Improving Beef Cattle Production: Safety and Effectiveness of New Immunocastration Vaccine.

Reproductive control in mammals, particularly in beef production systems, is crucial for managing behaviors driven by sex steroids, which can cause biosecurity issues, reduced weight gain, and decreased meat quality. Additionally, controlling sexual activity in females prevents unwanted pregnancies when both sexes are housed together for fattening. Surgical castration in cattle, commonly performed under field conditions, is associated with significant welfare concerns due to pain and infection risks. Furthermore, castrating female cattle in the field is often impractically expensive. Hence, new reproductive control methods that prioritize animal welfare and are suitable for both sexes are essential. Immunocastration (IC), which involves vaccination against the GnRH-I hormone, has emerged as a promising alternative, demonstrating efficacy and safety in various species. Immunocastration has proven to be an effective alternative to surgical castration in controlling reproduction and promoting animal welfare in several species. This study aims to evaluate the safety, immunogenicity, immunocastration effect, and productive impact of a novel IC vaccine developed in Chile for female cattle. Two consecutive trials were conducted, the first under controlled conditions and the second under field conditions. The results demonstrated that the new vaccine is safe and effective for use in beef cattle, inducing specific immunity against GnRH-I, reducing gonadal functionality, and improving productive parameters. These findings suggest that this new IC vaccine can significantly benefit the beef cattle industry by providing a welfare-friendly and efficient method of reproductive control.

Testicular morphometry as a tool to evaluate the efficiency of immunocastration in lambs.

This study aimed to evaluate the efficiency of immunocastration in lambs using testicular morphometry. Thirty lambs were randomly divided into two treatments (subcutaneous administration of 1.0 mL and 0.5 mL of an anti-GnRH vaccine) and a control group (1.0 mL saline solution). The animals were vaccinated at four months of age, received a second dose 30 days later, and were slaughtered 90 days after the first vaccine dose. After slaughter, testicles were collected, and samples were removed for histological processing and evaluation of testicular morphometric parameters. Analysis of variance, Tukey's test, and Kruskal-Wallis test were performed, with a 5% level of significance. There was a reduction in testicular weight, gonadosomatic index, seminiferous tubule diameter, germinal epithelium height, leydigosomatic index, and total tubule length. The total length per testicular gram increased in the immunocastrated group. Intrinsic spermatogenesis yield, Sertoli cell indices, and estimates of sperm and Sertoli cell production were reduced in the immunized groups (P < 0.05). The anti-GnRH vaccine in lambs at doses of 1.0 mL and 0.5 mL is sufficient to promote immunocastration, verified through severe changes in testicular morphometry from animals.

Testicular morphometry as a tool to evaluate the efficiency of immunocastration in lambs

This study aimed to evaluate the efficiency of immunocastration in lambs using testicular morphometry. Thirty lambs were randomly divided into two treatments (subcutaneous administration of 1.0 mL and 0.5 mL of an anti-GnRH vaccine) and a control group (1.0 mL saline solution). The animals were vaccinated at four months of age, received a second dose 30 days later, and were slaughtered 90 days after the first vaccine dose. After slaughter, testicles were collected, and samples were removed for histological processing and evaluation of testicular morphometric parameters. Analysis of variance, Tukey's test, and Kruskal-Wallis test were performed, with a 5% level of significance. There was a reduction in testicular weight, gonadosomatic index, seminiferous tubule diameter, germinal epithelium height, leydigosomatic index, and total tubule length. The total length per testicular gram increased in the immunocastrated group. Intrinsic spermatogenesis yield, Sertoli cell indices, and estimates of sperm and Sertoli cell production were reduced in the immunized groups (P < 0.05). The anti-GnRH vaccine in lambs at doses of 1.0 mL and 0.5 mL is sufficient to promote immunocastration, verified through severe changes in testicular morphometry from animals.(AU)

Immunocastrated female pigs' social and feeding behaviour

- This study compared the social and feeding behaviour of immunocastrated female pigs using different immunocastration protocols. We used seventy-two gilts from industrial crossbreeding (Agroceres × Topigs) at 15 weeks of age. The pigs were distributed in a randomised design with three treatments. The second dose of the immunocastration vaccine was applied in two groups, six weeks before slaughter (I6) and four weeks before slaughter (I4). A non-immunised group (NI) was used for comparison. Due to the divergence in the time of immunisation between the two groups, an individual comparison of each immunocastrated group with the control group (NI vs. I6 and NI vs. I4) was performed. Social behaviour was analysed through the collection of images by a monitoring camera, and the analysis period was from 6:00 to 18:00 h, with behaviour observed every ten minutes. Feeding behaviour data were collected by the automated FIRE® system. Anti-GnRH immunisation and the different protocols of application did not influence most social and feeding behaviours.(AU)

Effectiveness of a New Recombinant antiGnRH Vaccine for Immunocastration in Bulls.

