Managing the first lactation: Parity 1 feeding strategies

Editor’s note:  This is the first article in a two-part series about managing the first lactation.  In part 2, we discuss maximizing first-parity litter size and lactation length.

By Jaron Lewton

Replacement gilts are a huge investment required of every farm.  Increasing sow longevity and average parity of a farm can reduce costs and improves overall return.

The success of the second parity is highly dependent on how well a sow performs in the first-parity lactation. Relative to multiparous sows, first-parity (P1) sows do not consume as much feed during lactation, which often leads to greater bodyweight loss prior to weaning. Some estimate that P1 sows may mobilize as much as 15% of their body protein during lactation (Clowes et al., 2003).

This suboptimal feed intake during the first lactation – leading to significant weight loss – combined with the short wean-to-estrus interval of four to six days (industry average) can negatively affect follicle and oocyte development and impact litter size in the second parity (Soede et al., 2013). Furthermore, research indicates that sows with greater lactation weight loss and a smaller second-parity (P2) litter will also have smaller litters in all subsequent parities, increasing the likelihood of culling sows at a younger age (Hoving et al., 2011; Huerta et al., 2021). When considering P1 feed management, here are three strategies that help optimize performance and increase longevity of the sow herd.

1. Utilize P1 lactation diets
P1 sows have a greater nutritional need than older sows due to lower intake, greater bodyweight loss, and lower body fat stores as they are still growing at the first lactation (National Swine Nutrition Guide, 2010). Despite this heightened nutritional need, most farms feed a common lactation diet, formulated for the nutritional needs of the “average sow.” Maintaining a separate P1 lactation diet can improve sow and litter performance during the first lactation by providing more energy and amino acids in a greater-fortified diet.

2. Topdressing
Not all farms can feed two separate lactation diets. Doing so adds another layer of management to ensure each sow receives the right diet and the correct amount of feed is supplied for each new group of sows, some with more P1 sows than others. Topdressing a supplement to P1 sows is an alternative way to increase the nutrient density of those lactation diets.

3. Prefarrowing feed intake
Meal size and frequency in the few days prior to farrowing impact both sow reproductivity and litter performance. One study comparing prefarrowing feeding management methods found that pigs from sows fed either four small meals (1.5 pounds each) or placed on ad libitum intake for two to three days prior to farrowing had greater litter weight gain and weaning weights than pigs from sows fed a 6-pound ration once daily (Gourley et al., 2020). Sows fed ad libitum also had significantly less bodyweight loss during farrowing while those fed four times a day had lower prewean mortality.

Others have reported that, as the time between a sow’s last meal and onset of farrowing decreases, so does farrowing duration and number of stillborn pigs (Feyera et al., 2018). As longer farrowing duration is linked to decreased sow fertility, a shorter farrowing duration can positively impact total born alive and subsequent reproductive performance (Oliviero et al., 2013). Increasing feed intake and feeding multiple meals per day prior to farrowing provides many benefits to the sow and her litter.

Subsequent gestation diet
While feeding P1 sows separate lactation diets and/or topdressing may help decrease bodyweight loss and minimize negative effects on subsequent reproductive performance, it is not a bulletproof concept. For those sows that are not of ideal body condition post-weaning, producers must consider these two management practices:

1. Increase early gestation intake
Increasing dietary intake during the first third of gestation appears to be an effective way to improve subsequent litter performance of young or underconditioned sows. However, some research has shown negative effects of flush-feeding during late gilt development or during breeding (Lu et al., 2021; Mallmann et al., 2021). While some studies indicate positive results of increasing intake during early gestation (Hoving et al., 2011), less is known about how this impacts implantation (first 15 days after breeding) and embryo survival/growth. With limited, conflicting data, the best window for adjusting feed intake to improve body condition may be from day 15 to 45 of gestation.

2. Skip a cycle
While not ideal, allowing thin P1 sows to skip an estrous cycle prior to breeding may help eliminate some of the problems associated with poor reproductive performance in the second parity (Soede et al., 2013). Providing underconditioned sows an additional approximately 21-day cycle to recover prior to breeding has been shown to increase ovulation rate, farrowing rate and litter size (Martinat-Botte et al., 1995; Koutsotheodoros et al., 1998; Patterson et al., 2008). However, this also increases non-productive days and can become costly and difficult to manage.

Contact your Vita Plus nutritionist to discuss P1 feeding options for your farm and identify what strategy best fits your management and production goals.

About the author:  Jaron Lewton was raised on his family’s hobby farm in LaGrange, Indiana, and attended Huntington University to receive his bachelor’s degree in agribusiness.  During this time, he gained experience in animal husbandry as a farm hand in Laos, as well as greater knowledge of the feed industry through an internship with an egg production farm, where he specialized in nutrition and feed manufacturing.  Lewton then joined a management team of a 1,500-sow operation in northern Indiana before attending Michigan State University to receive his master’s degree in swine nutrition.  His thesis focused on utilizing feed additives in nursery pig diets.  Lewton joined Vita Plus as a swine technical sales manager in July 2020.