FIBRES CAN PREDICT PERFORMANCES IN BROILER
In past nutricles, we mentioned several times the importance of fibres in intensive farming. For the past few years, a lot of attention has been drawn on these nutrients underlining how they improve both performances, health and welfare. Most of publications on the subject have been done on Swine but little guidelines are available regarding recommended level of fibres in Poultry. This month Nutricle shed some light on the use of fibres in Poultry nutrition.
The scientific publications that I decided to illustrate this month have been released in 2013, 2016 and 2019 by Jimenez-Moreno et al. They compare several indicators of performance and health of broilers between 0 to 21 days when using four different sources of fibres as Oat hulls, Rice hulls, Sugar Beet Pulp and Sunflower hulls incorporated either at 2.5%, 5.0% or 7.5%. They tracked standard growth performance as ADG and FCR but they included as well indicators as length of small intestine, gizzard weight, nitrogen retention, gizzard pH.
If you are interested to have more details about these publications, the links to these publications are described below this article.
We analyse those data in different ways by looking at correlation between the fibre nutrients and performance indicators. Fibre nutrients were Crude fibre (CF), Neutral Detergent Fibre (NDF), Acide Detergent Fibre (ADF), Insoluble Fibre (iF), Soluble Fibre (sF) and Total Dietary Fibre (TDF). The CF is the most popular nutrient as it is cheap, quick and easy to analyse in any laboratory but it measures only a small portion of the fibre profile. The TDF, at the opposite, is the most complete picture of the fibre but it is expensive and difficult to analyse.
The tables below shows the correlation of each nutrient with the performance indicators. The closer is the correlation index to 1 and the best is the predictability of the results.
On the figure 1, we can see the correlation between TDF and FCR. This correlation (R2=0.79) is higher than correlation with crude fibre (R2=0.48). We can see a quadratic effect of TDF. It means that performance increase by increasing TDF until a breaking point where performance starts decreasing. From this graph, we can extrapolate the optimal level of TDF in Broiler diets with a good level of predictability.
Figure 1: FCR according to Total Dietary Fibre
The table below is gathering the FCR and the level of CF in the diet. As mentioned above, the correlation between this nutrient and the result is lower at only 0.48.
Figure 2 : FCR according to Crude Fibre
Optimizing fibre component in diets by looking at Crude fibre nutrient is not an efficient tool to predict performance in broilers. Nutritionist should start looking at other fibre nutrient namely TDF to ensure sufficient reliability in their diet performance.
Another important point from these studies is that there is no significant correlation between used raw materials (oat hulls, rice hulls, ...) and performance (ADG, FCR, ADFI). The important point is not from which material the fibre is coming from but rather what is the fibre profile of that ingredient. This point reinforces the message that it is critical to analyse the fibre profile of every ingredient. When we are confident about our ingredient matrix, we should focus on nutrients rather than ingredients preferences.
This lack of correlation between performance and ingredients is valid as long as the ingredients are not contaminated in mycotoxins. If ingredients are contaminated, then performance will obviously be negatively impacted. Selecting fibres sources free from mycotoxins should actually be the number one priority before looking at optimizing TDF optimum.
Considering the predictability between fibre TDF and performance, I used the graphs from this researches to define the optimum level of nutrient in Broilers. There are indeed several publications proposing optimal TDF in Swine but very little on that subject has been published for Broilers.
In the table below, I gathered my recommendations from the most predictable to the less. I let you decide what nutrient you want to use depending on your analytical capacities. But the ambition will be to develop these analytical capabilities in order to move up from CF, ADF to TDF overtime and increase your diet performance predictability.
Table 1: Fibre nutrient recommendations for broilers
(based on experimentation 0-21days)
Still, you need to take these numbers with precautions. I encourage you to set up experimentations in your farming context and check the cost / benefits of these numbers. As we discussed in some earlier nutricles and contrarily to what we think, fibres in Asia is rather scarce and could be expensive mostly when looking at mycotoxins-free ingredients.
Conclusion, After many years of researches on energy, proteins, vitamins and minerals, fibres is now the trendy topic. We now understand how fibres (