Today's animal production is changing. Consumers are increasingly aware of the process of food production, which is directly reflected back in the policies that are formulated by the agricultural ministers. Animal welfare is one of those topics that are of high public concern and political relevance.

Instead of ignoring or underestimating this relevance, I think the agricultural sector needs to embrace the matter. In terms of production and housing many improvements or additions can be considered. But, animal nutritionists can also contribute to this issue! A number of studies have already been carried out to explore how diet formulation and certain ingredients can influence the immune system and hence improve animal health and welfare. Especially in the pet food industry, an increasing amount of work is carried out to explore the potential effect of feed ingredients on pet health and wellbeing.

Less aggressive dogs
At the latest Pet Food Nutrition Update in Solingen, Germany Professor Wouter Hendriks from the Animal Sciences Group , Wageningen UR explained how certain ingredients can influence the behaviour of pet animals. Referring to Mugford, 1987, who said "When we are considering how a dog is behaving, we really should be considering what is inside the stomach", it makes sense to have a closer look at the interaction food and mood. Hendriks named protein/amino acids, antioxidants and phytoestrogens as some of the ingredients that have an effect on the way a dog behaves. Many nutrients are precursors to hormones; dietary changes therefore may lead to changes in behaviour.

A study in dogs (Dodman et al. (1996)) showed that territorial aggression scores were lower (p = 0.035) for medium- and low-protein diet compared to high protein diet. However, the effects that commercial pet foods have on pet behaviour are still largely unknown.

Stress and immunity
In farm animals, the focus is more in boosting the immune system and reducing stress. At the Feed and Wellness symposium in the Netherlands, organised by Schothorst Feed Research , Theo Niewold from the Katholieke Universiteit Leuven, Belgium spoke about the relationship between nutrition and immunity or health, and concludes that feed, immunity and the nervous system are indeed interconnected.

At the same time, he emphasised that it is very difficult to translate in vitro functional cell studies to in vivo health, and it is often equally hard to translate immune parameters measured in vivo to health. As some researchers said before (Field et al (2002)), Niewold also said we should be more open to "nutrient-directed management of immune-related syndromes." This may include an increase use of antioxidants in the feed for example, as Spears and Weiss recently reported in the Veterinary Journal. They say that a number of antioxidants – such as Vitamin E and beta-carotene - may affect health in transition dairy cows. Supplementation of these antioxidants showed reduced incidence of mastitis and retained placenta, and reduced duration of clinical symptoms of mastitis in some experiments.

Complexity
Although there are a number of studies – in pets and farm animals – that showed some new insights in how to formulate "healthy diets", some interactions between ingredients and health are still unclear. It is also questionable if animal welfare is improved if you reduce the stress level and increase the immune system. Of course it helps in preventing diseases - and thus animal wellbeing - but there are more factors involved to create an optimal living environment for farm animals.

In addition, the enormous complexity of the interactions requires research techniques which can cope with such intricacies, and real progress in this field is possibly only to be expected by application of genomic (micro-array) analysis. Nevertheless, increased knowledge on this topic will hopefully result in more animal friendly feeding strategies for the future. This is at least how animal nutritionists can do their bit to improve animal welfare and minimise animal diseases and immune related problems.