Prof. Chantal Farmer
Agriculture and Agri-Food Canada, Sherbrooke R & D Centre,
Canada
Biosketch
Dr. Farmer is a research scientist in sow lactation biology working at the Sherbrooke Research and Development Centre of Agriculture and Agri-Food Canada.
Dr. Farmer was a pioneer in studying mammary development in gilts and sows and identifying the various factors affecting it. She has published 166 scientific manuscripts, 9 book chapters, and is the sole editor of two books that were also translated and published in Chinese.
Dr. Farmer’s expertise is recognized internationally as evidenced by her being a guest-speaker in 13 European countries as well as China, Australia, Mexico, Canada and the USA. She was Editor-in-Chief of the Canadian Journal of Animal Science from 2006 to 2010.
She was on the board of the Canadian Society of Animal Science for 12 years, serving as its president in 1998-99, she received 2 national awards and was made a fellow of this Society in 2017.
Dr. Farmer was on the board of the American Society of Animal Science from 2014 to 2020, from which she received the 2022 President’s Award for International Achievements in Animal Science. Dr. Farmer is currently on the editorial board of the journals Translational Animal Science and Domestic Animal Endocrinology.
Abstract
Feeding to maximize mammary development and milk yield.
Sows do not produce enough colostrum and milk to optimize growth and survival of their piglets. Mammary development can affect milk yield but can only be stimulated when already ongoing. In swine, periods of rapid mammary development are from three months of age until puberty, 90 days of gestation until farrowing, and throughout lactation. Early studies showed that a 20% feed restriction from 90 days of age until puberty reduces mammary parenchymal tissue. Recently, sow milk yield was not affected by a 10% or 20% feed restriction, or a 25% dietary fibre addition from 90 days of age to breeding, likely due to greater feed intake of control gilts. During prepuberty, providing the phytoestrogen genistein increases the number of mammary cells. During late gestation, feeding very high energy levels may have detrimental effects on mammary development and subsequent milk production. Conversely, a 40% increase in SID Lys intake (via more soybean meal) led to a 44% greater mammary parenchymal mass. Increasing concentrations of the growth factor IGF-1 from days 90 to 110 of gestation increased mammary parenchymal weight by 22%. Feed intake throughout gestation is important because it affects body condition. Gilts that are too thin (<16 mm backfat thickness) in late gestation have reduced mammary development. It is important to ensure that all teats from primiparous sows are suckled for at least 2 days in order to optimize milk yield in the subsequent lactation. Hence, feeding management before lactation and piglet handling can be used to improve milk yield.
Key Words: feeding, mammary development, swine