G.C. Miranda-de la Lama

Effect of the pre-slaughter logistic chain on meat quality of lambs.

A total of 144 lambs were sampled in a 3×2×2 factorial design, testing three residence (stay) times at a pre-slaughter classification centre (0, 7, and 28days) and two seasons (summer and winter), with two replicates in each season. Meat from the longissimus dorsi was analysed in terms of pH, WHC, texture, colour (L∗a∗b∗, chroma and hue) and carcass bruising. Stay time had a significant effect (p<0.001) on meat texture, while season had a significant effect (p<0.001) on all variables analysed. Overall, stay time had less effect on meat quality than season and the interaction between treatments was not significant. Meat from lambs slaughtered in winter had some dark-cutting characteristics, with darker colour, higher ultimate pH, tougher meat and lower press juice. In conclusion, pre-slaughter classification and season are sources of stress for lambs and affect meat quality traits.

Livestock transport from the perspective of the pre-slaughter logistic chain: a review

New developments in livestock transport within the pre-slaughter chain are discussed in terms of three logistic nodes: origin, stopovers and slaughterhouse. Factors as transport cost, haulier, truck specifications, micro-environment conditions, loading density, route planning, vehicle accidents and journey length are discussed as well as causes of morbidity, mortality, live weight and carcass damage. Taking into account current trends towards increased transport times, logistics stopovers and mixed transport, there is a need to develop systems of evaluation and decision-making that provide tools and protocols that can minimize the biological cost to animals, which may have been underestimated in the past.

Risk factors influencing bruising and high muscle pH in Colombian cattle carcasses due to transport and pre-slaughter operations.

The aim of this study was investigate risk factors as possible causes for bruising and high muscle pH under commercial operating conditions in Colombia. Data was recorded for 86 journeys referring to 1179 animals. Carcasses were analyzed in terms of muscle pH and bruises (site, size, severity and shape). Our results indicate that truck load density, stops during transportation of cattle and the lairage time at the plant increased the risk of bruises appearing on carcasses. A lairage time of 18 to 24h at the plant increased the prevalence of bruises 2.1 times compared to lairage periods of between 12 and 18 h. Furthermore, intermittent stops during transit are a risk factor for the increase in the incidence of bruises. However, the transport time (up to 4h) was not related to the presence of bruises and high muscle pH. Finally, steers were found to have less risk of presenting a high muscle pH.

Mexican consumers' perceptions and attitudes towards farm animal welfare and willingness to pay for welfare friendly meat products

Increasing concerns about farm animal welfare have led to an increase in the availability of welfare-friendly-products (WFP), but little is known about how much more consumers are willing-to-pay (WTP) for WFP or about their buying trends in Latin America. In this study, a survey was given to 843 meat consumers in the city of Toluca, Mexico. The results show that consumers were interested in farm animal welfare issues and their ethical, sociological and economic implications, as in Europe. The people surveyed also conveyed a high level of empathy with animal feelings and emotions, however they clearly demanded more information and regulations related to farm animal welfare. The majority of respondents expressed that they were WTP more for properly certified WFP, but mostly based on the benefits in terms of product quality and human health. If the demand for WFP begins to increase in Mexico, the supply chain should consider a certification system to guarantee product origin based on current conditions.

Effects of two transport systems on lamb welfare and meat quality

The aim of this study was to analyse the effect of a direct transport system (DTS) versus transport with a logistic stopover system (TLS) on lamb welfare and meat quality at two seasons. A total of 96 lambs were sampled in a 2×2×2 factorial design, testing two transport systems and two seasons (summer and winter), with two replicates in each season. Significant interactions (P≤0.05) between transport system and season in both welfare and meat quality were found. In general, lambs subjected to direct transport and logistic stopover during winter had a more intense stress response and poorer meat quality than lambs transported during summer. However, direct transport during the cold season seemed to be the most stressful, compared to the rest of the groups, which was reflected in significantly higher levels of cortisol, lactate, glucose, ratio of N/L, higher pH24 and darker and tougher meat.

