Effect of active immunization against GnRH on androstenone concentration, growth performance and carcass quality in intact male pigs

This paper presents an analysis of the economic implications of alternative methods to surgical castration without anaesthesia. Detailed research results on the economic implications of four different alternatives are reported: castration with local anaesthesia, castration with general anaesthesia, immunocastration and raising entire males. The first three alternatives have been assessed for their impact on pig production costs in the most important pig-producing Member States of the EU. The findings on castration with anaesthesia show that cost differences among farms increase if the anaesthesia cannot be administered by farmers and when the veterinarian has to be called to perform it. The cost of veterinarian service largely affects the total average costs, making this solution economically less feasible in small-scale pig farms. In all other farms, the impact on production costs of local anaesthesia is however limited and does not exceed 1 hct per kg. General anaesthesia administered by inhalation or injection of Ketamin in combination with a sedative (Azaperone, Midazolan) is more expensive. These costs depend heavily on farm size, as the inhalation equipment has to be depreciated on the largest number of pigs possible. The overall costs of immunocastration -including the cost of the work load for the farmer -has to be evaluated against the potential benefits derived from higher daily weight gain and feed efficiency in comparison with surgical castrates. The economic feasibility of this practice will finally depend on the price of the vaccine and on consumer acceptance of immunocastration. The improvement in feed efficiency may compensate almost entirely for the cost of vaccination. The main advantages linked to raising entire males are due to the higher efficiency of feed conversion, to the better growth rate and to the higher leanness of carcass. A higher risk of boar taint on the slaughter line has to be accounted for. Raising entire males should not generate more than 2.5% of boar taint among slaughter pigs, in order to maintain the considerable economic benefits of better feed efficiency of entire males with respect to castrates.

Section: Immunocastrationmentioning

confidence: 90%

Section: Immunocastrationmentioning

confidence: 99%

Resource efficiency and economic implications of alternatives to surgical castration without anaesthesia

Roest

Montanari

Fowler

et al. 2009

“…Another explanation is that some animals do not react to the vaccination, or have not been correctly vaccinated. The so-called nonresponders have been identified by Zeng et al (2002a), Jaros et al (2005) and Hilbe et al (2006). …”

Section: Meat Qualitymentioning

confidence: 99%

Meta-analysis of the effect of immunocastration on production performance, reproductive organs and boar taint compounds in pigs

Batorek

Čandek-Potokar

Bonneau

et al. 2012

115

102

Meta-analytical approach was used to quantitatively synthesize the effect of immunocastration on growth, carcass, meat quality, reproductive organs and boar taint compounds. Altogether, 41 papers were collected for effect size (θ) calculation and the comparisons were made with entire males (EM) and surgical castrates (SC). The data for reproductive organs and growth performance are numerous enough to draw firm conclusions. In contrast, data for carcass and meat quality are more limited. Results of meta-analysis show efficient immunocastration with the magnitude of the response being by far the largest for reproductive organs (θ= −2.8 to −5.0) and boar taint substances (θ= −2.8 and −0.8 for androstenone and skatole, respectively). However, compared with SC, the immunocastrates exhibit larger bulbourethral glands (θ= 1.3) and slightly higher concentrations of androstenone and skatole (θ= 0.1 andθ= 0.2, respectively). The impact of immunocastration is also remarkable on performance, where the main advantage of the immunocastrates is their boar-like performance until revaccination. In the period following the second vaccination, they eat much more than EM (θ= 2.1), resulting in large effect size for growth rate compared with both EM and SC (θ= 1.1 andθ= 1.4, respectively). Considering the whole fattening period, their feed conversion ratio is higher compared with EM (θ= 0.6) and much lower than that of SC (θ= −1.3), although exhibiting moderately faster growth compared with both (θ= 0.6 andθ= 0.2, respectively). With regard to carcass quality, the immunocastrates take intermediate position between EM and SC. Besides, our analysis suggests no difference in meat quality with SC and some meat quality advantages of immunocastrates over EM because of higher intramuscular fat content (θ= 0.4) and lower shear force (θ= −0.6).

“…Immunological blocking of the signal from GnRH decreases the production of LH and -E-mail: Kristina.Andersson@huv.slu.se testicular steroids. It has been demonstrated that vaccination against GnRH reduces the concentration of testicular steroids, including androstenone, along with the size of reproductive organs and sperm numbers (Bonneau et al, 1994;Jaros et al, 2005;Einarsson et al, 2009). Tuyttens (2002) reviewed the effects of castration on welfare of pigs and concluded that 'Evaluating the animal welfare implications of not castrating male piglets requires the delicate balancing of an abolishment of a short-term pain sensation, the preservation of the animal's integrity, and a potentially lower morbidity and mortality, on the one hand, against a likely increase in agonistic behaviour on the other'.…”

Section: Introductionmentioning

confidence: 99%

Immunocastration reduces aggressive and sexual behaviour in male pigs

Rydhmer

Lundström

Andersson

2010

101

The aim of this study was to evaluate the effectiveness of a gonadotropin-releasing hormone (GnRH) vaccine, Improvac TM (Pfizer Ltd), in suppressing aggressive and sexual behaviour of male pigs. One hundred and thirty-six pigs were assigned to three treatments: entire male pigs (n 5 64), immunocastration against GnRH (n 5 48) and surgical castration (n 5 24). Surgical castration was performed before the age of 1 week. Vaccination comprised two injections: the first injection was given 8 to 11 weeks before slaughter and the second injection 4 weeks before slaughter. After the second injection, immunocastrated pigs showed less non-violent social and aggressive behaviours than entire male pigs of the same age. Mounting was reduced to the same low level as observed in surgically castrated pigs, and more immunocastrated pigs were without skin lesions compared with entire male pigs. Pigs that received the second injection only 1 week before the observation day did not differ significantly in behaviour from those that received the injection 3 weeks before the observation day. Thus, the behaviour seems to change soon after the second injection and these changes remain until slaughter.Keywords: entire male pigs, castration, immunocastration, behaviour ImplicationsThis study evaluated the effectiveness of a gonadotropinreleasing hormone (GnRH) vaccine, Improvac TM (Pfizer Ltd), in suppressing aggressive and sexual behaviour of entire male pigs. We found that immunocastrated pigs demonstrated much less aggressive and mounting behaviour after the second injection than entire males of the same age. However, timing of the second vaccination is crucial, as the full castration effect is not obtained until then.