Dr Kemp writes: "During the recent Banff Pork Seminar I attended a breakout session entitled 'Long Live the Hyperprolific Sow'. Two of the featured speakers were William Flowers, North Carolina State University and Chantal Farmer, Agriculture and Agri-Food Canada. All speakers identified a very important feature for the retention and production of hyperprolific sows: maximise feed intake during lactation. However in this article I will focus more on their comments on development of the gilt and first lactation female as this area is a very important one for the hyperprolific female.

"Dr Flowers stated that “whether or not a sow reaches her most productive parities depends on how well her reproductive machinery is built during her prepubertal development period and how well it performs as an adult” ( Flowers, 2014). Obviously this identifies areas that require significant focus. A current study being conducted by Dr Flowers places gilts from the same source into two farms, one with a history of high longevity and one with a lower longevity history.

"Early results indicate that 98 per cent of the gilts entering the high longevity farm were bred and entered production compared to only 83 per cent of their contemporaries on the low longevity farm. There were a few factors that contributed to this difference but it was very interesting to note that most of the gilts delivered to the low longevity farm that were not bred did ovulate at some point prior to their removal from the herd and their estrus was not detected. Dr Flowers stated: ”Early puberty is an excellent cumulative measure of management during the developmental period.” Early puberty is an important trait and its’ expression is a combination of genetic potential and management.

"Dr Farmer focused her talk on milk production and mammary development (Farmer 2014). She indicated that a number of factors influence milk yield but emphasized that milk yield is dependent on the number of milk producing cells that are present in the mammary gland at the onset of lactation. There are positive associations between the weight of the mammary tissue and milk yield and between the number of mammary cells and piglet growth rate. Clearly milk producing cells and mammary tissue development set the potential for the sow’s milk yield. Dr Farmer demonstrated that composition of diets fed to prepubertal gilts influenced their mammary development by showing results that a 20 to 26 per cent feed restriction from day 90 to puberty significantly reduced mammary tissue mass.

"Dr Farmer stated that feeding in lactation also affects mammary development. She showed that increased weight of functional mammary glands resulted when either increased energy or protein were fed to lactating sows and concluded that it is imperative to maximize sow feed intake during lactation.

"A final point made by Dr. Farmer dealt with challenging first parity gilts with a large number of piglets. Her novel research has shown that teats suckled in the first lactation produce more milk and show more development in second lactation compared to teats that were not suckled in first lactation. Mammary tissue development and use of teats in first lactations are important factors for milk yield.

"Genesus research and development continues to focus on the highly prolific and productive sow. Understanding the genetic components and their relationships underlying the sows potential will lead to positive results for our customers."

References

Farmer, C. 2014. Milk production and mammary development. Proceedings of the Banff Pork Seminar, Advances in Pork Production 25:63.

Flowers, W. 2014. Gilt and sow management considerations in sow longevity. Proceedings of the Banff Pork Seminar, Advances in Pork Production. 25:55.