Effect of cage and pen housing on the live performance, carcase, and meat quality traits of growing rabbits

Digestive problems in rabbit production: moving in the wrong direction?

Digestive problems, both those with a clear pathogenic origin (e.g., Escherichia coli) and those without obvious pathogen involvement [e.g., syndromes like epizootic rabbit enteropathy (ERE)], are common in production rabbits and account for the majority of losses in meat rabbit production. A multitude of nutritional, genetic and housing factors have been found to play a role in the occurrence of digestive problems. However, the exact early pathophysiological mechanism, including the links between aforementioned risk factors and subsequent development and expression of gastrointestinal disease, is less clear, especially in non-specific enteropathies without obvious pathogen involvement. In this review, we aim to shed more light on the derailment of the normal gastrointestinal functioning in rabbits. We discuss a conceptual integrated view of this derailment, based on an "overload" pathway and a "chymus jam" pathway, which may occur simultaneously and interact. The "overload" pathway centers around exposure to excess amounts of easily fermentable substrate (e.g., starch and protein) that might be incompletely digested prior to entering the caecum. Once there, hyperfermentation may result in changes in caecal pH and inhibition of the normal microflora. The second pathway centers around a chymus jam resulting from a compromised passage rate. Here, reduced hindgut motility (e.g., resulting from stress or limited fiber supply) leads to reduced flow of digesta and increased caecal retention times, which might lead to the production of abnormal caecal fermentation products and subsequent inhibition of the normal microflora. A central role in the presumed mechanism is attributed to the fusus coli. We discuss the suggested mechanisms behind both pathways, as well as the empirical substantiation and alignment between theoretical concepts and observations in practice. The proposed hypotheses may explain the effect of time-based restriction to prevent ERE, which is widely applied in practice but to date not really understood, and suggest that the particle size of fiber may be a key point in the normal functioning of the colon and fusus coli. Further insight into the circumstances leading to the derailment of physiological processes in the rabbit hindgut could provide a meaningful starting point to help improve their gastrointestinal resilience.

Effect of rearing system (free-range vs cage) on gut and muscle histomorphology and microbial loads of Italian White breed rabbits

OBJECTIVE

The growing consumers' interest on animal welfare has raised the request of products obtained by alternative rearing systems. The present study was conducted to assess the influence of housing system on gut and muscle morphology and on microbial load in rabbits reared under free-range (FR) and cage system (CS).

METHODS

A total of forty weaned (35 days of age) male Italian White breed rabbits were allotted according to the rearing system, and at 91 days of age were randomly selected and slaughtered for the morphological evaluation of tissue from duodenum and longissimus lumborum. Morphometric analysis of the villus height, villus width, crypt depth, villus height/crypt depth ratio, and villus surface was performed. The microbial loads on hind muscle was determined by total mesophilic aerobic count (TMAC), Escherichia coli and Enterobacteriaceae; whereas, total anaerobic bacteria count (TABC) and TMAC, E. coli and Enterobacteriaceae was determined on caecal content.

RESULTS

Rearing system did not interfere with the duodenum and muscle histomorphology in both rabbit groups. Similarly, microbial load of caecal content showed no significant differences on the TABC and TMAC. Conversely, significant difference was found for E. coli strains in caecal content, with the lower counts in FR compared to CS rabbits (p<0.01). Microbiological assay of muscle revealed significant lower TMAC in FR vs CS rabbits (p< 0.05). All rabbit meat samples were negative for E. Coli and Enterobacteriaceae.

CONCLUSION

Free-range could be considered a possible alternative and sustainable rearing system in rabbits to preserve gut environment and muscle quality.

The effect of housing system on rabbit growth performance, carcass traits, and meat quality characteristics of different muscles

The present study analysed the effect of housing system (caged versus penned) on the growth performance, carcass traits, and meat quality of rabbits. The physiochemical quality of five muscles was evaluated, together with the chemical composition and fatty acid profile of the meat from the hind leg. Sensory properties of the longissimus lumborum (LL) was also assessed. The LL yields were higher in caged rabbits. According to the results, meat from rabbits raised in cages had higher b* values for the LL (i.e., meat was yellower) than rabbits raised in pens. In addition, the quadriceps femoris from penned rabbits had higher a* and b* values (i.e., were redder and yellower) than caged rabbits. The MUFAs (18:1 n-9 and 20:1 n-9) and ash contents of the hind leg meat were higher in caged rabbits. In conclusion, while housing system influenced the physiochemical traits of rabbit meat, the sensory properties were not influenced.

