Piglet growth performance is improved using a low protein starter feed or by fortifying conventional starter feed with spray dried porcine plasma and (or) functional fibre

The composition of piglet starter feeds is an important determinant for the growth and health of weaned piglets (de Lange et al. 2010). Factors such as lowering dietary protein level and strategic use of specific ingredients such as spray-dried porcine plasma (SDPP) have been found to reduce disease incidence and promote growth (de Lange et al. 2010). Other ingredients, such as the functional fibres β-glucan (βG) and xylooligosaccharide (XOS), are also used commercially to improve piglet growth and health. This study tested the hypothesis that a low protein starter diet would support similar piglet growth and survival when compared to conventional diets with and without functional fibre sources and SDPP.

Eight hundred and forty piglets (PrimeGro™ Genetics, Corowa, NSW) were weaned at 26 days of age (8.9 ± 0.21 kg; mean ± SE) and housed in commercial pens (14 pigs/pen) with feed and water available ad libitum. Piglets were blocked by sex and pen and randomly allocated to one of four dietary treatments (n = 15): a low protein starter diet [LPS; 175 g/kg crude protein (CP), 14.25 MJ digestible energy (DE)/kg and 0.87 g available lysine (AvL)/MJ DE]; a conventional starter diet (CS; 205 g/kg CP, 15.3 MJ DE/kg, 0.92 g AvL/MJ DE); CS with functional fibres [0.05% XOS^® (Longlive Biotechnology) and 0.05% Fibosel^® (Selko Feed Additives)]; and CS with functional fibres and 2.5% SDPP. All starter diets were fed for 12 days before all pigs were weighed and fed a common weaner 1 and weaner 2 diet (210 g/kg CP, 15 MJ DE/kg, 0.90 g AvL/MJ DE; and 210 g/kg CP, 14.5 MJ DE/kg, 0.85 g AvL/MJ DE, respectively). Pig weights and feed consumption were recorded on a pen basis at 0, 12 and 35 days after weaning. All deaths and removals were recorded. Performance data were analysed using ANOVA and mortality data were analysed using Chi-square analysis (Genstat, 16th Edition; UK).

In the starter period, 0–12 days after weaning, piglets fed CS ate less and grew slower than piglets fed LPS and CS supplemented with functional fibres and SDPP (Table 1). Furthermore the pigs fed CS + XOS + βG + SDPP also grew faster than those fed the LPS and CS XOS + βG diets. However by 35 days after common weaner diets had been fed, these differences had diminished so that only pigs fed the CS from 0–12 days had lower feed intakes and growth rates than those fed CS + XOS + βG + SDPP. Pigs fed CS exhibited a trend for an increased mortality (P = 0.07), while mortality on diets LPS and CS with functional fibre sources tended to be lower. These results demonstrated that weaned pig growth and mortality is improved through use of low protein starter feeds or addition of SDPP and (or) functional fibre to conventional starter feeds.

Table 1.  Performance from 0 to 12 days and 0 to 35 days after weaning and mortalities at 35 days after weaning in pigs fed either a low protein starter diet (LPS) or conventional (CS) starter diets with a range of ingredients in the first 12 days following weaning