The relationship between growth and osteochondrosis in specific joints in pigs E.M. van Grevenhof a, ⁎, H.C.M. Heuven b , P.R. van Weeren c , P. Bijma a a Animal Breeding and Genomics Centre, Wageningen University, P.B. 338, 6700 AH Wageningen, The Netherlands b Faculty of Veterinary Medicine, Utrecht University, Department of Clinical Sciences of Companion Animals, Yalelaan 108, 3584 CM Utrecht, The Netherlands c Veterinary Faculty, Utrecht University, Department of Equine Sciences, Yalelaan 114, 3584 CM Utrecht, The Netherlands article info abstract Article history: Received 18 October 2010 Received in revised form 26 August 2011 Accepted 1 September 2011 Osteochondrosis (OC) is a disturbance of the process of endochondral ossification during skel- etal growth. Osteochondrosis is considered the main reason for leg weakness in pigs, which is the second reason for culling in sows, after fertility problems. Previous studies suggest there is a relationship between OC and growth. However, little is known about this relationship, in par- ticular about the timeframe in which growth influences ossification. The aim of the study was to identify the age at which growth and OC are related, and whether this relationship differs between joints. To understand the relationship between the growth pattern and the onset of OC, repeated body weight (BW) measurements and OC scores of 345 pigs were collected. An average of 17 body weight measurements from birth until slaughter at 6 months of age was used. OC was scored macroscopically after slaughter in 24 locations of five joints. Pigs were di- vided in three defined groups based on the severity of OC; no OC, minor, or severe OC. Until weaning at day 21 no differences in weight and gain were found between the three de- fined groups. From weaning onwards, pigs diagnosed with minor or severe OC showed higher BWs than pigs diagnosed without OC. The higher weights were due to increased growth before the age of three months. This period might coincide with the window of susceptibility for OC in pigs. The relationship with growth seems to be joint-dependent. Pigs with OC in the elbow joints or with OC in two joints had high BWs, whereas pigs with OC in the femoropatellar joints had low BWs compared to mean BW. Determination of the window of susceptibility and of the relationship between weight gain and OC may help in developing strategies to reduce OC in pig populations. © 2011 Elsevier B.V. All rights reserved. Keywords: Body weight Growth Joint Osteochondrosis Pigs Window of susceptibility 1. Introduction Osteochondrosis (OC) is a disturbance of the process of endo- chondral ossification during skeletal growth and affects growing pigs in many commercial breeds (Crenshaw, 2006; Grøndalen, 1974a,b; Uhlhorn et al., 1995). Osteochondrosis is a biomechan- ically induced disease, influenced by the combination of rapid skeletal growth and increasing muscle and body mass, which in- creases the pressure on joint surfaces while they are still devel- oping and structurally weak. In pigs, osteochondrosis is the main cause of leg weakness, which is the second reason for in- voluntary culling sows, next to fertility problems (Yazdi et al., 2000). Therefore, it is both for economic and welfare reasons im- portant to reduce OC in pig populations. Osteochondrosis is claimed to be associated with high BW or growth rate (GR), and not to occur or to be milder in slow growing or wild populations (Uhlhorn et al., 1995). Next to biomechanical influences, a high GR, either due to genetic se- lection or feeding, causes disturbances in bone metabolism, which may increase the prevalence of OC (Grøndalen, 1974a,b; Grøndalen and Grøndalen, 1974; Kadarmideen et al., 2004). In slowly growing animals, either on a nutritional or genetic basis, very little OC has been found (Reiland, Livestock Science 143 (2012) 85–90 ⁎ Corresponding author. Tel.: + 31 317 482282; fax: + 31 317 483929. E-mail address: ilse.vangrevenhof@wur.nl (E.M. van Grevenhof). 1871-1413/$ – see front matter © 2011 Elsevier B.V. All rights reserved. doi:10.1016/j.livsci.2011.09.002 Contents lists available at SciVerse ScienceDirect Livestock Science journal homepage: www.elsevier.com/locate/livsci