When nutritionists think of extra fats, Julia Holen says they most often think of them as a source of energy, but they also provide essential fatty acids (EFAs), primarily linoleic acid (LA) and linoleic acid. alpha-linolenic acid (ALA), to the animal. .
“From the literature, we know it can influence the composition of colostrum and milk, and in the past researchers have found that dietary fat intake in mid to late gestation can also influence the ability swine survival,” says the Kansas State University graduate student. “But we don’t necessarily know if these fat sources fed close to farrowing can also influence piglet survival and we don’t necessarily know how that might influence litter growth potential.”
So Holen and the Kansas State University swine nutrition team decided to conduct two studies to further assess pre-partum essential fatty acid intake and how this might influence both colostrum and milk composition as well as litter growth and survivability.
In the first study, researchers evaluated diet treatments on day 107 or day 112 of gestation, and in these treatments the diets either contained high essential fatty acids through the inclusion of soybean oil, or low essential fatty acids thanks to the inclusion of a source of animal fat. , such as beef tallow.
According to Holen, regardless of the timing of the treatments, whether the sows began consuming feed on day 107 or day 112 of gestation, colostrum and LA milk and ALA acid increased.
“When we include a high source of AGEs, the fatty acids are transferred efficiently to the mammary gland. Therefore, it is certain that the fat content of the diet can influence the composition of colostrum as well as the composition of milk”, says Holen.
To better understand how these changes may influence litter performance as well as sow reproductive performance and survivability, the K-State team partnered with Smithfield to assess the impacts of adding AGEs on overall sow performance, litter growth performance and subsequent survivability and reproductive performance.
In this study, 3451 mixed-parity sows were assigned to one of four treatments, with 850-874 sows per treatment. The sows entered the farrowing rooms at approximately 112 days of gestation and were assigned to one of the following treatments:
- Control: 89 grams per day (g/d) of LA and 5 g/d of ALA (0.5% white fat of your choice)
- Soybean oil: 189 g/d LA and 19 g/d ALA (3% soybean oil)
- CWG: 109 g/d LA and 6 g/d ALA (3% white fat of your choice)
- Combination: 205 g/d LA and 20 g/d ALA (3% soybean oil + 2% white fat of your choice)
Holen says it’s important to note that the predicted AGE intake for the Control and CWG diets was below the 125 LA g/d and 10 ALA g/d recommended by North Carolina State University for lactating sows.
Based on average daily feed intake and diet composition, sows that were allocated to soybean oil and the combination treatments consumed significantly more LA and ALA compared to those assigned a low dietary EFAs in control and CWG diets.
“This response was important to validate that we had achieved levels above the recommendations suggested by Rosero. [NC State] and others for our projected high and low AGE intake treatments,” says Holen.
Colostrum and milk samples were collected from a subset of sows in this study and sows that received high EFA content from soybean oil had significantly higher LA and ALA colostrum content. higher. The improvement in LA and ALA content was maintained throughout the lactation period, so the milk also contained higher levels of AGEs.
Holen says providing higher AGEs to sows also resulted in an overall improvement in average pig body weight at weaning.
“Pigs weighed a quarter pound to a third pound more when sow EFA intakes were higher than Rosero recommended levels, while providing diets low in LA and ALA had lower weaning weights for these pigs” , explains Holen.
By examining the survivability of piglets during the first 24 hours and then from 24 hours until weaning, the researchers found no evidence of differences in piglet survival during the first 24 hours, nor of differences in remaining lactation period as a function of EFA intake.
“We know that the sow’s EFA intake can influence colostrum composition and milk composition throughout the lactation period, but we also now know that the sow’s EFA intake has no farrowing performance or piglet survivability,” says Holen. “However, we observed that sows provided high EFA litters with higher average daily gain and higher piglet body weights at weaning compared to low litters.”
The research team also followed these sows for subsequent reproductive performance and found no evidence of differences in subsequent sow performance in terms of farrowing rate or litter size in the following litter.