Effect of lairage on lamb welfare and meat quality

The study analysed the effect of lairage on some indicators of welfare and meat quality in lambs. Forty-eight lambs were divided into two treatments: T1 without lairage and T2 with 12 h of lairage. Blood samples were collected at slaughter to analyse cortisol, lactate, glucose, creatinine kinase, non-esterified fatty acid, white blood cells, red blood cells, haematocrit and ratio of neutrophil : lymphocytes. Meat from the M. longissimus was analysed in terms of pH 24 h post-mortem, water-holding capacity, texture and colour. Sensory analyses were performed by a trained panel. Lairage had a significant effect on stress response, but had no effect on haematological variables. The lambs with a lairage period before slaughter (T2) had significantly (P ≤ 0.001) lower values of cortisol at the time of slaughter. A similar result was observed for lactate and glucose, with T1 lambs showing significantly (P ≤ 0.05) higher values than T2 lambs. The creatinine kinase activity and non-esterified fatty acid concentrations were highest in T2 lambs (P ≤ 0.05). Instrumental and sensory meat quality were not affected, with the exception of water-holding capacity and some meat colour indicators. The water-holding capacity was significantly higher for T2 (P ≤ 0.05), while T1 lambs had a higher yellow index (P ≤ 0.05) and hue (P ≤ 0.05). The results obtained in this study suggest that animals will be less stressed at the time of slaughter with an overnight lairage compared with slaughter on arrival at the abattoir. While stress at the time of slaughter can influence meat quality, these changes were small and always within the normal commercial range.

Effect of straw on lamb welfare, production performance and meat quality during the finishing phase of fattening.

The studies analyse the effect of straw on lamb welfare, production and meat quality in finishing lambs. Two studies were carried out. Study 1 included two treatments and two replicates with six lambs each (17.20±0.2 kg). One pen was provided with straw for forage and bedding while the other had none. Feeding with concentrate was ad libitum. Live weight and concentrate consumption were recorded and average daily gain and conversion index calculated. Stereotypes, agonistic and affiliative interactions and physiological indicators of stress were analysed. In study 2, 24 lambs were divided into two groups to analyse the effect of treatments on meat and carcass quality. No significant differences in production or meat quality traits were observed. Lambs housed without straw had higher levels of cortisol and stereotypes. Affiliative interactions were greater in lambs without straw. Results suggest that straw can be considered an effective environment-enriching tool to improve welfare.

Influence of social dominance on production, welfare and the quality of meat from beef bulls.

The aim of this study was to assess the effect of social dominance on some indicators of welfare, production and meat quality of young bulls. A total of 60 bulls of the Gasconne breed, 9 months old, housed indoors were used. Indices of success order were calculated to reflect social dominance of each bull into three ranking categories (low, middle and high). Blood samples were taken to measure cortisol, lactate, glucose, creatine kinase, non-esterified fatty acid and neutrophil/lymphocyte ratio (N/L). M. longissimus samples were analysed in terms of pH, water holding capacity (WHC), texture, colour and sensorial attributes. Social rank influenced cattle stress response, which had an effect on productive performance but not on meat quality traits, with the exception of the sensory traits. These results emphasize the importance of implementing best management practices during pre-harvest handling of cattle in order to modulate any possible risk factor for social stress.

Effect of enriched housing on welfare, production performance and meat quality in finishing lambs: the use of feeder ramps.

This study analyses the effect of environmental enrichment on the welfare, productive traits and meat quality of lambs housed in feedlots. Sixty lambs were placed in enriched (EE) or conventional (CO) pens (3 pens for each treatment, 10 lambs/pen) where EE had a wooden platform with ramps that provided access to a concentrate hopper, cereal straw as bedding and forage, and one play ramp. The CO pen was barren, similar to commercial feedlots. The physiological adaptation response of EE lambs was more efficient than CO, since the latter mobilised more body reserves (i.e., increased NEFA, P<0.05), and had lower levels of immunity (i.e., increased N/L, P<0.05), which indicate chronic stress, probably associated with the barren environment. The EE lambs had a higher (P<0.05) average daily gain, with heavier carcasses and higher fattening scores, as well as lower pHult, higher L and b values, and lower values of texture (P<0.05).

Effect of a screen with flaps and straw on behaviour, stress response, productive performance and meat quality in indoor feedlot lambs

We analysed the effect of a modified pen using a wooden screen with flaps and cereal straw as forage and bedding, on behaviour, stress response, performance and meat quality variables of lambs housed in feedlots. Sixty male lambs were placed in enriched (ESF) or conventional (CO) pens (3 pens/treatment, 10 lambs/pen). The CO environment was barren. The ESF lambs showed a great preference for the provided items, which encouraged more natural and richer behaviour, reducing stereotypies and lamb aggressions, and increasing affiliations (P ≤ 0.05), which improves group cohesion. However, ESF lambs also developed a more natural coping style to the handling, evidenced by the higher cortisol levels (65.4 vs. 43.8 nmol/L) and a higher eye temperature as response to the reactivity test (38.1 vs. 37.8 °C). The ESF lambs had a higher (P ≤ 0.05) slaughter weight (27.2 vs. 26.3 kg), conformation score (7.38 vs. 6.07) and pH 24 (5.63 vs. 5.56) but lower cooking losses (12.9 vs. 14.9%) than CO lambs.