Improving Meat Quality by Castration

Castration is a process of removal of the testicles or its function to sterilise or to decreases particular hormones so that the animal is having different characteristics of the physiological process, resulting in different characteristics of animal products (especially meat).

The most used method of castration is the surgical castration. This method, in principle, is making an incision in the scrotum and the removal of testes. After removal, the testes are absent in the piglet’s body so that it will be not producing any testosterone anymore. By this process, it is expected that the meat of the castrated group of animal has more intramuscular fat because the absence of testosterone which resembles the female meat production and metabolism (Lawrie, 2006).

 

Picture1

The anatomy of the genital tract of male piglets and localisation of incisions during surgical castration (*sites of cutting and/or tearing). Adapted from Prunier et al., 2006.

 

Besides surgical, there is another method of castration, namely immuno- castration. According to Animal Welfare Division of American Veterinary Medical Association (AVMA) (2013), immuno- castration involves an injection of a protein compound that similar to immunisation to triggers antibody production against gonadotropin releasing hormones (GnRH). This process is performed in two doses: the first 8 to 11 weeks before slaughter and the second 4 weeks before slaughter. This process resulting in the same outcome (decreases in gonadal steroids productions) with the surgical castration, so that there is also a decreasing trend in a boar taint and enhancement in meat quality.

Surgical castration will result in pain because the scrotum and testes innervated as well as other tissues (Prunier et al., 2006). Therefore the anesthesia should be used, especially for the piglets older than a week. Local anaesthesia is the most common method used in experiments designed to relieve pain in piglets at castration. Intratesticular administrations have been tested as well as subcutaneous administration at the site of the incision.

The castration is regulated under Commission Directive 2008/120/EC of Official Journal of European Communities (2009). In annexe chapter 1 of regulation as mentioned earlier, it is stated that castration of piglets aged one to seven days can be performed without anaesthesia. The piglets older than seven days have to be castrated, but with the use of anaesthesia and in the supervision of veterinary only.

Concerns about animal welfare arise because nowadays most of the people always wanted to express their sympathy to the animals. Von Borrell et al. (2009) studied that there is pain exist when piglets castrated. This fact is evidently supported by various indicators such as animal’s vocalisation in response to pain, cortisol profile, and behavioural aspects.

References:

American Veterinary Medical Associoation. (2013). Literature Review on the Welfare Implications of Swine Castration. Accessed from: https://www.avma.org/KB/Resources/LiteratureReviews/Documents/swine_castration_bgnd.pdf at 10-4-2017

Lawrie, R. A., & Ledward, D. (2006). Lawrie’s meat science (7th Edition). Cambridge: Woodhead Publishing.

Prunier, A., Bonneau, M., Cinotti, S., Gunn, M., Fredriksen, B., Giersing, M., & Velarde, A. (2006). A review of the welfare consequences of surgical castration in piglets and the evaluation of non-surgical methods, Animal Welfare 2006, 15: 277-289.

The Council of European Union. (2009). Council Directive 2008/120/EC of 18 December 2008. Laying down minimum standards for the protection of pigs. Accessed from: http://eur-lex.europa.eu/legal-content/EN/TXT/PDF/?uri=CELEX:32008L0120&from=EN at 10-4-2017.

von Borrell, E., & Baumgartner, J. (2014). Animal welfare implications of surgical castration and its alternatives in pigs. Animal (2009), 3:11, pp 1488–1496. doi:10.1017/S1751731109004728.

 

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Osteochondrosis in Swine

Is it Farmer’s Major Problem on Swine Production?

Locomotion is an important factor in whole pig production. With locomotion, pigs will be able to gather feed and move freely as they want. Failures in locomotion will not only decreases pig productivity, increases the stress level, but also against the animal welfare ethics. Osteochondrosis, more or less associated with the movement issue in swine production, at least it can make animals feel pain and decreases animal welfare. In this paper, I will focus on the mechanism of how osteochondrosis happens and its severity, relevance to locomotion problem, its impact on the livestock production, and in the end, try to construct an answer to the central question in the subtitle of this paper.