Rabbit meat trade of major countries: regional pattern and driving forces

In in the last 60 or so years, the global rabbit industry has been growing steadily. This paper studies the global rabbit meat trade by focusing on trade growth and regional pattern. First, rabbit meat productionand regional structure are introduced, as the basis of trade. Then, the global rabbit meat trade is studied in detail, including trade growth, regional structural changes, comparative advantages and competitiveness of major countries. Finally, a gravity model is built to test major factors affecting the rabbit meat trade andexplore the driving forces behind the trade. The data come from different channels, including the Food and Agriculture Organization of the United Nations, World Bank, the World Trade Organization and related government statistics. The results show that: (1) Over the past 60 yr, the global rabbit industry has achieved great progress. In the first half of the period, rabbit meat was mainly produced in Europe; then, rabbit meat production in Asia increased steadily and rapidly in the second half period, while European production decreased continuously. (2) The rabbit meat trade had been increasing for about 20 yr from 1961 to 1979, after which it fluctuated for another 20 yr. However, since 2001 it has been stable around an average level of 37 thousand tonnes, with only minor fluctuation. The trade pattern is currently from Asia (mainly China) and South America (mainly Argentina) to European countries. In 2018, the top 5 export destinations were Germany, Belgium, Italy, Portugal and France (3). Hungary and Argentina have been two strong competitorsin the last two decades, while Spain and Belgium are two new and promising countries in the rabbit meat trade. Now China no longer has comparative advantages in the rabbit meat trade (4). The gravity model results show that rabbit meat trade is mainly driven by demand. Countries with a high Gross Domestic Product tend to increase their imports more, but decrease their exports. Countries with higher populations export more rabbit meat but import less. Common language and contiguity of two countries have significant impacts on rabbit meat trade. Based on the above results, some suggestions and policy implications are provided. Rabbit farmers or processing companies should pay more attention to domestic consumers or neighbouring countries to survey potential markets; traders should explore more markets in order to reduce the degree of trade concentration and lower risks. Governments should popularise the nutritional knowledge of rabbit meat to encourage people (especially young people) to consume more healthy rabbit meat instead of pork, with a view to reducing obesity or other heart diseases, etc.

Prevalence of post mortem lesions recorded in the largest Italian rabbit slaughterhouse over a fifteen-years period (2003-2017)

<p>The present research was aimed at evaluating the prevalence of gross lesions in condemned rabbit carcasses by analysing data recorded in a large Italian slaughterhouse. From 2003 until 2017, a total of 103 080 019 rabbits were processed: 101 722 673 were finishing rabbits and 1 357 346 were breeding females. A total of 742 397 carcasses were condemned due to lesions. Condemned carcasses from young rabbits (n=545 070) evidenced: 33.6% enteritis, 31.5% subcutaneous abscesses, 29.7% cachexia and 3.84% lung disease. Among breeding rabbits (n=197 327) there were 38.9% cachexia, followed by 35.8% uterine pathologies (breeding females), 14.9% subcutaneous abscesses, 5.42% ulcerative pododermatitis, 2.61% chronic nephritis and 2.47% lung disease. Regarding season-related lesions, for growing rabbits the total prevalence of lesions and diseases was the highest in winter (enteritis increased in winter, but subcutaneous abscesses were higher in summer). Rabbit does showed the highest prevalence of subcutaneous abscesses in summer and ulcerative pododermatitis in winter. From 2003 to 2017, the overall number of condemned carcasses doubled in both categories, with a sharp increase from 2012 till 2017. The prevalence of lesions among slaughtered rabbits differed between growing and breeding categories, which was attributable to different farming conditions, physiological status and slaughter age. Based on the above-mentioned findings, better management strategies at different stages of the rabbit production chain seem to be a necessary way to manage resulting waste and address possible economic concerns.</p>