Alexopoulos, J.G., Lines, D.S., Hallett, S. and Plush, K.J., 2018. A review of success factors for piglet fostering in lactation. Animals 8: 38.

Alonso-Spilsbury, M., Mota-Rojas, D., Villanueva-García, D., Martínez-Burnes, J., Orozco, H., Ramírez-Necoechea, R., Mayagoitia, A.L. and Trujillo, M.E., 2005. Perinatal asphyxia pathophysiology in pig and human: a review. Animal Reproduction Science 90: 1-30.

Alvarenga, A.L.N., Chiarini-Garcia, H., Cardeal, P.C., Moreira, L.P., Foxcroft, G.R., Fontes, D.O. and Almeida, F.R.C.L., 2013. Intra-uterine growth retardation affects birthweight and postnatal development in pigs, impairing muscle accretion, duodenal mucosa morphology and carcass traits. Reproduction, Fertility and Development 25: 387-395.

Amdi, C., Hansen, C.F., Krogh, U., Oksbjerg, N. and Theil, P.K., 2013a. Less brain sparing occurs in severe intrauterine growth-restricted piglets born to sows fed palm fatty acid distillate. In: Manipulating Pig Production XIV. APSA Biennial Conference. November 24-27, 2013. Melbourne, Victoria, Australia, pp. 125.

Amdi, C., Jensen, L.L., Oksbjerg, N. and Hansen, C.F., 2017a. Supplementing newborn intrauterine growth restricted piglets with a bolus of porcine colostrum raises rectal temperatures one degree Celsius. Journal of Animal Science 95: 2968-2976.

Amdi, C., Klarlund, M.V., Hales, J., Thymann, T. and Hansen, C.F., 2016. Intrauterine growthrestricted piglets have similar gastric emptying rates but lower rectal temperatures and altered blood values when compared with normal-weight piglets at birth. Journal of Animal Science 94: 4583-4590.

Amdi, C., Krogh, U., Flummer, C., Oksbjerg, N., Hansen, C.F. and Theil, P.K., 2013b. Intrauterine growth restricted piglets defined by their head shape ingest insufficient amounts of colostrum. Journal of Animal Science 91: 5605-5613.

Amdi, C., Lynegaard, J.C., Thymann, T. and Williams, A.R., 2020. Intrauterine growth restriction in piglets alters blood cell counts and impairs cytokine responses in peripheral mononuclear cells 24 days post-partum. Scientific Reports 10: 4683.

Amdi, C., Moustsen, V.A., Oxholm, L.C., Baxter, E.M., Sørensen, G., Eriksson, K.B., Diness, L.H., Nielsen, M.F. and Hansen, C.F., 2017b. Comparable cortisol, heart rate and milk let-down in nurse sows and non-nurse sows. Livestock Science 198: 174-181.

Andersen, H.L. and Pedersen, L.J., 2016. Effect of radiant heat at the birth site in farrowing crates on hypothermia and behaviour in neonatal piglets. Animal 10: 128-134.

Andersen, I.L., Berg, S. and Bøe, K.E., 2005. Crushing of piglets by the mother sow (Sus scrofa) – purely accidental or a poor mother? Applied Animal Behaviour Science 93: 229-243.

Andersen, I.L., Haukvik, I.A. and Bøe, K.E., 2009. Drying and warming immediately after birth may reduce piglet mortality in loose-housed sows. Animal 3: 592-597.

Andersen, I.L., Nævdal, E. and Bøe, K.E., 2011. Maternal investment, sibling competition, and offspring survival with increasing litter size and parity in pigs (Sus scrofa). Behavioral Ecology and Sociobiology 65: 1159-1167.

Andersen, I.L., Tajet, G.M., Haukvik, I.A., Kongsrud, S. and Bøe, K.E., 2007. Relationship between postnatal piglet mortality, environmental factors and management around farrowing in herds with loose-housed, lactating sows. Acta Agriculturae Scandinaviae Section A 57: 38-45.

Andersson, E., Frössling, J., Engblom, L., Algers, B. and Gunnarsson, S., 2015. Impact of litter size on sow stayability in Swedish commercial piglet producing herds. Acta Veterinaria Scandinavica 58: 31.

Azain, M.J., Tomkins, T., Sowinski, J.S., Arentson, R.A. and Jewell, D.E., 1996. Effect of supplemental pig milk replacer on litter performance: seasonal variation in response. Journal of Animal Science 74: 2195-2202.

Balzani, A., Cordell, H.J. and Edwards, S.A., 2016. Relationship of sow udder morphology with piglet suckling behaviour and teat access. Theriogenology 86: 1913-1920.

Bandrick, M., Pieters, M., Pijoan, C., Baidoo, S.K. and Molitor, T.W., 2011. Effect of cross-fostering on transfer of maternal immunity to Mycoplasma hyopneumoniae to piglets. Veterinary Record 168: 100. Bartol, F.F., Wiley, A.A. and Bagnell, C.A., 2008. Epigenetic programming of porcine endometrial function and the lactocrine hypothesis. Reproduction in Domestic Animals 43: 273-279.

Bartol, F.F., Wiley, A.A., George, A.F., Miller, D.J. and Bagnell, C.A., 2017. Physiology and endocrinology symposium: postnatal reproductive development and the lactocrine hypothesis. Journal of Animal Science 95: 2200-2210.

Bartol, F.F., Wiley, A.A., Miller, D.J., Silva, A.J., Roberts, K.E., Davolt, M.L.P., Chen, J.C., Frankshun, A.L., Camp, M.E., Rahman, K.M. and Vallet, J.L., 2013. Lactation Biology Symposium: lactocrine signaling and developmental programming. Journal of Animal Science 91: 696-705.

Bauer, R., Walter, B., Hoppe, A., Gaser, E., Lampe, V., Kauf, E. and Zwiener, U., 1998a. Body weight distribution and organ size in newborn swine (Sus scrofa domestica) – a study describing an animal model for asymmetrical intrauterine growth retardation. Experimental Toxicology and Pathology 50: 59-65.

Bauer, R., Walter, B., Gaser, E., Rösel, T., Kluge, H. and Zwiener, U., 1998b. Cardiovascular function and brain metabolites in normal weight and intrauterine growth restricted newborn piglets – effect of mild hypoxia. Experimental Toxicology and Pathology 50: 294-300.

