Fiber in Animal Nutrition

29 Effect of fiber on swine performance As a result of insufficient water intake and/or diets with low fiber content, sows are predis- posed to suffer from constipation around far- rowing and subsequently can developMMA. Especially with todays highly prolific genetics reducing constipation and ensuring a rapid parturition is necessary to achieve large litter sizes with viable piglets. All practical measures need to be taken, in order to prevent overly burdening the sow during farrowing. A fast birth followed by good milk production and no impairment by MMA is the goal. Reese (1997) and Reese et al. (2008) revie- wed the effects of dietary fiber in gestation diets for sows by evaluating different scientific reports (1975–2007) that had recorded live born and weaned piglets. Feeding sows with different fibrous feed stuffs like wheat straw, oat hulls/oats, alfalfa hay/haylage or corn gluten feed showed positive effects while distillers grain and alfalafa meal revealed negative effects on performance data (table 7) Another feeding trial revealed that feeding straw as extra insoluble fiber in addition to four pounds of a standard feed increased feed intake during lactation. Furthermore sows fed wheat straw farrowed significantly more piglets than the control in the second and third farrowing (ca. +1.5). Additionally 0.7 piglets more were weaned in this group. This overview shows that increasing the NDF intake >300 g/day can take positive influence on litter size but this obviously also depends on the source of NDF. Reese (1997) assumes that the fiber source inter- acts with the NDF content. In the overview (table 7) the animals fed wheat straw consu- med approximately 50% less NDF than the animals fed alfalfa hay but the influence on performance is comparable. Maybe the parameters solubility and fer- mentability need to be considered in future trials. CF and NDF do not seem to describe fiber sources sufficiently enough. Lignocellulose is def ined as insoluble f ibrous component in sow feed that can take influence on important performance parameters subsequently reflected in litter size, litter weight, live born piglets and number of weaned piglets. The following aspects explain their joint impact on reproductive performance: • Less mycotoxins (replacement/ reduction of main contaminants) Fiber source Daily NDF intake, g a No. pigs born alive No. pigs weaned No. litter b No. reference Control Fiber Alfalfa meal 264 381 -0.4 -0.7 269 3 Alfalfa hay/haylage 246 721 +0.5 +0.8 647 6 Corn gluten feed 166 794 +0.7 +0.4 229 2 Distillers grains 139 418 -0.3 -0.4 118 2 Oat hulls/oats 260 1221 +1.8 +0.7 96 3 Wheat straw 150 368 +0.5 +0.7 699 1 a Average NDF intake by the sow consuming control and fibrous diets during gestation b Total number litters produced by sows fed control and fibrous diets Table 7: Nebraska Swine Report (Reese, 1997) Average change in litter size according to source of dietary fiber fed to the sow during gestation © ERLING Verlag