Growth Gradients in the Skeleton of Cattle, Sheep and Pigs

Abstract

A study of growth gradients of the limbs and axial skeleton was carried out in cattle, sheep and pigs, with the aid of gross anatomical dissection. The comparative study is discussed relative to each individual species and to interspecies differences. IntroductionA concept of postnatal growth gradients in bones was suggested by MCMEEKAN (1943) and PALSSON (1955). They described an axial craniocaudal gradient of increasing growth, and a distoproximal gradient of increasing growth in the limbs. Nevertheless, to date there are no reports available on the growth patterns of a topographical series of bone weights in the axial skeleton or in the limbs, covering the entire postnatal growth of any species.This paper reports an allometric analysis of bone growth within single breeds of cattle, sheep and pigs. By comparing growth patterns between these species, any patterns common to quadrupeds should become apparent. These species have also provided material to examine the effect of sex in a species and breed in which sex differences in external appearance are particularly evident (Jersey cattle), the effect of breed in a species for which two breeds differing markedly in mature body size, fat deposition and body shape were available (German Landrace and Gottingen Miniature pigs), and the effect of stage of growth in a species for which fetuses are a suitable size, and are readily available, for dissection (sheep).Results for some of the pigs have been previously published (DAVIES, 1979). Results for the growth of cattle formed part of one of the authors's PhD thesis (TAN, 1981). The results for all the material used have been briefly reported in a previous communication (DAVIES, 1980). Material and MethodsA total of 33 Jersey cattle, 38 Romney sheep and 61 pigs were dissected for this study (Tables 1 and 2). A half carcass of each animal was separated into component muscles, bones and fat depots. The methods have already been described by TAN (1981) for cattle, by BROAD/DAVIES (1980) for sheep, and by DAVIES/&LLWEIT (1979) for pigs. The carcasses were divided in the median plane in such a way as to leave the vertebral column intact and attached to the dissected side. The bones were cleaned of attached muscles, tendons and ligaments, leaving cartilagenous, periosteal and medullary tissues. Half U. S.

Genotype and gender effects on sheep limb bone growth and maturation: selection for loin depth causes bone hypotrophy

“…The absent or minor differences in allometric b terms suggest that genotypic differences in bone length are mainly secondary to differences in prenatal or early antenatal growth. These results conform with other studies showing limb bone growth coefficients to be highly conserved genetically, for example between male and female Jersey cattle, or various pig breeds (Richmond et al 1979;Davies et al 1984). Results suggest that, although genotype and gender differences in conformation (for example, the predominance of distal over proximal parts in M × M sheep, and vice versa in PD g × BLM sheep) are partly explained by differences in allometric growth gradients, heterochronic alterations in whole limb growth rate play a greater role.…”

Mechanical properties of the porcine growth plate vary with developmental stage

“…This difference in mechanical properties may be attributed to rapid porcine developmental changes at the 3-4 week period, where it was shown that pigs experience an increase in growth at 3 weeks followed by a decrease at 4 weeks. Indeed, between 2 and 3 weeks, pigs increase by about 60% in mass, followed by a 20% decrease between 3 and 4 weeks (Davies et al 1984;Corson et al 2008). Bone growth is directly stimulated by increased levels of testosterone and decreased levels of estrogen due to the presence of receptors within the growth plate, or indirectly by stimulating growth hormone that increases cellular proliferation (Peralta et al 1994;Maor et al 1999;Juul 2001;Phillip et al 2001;Van der Eerden et al 2002;Irie et al 2005;Savendahl 2005;Chagin and Savendahl 2007).…”

Relationships in red deerCervus elaphus mandibles

“…Classic studies on domestic species have demonstrated that growth follows a centripetal pattern caused by waves of high growth intensity commencing in distal parts of body extremities and converging along the back line towards the pelvic region (Hammond 1932, Hammond 1940, McMeekan 1940, Walker 1964). This pattern is described as a change in timing of differentially declining growth rates of specific parts of the body (Wallace 1948), which explain the progress of the proximodistal-distoproximal pattern in the limbs, and craniocaudal-cranionasal pattern in the axial skeleton (Hammond 1940, McMeekan 1940, Davies et al 1984. Differences in timing for maturation and growth intensity in various organs seem to be associated with their functional importance both in pre-and post natal life (Wenham and Pennie 1986).…”

“…Differences in timing for maturation and growth intensity in various organs seem to be associated with their functional importance both in pre-and post natal life (Wenham and Pennie 1986). Although species differences occur (Hammond 1940, Davies et al 1984, the general pattern applies to most large mammals and tissues over the entire ontogenetic process (Wallace 1948).…”