Effect of pre-slaughter environment on some physiological parameters and meat quality in New Zealand rabbits (Oryctolagus cuniculus)

On-Farm and Processing Factors Affecting Rabbit Carcass and Meat Quality Attributes

Rabbit meat has high nutritional and dietetic characteristics, but its consumption rate is comparatively lower than other meat types. The nutritional profile of rabbit meat, by comparison with beef, pork, and poultry, is attributed to relatively higher proportions of n-3 fatty acids and low amounts of intramuscular fat, cholesterol, and sodium, indicating its consumption may provide health benefits to consumers. But, the quality attributes of rabbit meat can be originated from different factors such as genetics, environment, diet, rearing system, pre-, peri-, and post-slaughter conditions, and others. Different rabbit breeds and the anatomical location of muscles may also affect the nutritional profile and physicochemical properties of rabbit meat. However, adequate information about the effect of those two factors on rabbit meat is limited. Therefore, cumulative information on nutritional composition and carcass and meat quality attributes of rabbit meat in terms of different breeds and muscle types and associated factors is more important for the production and processing of rabbits. Moreover, some studies reported that rabbit meat proteins exhibited angiotensin-converting enzyme inhibitory characteristics and antioxidant properties. The aim of this review is to elucidate the determinants of rabbit meat quality of different breeds and its influencing factors. In addition, the proven biological activities of rabbit meat are introduced to ensure consumer satisfaction.

Mortality in rabbits transported for slaughter

During transport rabbits may be exposed to various stressors which can compromise both their welfare and meat quality. Mortality related to the commercial transport of rabbits for slaughter was analyzed in the Czech Republic in the period from 2009 to 2016. The overall transport-related mortality of rabbits was 0.19%. Transport distance was found to have an impact on rabbit mortality; significantly (p < .001) greater losses were found in rabbits transported over longer distances. Mortality rates ranged from 0.02% in rabbits transported over distances of less than 50 km to 0.29% in rabbits transported over distances exceeding 400 km. A significantly (p < .001) increased risk was also associated with shipments in which 500 and more rabbits were delivered per batch. No effect of season was found. Our results show that rabbits can be transported within a wide range of temperatures (from -5 to 19.9°C) with no negative impact on mortality in transit. However, journeys carried out at temperatures below -5°C and above 20°C were associated with increased death losses (0.17% and 0.15%, respectively).

Comparison of Carcass and Meat Quality Traits among Three Rabbit Breeds

The objective of this study was to compare carcass composition and meat quality traits in the longissimus dorsi and biceps femoris muscles in the Hyla, Champagne and Tianfu Black rabbit breeds. Tianfu Black rabbits had the heaviest head, skin, thoracic viscera and commercial carcass percentage (p<0.05). In addition, Tianfu Black had the highest pH_{0 h} value, followed by the Champagne and Hyla breeds (p<0.01) in the longissimus dorsi and biceps femoris muscles. Tianfu Black had a higher a* (0 h and 24 h) than the other two breeds in both longissimus dorsi and biceps femoris muscles (p<0.05). The Hyla, Champagne, and Tianfu Black breeds showed a similar pattern of differences for meat quality traits (pH, L*, a* and b*) measured in fresh meat (0 h) and meat stored for 24 h. Hyla had the highest IMF values of the three breeds (p<0.01). The lower intramuscular fat of Tianfu Black and Champagne rabbits gives them an advantage over Hyla rabbits among most consumers seeking lean rabbit meat.

Changes in Blood Constituents of Rabbits Subjected to Transportation under Hot, Humid Tropical Conditions

Unlike Europe (particularly, Italy and Spain), where a number of studies have been conducted on the stressful effects of transport on rabbit welfare, few studies have been conducted on transportation of rabbits under hot, humid tropical conditions experienced in countries like Malaysia. We studied the effects of transportation in hot humid tropical conditions of Malaysia on physiometabolic changes in New Zealand white rabbits. Eighty experimental animals were divided into two groups of 40 bucks each and transported for either 3 or 1 h. Transportation caused a significant upsurge of aspartate aminotransferase, alanine aminotransferase and creatine kinase activities (p<0.001) though did not significantly affect lactate dehydrogenase (LDH) activity (p = 0.0706). Both transportation periods caused elevation in plasma glucose levels, lactic acidosis and dehydration as evidenced through elevated packed cell volume and plasma protein concentration. It was concluded that regardless of the duration, transport of rabbits under hot humid tropical conditions, resulted in heat distress since the rabbits showed hyperglycemia, hypercalcemia, lactacidemia, lymphocytopenia, dehydration and increase in blood enzyme activities.

Reduction of the olfactory cognitive ability in horses during preslaughter: stress-related hormones evaluation

As horses may perceive several odour signals of danger at slaughter, application of mentholated ointment to their nostrils may limit their perception of danger. To assess the effect of the application of a mentholated ointment to horse nostrils on the stress response during pre-slaughter handling, plasma levels were evaluated for cortisol, beta-endorphin, epinephrine and norepinephrine prior to and after stunning. Twenty draught-type horses were divided into control (n=10) and treated (n=10) groups and a mentholated ointment applied to the nostrils of the treated horses following blood sampling in lairage 45 min prior to slaughter. Treatment did not affect plasma concentrations of beta-endorphin or cortisol but significantly reduced the concentrations of epinephrine and norepinephrine observed in post-stun plasma. These results indicated that mentholated ointment applied to the nostrils of horses pre-slaughter reduced their adrenergic response to the slaughter environment, implying that the stress response may be reduced with this technology.