DIET REFORMULATION AND DIGESTIBILITY
By optimizing fat digestion, nutritional emulsifiers improve nutrients’ digestibility and energy efficiency. This is why they are already used in different animal species and different types of diets, with different fat/oil sources and levels. Use of nutritional emulsifiers can be explained by the flexibility in the types of inclusion in feed. Nutritional emulsifiers can be used on-top of the initial diet or in energy diluted diets. On-top application will result in improved feed efficiency and performance, due to the better use of energy for growth and milk production. To reduce feed cost, nutritional emulsifiers can also be used in energy diluted diets. Lower fat inclusion will be compensated by a higher digestibility and absorption of sources which are high in energy. Reformulation can be done by determining matrix values and the energy upgrade of the additive, and including the nutritional emulsifier in a classical feed formulation tool, as an ingredient.
Both strategies were tested in a recent Brazilian trial, coordinated by the University of Sao Paulo. In total, 116 lactating sows were followed for 26 days, from 5 days before farrowing to weaning of their piglets. The sows were divided into three groups. A control group, on a basal diet. A second group on an energy reduced diet, which received the basal diet with a reduction of metabolizable energy by 50 kcal/kg feed and the inclusion of a nutritional emulsifier (Excential Energy Plus, Orffa Additives BV). The third group received the basal diet with the same nutritional emulsifier on-top. In total, the trial followed 1596 born piglets and 1451 weaned piglets, with a homogeneous distribution amongst the sows’ groups.
It was clear that the addition of the nutritional emulsifier in lactation diets increased the piglet weight gain from birth till weaning for both inclusion strategies. Compared to the control group, piglet growth increased by 8.6% for the reduction of energy treatment and by 7.3% for the on-top treatment. Enhanced piglet growth can be explained by the numerical improvement of the milk production of the sows related to the addition of the nutritional emulsifier (Figure 2). Moreover, the feed conversion rate of the sows, measured by the kg of feed consumed divided by the kg of piglet weight gain, was numerically improved (Figure 3). No effects on sows’ feed intake and piglets’ mortality could be observed. Beneficial effects on health were observed by an improved colostrum Brix value. The Brix value was measured by a refractometer (a device measuring the refraction index) within 12 hours after delivery and is an estimation of the immunoglobulins G (IgG) in the colostrum. Higher IgG intake could result in an improved immune function of the suckling piglets. When classifying the proportion of sows having a poor (< 19.9), limit (20 – 24.9), adequate (25 – 29.9) and good (> 30) Brix value, a higher proportion of sows having an adequate Brix value in the nutritional emulsifier treatments was observed (53% with energy reduction treatment and 58% with ontop treatment, compared to 38% for the control).