Performance and plasma urea nitrogen of immunocastrated males pigs of medium genetic potential

ABSTRACT Objective. A study was carried out to evaluate the performance and the plasma urea nitrogen (PUN) of male pigs of medium genetic potential for lean meat deposition in carcass, which underwent immunocastration. Materials and methods. Forty-five seventy-days old Large White x Landrace crossbred were used. The pigs were distributed in a randomized design in three treatments: castrated males, females and immunocastrated males. Each treatment group was replicated three times with five pigs per replicate. The trial period was of 70 days, divided into phases of growing (70 to 110 days old) and finishing (111 to 140 days old). The pigs were weighed four times: at the beginning of the trial, at the first immunocastration vaccine dose (80 days old), at the second immunocastration vaccine dose (110 days old) and just before slaughter (140 days old). Blood samples were taken on the same day that the animals were weighed. Results. Between 80 and 110 days old, there was an increase in PUN value, only for castrated males and females. No differences were found in weight gain between the studied groups within the periods. Immunocastrated males had lower feed intake than females and these had a lower feed intake than castrated males. To 110 days old, immunocastrated animals showed feed conversion ratio similar to females and better than castrated males. However, after the second dose of the vaccine, feed conversion was similar between groups. Conclusions. The benefits of immunocastration are prominent in animals with low to medium genetic potential. RESUMEN Objetivo. Se realizó un estudio para evaluar el rendimiento y la concentración de urea en plasma (PUN) de los cerdos machos de medio potencial genético de carne magra en la canal sometidos a la inmunocastración. Materiales y métodos. Se utilizaron 45 cerdos de 70 días de edad Landrace x Large White. Los animales se distribuyeron en un diseño completamente al azar con tres tratamientos: machos castrados, hembras y machos inmunocastrados. Cada tratamiento consistió en tres repeticiones, con cinco animales por réplica. El período experimental fue de 70 días, divididos en las etapas de crecimiento (70 a 110 días de edad) y terminación (111 a 140 días de edad). Los cerdos fueron pesados cuatro veces: al inicio del experimento, en la primera dosis de vacuna de inmunocastración (80 días de edad), en la segunda dosis de la vacuna de inmunocastración (110 días de edad) y antes de el sacrificio (140 días de edad). Las muestras de sangre se recogieron en el mismo día en que se pesaron los animales. Resultados. Entre 80 y 110 días de edad, hubo un aumento en la cantidad de PUN, sólo para machos castrados y hembras. No hubo diferencias en la ganancia de peso entre los grupos en ninguno de los períodos estudiados. Machos inmunocastrados tuvieron menor consumo de alimento que las hembras y éstas mostraron un menor consumo que los machos castrados. En 110 días de edad, los animales inmunocastrados mostraron la conversión de alimento similar a las hembras y mejor que los machos castrados. Sin embargo, después de la segunda dosis de la vacuna, la conversión alimenticia fue similar entre los grupos. Conclusiones. Los beneficios de inmunocastración son prominentes en animales con bajo a médio potencial genético.