To begin with, I will briefly discuss how osteochondrosis happens. Osteochondrosis is one of the developmental orthopaedic disease that is encountered worldwide (Ekman et al., 2009). Osteochondrosis occurs when there is a focal disturbance in endochondral ossification that may result in the malfunction of the blood supply to epiphyseal growth (Olstad et al., 2015). This failure started when there is a leakage of blood vessels between metaphysis and epiphysis sections inside the extension sections of articular-epiphyseal cartilage complex (AECC). This leakage may be caused by the disruption of anastomoses connection which is a weak binding between growing blood vessels across regions to undergo the longitudinal growth of metaphyseal growth cartilage and the spherical growth of epiphyseal growth cartilage (Ytrehus et al., 2004). This leakage may cause necrosis cells in the resting zone that disrupting matrix calcification or vascular invasion, and the matrix does not become converted to bone (Ytrehus et al., 2007). It is still unclear of what factor that causes this leakage, as this disease’s cause are multifactorial including both genetic and environmental factors (de Koning et al., 2014). However, it is likely caused mainly by the overpressure of the animal’s upper body, caused by weight, activity, and heredity (Ytrehus et al., 2007; Wittwer et al., 2009).

Overpressure in the cartilage may be caused by the high growth of the animal itself. Van Grevenhof et al. (2012) studied that at the latter stages of pig’s life (from weaning onwards), pigs diagnosed with minor or severe osteochondrosis were having a higher body weight than that without osteochondrosis. This fact then makes sense with the simple logical paradigm that joints that receive heavier weight from the upper body will be more prone to injuries that disrupt anastomoses connection between blood vessels in the epiphyseal and metaphyseal regions. Body weight will be connected with nutrition as well. A study by De Koning (2013) resulted that gilts that fed ad libitum diet in their later life (10 weeks onwards), preceded by restricted diet in their earlier life have higher prevalence of osteochondrosis than they that fed all time ad libitum diet, all time-restricted diet, and ad libitum switched to restricted diet. This is also logical since there is a possibility that gilts that fed ad libitum diet in their earlier life have already optimised their bone and muscular capacity to support the expected high body weight in their late life. However, if this feed restriction implemented into swine production industry, in my opinion, there will be no optimum efficiency, since it will not yield maximum average daily gain or total body weight at slaughter age.

The severity of osteochondrosis can be divided into three categories: latens, manifesta, and dissecans (Ytrehus et al., 2007). In osteochondrosis latens, the necrosis cells are located in the resting zone of

the growth cartilage, which not overlying the articular cartilage or subchondral bone. Whereas, osteochondrosis manifesta resulting the necrosis up into the subchondral bone. The most severe one, osteochondrosis dissecans, may lead to a rupture of articular cartilage because there is an overlying necrotic cartilage cell inside region of articular cartilage (Ytrehus et al., 2007). In my opinion, all these three conditions can make piglets in pain, since there are abundant nervous tissues in metaphyseal and lower epiphyseal regions.

Osteochondrosis is one of the abnormalities that may lead to locomotion problem. Nonetheless, it is still unclear about the exact number on how much the contribution of osteochondrosis in movement problems. In my opinion, since there is an existence of pain, animals will suffer from osteochondrosis. This shocks will make the animal prevent to move actively (Van Grevenhof et al., 2012). In the end, it may drive to different production problem such as low feed intake as a result of locomotion problem.

Osteochondrosis increases the risk of premature culling (De Koning et al., 2012). A study by Kirk et al. (2005) resulted that 72% of mortality of pigs were associated with the locomotive problem, which arthritis caused 24% of locomotion disorders. Ytrehus et al. (2007) affirmed that severe osteochondrosis (dissecans) might lead to osteoarthritis if there is an overweight of animal’s body. This high number of mortality is associated with the premature culling. Most of the pigs that have locomotive disorders are intentionally killed, as an action of culling. Another statement from Kirk et al. (2005) is that 49% of 35 sows that he randomly selected are suffering from osteochondrosis. This finding convinces us that the prevalence of osteochondrosis is considerably high, although this is only found in one herd. These premature culling may have an impact on economics aspect of the livestock production, despite there is no clear and consistent connection yet.

Studies also focused on the clinical aspect such as gait scoring to detect whether a pig suffers osteochondrosis or not. Stavrakakis et al. (2014) reported that pigs with clinical deficiencies and degenerative joint lesions had altered kinematics. Gait or movement patterns were significantly associated with the occurrence and severity of osteochondrosis (De Koning et al., 2012). However, Etterlin et al. (2015) stated that the association between gait score and joint condemnation caused by osteochondrosis appeared to be poor.

