Cameron Jose

Current iron (Fe) levels in fresh pork are below requirements to claim for a source of Fe (Anonymous, 2013). Dietary studies to increase muscle Fe in pork have generally failed, although an increase in muscle redness, associated with increased haem Fe, was observed (Apple et.al 2007). Under normal feeding conditions about 10% of dietary Fe is absorbed, however this value increases markedly under Fe deficiency (West and Oates 2008). This study tested the hypothesis that feeding lower levels of dietary Fe (depletion) followed by feeding higher levels of dietary Fe (repletion) to pigs will increase muscle Fe levels.

Variation in pork quality has been proposed to be mostly due to different rates of post-mortem muscle pH decline (Ryu and Kim, 2006) and its influence on tenderness (Pomponio et al. 2010), which is an important eating quality discriminator. The variable nature and inconsistency of meat quality attributes, such as meat colour and pH, in outdoor bred pigs in Western Australia, and the related quantity of stored muscle glycogen at slaughter, led to this investigation. High levels of muscle glycogen pre-slaughter increases potential lactic acid production, the extent of pH decline, and the lightness of pork. The effect of high glycogen levels on the rate of pH decline is controversial (Scheffler and Gerrard, 2007) and has never been examined in outdoor bred pigs in Australia. The aim of this experiment was to investigate the influence of loin glycogen stores pre-slaughter on post-slaughter pH decline in outdoor bred pigs in Western Australia.

The age-weight relationship of growing lambs is of major economic importance to the Australian sheep industry. Birth, weaning and slaughter weights can be used to derive important growth traits such as relative and absolute growth rates by the use of nonlinear growth functions such as Brody (1945). These functions have been used to model liveweight gain, providing a relatively precise description of the growth pattern of animals with a clear biological interpretation. Analysis of animal growth performance is essential to establish precise feeding strategies as well as providing accurate age estimates for animals to reach target slaughter weights. Early estimation of these traits is vital to optimise production and genetic selection. The objectives of this study were to determine environmental and genetic factors affecting post-weaning weight gains in Australian sheep flocks with known genetic potential for growth.