Castration by surgical techniques is common in livestock; however, post-surgery complications and concerns for animal wellbeing have created a need for new non-invasive alternatives. The objective of this study was to evaluate immunocastration in bulls using antigen GnRX G/Q; a recombinant peptide proved to be effective in laboratory and companion animals. A nine-month trial with 80 9-month-old Normand x Hereford bulls, kept in a pastured system, was conducted. The herd was divided in half with 40 bulls surgically castrated (SC) and 40 castrated by immunization against GnRH (IC). The antigen was injected on days 0 and 40 of the experiment. After the second dose, the IC group had elevated GnRH antibodies and decreased testosterone levels (below 5 ng/mL) that were maintained for 23 weeks. At slaughter on day 190, the immunocastrated group obtained a higher weight, hot carcass, and dressing percentage than the SC group. There was no difference in pH, color of meat, fat coverage, cooking loss, or tenderness between groups. The bulls showed no inflammatory reaction at the injection site or adverse side effects from the vaccine. Our results demonstrate that immunocastration with GnRX G/Q is an efficient and safe alternative to surgical castration in livestock. Additional work evaluating antigen effects over a longer period is needed to validate commercial viability.

Effect of a single or two doses of an anti-GnRH vaccine on testicle morpho-functional characteristics in Nelore bulls.

The aim of this study was to compare testicle morpho-functional characteristics in bulls undergoing a single or two immunizations against GnRH. Nelore (Bos taurus indicus) bulls were randomly allocated into three experimental groups: G1 (n=12), a single 400 µg dose of anti-GnRH vaccine on day 0; G2 (n=11), a first 400 µg dose of anti-GnRH vaccine on day 0 followed by a second (boost) dose 30 days later; and control group (CG, n=12), 1 mL saline 0.9% at day 0. Every 30 days, from day 0 until slaughter at day 90, the bulls were weighed and underwent testicular biometry, semen collection and analysis, and blood sample collection for testosterone measurement. Immediately after slaughter, the testicles were removed and transport at 15°C to the laboratory for histopathological analysis. There was a decrease in testicular height (P=0.0476), width (P=0.0021), and in scrotal circumference (P=0.0001), after either a single (G1) or two (G2) immunizations against GnRH. Both G1 and G2 had lower testosterone concentrations than CG from day 60 on (P<0.01), but in G2, it was also lower than in G1 at day 90 (P=0.0006). All sperm parameters were affected by active immunization against GnRH (P<0.05), and in G2, averages were lesser (P<0.05) than in G1 from day 60 on. No signs of seminiferous tubule degeneration were found in any sample from the CG, contrasting with 75.0% and 100.0% of the samples from G1 and G2, respectively. In summary, immunocastration affected testicle morpho-functional characteristics in bulls in a time- and dose-dependent way.

On the Road to End Pig Pain: Knowledge and Attitudes of Brazilian Citizens Regarding Castration.

We explored the attitudes of Brazilians towards different methods to deal with boar taint in pork (surgical castration without pain control, SC; surgical castration with pain control, SC+PC; immunocastration, IC; raising entire males, EM). Two surveys (Sv1, n = 441 and Sv2, n = 768) containing closed and open questions were conducted. Nearly 70% of Sv1 and Sv2 participants were unaware that meat of entire males may have boar taint and that SC is widely used in pig production in Brazil. In Sv1, acceptability of SC+PC (63%) and IC (53%) was greater than of SC (15%). In Sv2, acceptability of IC (55%) and EM (52%) was greater than of SC (18%). Open-ended responses indicated that participants objected to inflicting pain to pigs to attain a production goal, and were concerned with organoleptic traits and risks of exogenous residues in pork. Participants' views regarding the potential increases in the cost of meat due to adoption of alternative methods varied; some argued that avoiding pain justifies an increase in the price of pork and others that this would impact especially lower income citizens. Our findings indicate that participants opposed surgical castration without pain control, and supported alternative methods. However, the concern with potential risks of presence of residues in meat, expressed by a few participants, may need to be addressed among consumers.

Reproductive and Behavioral Evaluation of a New Immunocastration Dog Vaccine.

