Wageningen UR performed a literature study on the nutritional demands of lactating sows in welfare friendly housing systems with an extended lactation and insemination during lactation. The literature showed that knowledge about the feeding of sows that are both gestating and lactating during an extended lactation is limited.
As part of a joint research project within the pig production chain, a group housing system for farrowing sows and her piglets is developed. In this system, lactation is prolonged to 6 weeks compared to 4 weeks in conventional housing and sows are inseminated during lactation. As part of the Public Private Partnership Feed4Foodure, a literature study was performed on the nutritional demands of sows that are both lactating and gestating.
Feeding level after insemination not clear yet
In general, sows have a negative energy balance during lactation which could negatively affect the number of sows becoming in oestrus. Therefore, a high feeding level before insemination is necessary. Also for a good follicle development a high feeding level is important.
The optimum feeding level after insemination during lactation, however, is not clear. Because the sows are still lactating, a high feeding level is probably desirable. A high feeding level might ensure that enough energy is available for development of the embryos, besides energy for maintenance and milk production. However, a high feeding level after insemination reduces the progesterone level in the blood and this might negatively affect embryonic survival rate, especially in young sows. In a recent study, however, there were no indications that a high feeding level after insemination negatively affected litter size in the next parity. The literature study shows that the effects of a high or a low feeding level after insemination during lactation on farrowing percentage and litter size in the next parity are not clear. In 2014, the latter will be further studied in an experiment which will be conducted at de Swine Innovation Centre Sterksel in the Netherlands.
This study was carried out by Wageningen UR Livestock Research as part of the Public Private Partnership (PPS) Feed4Foodure. Feed4Foodure is a public-private cooperation between the Dutch Ministry of Economic Affairs and a consortium of various organizations within the animal feed industry and the animal production chain .