INFLUENCE OF TERMINAL SIRE ON CARCASS AND MEAT QUALITY TRAITS OF GILTS AND CASTRATED, IMMUNOCASTRATED AND ENTIRE MALE PIGS

U istraživanje je bilo uključeno 240 tovljenika, potomaka krmača i nazimica iste pasmine, pripuštenih s tri različite linije komercijalnih nerastova („A“, „B“ i „C“), koji su podijeljeni u četiri fiziološka statusa: kirurški kastrati (SC), imunokastrati (IC), nerastovi (EM) i nazimice (F). Tijekom tova životinje su vagane pri odbiću (25 dana starosti), sa 72 dana starosti (vrijeme aplikacije 1. vakcine - V1), 116 dana starosti (rano razdoblje tova), 146 dana starosti (vrijeme aplikacije 2. vakcine - V2) i 168 dana starosti (završetak tova) te su na osnovi ovih pokazatelja izračunati prosječni dnevni prirasti u pojedinim razdobljima, kao i ukupni završni dnevni prirast. Sa 168 dana starosti svinje su zaklane te su utvrđeni slijedeći pokazatelji: masa polovica, duljine polovica „a“ i „b“, duljina buta, opseg buta, debljina mišića i leđne slanine, pH45 u m. longissimus dorsi (LD) i u m. semimembranosus (MS), a nakon 24 h pH24, CIE-L* a* b*, otpuštanje mesnog soka, kalo kuhanja, nježnost mesa, te koncentracije androstenona i skatola. Istraživane se svinje nisu razlikovale u masama ni prosječnom dnevnom prirastu u vrijeme odbića i sa 72 dana starosti. Najviše dnevne mase sa 116 dana starosti postigli su SC, dok su sa 141. danom starosti najviše mase utvrđene u EM i IC. Slično tome, u ranom razdoblju tova SC imali su značajno više priraste u odnosu na ostale fiziološke statuse, dok je u razdoblju od V2 i kasnom razdoblju tova najviši prirast utvrđen u EM i IC. Najviši ukupni dnevni prirast postignut je u IC potomaka „C“ terminalne linije nerastova. Najmanja debljina slanine utvrđena je kod EM i F, a najveća debljina mišića i posljedično tome mesnatost utvrđena je u F. SC i F imali su veće duljine polovice u odnosu na IC i EM, a najveći opseg buta postignut je u SC. Najveća debljina slanine utvrđena je u pripadnika terminalne linije „C“, u koje je ujedno utvrđena najniža mesnatost. Međutim, pripadnici terminalne linije nerastova „C“ imali su najveće duljine polovica „a“ i „b“ te opseg buta. Najviši pH45 u SM imali su IC, dok je najviši pH24 u SM i LD postignut kod EM. Najniže otkapavanje mesnog soka i CIE L* utvrđeno je u F, dok su EM imali najviše CIE a* vrijednosti. Kalo kuhanja u SC i F bilo je značajno niže (P<0,05) od IC i EM; EM i F imali su značajno niže WBSF vrijednosti od IC, dok se SC nisu razlikovali od ostalih fizioloških statusa u ovom svojstvu. Potomci terminalnih linija nerastova „A“ i „B“ imali su značajno niže vrijednosti pH45 u MS i LD te pH24 u SM. Najveće otpuštanje mesnog soka utvrđeno je u „B“ terminalne linije nerastova; pripadnici terminalne linije „C“ imali su najveći CIE a* i najniži WBSF. U gotovo svih istraživanih svojstava utvrđena je značajna interakcija fiziološkog statusa i terminalne linije nerasta. Najveća debljina mišića i mesnatost u svih terminalnih linija utvrđena je kod F, a slijede ih EM, IC i potom SC. Najveća duljina polovice „a“ i duljina buta utvrđena je u IC pripadnika terminalne linije „C“. U LD mišiću nisu utvrđene značajne razlike u završnim pH vrijednostima između istraživanih fizioloških svojstava i linija terminalnih nerastova. Najviše otkapavanje mesnog soka u „A“ i „C“ terminalnih linija nerastova utvrđeno je u IC, a u terminalne linije nerastova „B“ u EM. Najviše CIE L* vrijednosti kod terminalnih linija nerastova „A“ i „C“ utvrđene su u IC, a u terminalne linije „B“ kod SC. SC terminalnih linija „A“ i „B“ imali su najviše CIE a* vrijednosti, dok su u terminalne linije „C“ najviše CIE a* vrijednosti utvrđene u EM. Najveće kalo kuhanja u terminalnih linija „A“ i „B“ utvrđeno je kod nerastova, dok su WBSF vrijednosti bile najviše u IC kod A i B terminalnih linija nerastova i EM u terminalne linije nerastova „C“. Najveća koncentracija androstenona utvrđena je u nerastova pripadnika „C“ terminalne linije nerastova, dok u koncentraciji skatola nisu utvrđene značajne razlike između nerastova potomaka pojedinih terminalnih linija nerastova. U terminalne linije nerastova „A“ utvrđena je jaka korelacija između koncentracije androstenona i skatola, dok je u terminalnih linija „B“ i „C“ utvrđena srednje jaka korelacija. Ovo upućuje na mogućnost redukcije skatola, a posljedično