Baxter, E.M. and Edwards, S.A., 2018. Piglet mortality and morbidity: inevitable or unacceptable? In: Spinka, M. (ed.) Advances in pig welfare. Woodhead Publishing, Cambridge, UK, pp. 73-100.

Baxter, E.M., Andersen, I.L. and Edwards, S.A., 2018. Sow welfare in the farrowing crate and alternatives. Chapter 2. In: Spinka, M. (ed.) Advances in pig welfare. Woodhead Publishing, Cambridge, UK, pp. 27-72.

Baxter, E.M., Jarvis, S., D’Eath, R.B., Ross, D.W., Robson, S.K., Farish, M., Nevison, I.M., Lawrence, A.B. and Edwards, S.A., 2008. Investigating the behavioural and physiological indicators of neonatal survival in pigs. Theriogenology 69: 773-783.

Baxter, E.M., Lawrence, A.B. and Edwards, S.A., 2011. Alternative farrowing systems: design criteria for farrowing systems based on the biological needs of sows and piglets. Animal 5: 580-600.

Baxter, E.M., Lawrence, A.B. and Edwards, S.A., 2012. Alternative farrowing accommodation: welfare and economic aspects of existing farrowing and lactation systems for pigs. Animal 6: 96-117.

Baxter, E.M., Rutherford, K.M.D., D’Eath, R.B., Arnott, G., Turner, S.P., Sandøe, P., Moustsen, V.A., Thorup, F., Edwards, S.A. and Lawrence, A.B., 2013. The welfare implications of large litter size in the domestic pig II: management factors. Animal Welfare 22: 219-238.

Benevenga, N.J., Steinman-Goldsworthy, J.K., Crenshaw, T.D. and Odle, J., 1989. Utilization of medium-chain triglycerides by neonatal piglets: I. Effects on milk consumption and body fuel utilization. Journal of Animal Science 67: 3331-3339.

Bergman, P., Gröhn, Y.T., Rajala-Schultz, P., Virtala, A.M., Oliviero, C., Peltoniemi, O. and Heinonen, M., 2018. Sow removal in commercial herds: Patterns and animal level factors in Finland. Preventive Veterinary Medicine 159: 30-39.

Berthon, D., Herpin, P. and Le Dividich, J., 1994. Shivering thermogenesis in the neonatal pig. Journal of Thermal Biology 19: 413-418.

Berthon, D., Herpin, P., Duchamp, C., Dauncey, M.J. and Le, J.D., 1993. Modification of thermogenic capacity in neonatal pigs by changes in thyroid status during late gestation. Journal of developmental Physiology 19: 253-261.

Biensen, N.J., Von Borell, E.H. and Ford, S.P., 1996. Effects of space allocation and temperature on periparturient maternal behaviours, steroid concentrations, and piglet growth rates. Journal of Animal Science 74: 2641-2648.

Black, J.L., Mullan, B.P., Lorschy, M.L. and Giles, L.R., 1993. Lactation in the sow during heat stress. Livestock Production Science 35: 153-170.

Blackshaw, J.K. and Hagelsø, A.M., 1990. Getting-up and lying-down behaviours of loose-housed sows and social contacts between sows and piglets during day 1 and day 8 after parturition. Applied Animal Behaviour Science 25: 61-70.

Blackshaw, J.K., Swain, A.J., Blackshaw, A.W., Thomas, F.J.M. and Gillies, K.J., 1997. The development of playful behaviour in piglets from birth to weaning in three farrowing environments. Applied Animal Behaviour Science 55: 37-49.

Bolhuis, J.E., Raats-Van den Boogaard, A.M.E., Hoofs, A.I.J. and Soede, N.M., 2018. Effects of loose housing and the provision of alternative nesting material on peri-partum sow behaviour and piglet survival. Applied Animal Behaviour Science 202: 28-33.

Bonde, M., 2008. Prevalence of decubital shoulder lesions in Danish sow herds. Internal Report 12, University of Aarhus, Faculty of Agricultural Sciences, Aarhus, Denmark, 8 pp.

Bruininx, E.M.A.M., Binnendijk, G.P., Van der Peet-Schwering, C.M.C., Schrama, J.W., Den Hartog, L.A., Everts, H. and Beynen, A.C., 2002. Effect of creep feed consumption on individual feed intake characteristics and performance of group-housed weanling pigs. Journal of Animal Science 80: 1413-1418.

Cabezon, F.A., Schinckel, A.P., Smith, A.J., Marchant-Forde, J.N., Johnson, J.S. and Stwalley, R.M., 2017. Initial evaluation of floor cooling on lactating sows under acute heat stress. The Professional Animal Scientist 33: 254-260.

Cabrera, R.A., Boyd, R.D., Jungst, S.B., Wilson, E.R., Johnston, M.E., Vignes, J.L. and Odle, J., 2010. Impact of lactation length and piglet weaning weight on long-term growth and viability of progeny. Journal of Animal Science 88: 2265-2276.

Campos, P.H.R.F., Silva, B.A.N., Donzele, J.L., Oliveira, R.F.M. and Knol, E.F., 2012. Effects of sow nutrition during gestation on within-litter birth weight variation: a review. Animal 6: 797-806.

Casellas, J., Casas, X., Piedrafita, J. and Manteca, X., 2005. Effect of medium-and long-chain triglyceride supplementation on small newborn-pig survival. Preventive Veterinary Medicine 67: 213-221.

Chen, J.C., Frankshun, A.L., Wiley, A.A., Miller, D.J., Welch, K.A., Ho, T.Y., Bartol, F.F. and Bagnell, C.A., 2011. Milk-borne lactocrine-acting factors affect gene expression patterns in the developing neonatal porcine uterus. Reproduction 141: 675.

Chevaux, E., Sacy, A., Le Treut, Y. and Martineau, G., 2010. Intrauterine growth retardation (IUGR): morphological and behavioural description. In: Proceedings of the 21st IPVS Congress, Vancouver, Canada, 209 pp.

Christison, G.I., Wenger, I.I. and Follensbee, M.E., 1997. Teat seeking success of newborn piglets after drying or warming. Canadian Journal of Animal Science 77: 317-319.

Cranwell, P.D., 1995. Development of the neonatal gut. In: Varley, M.A. (ed.) The neonatal pig: development and survival. CAB International, Wallingford, UK, pp. 99-154.