Canine immunocastration development has been of interest for many years as a complementary strategy to surgical castration. The purpose of this paper was to verify the effect of a recombinant vaccine for dog immunocastration. Two tests were done, one under controlled conditions and a second under field conditions. Animals were injected with 1 mL of 500 µg GnRXG/Q recombinant protein; 500 µg of low molecular weight chitosan as adjuvant; 1 mL NaCl 0.9% q.s. In the first trial, eight Beagle male dogs between the ages of 1 and 3 comprised the sample, randomly divided into two groups: vaccinated group (n = 7) and control group (n = 2). The second trial had 32 dogs with owners. In the first controlled conditions trial, the vaccine produced specific antibodies that remained until the end of the trial (day 270), inducing reduced testosterone and spermiogram changes in the immunized animals. In a second trial, on the field, specific immunity was induced, which remained high up to day 150. The vaccine also reduced sexual agonistic and marking behaviors. This new vaccine proved to be safe, immunogenic, capable of reducing gonadal functionality, and had a positive effect on inducing reduced sexual, agonistic, and marking behavior of the animals.

Alterações fisiológicas e comportamentais de bovinos de corte após o manejo de castração / Physiological and behavioral changes of beef cattle after castration management

Objetivou-se avaliar o desempenho, parâmetros fisiológicos e temperamentais de bovinos de corte não castrados ou submetidos à castração cirúrgica ou à imunocastração. O período experimental foi dividido em dois subperíodos de observações: primeiros 15 dias pós-castração (período de cicatrização) e os 25 dias seguintes à cicatrização. Nos primeiros 15 dias de avaliação, os animais não castrados obtiveram maior ganho médio diário de peso em relação aos castrados cirurgicamente. A frequência cardíaca foi maior para os animais castrados cirurgicamente, com 126,51 batimentos/minuto, em relação aos demais tratamentos. A distância de fuga foi superior para os novilhos castrados cirurgicamente, com valor de 12,22 metros. Nos 25 dias seguintes à castração cirúrgica, o ganho médio diário de peso foi superior nos bovinos castrados cirurgicamente em relação aos bovinos não castrados ou imunocastrados. A velocidade de fuga, no segundo subperíodo de avaliação, foi superior nos bovinos castrados em relação aos não castrados. O período imediato à castração, os primeiros 15 dias, prejudicou o ganho médio diário e o ganho de peso total, o que causou maior reatividade, com alterações nos parâmetros fisiológicos e temperamentais de bovinos castrados cirurgicamente em comparação com bovinos não castrados, entretanto, transcorrido o período de cicatrização, essas diferenças diminuíram ou desapareceram.(AU)

The aim of this study was to evaluate the performance, physiological and temperamental parameters of uncastrated beef cattle or those submitted to surgical castration or immunocastration, in the post-castration period. The experimental period was divided into two subperiods of observations: the first 15 days post-castration (healing period) and the 25 days following healing. In the first 15 days of evaluation, the non-castrated animals obtained a greater average daily gain of weight in relation to surgically castrated. The heart rate was higher for surgically castrated animals with 126,51 beats/minute, compared to the other treatments. The distance of escape was higher for the surgically castrated steers, with a value of 12,22 meters, when compared to the other groups studied. During the next 25 days of surgical castration, the mean daily gain of weight was higher in surgically castrated cattle than in non-castrated or immunocastrated cattle. The escape velocity, in the second evaluation subperiod, was superior in the castrated cattle, in relation to the not castrated. The immediate castration period, the first 15 days, altered the mean daily gain and the total weight gain, the physiological and temperamental parameters of surgically castrated cattle, however, after the healing period, these differences diminish or disappear.(AU)

Alterações fisiológicas e comportamentais de bovinos de corte após o manejo de castração / Physiological and behavioral changes of beef cattle after castration management

Objetivou-se avaliar o desempenho, parâmetros fisiológicos e temperamentais de bovinos de corte não castrados ou submetidos à castração cirúrgica ou à imunocastração. O período experimental foi dividido em dois subperíodos de observações: primeiros 15 dias pós-castração (período de cicatrização) e os 25 dias seguintes à cicatrização. Nos primeiros 15 dias de avaliação, os animais não castrados obtiveram maior ganho médio diário de peso em relação aos castrados cirurgicamente. A frequência cardíaca foi maior para os animais castrados cirurgicamente, com 126,51 batimentos/minuto, em relação aos demais tratamentos. A distância de fuga foi superior para os novilhos castrados cirurgicamente, com valor de 12,22 metros. Nos 25 dias seguintes à castração cirúrgica, o ganho médio diário de peso foi superior nos bovinos castrados cirurgicamente em relação aos bovinos não castrados ou imunocastrados. A velocidade de fuga, no segundo subperíodo de avaliação, foi superior nos bovinos castrados em relação aos não castrados. O período imediato à castração, os primeiros 15 dias, prejudicou o ganho médio diário e o ganho de peso total, o que causou maior reatividade, com alterações nos parâmetros fisiológicos e temperamentais de bovinos castrados cirurgicamente em comparação com bovinos não castrados, entretanto, transcorrido o período de cicatrização, essas diferenças diminuíram ou desapareceram.(AU)

