilt models were used to assess LH response profiles. The lowest dose of triptorelin that induced the most gilts to show an LH surge was 100 μg in 1.2% methylcellulose gel. This formulation had a similar effect in weaned sows while also advancing ovulation. The timing of administration was evaluated in sows after weaning. Administration at 96 h induced more sows to ovulate (58%) by 48 h compared to treatment at estrus (45%) or for controls (34%), but the desired level of ovulation synchrony was not achieved. As a result, greater doses of triptorelin were tested and 200 μg given at 96 h after weaning, induced 81% of sows to ovulate within 48 h after treatment. The best synchrony of ovulation occurred when given at 96 h after weaning compared to earlier or later intervals. The optimum time to give a single fixed time AI (SFT-AI) after administration of 200 μg of triptorelin in 1.2% gel (OvuGel®) at 96 h after weaning was tested. A SFT-AI at 22 ± 2 h after OvuGel achieved the highest fertility and was practical for staff during the normal work day. In field trials, a SFT-AI 22 ± 2 h after all weaned sows were treated with OvuGel improved (P = 0.04) farrowing rate to 82.5% compared to control sows weaned (80.1%), with no effect on numbers of pigs born alive (12.1). Research continues for identifying the advantages for use of OvuGel in different production systems, and potential application for use in gilts.

Knox RV, Stewart KR, Flowers WL, Swanson ME, Webel SK, Kraeling RR;
Design and Biological Effects of a Vaginally Administered Gel Containing the GnRH Agonist, Triptorelin, for Synchronizing Ovulation in Swine;
Theriogenology. 2018 May;112:44-52. doi: 10.1016/j.theriogenology.2017.08.021. Epub 2017 Aug 24. PMID: 28863964 DOI: 10.1016/j.theriogenology.2017.08.021

May 2018

This trick tries to reduce the number of deaths by providing the piglets more resting space by using the corridor.

The goal is to avoid the crushing of piglets in the farrowing pens. The reduced size of the farrowing pens on a farm may be the culprit for a great part of the deaths due to crushings as of their first week of life. With this method we try to reduce the number of deaths by providing the piglets more resting space by using the corridor.

March 2018

Tad Sonstegard

Castrating pigs is not a favorite chore for pork producers, but it’s necessary for meat quality and barn management. Now, scientists at the gene-editing company, Recombinetics, have developed a precision breeding method resulting in male piglets that remain in a prepubertal state, thus, ending the need for castration. Recombinetics has partnered with Nebraska-based swine genetics supplier DNA Genetics to evaluate, develop, and commercialize the castration-free (CF) swine trait. Research is being led by Tad Sonstegard.

By 
Betsy Freese
3/6/2018

February 2018

The average piglet birth weight from the 3 groups of vaccinated sows was statistically higher than that from the unvaccinated sows.