De Leeuw, J.A., Bolhuis, J.E., Bosch, G. and Gerrits, W.J.J., 2008. Effects of dietary fibre on behaviour and satiety in pigs: symposium on ‘Behavioural nutrition and energy balance in the young’. Proceedings of the Nutrition Society 67: 334-342.

De Vos, M., Huygelen, V., Willemen, S., Fransen, E., Casteleyn, C., Van Cruchten, S., Michiels, J. and Van Ginneken, C., 2014. Artificial rearing of piglets: effects on small intestinal morphology and digestion capacity. Livestock Science 159: 165-173.

D’Eath, R.B. and Lawrence, A.B., 2004. Early life predictors of the development of aggressive behaviour in the domestic pig. Animal Behaviour 67: 501-509.

Decaluwé, R., Maes, D., Declerck, I., Cools, A., Wuyts, B., De Smet, S. and Janssens, G.P.J., 2013. Changes in back fat thickness during late gestation predict colostrum yield in sows. Animal 7: 1999-2007.

Declerck, I., Dewulf, J., Decaluwé, R. and Maes, D., 2016. Effects of energy supplementation to neonatal (very) low birth weight piglets on mortality, weaning weight, daily weight gain and colostrum intake. Livestock Science 183: 48-53.

Declerck, I., Sarrazin, S., Dewulf, J. and Maes, D., 2017. Sow and piglet factors determining variation of colostrum intake between and within litters. Animal 11: 1336-1343.

Devillers, N., Le Dividich, J. and Prunier, A., 2011. Influence of colostrum intake on piglet survival and immunity. Animal 5: 1605-1612.

Díaz, J.A.C., Diana, A., Boyle, L.A., Leonard, F.C., McElroy, M., McGettrick, S., Moriarty, J. and Manzanilla, E.G. 2017. Delaying pigs from the normal production flow is associated with health problems and poorer performance. Porcine Health Management 3: 13.

Donovan, T.S. and Dritz, S.S., 2000. Effect of split nursing on variation in pig growth from birth to weaning. Journal of the American Veterinary Medical Association 217: 79-81.

Douglas, S.L., Edwards, S.A. and Kyriazakis, I., 2014. Management strategies to improve the performance of low birth weight pigs to weaning and their long term consequences. Journal of Animal Science 92: 2280-2288.

Douglas, S.L., Edwards, S.A., Sutcliffe, E., Knap, P.W. and Kyriazakis, I., 2013. Identification of risk factors associated with poor lifetime growth performance in pigs. Journal of Animal Science 91: 4123-4132.

Dunshea, F.R., Boyce, J.M. and King, R.H., 1998. Effect of supplemental nutrients on the growth performance of sucking pigs. Australian Journal of Agricultural Research 49: 883-888.

Dunshea, F.R., Kerton, D.J., Eason, P.J. and King, R.H., 1999. Supplemental skim milk before and after weaning improves growth performance of pigs. Australian Journal of Agricultural Research 50: 1165-1170.

Edwards, S.A. and Baxter, E.M., 2015. Piglet mortality: causes and prevention. In: Farmer, C. (ed.) The gestating and lactating sow. Wageningen Academic Publishers, Wageningen, the Netherlands, pp. 649-653.

Edwards, S.A., 2002. Perinatal mortality in the pig: environmental or physiological solutions? Livestock Production Science 78(1): 3-12.

Edwards, S.A., Matheson, S.M. and Baxter, E.M., 2019. Genetic influences on intra-uterine growth retardation of piglet and management interventions for low birth weight piglets. In: Nutrition of hyperprolific sows. Libro Novus, Saint Charles, MO, USA, pp. 141-166.

Engelsmann, M.N., Hansen, C.F., Nielsen, M.N., Kristensen, A.R. and Amdi, C., 2019. Glucose injections at birth, warmth and placing at a nurse sow improve the growth of IUGR piglets. Animals 9(8): 519.

European Union (EU), 2001. Commission directive 2001/93/EC of 9 November 2001amending Directive 91/630/EEC laying down minimum standards for the protection of pigs. Official Journal of the European Union L 316: 36-38. Available at: https://tinyurl.com/r2ep2cc.

European Union (EU), 2009. Council Directive 2008/120/EC of 18 December 2008 laying down minimum standards for the protection of pig. Official Journal of the European Union L 47: 5-13. Available at: https://tinyurl.com/y4kns95x.

Farmer, C. and Edwards, S., 2020. The neonatal pig: developmental influences on vitality. In: Farmere, C. (ed.) The suckling and weaned piglet. Wageningen Academic Publishers, Wageningen, the Netherlands, pp. 9-39.

Ferret-Bernard, S. and Le Huërou-Luron, I., 2020. Development of the intestinal immune system in young pigs – role of the microbial environment. In: Farmere, C. (ed.) The suckling and weaned piglet. Wageningen Academic Publishers, Wageningen, the Netherlands, pp. 159-177.

Feyera, T., Højgaard, C.K., Vinther, J., Bruun, T.S. and Theil, P.K., 2017. Dietary supplement rich in fiber fed to late gestating sows during transition reduces rate of stillborn piglets. Journal of Animal Science 95(12): 5430-5438.

Feyera, T., Pedersen, T., Krogh, U., Foldager, L. and Theil, P., 2018. Impact of sow energy status during farrowing on farrowing kinetics, frequency of stillborn piglets, and farrowing assistance. Journal of Animal Science 96: 2320-2331.

Foxcroft, G.R., 2008. Hyperprolificacy and acceptable post-natal development – a possible contradiction. Advances in Pork Production 19: 205-211.

Frei, D., Würbel, H., Wechsler, B., Gygax, L., Burla, J.B. and Weber, R., 2018. Can body nosing in artificially reared piglets be reduced by sucking and massaging dummies? Applied Animal Behaviour Science 202: 20-27.

Gieling, E.T., Park, S.Y., Nordquist, R.E. and Van der Staay, F.J., 2012. Cognitive performance of low- and normal-birth-weight piglets in a spatial hole-board discrimination task. Pediatric Research 71: 71-76.

Gluckman, P.D., 2004. The fetal matrix: evolution, development and disease. Cambridge University Press, Cambridge, UK.