The aim of this study was to evaluate the performance, physiological and temperamental parameters of uncastrated beef cattle or those submitted to surgical castration or immunocastration, in the post-castration period. The experimental period was divided into two subperiods of observations: the first 15 days post-castration (healing period) and the 25 days following healing. In the first 15 days of evaluation, the non-castrated animals obtained a greater average daily gain of weight in relation to surgically castrated. The heart rate was higher for surgically castrated animals with 126,51 beats/minute, compared to the other treatments. The distance of escape was higher for the surgically castrated steers, with a value of 12,22 meters, when compared to the other groups studied. During the next 25 days of surgical castration, the mean daily gain of weight was higher in surgically castrated cattle than in non-castrated or immunocastrated cattle. The escape velocity, in the second evaluation subperiod, was superior in the castrated cattle, in relation to the not castrated. The immediate castration period, the first 15 days, altered the mean daily gain and the total weight gain, the physiological and temperamental parameters of surgically castrated cattle, however, after the healing period, these differences diminish or disappear.(AU)

Performance and ingestive and social behavior of young cattle with different sexual conditions supplemented in Aruana pasture / Desempenho, comportamento ingestivo e social de bovinos jovens com diferentes condições sexuais suplementados em pastagem de Aruana

This study was conducted aiming at measuring the performance and behavior of beef cattle surgically castrated, immunocastrated or non-castrated, finished at 18 months old in Aruana pasture and with energy supplementation. Thirty-nine male bovines with an initial average body weight and age of 284.1 ± 31.4 kg and 14 months old, respectively, were used. The bromatological composition analysis and productive parameters of the pasture did not differ between treatments. The performance of young cattle was not changed by the sexual condition. When evaluating the agonistic behavior, the non-castrated bovine presented a higher number of activities, such as threats and fights, in relation to those immunocastrated. The time spent on the feeder by non-castrated young cattle (56.20 minutes) was higher than that observed for surgically castrated or immunocastrated (41.43 and 32.38 minutes, respectively). The combination between the correct management of Aruana pasture and use of supplementation showed to be promising for finishing bovines. Both surgically castrated and immunocastrated steers demonstrated to be equivalents in the performed evaluations. Therefore, if the farmer chooses castration, the use of immunocastration is suggested. This practice is less invasive, preserves animal welfare more than surgical castration, and has a lower cost.(AU)

Objetivou-se mensurar o desempenho e comportamento de bovinos de corte, castrados cirurgicamente, imunocastrados ou não castrados, terminados aos 18 meses em pastagem de Aruana, recebendo suplementação energética. Foram utilizados trinta e nove bovinos machos, com peso corporal e idade iniciais médios de 284,1 ± 31,4 kg e 14 meses, respectivamente. A análise da composição bromatológica e os parâmetros produtivos da pastagem não diferiram entre tratamentos. O desempenho dos novilhos não foi alterado pela condição sexual (P > 0,05). Ao avaliar o comportamento agonístico, verifica-se que os não castrados apresentaram maior número de atividades, como ameaças e brigas, em relação aos imunocastrados. O tempo de permanência no comedouro dos não castrados (56,20 minutos) foi superior ao detectado para castrados cirurgicamente ou imunocastrados (41,43 e 32,38 minutos), respectivamente. A combinação entre o correto manejo da pastagem de Aruana e o uso de suplementação se mostrou promissora para a terminação de bovinos. Quando compara-se os novilhos castrados cirurgicamente e os imunocastrados ambos demostraram ser equivalentes nas condições do presente estudo. Portanto, se o produtor optar pela castração sugere-se a imunização contra o fator de liberação de gonatrofinas. Essa prática é menos invasiva, preserva o bem-estar animal mais do que a castração cirúrgica e tem menor custo.(AU)

