Recent studies add important knowledge about the impact of diet and feeding strategies on the development and performance of gilts and sows. One of the findings was the discovery of a positive energy balance for sows during late lactation.
In December 2013, Norsvin scientist Signe Lovise Thingnes successfully defended her thesis “The impact of diet and feeding strategies on gilt and sow performance” at the Norwegian School of Veterinary Science.
The thesis work
- Three studies all carried out in Norwegian commercial herds.
- The animals studied were the Norsvin LY parent females (Norsvin Landrace x Norsvin Yorkshire).
- The first study aimed to investigate the effect of dietary energy supply offered during rearing and parts of first gestation, on development and performance of gilts and sows over successive parities.
- The second and third study evaluated the effect of feeding strategies and diet composition on sow and litter performance during lactation.
Lifetime development and performance
The first study provided a lot of knowledge on the lifetime performance and development of the Norsvin LY parent females included in the trial. These are sows with a good growth potential, and contrary to research reports on other swine genotypes this study showed that the Norsvin LY does not become leaner with increasing parity, but continues to deposit backfat for the first four parities before reaching a plateau (Figure 1). The Norsvin LY also continues to put on weight through the first five parities.
Improving body condition during lactation with a high feed intake
Two studies involving lactating sows showed that there were large individual variations in feed consumption, weight- and backfat changes, and there was no clear relationship between losses of fat relative to losses of protein. Some sows could have a moderate backfat loss combined with a high weight loss and opposite.
In other words, these sows went from an negative energy balance during the earlier stages of lactation to a positive energy balance during peak lactation. This contradicts the more common view that a long lactation period results in unnecessary depletion of sow body stores, increasing the risk of reproductive problems.
The most surprising finding in both lactational studies was that several sows started to regain some of the weight lost during the earlier stages of lactation during the last two weeks of lactation, indicating that they had a feed consumption in this period exceeding the nutrient need for milk production and maintenance (Figure 2).
Read full article here: Sow feeding and performance (Norsvin Annual Report 2013).