Gondret, F., Lefaucheur, L., Louveau, I., Lebret, B., Pichodo, X. and Le Cozler, Y., 2006. Influence of piglet birth weight on postnatal growth performance, tissue lipogenic capacity and muscle histological traits at market weight. Livestock Production Science 93: 137-146.

Hales, J., Moustsen, V.A., Devreese, A.M., Nielsen, M.B.F. and Hansen, C.F., 2015. Comparable farrowing progress in confined and loose housed hyperprolific sows. Livestock Science 171: 64-72.

Hales, J., Moustsen, V.A., Nielsen, M.B.F. and Hansen, C.F., 2013. Individual physical characteristics of neonatal piglets affect pre-weaning survival of piglets born in a non-crated system. Journal of Animal Science 91: 4991-5003.

Hales, J., Moustsen, V.A., Nielsen, M.B.F. and Hansen, C.F., 2014. Higher pre-weaning mortality in free farrowing pens compared with farrowing crates in three commercial pig farms. Animal 8: 113-120.

Hansen, C., 2019. Landsgennemsnit for produktivitet I produktionen af grise, 2018. Report #1920. SEGES Pig Production, Denmark. Available at: https://svineproduktion.dk/publikationer/kilder/notater/2019/1920.

Hansen, C.F., Hales, J., Amdi, C. and Moustsen, V.A., 2019. Intrauterine growth-restricted piglets defined by their head shape have impaired survival and growth during the suckling period. Animal Production Science 59: 1056-1062.

Hasan, S., Orro, T., Valros, A., Junnikkala, S., Peltoniemi, O. and Oliviero, C., 2019. Factors affecting sow colostrum yield and composition, and their impact on piglet growth and health. Livestock Science 227: 60-67.

Heo, K.N., Lin, X., Han, I.K. and Odle, J., 2002. Medium-chain fatty acids but not L-carnitine accelerate the kinetics of [14C]triacylglycerol utilization by colostrum-deprived newborn pigs. Journal of Nutrition 132: 1989-1994.

Herpin, P., Damon, M. and Le Dividich, J., 2002. Development of thermoregulation and neonatal survival in pigs. Livestock Production Science 78: 25-45.

Horrell, I. and Bennett, J., 1981. Disruption of teat preferences and retardation of growth following cross-fostering of 1-week-old pigs. Animal Science 33: 99-106.

Jarvis, S., Calvert, S.K., Stevenson, J., Vanleeuwen, N. and Lawrence, A.B., 2002. Pituitary-adrenal activation in pre-parturient pigs (Sus scrofa) is associated with behavioural restriction due to lack of space rather than nesting substrate. Animal Welfare 11: 371-384.

Jensen, P., 1988. Maternal behaviour and mother – young interactions during lactation in freeranging domestic pigs. Applied Animal Behaviour Science 20: 297-308.

Jeon, J.H., Yeon, S.C., Choi, Y.H., Min, W., Kim, S., Kim, P.J. and Chang, H.H., 2006. Effects of chilled drinking water on the performance of lactating sows and their litters during high ambient temperatures under farm conditions. Livestock Science 105: 86-93.

Jiang, L., Feng, C., Tao, S., Zuo, B., Han, D. and Wang, J., 2019. Maternal imprinting of the neonatal microbiota colonization in intrauterine growth restricted piglets: a review. Journal of Animal Science and Biotechnology 10: 88.

Kammersgaard, T.S., Malmkvist, J. and Pedersen, L.J., 2013. Infrared thermography – a noninvasive tool to evaluate thermal status of neonatal pigs based on surface temperature. Animal 7: 2026-2034.

Kirkden, R.D., Broom, D.M. and Andersen, I.L., 2013. Piglet mortality: the impact of induction of farrowing using prostaglandins and oxytocin. Animal Reproduction Science 138: 14-24.

Klobasa, F., Werhahn, E. and Butler, J.E., 1987. Composition of sow milk during lactation. Journal of Animal Science 64 1458-1466.

Kobek-Kjeldager, C., Moustsen, V.A., Theil, P.K. and Pedersen, L.J., 2019. Effect of litter size, milk replacer and housing on production results of hyper-prolific sows. Animal 14: 824-833.

Kyriazakis I. and Edwards, S.A., 1986. The effect of ‘split-suckling’ on behaviour and performance of piglets. Applied Animal Behaviour Science 16: 92.

Langendijk, P., Fleuren, M., Van Hees, H. and Van Kempen, T., 2018. The course of parturition affects piglet condition at birth and survival and growth through the nursery phase. Animals 8: 60.

Larsen, M.L.V. and Pedersen, L.J., 2015. Does light attract piglets to the creep area? Animal 9: 1032-1037.

Latham, N.R. and Mason, G.J., 2008. Maternal deprivation and the development of stereotypic behaviour. Applied Animal Behaviour Science 110: 84-108. https://doi.org/10.1016/j.applanim.2007.03.026

Lawrence, A.B., McLean, K.A., Jarvis, S., Gilbert, C.L. and Petherick, J.C., 1997. Stress and parturition in the pig. Reproduction in Domestic Animals 32: 231-236.

Le Dividich, J., Mormede, P., Catheline, M. and Caritez, J.C., 1991. Body-composition and cold resistance of the neonatal pig from European (Large White) and Chinese (Meishan) breeds. Biology of the Neonate 59: 268-277.

Le Dividich, J., Rooke, J.A. and Herpin, P., 2005. Nutritional and immunological importance of colostrum for the new-born pig. Journal of Agricultural Science 143: 469-485.

Lepine, A.J., Boyd, R.D., Welch, J.A. and Roneker, K.R., 1989. Effect of colostrum or mediumchain triglyceride supplementation on the pattern of plasma glucose, non-esterified fatty acids and survival of neonatal pigs. Journal of Animal Science 67: 983-990.

Lynegaard, J.C., Hansen, C.F., Kristensen, A.R. and Amdi, C., 2019. Body composition and organ development of intra-uterine growth restricted pigs at weaning. Animal 14: 322-329.

Malmkvist, J., Damgaard, B.M., Pedersen, L.J., Jørgensen, E., Thodberg, K., Chaloupková, H. and Bruckmaier, R.M., 2009. Effects of thermal environment on hypothalamic-pituitary-adrenal axis hormones, oxytocin, and behavioural activity in periparturient sows. Journal of Animal Science 87: 2796-2805.

