Physiological response and carcass and meat quality of suckling lambs in relation to transport time and stocking density during transport by road

Abstract

To evaluate the effect of stocking density and transport time on physiological responses and meat quality, 72 male suckling lambs were transported by road to the slaughterhouse at three different stocking densities (0.12, 0.20 or 0.25 m 2 /lamb) and two transport times (5 h or 30 min). Blood samples were collected pre-transport at the farm and after unloading in the slaughterhouse to measure levels of cortisol, creatine kinase (CK) and lactate dehydrogenase (LDH). After slaughter, the weights of the hot carcass, liver and spleen were recorded and pH in Musculus longisimus thoracis et lumborum (L), Musculus semitendinosus (ST) and Musculus psoas major (PM) were determined. Colour, water-holding capacity (WHC), texture and thiobarbituric acid-reactive substances (TBARS) values were measured in samples of L, at 24 h post mortem and after 5 days of ageing. Cortisol and LDH were higher in suckling lambs transported for 30 min than those transported for 5 h. Stocking density did not affect blood parameters studied. Transport time significantly affected some carcass quality parameters, but stocking density had no significant effect. Suckling lambs transported for 5 h had lower liver weights and dressing percentages than those transported for 30 min. Transport time influenced pH values, with lambs subjected to the longer journey showing the lowest pH at 0 h in the three muscles studied, with the lowest final pH in L and PM. The PM lambs transported at high density (0.12 m 2 /lamb) had the lowest pH at 24 h. Transport time and stocking density did not greatly affect colour and texture parameters. The meat from lambs transported for 30 min had higher WHC than meat from lambs transported for 5 h. Animals transported for longer journeys showed higher lipid oxidation after 5 days of ageing than those transported for 30 min. Loading and initial transport caused significant stress response in suckling lambs, that stress response was reduced over the time course of the journey.Keywords: stocking density, transport time, animal welfare, meat quality, suckling lambs ImplicationsThis study attempts to be of practical value for the transport of suckling lambs, considering animal welfare of lambs as well as the economical aspects of improving meat quality and reducing costs of transport. European Union establishes a minimum space allowance per head of 0.20 m 2 for lambs over 26 kg of live weight, but operators can reduce this minimum without any regulation in small lambs. The results of this study show that stocking density could be reduced up to 0.12 m 2

Effect of season and stocking density during transport on carcass and meat quality of suckling lambs

“…In fact, as discussed by Warriss (1990), the mobilisation of tissues to provide energy to maintain vital body functions could result in losses in the weight of liver. The SD did not affect carcass quality, in agreement with results found by De la Fuente et al (2010) in suckling lambs.…”

“…Cooking loss percentage was determined as the loss with respect to the initial weight after cooking the samples for 30 min in plastic bags immersed in a water bath at 75°C according to De la Fuente et al (2010).…”

“…In this respect, Richardson (2002) recommends reducing the SD for sheep transport at high temperatures. Previous authors (Dalla Costa et al, 2007;Kadim et al, 2008;De la Fuente et al, 2010) have studied the transportbased factors, such as SD and season, on welfare and carcass and meat quality in different species. However, little information about these aspects is available on suckling lambs.…”

The effect of dietary supplementation with β-1,3/1,6-D-glucan on stress parameters and meat quality in lambs

“…Body weight losses have been investigated in small ruminants that differed in age, breed, duration of transport and pre-slaughter fasting (Hall et al, 1997;Kadim et al, 2006;De la Fuente et al, 2010), Dobicki et al (2005). Milewski (2009) also noted a significant increase (P ≤ 0.01) in the percentage of lymphocytes and a tendency towards a lower percentage of neutrophils in the blood of lambs fed diet with dried yeast addition.…”

Effect of pre-slaughter handling, exercise and the presence of a dog on lamb welfare and meat quality

“…Interestingly, De la Fuente et al (2010) found that lactate dehydrogenase was greater in lambs after a 30 min transport period but lower after a 5 h transport period compared with baseline values. In addition, lactate concentrations of sheep exercised for 2 h on a treadmill at a speed of 4.5 km/h increased by 55% in the first 15 min before declining below baseline levels (Pethick et al, 1987).…”