Split-Sexing of Finishing Pigs: the Benefits
IRELAND - Are you split- sexing the finishing pigs on your farm? If not, maybe this performance data will make you reconsider, says Hermitage Genetics.Hermitage Genetics has increased the individual ‘testing’ capacity at the Freneystown and Muckalee nucleus farms in Ireland. Between both farms,there is now the capacity to put more than 5,500 animals through the individual ‘test’ system annually.
Freneystown has just completed its first full year of testing in the new MLP feed registration stations. In addition at Nucleus level we also individually measure growth,backfat,loin-muscle depth and lean meat percentage on a further 30,000 pigs each year.
In these individual feed test station pens – feed recording commences on both male and female groups of animals from about 50kg and continues until approximately 110kg.
Each pen and feed station has the capacity to feed 15 pigs and every pig in the group is tagged with a unique coded ear tag transponder. Every visit to the feed station by each individual pig is recorded. The duration of the test period is a minimum of 40 days. The groups ‘on-test’ are categorised by sex and breed.
The system operates on the principle that when the pig is finished eating at the station and withdraws from the Feed Station trough area, the electronic system records the difference between the pre- and post-visit trough weight and the data is then stored in a file with the pen number, the pig’s identification number, and the date and the time of entry and exit.
The recorded data is used to calculate the individual feed intake. Pigs are weighed at the start of the test period and at the end of the test period, this in combination with daily feed intake data allows the feed conversion efficiency to be calculated.
Feed conversion efficiency is then used in combination with other traits of economic importance for both maternal and terminal lines to select the top performing replacement breeding boars for the pig genetics AI stud and best replacement breeding females for the Hermitage nucleus farms.
The results to date clearly demonstrate the significant advantages of split-sexing entire boars and gilts and grading for size prior to commencing the finishing period. Separating the sexes has several benefits (Table 1 below).
Boars and gilts grow at different rates and utilize feed differently. Boars tend to have a higher lean meat percentage than gilts when they reach slaughter weight. On-farm observations show that groups of separately penned boars and gilts:
- show less aggressive behaviour within the group, therefore less fighting
- exhibit less competition for feed, and
- demonstrate more uniform gains therefore less variation within a group.
As a result, less time is required in sorting pigs at point of sale. This system allows for the marketing of more uniform groups of pigs which can result in a higher return at the abattoir. If there is less variation in a group, this means a higher portion of the group will be able to meet the specific carcass specifications of the factory, therefore optimising grading results by size and reducing the possibility of financial penalties.
Hermitage is currently testing all of the replacement females for the Hermitage nucleus herds and all boars for the AI stations for FCE, backfat, loin muscle depth and lean meat percentage.
Table 2 below outlines the average growth performance characteristics of the Hermitage Terminal and Maternal Lines. From the tested animals only the animals with the best Terminal Line and Maternal Line indices and body conformation are selected.
Only the best-performing animals from those tested are selected as replacements. By utilising this on-farm testing protocol it ensures that we select the very best animals for FCE, lean meat percentage and growth rate in the terminal lines; whereas in the maternal lines the aforementioned parameters are used in combination with reproductive characteristics including numbers born alive, litter weaning weight and litters per sow per year.