Malmkvist, J., Pedersen, L.J., Damgaard, B.M., Thodberg, K., Jørgensen, E. and Labouriau, R., 2006. Does floor heating around parturition affect the vitality of piglets born to loose housed sows? Applied Animal Behaviour Science 99: 88-105.

Malmkvist, J., Pedersen, L.J., Kammersgaard, T.S. and Jørgensen, E., 2012. Influence of thermal environment on sows around farrowing and during the lactation period. Journal of Animal Science 90: 3186-3199.

Marco, E., 2018. How to deal with disease in large litters. Proceedings of the 10th European Symposium on Porcine Health and Management (ESPHM). Barcelona, Spain, pp. 48-52.

Matheson, S.M., Walling, G.A. and Edwards, S.A., 2018. Genetic selection against intrauterine growth retardation in piglets: a problem at the piglet level with a solution at the sow level. Genetics Selection Evolution 50: 46.

Meunier-Salaün, M.C., Edwards, S.A. and Robert, S., 2001. Effect of dietary fibre on the behaviour and health of the restricted fed sow. Animal Feed Science and Technology 90: 53-69.

Miller, Y., Collins, A., Smits, R., Thomson, P. and Holyoake, P., 2012. Providing supplemental milk to piglets pre-weaning improves the growth but not survival of gilt progeny compared with sow progeny. Journal of Animal Science 90: 5078-5085.

Moreira, L.P., Menegat, M.B., Barros, G.P., Bernardi, M.L., Wentz, I. and Bortolozzo, F.P., 2017. Effects of colostrum, and protein and energy supplementation on survival and performance of low-birth-weight piglets. Livestock Science 202: 188-193.

Morise, A., Louveau, I. and Le Huerou-Luron, I., 2008. Growth and development of adipose tissue and gut and related endocrine status during early growth in the pig: impact of low birth weight. Animal 2: 73-83.

Mount, L.E., 1963. Environmental temperature preferred by the young pig. Nature 199(4899): 1212-1213.

Mount, L.E., 1967. The heat loss from new-born pigs to the floor. Research in Veterinary Science 8: 175-186.

Moustsen, V.A. and Poulsen, H.L., 2004. Anbefalinger vedr. dimensioner på fareboks og kassesti. Landsudvalget for Svin, Danske Slagterier, Notat nr. 414

Muns, R., Malmkvist, J., Larsen, M.L.V., Sørensen, D. and Pedersen, L.J., 2016. High environmental temperature around farrowing induced heat stress in crated sows. Journal of Animal Science 94: 377-384.

Muns, R., Manteca, X. and Gasa, J., 2015. Effect of different management techniques to enhance colostrum intake on piglets’ growth and mortality. Animal Welfare 24: 185-192.

Muns, R., Nuntapaitoon, M. and Tummaruk, P., 2017. Effect of oral supplementation with different energy boosters in newborn piglets on pre-weaning mortality, growth and serological levels of IGF-I and IgG. Journal of Animal Science 95: 353-360.

Muns, R., Silva, C., Manteca, X. and Gasa, J., 2014. Effect of cross-fostering and oral supplementation with colostrums on performance of newborn piglets. Journal of Animal Science 92: 1193-1199.

Neal, S.M. and Irvin, K.H., 1991. The effects of cross-fostering pigs on survival and growth. Journal of Animal Science 69: 41-46.

Neil, M., Ogle, B. and Anner, K., 1996. A two-diet system and ad libitum lactation feeding of the sow 1. Sow performance. Animal Science 62: 337-347.

Newberry, R.C. and Swanson, J.C., 2008. Implications of breaking mother-young social bonds. Applied Animal Behaviour Science 110: 3-23.

Nielsen, B., Su, G., Lund, M.S. and Madsen, P., 2013. Selection for increased number of piglets at d 5 after farrowing has increased litter size and reduced piglet mortality. Journal of Animal Science 91: 2575-2582.

Nissen, P.M. and Oksbjerg, N., 2011. Birth weight and postnatal dietary protein level affect performance, muscle metabolism and meat quality in pigs. Animal 5: 1382-1389.

Ocepek, M. andersen-Ranberg, I., Edwards, S.A., Fredriksen, B., Framstad, T. and Andersen, I.L., 2016. Can a super sow be a robust sow? Consequences of litter investment in purebred and crossbred sows of different parities. Journal of Animal Science 94: 3550-3560.

Oliviero, C., Heinonen, M., Valros, A. and Peltoniemi, O., 2010. Environmental and sow-related factors affecting the duration of farrowing. Animal Reproduction Science 119: 85-91.

Oliviero, C., Junnikkala, S. and Peltoniemi, O., 2019. The challenge of large litters on the immune system of the sow and the piglets. Reproduction in Domestic Animals 54: 12-21.

Oostindjer, M., Bolhuis, J.E., Mendl, M., Held, S., Gerrits, W., Van den Brand, H. and Kemp, B., 2010. Effects of environmental enrichment and loose housing of lactating sows on piglet performance before and after weaning. Journal of Animal Science 88: 3554-3562.

Oostindjer, M., Kemp, B., Van den Brand, H. and Bolhuis, J.E., 2014. Facilitating ‘learning from mom how to eat like a pig’ to improve welfare of piglets around weaning. Applied Animal Behaviour Science 160: 19-30.

Orgeur, P., Hay, M., Mormède, P., Salmon, H., Le Dividich, J., Nowak, R., Schaal, B. and Lévy, F., 2001. Behavioural, growth and immune consequences of early weaning in one-week-old largewhite piglets. Reproduction, Nutrition and Development 41: 321-332.

Papadopoulos, G.A., Vanderhaeghe, C., Janssens, G.P., Dewulf, J. and Maes, D.G., 2010. Risk factors associated with post-partum dysgalactia syndrome in sows. The Veterinary Journal 184: 167-171.

Pedersen, L.J. and Jensen, T., 2008. The effect of late introduction to the farrowing environment (crates and pens) on the progress of parturition and maternal behaviour. Journal of Animal Science 86: 2730-2737.

Pedersen, L.J., Berg, P., Jørgensen, G. and Andersen, I.L., 2011a. Neonatal piglet traits of importance for survival in crates and indoor pens. Journal of Animal Science 89: 1207-1218.

