The hypothesis that spray dried plasma (SDP) complements low crude protein (CP) phase 1 diets by improving growth performance, decreasing diarrhea, reducing immune system activation, and maintaining intestinal health of weanling pigs was tested. Four phase 1 diets were formulated (CP: 18.5% or 23.0%; SDP: 0% or 6%). One-hundred and sixty weaned pigs (5.89 ± 0.39 kg; 20 ± 2 days) were fed one of the four phase 1 diets (days 1–14) and a phase 2 diet (days 15–28). Results indicated that pigs fed the 18.5% CP diet instead of the 23.0% CP diet had reduced ( P < 0.05) average daily gain (ADG) and gain to feed ratio (G:F), and pigs fed 6% SDP had greater ( P < 0.05) ADG and G:F than pigs fed no SDP. Diarrhea scores were reduced ( P < 0.05) for pigs fed the 18.5% CP diet. Villus height in the ileum and mucosa width in the colon increased if SDP was included in the 23.0% CP diet, but not in the 18.5% CP diet (interaction, P < 0.05). In conclusion, including 6% SDP in phase 1 diets resulted in improved ADG and G:F and reduced inflammatory responses.
Bailey et al. (Wed,) studied this question.