The animal article of the month for February is “Increased dietary protein for lactating sows affects body composition, blood metabolites and milk production” by Strathe et al.

Increased dietary protein for lactating sows affects body composition, blood metabolites and milk production. Breeding has made the sows bigger and leaner and simultaneously litter size has increased. The larger litter size has increased the demand for the sow to produce more milk in order to cover the requirements of the piglets. Altogether we therefore assumed that these hyper-prolific sows nursing 14 piglets had an increased requirement of dietary protein compared to older genotypes that were the basis of the current Danish dietary recommendations. When studying the nutrient requirements of lactating sows you should not only optimize for litter growth rate, but also consider how the diet affects the body condition of the sow. Often sows start to mobilize nutrients from their body reserves during lactation because of insufficient feed intake, especially in early lactation, but excessive body weight loss can have a negative effect on their health and reproductive performance in the following cycle. If the sows are under-supplied with protein, the sows will mobilize protein from their muscles to maintain a high milk yield. It is however very energetically unfavorable for the sow especially to mobilize muscle protein, because it needs to be restored in the following gestation. Besides affected body composition of the sows, a change in dietary protein intake might also affect milk production and composition concentrations of metabolites in the blood. Altogether it is important to the see the growth performance of the nursing piglets as interplay between intake, body mobilization and milk production of the sow.

Therefore this study included all the mentioned measurements to determine if all parameters were optimized at the same dietary protein level. The goal was to optimize milk production and composition and thereby increase litter growth rate, but at the same time also minimize mobilization of body tissues, especially body protein.

The study showed, as might be expected, that the measured parameters were not optimized or minimized at exactly the same dietary protein concentrations and this adds to the ongoing discussion on how to optimize the requirement of lactating sows. This study underlines the importance of both optimizing sow metabolism and piglet growth to improve health and longevity of the sows.

Another aspect of dietary protein provision is that excessive intake of protein increases the excretion of nitrogen. It is therefore important that the actual protein provision matches the requirement of the animal. In this study the sows were fed increasing levels of both protein and essential amino acids and therefore we do not know whether the increased response was a result of both increased nitrogen and amino acid provision or only an increased amino acid intake. Following this study, experiments are now carried out to investigate if the same results can be obtained by reducing the intake of protein with the same concentrations of essential amino acids. This is of course important, because we must embrace that animal production includes taking care of the environment as well as the animals.

The animal article of the month for February “Increased dietary protein for lactating sows affects body composition, blood metabolites and milk production”  is freely available for a month. 

Authors: A. V. Strathe, T. S. Bruun, A.-H. Tauson, P. K. Theil, C. F. Hansen

The animal Article of the Month is selected by the Editor-in-Chief and is freely available for one month. View the recent selections