Pedersen, L.J., Larsen, M.L.V. and Malmkvist, J., 2016. The ability of different thermal aids to reduce hypothermia in neonatal piglets. Journal of Animal Science 94: 2151-2159.

Pedersen, L.J., Malmkvist, J. and Andersen, H.M.L., 2013. Housing of sows during farrowing: a review on pen design, welfare and productivity. Livestock housing: modern management to ensure optimal health and welfare of farm animals. Wageningen Academic Publishers, Wageningen, the Netherlands, pp. 285-297.

Pedersen, M.L., Moustsen, V.A., Nielsen, M.B.F. and Kristensen, A.R., 2011b. Improved udder access prolongs duration of milk letdown and increases piglet weight gain. Livestock Science 140: 253-261.

Peltoniemi, O.A.T. and Oliviero, C., 2015. Housing, management and environment during farrowing and early lactation. In: Farmer, C. (ed.) The gestating and lactating sow. Wageningen Academic Publishers, Wageningen, the Netherlands, pp. 77-84.

Perin, J., Gaggini, T.S., Manica, S., Magnabosco, D., Bernardi, M.L., Wentz, I. and Bortolozzo, F.P., 2016. Evaporative snout cooling system on the performance of lactating sows and their litters in a subtropical region. Ciência Rural 46: 342-347.

Piccolo, B.D., Mercer, K.E., Bhattacharyya, S., Bowlin, A.K., Saraf, M.K., Pack, L., Chintapalli, S.V., Shankar, K., Adams, S.H. and Badger, T.M., 2017. Early postnatal diets affect the bioregional small intestine microbiome and ileal metabolome in neonatal pigs. Journal of Nutrition 147: 1499-1509.

Poletto, R., Steibel, J.P., Siegford, J.M. and Zanella, A.J., 2006. Effects of early weaning and social isolation on the expression of glucocorticoid and mineralocorticoid receptor and 11β-hydroxysteroid dehydrogenase 1 and 2 mRNAs in the frontal cortex and hippocampus of piglets. Brain Research 1067: 36-42.

Poonsuk, K. and Zimmerman, J., 2018. Historical and contemporary aspects of maternal immunity in swine. Animal Health Research Reviews 19: 31-45.

Poore, K.R. and Fowden, A.L., 2003. The effect of birth weight on hypothalamo-pituitary-adrenal axis function in juvenile and adult pigs. Journal of Physiology 547: 107-116.

Power, M.L. and Schulkin, J., 2013. Maternal regulation of offspring development in mammals is an ancient adaptation tied to lactation. Applied and Translational Genomics 2: 55-63.

Price, E.O., Hutson, G.D., Price, M.I. and Borgwardt, R., 1994. Fostering in swine as affected by age of offspring. Journal of Animal Science 72: 1697-1701.

Prims, S., Pintens, N., Vergauwen, H., Van Cruchten, S., Van Ginneken, C. and Casteleyn, C., 2017. Effect of artificial rearing of piglets on the volume densities of M cells in the tonsils of the soft palate and ileal Peyer’s patches. Veterinary Immunology and Immunopathology 184: 1-7.

Prunier, A., De Braganca, M.M. and Le Dividich, J., 1997. Influence of high ambient temperature on performance of reproductive sows. Livestock Production Science 52: 123-133.

Quesnel, H., Brossard, L., Valancogne, A. and Quiniou, N., 2008. Influence of some sow characteristics on within‐litter variation of piglet birth weight. Animal 2: 1842-1849.

Quesnel, H., Farmer, C. and Devillers, N., 2012. Colostrum intake: influence on piglet performance and factors of variation. Livestock Science 146: 105-114.

Quiniou, N. and Noblet, J., 1999. Influence of high ambient temperatures on performance of multiparous lactating sows. Journal of Animal Science 77: 2124-2134.

Rangstrup-Christensen, L., Krogh, M.A., Pedersen, L.J. and Sørensen, J.T., 2017. Sow-level risk factors for stillbirth of piglets in organic sow herds. Animal 11: 1078-1083.

Read, E., Baxter, E.M., Farish, M. and D’Eath, R.B., 2020. Trough half empty – pregnant sows are fed under half of their ad libitum intake. Animal Welfare 29: 151-162.

Rees, S., Mallard, C., Breen, S., Stringer, M., Cock, M. and Harding, R., 1998. Fetal brain injury following prolonged hypoxemia and placental insufficiency: a review. Comparative Biochemistry and Physiology Part A: Molecular and Integrative Physiology 119: 653-660.

Rehfeldt, C. and Kuhn, G., 2006. Consequences of birthweight for postnatal performance and carcass quality in pigs as related to myogenesis. Journal of Animal Science 84: E113-123.

Rekiel, A., Więcek, J., Batorska, M. and Kulisiewicz, J., 2014. Effect of sow prolificacy and nutrition on pre- and post-natal growth of progeny – a review. Annals of Animal Science 14: 3-15.

Rioja-Lang, F.C., Seddon, Y.M. and Brown, J.A., 2018. Shoulder lesions in sows: a review of their causes, prevention, and treatment. Journal of Swine Health and Production 26: 101-107.

Robert, S. and Martineau, G.P., 2001. Effects of repeated cross-fosterings on preweaning behaviour and growth performance of piglets and on maternal behaviour of sows. Journal of Animal Science 79: 88-93.

Roehe, R., Shrestha, N.P., Mekkawy, W., Baxter, E.M., Knap, P.W., Smurthwaite, K.M., Jarvis, S., Lawrence, A.B. and Edwards, S.A., 2010. Genetic parameters of piglet survival and birth weight from a two-generation crossbreeding experiment under outdoor conditions designed to disentangle direct and maternal effects. Journal of Animal Science 88: 1276-1285.

Rosvold, E.M., Kielland, C., Ocepek, M., Framstad, T., Fredriksen, B., Andersen-Ranberg, I., Næss, G. and Andersen, I.L., 2017. Management routines influencing piglet survival in loose-housed sow herds. Livestock Science 196: 1-6.

Roza, S.J., Steegers, E.A., Verburg, B.O., Jaddoe, V.W., Moll, H.A., Hofman, A., Verhulst, F.C. and Tiemeier, H., 2008. What is spared by foetal brain-sparing? Foetal circulatory redistribution and behavioural problems in the general population. American Journal of Epidemiology 168: 1145-1152.

