Projects / Programmes
Raising entire males or immunocastration? Research of measures for boar taint reduction and emerging problems of product quality
| Code |
Science |
Field |
Subfield |
| 4.02.03 |
Biotechnical sciences |
Animal production |
Ethology and technology in stock-breeding |
| Code |
Science |
Field |
| B400 |
Biomedical sciences |
Zootechny, animal husbandry, breeding |
| Code |
Science |
Field |
| 4.02 |
Agricultural and Veterinary Sciences |
Animal and Dairy science |
boar taint; skatole, androstenone; meat quality; nutrition; tannins; immunocastration; pigs
Researchers (22)
Organisations (4)
Abstract
Surgical castration of piglets is a routine practice in pig production used as a preventive measure to avoid boar taint, un unpleasant smell which develops with puberty in uncastrated male pigs. This practice is presently being questioned in the EU and there is a strong initiative to end it until 2018. The initiative is presently voluntary, however EC strongly supports the actions which have been taken by the stakeholders (see EC decison OJ EU 2011/C 243/06 on key research necessities). However, before a decision related to ending of this practice is put into force, a lot of potential problems need to be addressed in view of the adaptation of pig sector. This project is designed to answer some issues of scientific and practical relevance related to two most viable alternatives, the raising of entire males (boars) and immunocastration. Measures to reduce the prevalence of boar taint (the causative compounds are androstenone and skatole which accumulate in the fat tissue of uncastrated male pigs) concern genetic factors and herd management (nutrition, hygiene and health status). The level of androstenone depends on sexual maturity (genotype), its reduction by means of genomic selection seems feasible, but it is a long-term challenge. Moreover the majority of pig production in Slovenia is based on imported genetic lines making the issue less urgent for national research. Therefore the project will study possibility for boar taint reduction by means of nutrition. In particular, studying the potential influence of the diet supplemented with tannins. Tannins are susceptible to affect skatole metabolism due to their effect on protein utilization and interaction with gut microbiota. It is therefore reasonable to expect that skatole metabolism could be affected by tannins, which we plan to investigate in the proposed project. Due to the lack of the literature data on that matter, this study provides scientific originality but has also relevance for economy (namely one of the main producers of tannin reach wood extracts Tanin, Sevnica is located in Slovenia). Another objective of the proposed project relates to the nutrition of immunocastrates, the other viable alternative to surgical castration. Immunocastrates are a new 'type' of animals and there are a lot of unanswered questions related to the feeding strategies in order to preserve their boar-like potential for growth and body composition after the immunocastration becomes effective. In the present study we plan to study the consequences of restricting energy level (10 and 15% energy reduction) of their diet. If raising boars is to become a predominant practice in pig meat production, the problems of meat quality could emerge (not only related to boar taint) due to lower water holding capacity and tenderness of such meat. This is another hypothesis which we plan to address in the project by studying the aetiology of the phenomenon at structural and proteomic level. Moreover both alternatives, raising entire and castrated males will also be evaluated for dry-cured ham ‘kraški pršut’ processing (in relation to salt intake and product quality), another approach interesting not only scientificaly, but also economically due to the importance of this product at a national level.
Significance for science
The project addresses many questions with high scientific relevance and originality. • There is scientifically based evidence that some nutritional strategies can be effective in reducing skatole-related boar taint of entire males. No literature data is available on the potential effect of tannins on skatole metabolism and consequently boar taint. The results of the project demonstrated that tanin supplement affects apoptosis and mitosis in large intestine and reduces skatole production. • Immunocastrated pigs are a new 'type' of animals that are gradually coming into the market (in some countries, like New Zealand or Australia, they have been used for some years now, whereas in Europe the vaccine was registered only recently). An original aim of the present project adresses feeding strategies for immunocastrated pigs and project results have demonstrated different energetic metabolism demanding adapted nutritional strategy. • The fattening of entire males seems the most viable alternative for the future (fresh meat market) intensive pig production in Europe; if it is to become the predominant practice then fresh meat quality (not only due to higher risk of tainted meat) could be compromised. The results have demonstrated differences in proteomic profile between castrates and entire males, indicating increased proteolytic potential of the latter. • The experiment with dry-cured hams has opened new challenges of research, namely are boar taint substances reduced during the process and that in the case of dry-cured or fermented products eaten cold high proteolytic potential can be sensorily more probmematic than boar taint substances
Significance for the country
Surgical castration of piglet has recently become one of the major concerns of pig meat industry in EU, due to the strong initiative to ban this practice performed to avoid boar taint of meat. The European Comission (EC) supports the initiative as demonstrated by workplan (see http://ec.europa.eu/food/animal/welfare/farm/initiatives_en.htm; already finished (PIGCAS, ALCASDE, CAMPIG, CASTRUM) and on-going projects (IPEMA, ERA-NET SuSI). Before taking the final steps however, the countries must prepare their pig sector to the forth coming changes. That is why it is important that each member state conducts the studies in their particular pig breeding conditions of herd management (e.g. breeds, nutrition, housing systems) to get acquainted with the possible problems and solutions for their sector. In Slovenia, the problem has additional dimension since we are not self-sufficient and a lot of pig meat comes from external markets. In particular for the industry of dry-cured ham this could become a problem, because they don't use locally produced raw material. This is also why the project addresses this issue and is supported by one of the main dry-cured ham processors in Slovenia. Another important benefit of the project relates to testing of the supplementation of pig diet with tannins. In Slovenia we have a big producer of tannin rich wood extracts (http://www.tanin.si/), who will provide the extracts. It may also be worth noting, that using entire males in pig production would lower the environmental impact of pig production due to their higher efficiency; on that matter the results of the study would be in particular interesting in case of variables 'animal types' and diets. The Ministry of agriculture has co-financed the project, meaning that they also consider the project relevant for the Slovenian society and economy. The project has been supported also by meat industry (Celjske mesnine).
Most important scientific results
Annual report
2013,
2014,
2015,
final report
Most important socioeconomically and culturally relevant results
Annual report
2013,
2014,
2015,
final report