tome i androstenona i metodama koje su jeftinije i manje zahtjevne od genomske selekcije u ovih križanaca.The investigation was carried out on 240 fatteners, originating from gilts and sows of the same breed inseminated with the semen from three commercial terminal sires (lines “A”, “B”, “C”), and divided into four genders: surgical castrates (SC), immunocastrates (IC), entire males (EM) and females (F). During fattening animals were weighed at weaning (at 25 days), at 72 days of age (time of 1st vaccination-V1), 116 days (Early fattening period), 146 days (time of 2nd vaccination-V2) and 168 days (End of fattening). Based on these measures average daily gains in certain periods of growth, as well as total daily gain were calculated. At 168 days of age pigs were slaughtered and following traits were determined: carcass weight, carcass lengths “a” and “b”, ham length and circumference, muscle and fat thickness, pH45 in m. longissimus dorsi (LD) and m. semimembranosus (SM). After 24 h of cooling the carcasses pH24 at LD and MS muscles, CIE L* a* b*, drip loss, cooking loss, instrumental tenderness (WBSF) and concentrations of androstenone and skatole were also estimated. Investigated pigs did not differ in weights and average daily gains at the time of weaning and at 72 days of age. The highest weights at 116 days were observed in SC, and at 141 days in EM and IC. Similarly, at Early fattening period SC had the highest average daily gain, while at V2 and at the End of fattening the highest average daily gain determined in EM and IC. The highest total daily gain was determined in IC, members of “C” terminal sire line. The smallest fat thickness was determined in EM and F, the highest muscle thickness and consequently leanness was determined in F. SC and F had longer carcasses comparing to IC and EM, while the highest ham circumference was determined in SC. The highest fat thickness and the lowest leanness was determined in members of “C” terminal sire line. However, these pigs had the longest carcasses (lengths “a” and “b”) and ham circumference. The highest pH45 in SM was observed in IC, while the highest pH24 in SM and LD muscles was estimated in EM. The lowest drip loss and CIE L* was determined in F, while EM had the highest CIE a* values. Cooling loss of SC and F was significantly lower (P<0.05) than IC and EM; EM and F had significantly lower WBSF than IC, while SC did not differ from other genders in this trait. Pigs originating from terminal sire lines “A” and “B” had significantly lower pH45 in MS and LD muscles, as well as pH24 in SM muscle. The highest drip loss was determined in pigs originating from “B” terminal sire line; pigs members of “C” terminal sire line had highest CIE a* and lowest WBSF values. In almost all investigated traits, interaction between gender and terminal sire line was significant. In all terminal sire lines the highest muscle thickness and leanness was determined in F followed by EM, IC and SC. The highest carcass length “a” and ham length was determined in IC originating from “C” terminal sire line. No significant differences in pH values between investigated genders according to specific sire line were observed. The highest drip loss in “A” and “C” terminal sire lines was determined for IC, and in “B” terminal sire line for EM. In “A” and “C” terminal sire lines IC had the highest CIE L* values and in “B” terminal sire line SC. SC of terminal sire lines “A” and “B” had the highest CIE a* values; in terminal sire line “C” EM had the highest CIE a* values. EM had the highest cooking loss in “A” and “B” terminal sire lines and the highest WBSF was determined in IC of “A” and “B” terminal sire lines and EM of “C” terminal sire line. The highest androstenone concentration was observed in EM originating from “C” terminal sire line. There were no significant differences between EM of investigated sire lines in skatole concentrations. In terminal sire line “A” strong correlation between skatole and androstenone concentrations was determined; in “B” and “C” terminal sire lines moderate correlation between investigated concentrations was observed. This indicates a possibility of skatole and consequently androstenone reduction using cheaper and less demanding methods than genomic selection in investigated crossbreds