Rutherford, K.M.D., Baxter, E.M., D’Eath, R.B., Turner, S.P., Arnott, G., Roehe, R., Ask, B., Sandøe, P., Moustsen, V.A., Thorup, F. and Edwards, S.A., 2013. The welfare implications of large litter size in the domestic pig I: biological factors. Animal Welfare 22: 199-218.

Rutherford, K.M.D., Donald, R.D., Arnott, G., Rooke, J.A., Dixon, L., Mehers, J.J.M., Turnbull, J. and Lawrence, A.B., 2012. Farm animal welfare: assessing risks attributable to the prenatal environment. Animal Welfare 21: 419-429.

Rzezniczek, M., Gygax, L., Wechsler, B. and Weber, R., 2015. Comparison of the behaviour of piglets raised in an artificial rearing system or reared by the sow. Applied Animal Behaviour Science 165: 57-65.

Schmitt, O., Baxter, E.M., Boyle, L.A. and O’Driscoll, K., 2019b. Nurse sow strategies in the domestic pig: II. Consequences for piglet growth, suckling behaviour and sow nursing behaviour. Animal 13: 590-599.

Schmitt, O., Baxter, E.M., Boyle, L.A. and O’Driscoll, K., 2019c. Nurse sow strategies in the domestic pig: I. Consequences for selected measures of sow welfare. Animal 13: 580-589.

Schmitt, O., Baxter, E.M., Lawlor, P.G., Boyle, L.A. and O’Driscoll, K., 2019a. A single dose of fatbased energy supplement to light birth weight pigs shortly after birth does not increase their survival and growth. Animals 9: 227.

Schmitt, O., O’Driscoll, K., Boyle, L.A. and Baxter, E.M., 2019d. Artificial rearing affects piglets pre-weaning behaviour, welfare and growth performance. Applied Animal Behaviour Science 210: 16-25.

Schmitt, O., O’Driscoll, K., Baxter, E.M. and Boyle, L.A., 2019e. Artificial rearing affects the emotional state and reactivity of pigs post-weaning. Animal Welfare 28: 433-442.

Smith, F., Clark, J.E., Overman, B.L., Tozel, C.C., Huang, J.H., Rivier, J.E.F., Blisklager, A.T. and Moeser, A.J., 2009. Early weaning stress impairs development of mucosal barrier function in the porcine intestine. American Journal of Physiology – Gastrointestinal and Liver Physiology 298: 352-363. https://doi.org/10.1152/ajpgi.00081.2009

Sørensen, J.T. and Pedersen, L.J., 2015. Omfanget af brugen af ammesøer og mulige tiltag til forbedring af deres velfærd. Institut for Husdyrvidenskab, DCA – Nationalt Center for Jordbrug og Fødevarer, Aarhus Universitet, Aarhus, Denmark.

Sørensen, J.T., Rousing, T., Kudahl, A.B., Hansted, H.J. and Pedersen, L.J., 2016. Do nurse sows and foster litters have impaired animal welfare? Results from a cross-sectional study in sow herds. Animal 10: 681-686.

Stansbury, W.F., McGlone, J.J. and Tribble, L.F., 1987. Effects of season, floor type, air temperature and snout coolers on sow and litter performance. Journal of Animal Science 65: 1507-1513.

Stewart, T.S. and Diekman, M.A., 1989. Effect of birth and fraternal litter size and cross-fostering on growth and reproduction in swine. Journal of Animal Science 67: 635-640.

Straw, B.E., Dewey, C.E. and Bürgi, E.J., 1998. Patterns of crossfostering and piglet mortality on commercial US and Canadian swine farms. Preventive Veterinary Medicine 33: 83-89.

Swan, K.M., Peltoniemi, O.A.T., Munsterhjelm, C. and Valros, A., 2018. Comparison of nestbuilding materials in farrowing crates. Applied Animal Behaviour Science 203: 1-10.

Thorsen, C.K. and Pedersen, L.J., 2019. Metoder til forbedring af søer og pattegrises velfærd i store kuld som erstatning for brug af ammesøer. DCA – Nationalt center for fødevarer og jordbrug. Aarhus Universitet, Aarhus, Denmark,

Thorsen, C.K., Schild, S.L.A., Rangstrup-Christensen, L., Bilde, T. and Pedersen, L.J., 2017. The effect of farrowing duration on maternal behaviour of hyperprolific sows in organic outdoor production. Livestock Science 204: 92-97.

Thorup, F., Wedel-Müller, R.L., Hansen, C.F., Kanitz, E., Tuchscherer, M., 2015. Neonatal mortality in piglets is more due to lack of energy than lack of immunoglobulins. In: International conference on pig welfare: Improving pig welfare – what are the ways forward? Copenhagen, Denmark, p. 84. Available at: https://curis.ku.dk/ws/files/137055997/2015_075_IPWC_Abstract.pdf.

Torrey, S. and Widowski, T.M., 2006. Is belly nosing redirected suckling behaviour? Applied Animal Behaviour Science 101: 288-304.

Touchette, K.J., Carroll, J.A., Allee, G.L., Matteri, R.L., Dyer, C.J., Beausang, L.A. and Zannelli, M.E., 2002. Effect of spray-dried plasma and lipopolysaccharide exposure on weaned pigs: I. Effects on the immune axis of weaned pigs. Journal of Animal Science 80: 494-501.

Tuboly, S., Bernath, S., Glavits, R. and Medveczky, I., 1988. Intestinal absorption of colostral lymphoid cells in newborn piglets. Veterinary Immunology and Immunopathology 20: 75-85.

Tuchscherer, M., Puppe, B., Tuchscherer, A. and Tiemann, U., 2000. Early identification of neonates at risk: traits of newborn piglets with respect to survival. Theriogenology 54: 371-388.

Valros, A.E., Rundgren, M., Špinka, M., Saloniemi, H., Rydhmer, L. and Algers, B., 2002. Nursing behaviour of sows during 5 weeks lactation and effects on piglet growth. Applied Animal Behaviour Science 76: 93-104.

Van Beirendonck, S., Schroijen, B., Bulens, A., Van Thielenab, J. and Driessena, B., 2015. A solution for high production numbers in farrowing units? In: Proceedings of the International Conference on Pig Welfare: improving pig welfare – what are the ways forward? April 29-30, 2015. Copenhagen, Denmark.

