Pigs from 154 litters (n = 1132, 19 ± 3 days of age, 4.9 ± 1.1 kg of bodyweight) were used in a 3 × 2 factorial design to evaluate two raw materials with nutraceutical properties being used in feeds, spray-dried porcine plasma (SDPP) and a yeast protein meal, and their effects on growth performance, immune parameters and gastrointestinal adaption of piglets to weaning. Factors included dietary treatments being (1) 5% SDPP (PLA), (2) 3.5% yeast protein meal (NUP) and (3) medicated control (TMC) and parity (primiparous versus multiparous). The treatment groups were imposed from Day 19 through to weaning at Day 27. Selected pigs (n = 720, 28 ± 3 days of age, 7.4 ± 1.0 kg of bodyweight) were weaned and remained on their respective diets from Day 28 to Day 34. From Day 35 to Day 48 all group-housed pigs were offered a commercial weaner 1 diet, and from Day 49 to Day 68 pigs were offered a commercial weaner 2 diet. Growth performance, survival, and serum immunoglobulin G were monitored throughout the nursery phase (Day 28 to Day 68). Adaptation of the gastrointestinal tract in the acute post-weaning phase (Day 28 to Day 34) was assessed in 36 individually housed male weaners, with the effects of feed on structural, digestive, microbial and immune parameters along the gastrointestinal tract determined at Day 34. Pre-weaning feed disappearance was greater (P < 0.01) in multiparous litters independent of diet. In the commercial nursery, total removals (mortality and morbidity) were highest (P < 0.01) in primiparous sow progeny, with pigs offered NUP having greater (P ≤ 0.05) total removals. Pigs offered PLA had superior average daily gain, average daily feed intake and feed conversion ratio from Day 28 to Day 34 (P < 0.05). Pigs offered NUP tended to (P = 0.07) have superior average daily gain from Day 35 to Day 49. Pigs offered NUP had higher (P < 0.05) serum immunoglobulin G concentrations at Day 68 compared with pigs offered TMC, with the effect most pronounced in primiparous sow progeny. Individually housed weaners offered PLA consumed more (P < 0.05) feed on Day 30 to Day 31, had shorter relative intestine length (P < 0.05), greater villous height in the medial jejunum (P < 0.10) and lower immuno-pathology scores along the intestine. Pigs offered PLA also tended (P < 0.10) to have increased pancreatic-specific lipase and amylase activity compared with pigs offered NUP. Pigs offered NUP had a higher ratio of E. coli : coliforms in the colon (P < 0.01) and more counts of β-haemolytic bacteria in the medial jejunum (P < 0.05) and colon (P < 0.10). Diets containing either SDPP or NUP offered pigs benefits beyond nutrition relative to the medicated control diet. The benefits of SDPP were highly effective but transient, while the yeast derived protein had a successive or accumulative effect which was more pronounced in primiparous sow progeny.

a b s t r a c tAn 80 day study was conducted to evaluate the growth promoting effects of a unique mannose rich fraction (MRF) derived from yeast cell walls of Saccharomyces cerevisiae, relative to copper and tylosin in commercially housed grower and finisher pigs. 1008 male grower pigs (29.7 ± 1.99 kg live weight) were randomly allocated to four treatment groups of 252 pigs. There were 12 replicates for growth rates (21 pigs per pen) and 6 replicates for feed intake and FCR (42 pigs per feeder). The dietary treatments consisted of a control (CON, containing no growth promoting feed additives), copper (COP, containing 200 ppm of copper as copper sulphate in both grower and finisher pigs), MRF (containing 400 ppm and 200 ppm of Actigen TM (Alltech Biotechnology, Nicholasville, KY) in grower and finisher diets respectively), and tylosin (TYL, containing 40 g and 20 g of tylosin in grower and finisher diets respectively). Growth performance and mortality were monitored over the grower (d 0-38) and finisher (d 39-80) periods. Slaughter characteristics (carcass weight and backfat thickness at the P2 position) were recorded at d 80. Mannose rich fraction pigs grew faster (P<0.01) than CON or COP pigs during the grower phase. Mannose rich fraction and TYL pigs also tended to (P=0.08) have better FCR during the grower phase than those on the CON and COP treatments. No significant treatment effects were observed for growth performance during the finisher phase or over the entire study (d 0-80). However, MRF pigs had a significantly higher (P<0.01) dressing percentage and heavier carcass weight than pig on all other treatments. There was no influence of growth promoting feed additives on backfat thickness. Overall, MRF was as effective as tylosin and more effective than copper as a growth promoter in grower pigs. Mannose rich fraction inclusion was able to enhance the yield of saleable pork, and was the most effective growth promoting option tested.

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