How to Improve Prolificacy

and Hyperprolificacy in French Data

Dr. Christian Lecour

MULTIGENE USA, LLC

Presently the tools we use to improve hyperprolificacy are:

Hyperprolific boars and females

Use of Blup index with emphasis on number of piglets total born or born alive

Maximization of heterosis effect

Biotechnology, MAS, QTL…

In 1976, Christian LEGAULT from INRA (French National Research Institute of Agriculture) found that 1 sow in 1000 had the ability to produce a very different level of number of piglets and would be able to transmit this capacity to their daughters.

One sow in one thousand has a genetic potential of + 2.5 piglets per litter.

This sow is used to make boars and gilts, which will have a genetic potential of one half of their parents.

The potential of the daughters of such a boar is between +0.6 and +1.1 piglets per litter.

The breeding program produces boars from hyperprolific sows; these boars are used on normal sows to improve the number of piglets in the first generation. Finally, breed the gilts from these boars with a new hyperprolific boar and so on for each generation.

Use of Blup index with emphasis on number of piglets total born

This method is used in the French open lines, and permits a very fast increase in the genetic potential of total born piglets.

The effect of selection on total born is not highly correlated with the number of live and weaned piglets. Don’t forget the importance of weaned piglets on cost of slaughter pigs.

Selection on only one or two criteria makes a big difference between genetic level and the genotype result.

This graphic shows that a high selection on the total born criteria in not enough, we must also make selection on all the characters who influence the prolificacy.

In addition to genetic value, other criteria must be integrated into a breeding plan!

· Mortality rate (for both, sows and piglets)

· Extreme leanness (<12 mm) can affect the ability for good adaptation of gilts, and mortality rate of sows.

· Piglets’ weight, both total and individual, and repartition of weight in each litter make a large difference at weaning time.

· Ability to wean heavy piglets (milky sows)

· Not only the number of teats but also their size, and the ability of sows to produce milk should be registered if you are to select for it.

· Non aggressive sows with man and pigs

· Outdoor or indoor sows must have the capacity to adapt themselves without stress.

· Easy return to heat after weaning

· Stress or quiet sows make the differences in control or expression of heat. Selection is possible on the character of sows.

· Good conception rate

· Easy return to heat is advantageous to good AI, and improves conception rate.

· Ability to farrowing with less manual intervention

· Time is money… Easy to farrow sows may also have genetic influence and must be selected even if the subjective effect is great…

The Heterosis Effect

Estimated effect of Heterosis on pig (Sellier 1970)

	ONE BREED	TWO BREED	3 BREED CROSS
Piglets born alive	100	102	108
Number of weaned piglets	100	108	116
Litter weight at birth	100	104	110
Litter weight at weaning age	100	115	125
Individual piglet wt. at weaning	100	106	107
Daily gain after weaning	100	106	107
Pig weight at 154 days	100	110	110
Feed conversion	100	103	103
Body fat composition	100	100	100
Percent of meat	100	100	100

The heterosis has an increased effect each time you introduce a new breed, or you have a significant difference between each breed. To maximize the effect of heterosis, SCAPAAG – MULTIGENE has developed three maternal lines, selected on prolificacy, with a great number of criteria adding to the ability to wean the maximum number of piglets per sow per year. Some criteria are in a Blup index, others are individual indexes, including subjective notation.