Immunocrit, serum amino acid concentrations and growth performance in light and heavy piglets depending on sow’s farrowing system

BACKGROUND: The conventional farrowing crate is criticised due to the limited mobility of sows during farrowing and lactation. The present study aims to investigate the effects of three different farrowing systems on the performance of suckling neonates on the basis of immunocrit (IC; a quantification of immunoglobulins), serum amino acid (AA) concentrations and growth performance. METHODS: From a total of 149 sows placed in three housing systems (farrowing crate – FC, loose housing – LH, group housing – GH), 18 sows and their respective litters, formed the basis for a two-factorial study design (farrowing system and body weight (BW) of neonates). Therefore, also blood samples of two light (1.0–1.4 kg) and two heavy (≥ 1.4 kg) piglets were taken within 48 h post natum (p.n.) and on the day of weaning (day 26) to determine the immunocrit (IC; a quantification of immunoglobulins) and levels of serum AAs. RESULTS: The IC (FC: 0.148(a), LH: 0.153(a), GH: 0.117(b)) as well as serum levels of arginine, leucine, lysine, proline and threonine within 48 h p.n. were significantly lower in GH. Additionally, in general, these piglets showed (except for the first week of life) the lowest average daily weight gain. On the day of weaning, piglets in GH had the lowest levels of arginine (in mg/dL; FC: 3.68(a), LH: 3.40(ab), GH: 2.94(b)) and threonine (in mg/dL; FC: 3.59(a), LH: 3.02(ab), GH: 2.49(b)). The concentrations of leucine, lysine, proline and valine at this time were significantly lower in LH. CONCLUSION: The observed significant lower IC indicates a lower Ig intake of piglets in the tested GH. No significant differences regarding the IC and AA levels within 48 h p.n. of the piglets in FC and LH could be seen. In principle, differences at weaning in AA levels were rather small, although the body weight of GH piglets at weaning was lower. Therefore, further research needs to clarify whether there are medium-term effects on health and performance. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1186/s40813-019-0121-1) contains supplementary material, which is available to authorized users.