After studied several works of literature, I came up with this conclusion. Osteochondrosis can lead to locomotion problem in pigs. The prevalence is relatively high in one herd, also can lead to another physiological stress that causes lower productivity, premature culling, welfare issue, and economics losses. However, that impact is still unclear until I write this paper and several pieces of literature not that convinced to link causal interrelation between osteochondrosis and production problems. Because of that condition, I will say that osteochondrosis is a major problem only when there is a case that pigs are lame because of osteochondrosis so that pigs cannot moves freely as they want and cannot grow as it have to. I believe there are studies still in progress on how to detect osteochondrosis clinically without sacrifices pigs to be slaughtered. Until that time, I will conclude that osteochondrosis is a middle priority problem because its occurrence is varied in each herd and cannot be generalised yet. Hence, the impact is also varied regarding production and needed different approach and handling in different herd condition.

References:

de Koning, D. B., Van Grevenhof, E. M., Laurenssen, B. F. A., Ducro, B. J., Heuven, H. C. M., De Groot, P. N., Kemp, B. (2012). Associations between osteochondrosis and conformation and locomotive characteristics in pigs. Journal of Animal Science, 90(13), 4752–4763. https://doi.org/10.2527/jas.2012-5310

de Koning, D. B., Van Grevenhof, E. M., Laurenssen, B. F. A., & Weeren, P. R. Van. (2013). The influence of dietary restriction before and after 10 weeks of age on osteochondrosis in growing gilts Hazeleger and B. Kemp. Journal of Animal Science, 2013.91:5167–5176. https://doi.org/10.2527/jas2013-6591

de Koning, D. B., Van Grevenhof, E. M., Laurenssen, B. F. A., van Weeren, P. R., Hazeleger, W., & Kemp, B. (2014). The influence of floor type before and after 10 weeks of age on osteochondrosis in growing gilts. Journal of Animal Science, 92(8), 3338–3347. https://doi.org/10.2527/jas2014- 7902

Ekman, S., Carlson, C. S., & van Weeren, P. R. (2009). Workshop report. Third International Workshop on Equine Osteochondrosis, Stockhom, 29-30th May 2008. Equine Veterinary Journal, 41(5), 504–507. https://doi.org/10.2746/042516409X431902

Etterlin, P. E., Morrison, D. A., Österberg, J., Ytrehus, B., Heldmer, E., & Ekman, S. (2015). Osteochondrosis, but not lameness, is more frequent among free-range pigs than confined herd- mates. Acta Veterinaria Scandinavica, 57(1), 63. https://doi.org/10.1186/s13028-015-0154-7

Kirk, R. K., Svensmark, B., Ellegaard, L. P., & Jensen, H. E. (2005). Locomotive disorders associated with sow mortality in Danish pig herds. Journal of Veterinary Medicine Series A: Physiology Pathology Clinical Medicine, 52(8), 423–428. https://doi.org/10.1111/j.1439-0442.2005.00747.x

Olstad, K., Ekman, S., & Carlson, C. S. (2015). An Update on the Pathogenesis of Osteochondrosis. Veterinary Pathology, 52(5), 785–802. https://doi.org/10.1177/0300985815588778

Stavrakakis, S., Guy, J. H., Warlow, O. M. E., Johnson, G. R., & Edwards, S. A. (2014). Walking kinematics of growing pigs associated with differences in musculoskeletal conformation, subjective gait score and osteochondrosis. Livestock Science, 165(1), 104–113. https://doi.org/10.1016/j.livsci.2014.04.008

Van Grevenhof, E. M., Heuven, H. C. M., van Weeren, P. R., & Bijma, P. (2012). The relationship between growth and osteochondrosis in specific joints in pigs. Livestock Science, 143(1), 85–90. https://doi.org/10.1016/j.livsci.2011.09.002

Wittwer, C., Hamann, H., & Distl, O. (2009). The candidate gene XIRP2 at a quantitative gene locus on equine chromosome 18 associated with osteochondrosis in fetlock and hock joints of south german coldblood horses. Journal of Heredity, 100(4), 481–486. https://doi.org/10.1093/jhered/esp006

Ytrehus, B., Ekman, S., Carlson, C. S., Teige, J., & Reinholt, F. P. (2004). Focal changes in blood supply during normal epiphyseal growth are central in the pathogenesis of osteochondrosis in pigs. Bone, 35(6), 1294–1306. https://doi.org/10.1016/j.bone.2004.08.016

Ytrehus, B., Carlson, C. S., & Ekman, S. (2007). Etiology and pathogenesis of osteochondrosis. Veterinary Pathology, 44(4), 429–448. https://doi.org/10.1354/vp.44-4-429