Fiber in Animal Nutrition

47 Performance This positive impact on the performance of insoluble CFC has been confirmed by Westendarp et al. (2014) in terms of weight gain (p< 0.05) as the insoluble CFC Arbocel caused 100 g extra weight gain in 33 days at an inclusion rate of 0.8%. 3.5.3 Layer In this chapter we have to differentiate bet- ween direct performance parameters like the laying percentage and the FCR on the one hand and on the other hand the gizzard size at the end of the pullet stage. I would call the gizzard size an indirect performance related parameter as a small gizzard could limit the feed intake and consequently limit therefore the performance in terms of FCR and laying percentage. 3.5.3.1 Gizzard size in pullets The size of the gizzard in pullets is a main obstacle concerning the feed intake in the early laying stage. A reduced feed intake can often be observed during heat stress situa- tions. Consequently there will be a negative impact on the performance as well. The aim of the integrations and farmers should be therefore to make sure the gizzard at the end of the pre laying stage is as big as possible. It is well established that the particle size has an impact on the gizzard size.There is not that much information available concerning the fiber source and nature on the gizzard size. Yokhana et al. (2014) introduced their results at the EPCmeeting in Norway. They fed pullets fromweek 8 till 16 with standard feed and with two feeds containing different CFCs. One feed contained 1.5% of a not 100 percent insoluble CFC. The author calls it mixed fiber. The other feed contained 1.5 of a 100% insoluble CFC. The results are shown in table 22. The insoluble fiber caused significantly higher organ weight as well as a better weight gain as compared to the control animals. This effect could be not achieved with the CFC based on mixed fiber. This confirms the importance of the nature (soluble vs. insoluble) of the fiber as described in the first chapter of this paper. A quite interesting observation in this pullet trial is the live weight gain, which was significantly improved due to the use of the insoluble CFC. It is well known that Figure 9: Impact of different level of CFC on the weight gain of broilers (Liu et al., 2003) 64.5 63.5 62.5 61.5 60.5 60.0 65.0 64.0 63.0 62.0 61.0 0.9 1.2 0.6 0 0.3 Daily weight gain (Week 1–5) 0,76 Optimum y = -4.7619x 2 + 7.2476x + 61.343 R 2 = 0.8966 © ERLING Verlag