Influence of the metabolic state during lactation on milk production in modern sows

Abstract

Selection for prolificacy in sows has resulted in higher metabolic demands during lactation. In addition, modern sows have an increased genetic merit for leanness. Consequently, sow metabolism during lactation has changed, possibly affecting milk production and litter weight gain. The aim of this study was to investigate the effect of lactational feed intake on milk production and relations between mobilization of body tissues (adipose tissue or skeletal muscle) and milk production in modern sows with a different lactational feed intake. A total of 36 primiparous sows were used, which were either full-fed (6.5 kg/day) or restricted-fed (3.25 kg/day) during the last 2 weeks of a 24-day lactation. Restricted-fed sows had a lower milk fat percentage at weaning and a lower litter weight gain and estimated milk fat and protein production in the last week of lactation. Next, several relations between sow body condition (loss) and milk production variables were identified. Sow BW, loin muscle depth and backfat depth at parturition were positively related to milk fat production in the last week of lactation. In addition, milk fat production was related to the backfat depth loss while milk protein production was related to the loin muscle depth loss during lactation. Backfat depth and loin muscle depth at parturition were positively related to lactational backfat depth loss or muscle depth loss, respectively. Together, results suggest that sows which have more available resources during lactation, either from a higher amount of body tissues at parturition or from an increased feed intake during lactation, direct more energy toward milk production to support a higher litter weight gain. In addition, results show that the type of milk nutrients that sows produce (i.e. milk fat or milk protein) is highly related to the type of body tissues that are mobilized during lactation. Interestingly, relations between sow body condition and milk production were all independent of feed level during lactation. Sow management strategies to increase milk production and litter growth in modern sows may focus on improving sow body condition at the start of lactation or increasing feed intake during lactation.

The in-utero experience of piglets born from sows with lameness shapes their life trajectory

“…In our experiment, sows were fed individually during pregnancy, which meant that no effect of lameness on the ability of the sow to compete for food could account for the lower piglet body weight at weaning 25 . Feeding regime during lactation was the same for all the sows, but consumption was not controlled so if lame sows consumed a lesser quantity of food, it could, potentially affect milk production 48 , 49 . The aspect of a possible difference in food consumption, together with increased lying behavior reported in lactating lame sows 7 , is a plausible alternative explanation for the reduced piglet weight at 27 days of age, in the offspring of lame sows.…”

Protein Digestion Kinetics Influence Maternal Protein Loss, Litter Growth, and Nitrogen Utilization in Lactating Sows

“…Also, as a reflection of total milk production, the total weight gain of litters did not respond to the level of dietary slow protein. In lactating sows, milk production is recognized to have highest priority ( 37 ), and given that the protein derived from body protein tissue mobilization can only account for a small part of milk protein ( 6 ), the milk protein may largely originate from dietary protein. The previous studies indicated that elevating dietary protein level could increase milk protein output ( 8 , 38 , 39 ) and improved weight gain of suckling litters ( 8 , 40 ).…”

“…Sow body loss in lactation has been associated with negative impacts on post-lactational reproductive metrics, which include prolonged weaning-to-estrus interval, anestrus, reduced farrowing rate, and reduced litter size in the subsequent cycle ( 2 – 4 ). It has been indicated that high body protein tissue mobilization in modern sows is associated with impaired follicular development and reduced milk production ( 4 – 6 ). Increasing dietary protein levels can be effective in saving sow body protein mobilization and increasing milk production during lactation ( 3 , 7 , 8 ), but may bring negative impacts on the environment, as the nitrogen output in animal excreta has been recognized as a threat to the quality of water, air, and soil ( 9 ).…”

Identification of SNPs and Candidate Genes for Milk Produce Ability in Yorkshire Pig

“…Lactation process includes initiation and maintenance, which are mainly regulated by hormone-nerve. Milk production is highly influenced by the sow's body reserves at the start of lactation as well as the degree and type of body tissues that are mobilized during lactation [22]. Selection for high prolificacy in modern sows has led to increased litter size and to a higher number of piglets weaned per litter, and this results in greater metabolic demands during lactation due to a higher milk production [23].…”