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Association of IgG concentration in colostrum with diarrhea in piglets born to Minpig and Landrace sows
Minpig is a native breed in Northeastern China, well known for its good meat quality, high prolificacy and high resistance to disease. Diarrhea in piglets is a common disease which can cause significant losses for swine producers. To investigate resistance of Minpig to diarrhea, 31 Minpig sows and their 335 piglets were compared with 35 Landrace sows and their 351 piglets. The two breeds of sows were housed in pens on solid concrete floors in two identical rooms. From birth to weaning (5 wk), the feces and anus of all piglets were scored daily to assess the severity of diarrhea following the criteria: No diarrhea (Score=0) is that feces appeared normal; Slight diarrhea (Score=1) is that feces were soft blobs formed, but with thick liquid substance; Moderate diarrhea (Score=2) is that feces were loose and pulpy with semiliquid substance; Severe diarrhea (Score=3) is that feces were watery, no solid pieces, entirely liquid with mucus and pus. Litter diarrhea index during lactation was calculated using the equation: Litter Diarrhea Index (LDI) = total fecal scores in a litter/total number of piglets nursed by the sow. Colostrum samples were collected from all sows at 0h and 12h after farrowing to determine concentrations of IgG using ELISA. Compared with Landrace sows, Minpig sows had higher accumulative amount of IgG (830.61±67.58 vs. 742.49±80.47; P<0.05) between 0h to 12h in colostrum (IgG0-12, the area of trapezoid under a line between 0h to 12h when X-axis represented the time after farrowing and Y-axis represented the IgG concentration at that time). In addition, IgG0-12 was negatively correlated with LDI in both breeds (r=−0.5189 for MinPig, P<0.05; r=−0.5077 for Landrace, P<0.05). Sows were categorized as slight, moderate and severe diarrhea group based on LDI according to Fisher method and Fastclus process. No severe diarrhea group was observed in Minpig sows. Compared with Landrace sows, Minpig sows had higher IgG0-12 in both slight (885.30±58.02, vs. 786.93±35.91; P<0.01) and moderate (775.79±31.74, vs. 698.19±56.82; P<0.05) diarrhea groups. These results suggest that IgG concentrations in colostrum can be associated with resistance of piglets to diarrhea, and high IgG levels in colostrum of Minpig sows result in stronger resistance of Minpig piglets to diarrhea compared with Landrace piglets.
Keywords:
colostrum, diarrhea, Landrace, Minpig, piglet