Use of cross-fostering to enhance growth of pigs that are predicted to grow poorly based on plasma a-1 acid glycoprotein concentration

Authors: Ramsay, Timothy; Stoll, Margo; Schreier, Lori; Shannon, Amy

Submitted to: Open Journal of Animal Sciences
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/17/2017
Publication Date: 12/20/2017
Citation: Ramsay, T.G., Stoll, M.J., Schreier, L.L., Shannon, A.E. 2017. Use of cross-fostering to enhance growth of pigs that are predicted to grow poorly based on plasma a-1 acid glycoprotein concentration. Open Journal of Animal Sciences. https://doi.org/10.4236/ojas.2018.81004.
DOI: https://doi.org/10.4236/ojas.2018.81004

Interpretive Summary: Scientists at USDA-ARS Beltsville have previously identified a blood protein, alpha-1 acid glycoprotein (AGP), that can predict at birth whether a piglet will need some intervention to improve the quality of its life and its ability to grow. The present study examined ways that the farmer can intervene to improve the health and well being of these very young pigs with impaired growth. This study demonstrates that a simple nutritional intervention can improve their growth rate to that of their siblings, thus increasing their chance at survival. The cost to the farmer is minimal, but with a significant benefit as it reduces potential pig losses and returns a pig with economic benefits. Pigs were identified as potentially at risk by the level of plasma AGP. Pigs with high plasma AGP are at risk, while pigs with low plasma AGP grow quite well. The mechanism of how AGP does this is not known. However, it is quite effective at identifying these at-risk piglets at birth. This permits the farmer to make a rapid intervention to assist the pig. Two methods were tested for intervention. Fostering the pig onto another mother with a smaller litter of pigs (approximately 8) was very effective in permitting these pigs to grow as fast as their littermates through weaning age. The addition of a soluble milk replacer to boost their intake was not necessary to reverse their impaired growth. These milk replacers are quite expensive and reducing their use saves money and time. Simply transferring the piglet to another mother with a smaller litter involves minimal labor and produces maximal benefit for the farmer and the piglet.

Technical Abstract: Alpha-1 acid glycoprotein (AGP) is a negative acute phase protein that can be quantified in the plasma at birth and used to predict growth rate through weaning. Neonatal plasma (AGP) may be useful as a marker to predict growth impairment and permit nutritional support to prevent the identified pigs from growing more slowly and attaining a lower weaning weight than littermates. Cross-fostering (CF) and CF plus a milk supplement (CF+MS) were used to attempt to improve the growth performance of pigs predicted to grow poorly based on their elevated plasma AGP relative to paired littermates predicted to grow normally. Plasma AGP was measured by ELISA on d2 postnatally from all pigs in all 32 litters comprising the study. Pigs with the highest plasma AGP were weight and sex matched to a littermate with a low plasma AGP (within that specific litter) and four pairs of these weight and sex matched pigs comprised each foster litter with 4 litters comprising each treatment group (CF or CF+MS). Pigs remained on treatment until weaning at 21 days of age. A control group was acquired by selecting a pair of pigs remaining in the donor litter that differed in plasma AGP. Pigs were transferred to the nursery but maintained in their CF or CF+MS litters. At 35 days of age, CF and CF+MS pigs were weighed and dual energy X-ray absorptiometry (DXA) was performed to evaluate live animal carcass composition. Control pairs that remained in large litters on their sow of origin differed in weaning weight with pigs with higher plasma AGP at 1 day of age having smaller weaning weights than their littermate of similar birth weight (P< 0.05). However, CF eliminated the difference in weaning weight between the slow growing pigs and their birth weight matched littermate. CF+MS produced a similar effect (P > 0.05). At 35 days of age, body weights were still similar between CF littermates and between CF+MS littermates (P> 0.05). DXA analysis demonstrated that body composition was similar, although total lean accretion (grams) was higher in CF+MS litters than CF litters, because CF+MS pigs were larger than CF pigs. These data demonstrate that CF can be used to correct the growth impairment in pigs predicted to grow poorly using plasma AGP as the marker. CF+MS can do the same, but at a much higher cost.