Van den Brand, H., Van Enckevort, L.C.M., Van der Hoeven, E.M. and Kemp, B., 2009. Effects of dextrose plus lactose in the sows diet on subsequent reproductive performance and within litter birth weight variation. Reproduction in Domestic Animals 44: 884-888.

Van Dijk, A.J., Everts, H., Nabuurs, M.J.A., Margry, R.J.C.F. and Beynen, A.C., 2001. Growth performance of weanling pigs fed spray-dried animal plasma: a review. Livestock Production Science 68: 263-274.

Van Wagenberg, A.V., Van der Peet-Schwering, C.M.C., Binnendijk, G.P. and Claessen, P.J.P.W., 2006. Effect of floor cooling on farrowing sow and litter performance: field experiment under Dutch conditions. Transactions of the ASABE 49: 1521-1527.

Vasdal, G. and Andersen, I.L., 2012. A note on teat accessibility and sow parity; consequences for newborn piglets. Livestock Science 146: 91-94.

Vasdal, G., Glærum, M., Melišová, M., Bøe, K.E., Broom, D.M. and Andersen, I.L., 2010. Increasing the piglets’ use of the creep area – a battle against biology? Applied Animal Behaviour Science 125: 96-102.

Vasdal, G., Østensen, I., Melišová, M., Bozděchová, B., Illmann, G. and Andersen, I.L., 2011. Management routines at the time of farrowing – effects on teat success and postnatal piglet mortality from loose housed sows. Livestock Science 136: 225-231.

Vergauwen, H., Degroote, J., Prims, S., Wang, W., Fransen, E., De Smet, S., Casteleyn, C., Van Cruchten, S., Michiels, J. and Van Ginneken, C., 2017. Artificial rearing influences the morphology, permeability and redox state of the gastrointestinal tract of low and normal birth weight piglets. Journal of Animal Science and Biotechnology 8: 1-14.

Wattanakul, W., Bulman, C.A., Edge, H.L. and Edwards, S.A., 2005. The effect of creep feed presentation method on feeding behaviour, intake and performance of suckling piglets. Applied Animal Behaviour Science 92: 27-36.

Weary, D.M., Appleby, M.C. and Fraser, D., 1999. Responses of piglets to early separation from the sow. Applied Animal Behaviour Science 63: 289-300. https://doi.org/10.1016/S0168-1591(99)00021-0

Weary, D.M., Jasper, J. and Hötzel, M.J., 2008. Understanding weaning distress. Applied Animal Behaviour Science 110: 24-41.

White, K.R., Anderson, D.M. and Bate, L.A., 1996. Increasing piglet survival through an improved farrowing management protocol. Canadian Journal of Animal Science 76: 491-495.

Widowski, T.M., Torrey, S., Bench, C.J. and Gonyou, H.W., 2008. Development of ingestive behaviour and the relationship to belly nosing in early-weaned piglets. Applied Animal Behaviour Science 110: 109-127.

Widowski, T.M., Yuan, Y. and Gardner, J.M., 2005. Effect of accommodating sucking and nosing on the behaviour of artificially reared piglets. Laboratory Animals 39: 240-250.

Williams, A.M., Safranski, T.J., Spiers, D.E., Eichen, P.A., Coate, E.A. and Lucy, M.C., 2013. Effects of a controlled heat stress during late gestation, lactation, and after weaning on thermoregulation, metabolism, and reproduction of primiparous sows. Journal of Animal Science 91: 2700-2714.

Wolf, J., Žáková, E. and Groeneveld, E., 2008. Within-litter variation of birth weight in hyperprolific Czech Large White sows and its relation to litter size traits, stillborn piglets and losses until weaning. Livestock Science 115: 195-205.

Wolter, B., Ellis, M., Corrigan, B. and Dedecker, J., 2002. The effect of birth weight and feeding of supplemental milk replacer to piglets during lactation on preweaning and postweaning growth performance and carcass characteristics. Journal of Animal Science 80: 301-308.

Worobec, E.K., Duncan, I.J.H. and Widowski, T.M., 1999. The effects of weaning at 7, 14 and 28 days on piglet behaviour. Applied Animal Behaviour Science 62: 173-182.

Wu, G., Bazer, F.W., Burghardt, R.C., Johnson, G.A., Kim, S.W., Li, X.L., Satterfield, M.C. and Spencer, T.E., 2010. Impacts of amino acid nutrition on pregnancy outcome in pigs: mechanisms and implications for swine production. Journal of Animal Science 88: E195-E204.

Yan, L., Jang, H. and Kim, I., 2011. Effects of varying creep feed duration on pre-weaning and post-weaning performance and behaviour of piglet and sow. Asian-Australasian Journal of Animal Sciences 24: 1601-1606

Yeruva, L., Spencer, N.E., Saraf, M.K., Hennings, L., Bowlin, A.K., Cleves, M.A., Mercer, K., Chintapalli, S.V., Shankar, K., Rank, R.G., Badger, T.M. and Ronis, M.J.J., 2016. Formula diet alters small intestine morphology, microbial abundance and reduces VE-cadherin and IL-10 expression in neonatal porcine model. BMC Gastroenterology 16: 1-13.

Yun, J., Swan, K.M., Farmer, C., Oliviero, C., Peltoniemi, O. and Valros, A., 2014a. Prepartum nest-building has an impact on post-partum nursing performance and maternal behaviour in early lactating sows. Applied Animal Behaviour Science 160: 31-37.

Yun, J., Swan, K.M., Oliviero, C., Peltoniemi, O. and Valros, A., 2015. Effects of pre-partum housing environment on abnormal behaviour, the farrowing process, and interactions with circulating oxytocin in sows. Applied Animal Behaviour Science 162: 20-25.

Yun, J., Swan, K.M., Vienola, K., Kim, Y.Y., Oliviero, C., Peltoniemi, O.A.T. and Valros, A., 2014b. Farrowing environment has an impact on sow metabolic status and piglet colostrum intake in early lactation. Livestock Science 163: 120-125.

Zhong, X., Li, W., Huang, X., Wang, Y., Zhang, L., Zhou, Y., Hussain, A. and Wang, T., 2012. Effects of glutamine supplementation on the immune status in weaning piglets with intrauterine growth retardation. Archives of Animal Nutrition 66: 347-356.