Ingestive behavior of feedlot-finished steers submitted to energy supply patterns / Comportamento ingestivo de novilhos terminados em confinamento submetidos a padrões de fornecimento de energia

This study aimed to verify the effects of supplying different energy patterns on ingestive behavior of feedlot-finished cattle. Twenty-seven pure and crossbred Charolais or Nellore steers with an initial average age and weight of 22 months and 252.8 kg, respectively, were used. Three treatments were carried out, two of them with an increasing rate of concentrate in the diet during the finishing period (IT5 and IT10) and one with constant roughage to concentrate ratio (CT). The experimental design was a completely randomized design with three treatments, five periods, and nine replications. Feeding time was higher for CT (4.31 hours) when compared to IT5 (3.85 hours). Steers from the treatment IT10 remained longer in lying leisure (8.14 hours) when compared to the treatment CT (7.24 hours). A superiority of chewing per ruminated bolus was observed in IT10 (58.59 seconds) when compared to IT5 (54.11 seconds) whereas a higher number of ruminated bolus was observed in TC5 (534.68 ruminated bolus day−1) when compared to IT10 (473.77 ruminated bolus day−1). Animals from CT presented a higher dry matter intake (9.54 kg day−1) than those from IT10 (8.63 kg day−1). Steers from CT and IT5 showed a higher NDF intake (3.63 and 3.58 kg NDF day−1, respectively) when compared to IT10 (3.29 kg NDF day−1). The constant energy pattern increases feeding time and dry matter intake. The one of less vigorous growth increases the number of bolus ruminated per day, while the one of more vigorous growth increases idle time and chews per bolus and decreases the intake of neutral detergent fiber.(AU)

O objetivo foi verificar os efeitos do fornecimento de diferentes padrões de energia no comportamento ingestivo de bovinos terminados em confinamento. Foram utilizados 27 novilhos, puros e cruzados das raças Charolês ou Nelore com idade e peso médios iniciais respectivos de 22 meses e 252,8 kg. Utilizaram-se três tratamentos, sendo dois com taxa crescente da participação do concentrado ao longo do período de terminação (TC5 e TC10) e um com relação volumoso:concentrado constante (TC). O delineamento experimental foi o inteiramente casualizado, com três tratamentos, cinco períodos e nove repetições. O tempo de alimentação foi maior para o TC (4,31 horas) em relação ao TC5 (3,85 horas). Os novilhos do tratamento TC10 permaneceram mais tempo em ócio deitado (8,14 horas) em relação aos do tratamento TC (7,24 horas). Houve superioridade do tempo de mastigadas por bolo ruminado do TC10 (58,59 segundos) em relação ao TC5 (54,11 segundos) e maior número de bolos ruminados do TC5 (534,68 bolos ruminados por dia) em relação ao TC10 (473,77 bolos ruminados por dia). O TC apresentou maior consumo de matéria seca (9,54 kg dia-1) que o TC10 (8,63 Kg dia-1). O TC e TC5 demonstraram maiores consumos de FDN (3,63 e 3,58 kg de FDN dia-1, respectivamente) que o TC10 (3,29 kg de FDN dia-1). O padrão constante de energia aumenta o tempo de alimentação e consumo de matéria seca, o de crescimento menos acentuado aumenta o número de bolos ruminados por dia, enquanto o crescimento mais acentuado aumenta os tempos de ócio deitado e mastigadas por bolo e diminui o consumo de fibra em detergente neutro.(AU)

The immune profile induced is crucial to determine the effects of immunocastration over gonadal function, fertility, and GnRH-I expression.

PROBLEM: Immunocastration or vaccination against the GnRH-I hormone is a promising alternative to reproductive control in different animal species. Given the low immunogenicity of this hormone, the use of adjuvants becomes necessary. METHOD OF STUDY: This study evaluated the effects of three adjuvants that induce different immune response profiles over gonadal function, fertility, and expression of GnRH-I. Female mice (n = 6) were vaccinated at days 1 and 30 with a recombinant antigen for immunocastration and different adjuvants that induced preferentially Th1/Th2, Th2, and Th1 immune profiles. RESULTS: Th1/Th2 response is the most efficient to block reproductive activity in vaccinated animals, reducing the number of luteal bodies and pre-ovulatory follicles. Th2 and Th1/Th2 responses induced an increase in GnRH-I at the hypothalamus. CONCLUSION: The immune profile induced by different adjuvants is essential on the effects over fertility, gonadal function, and hypothalamic GnRH-I expression in immunocastrated animals.

Ingestive behavior of feedlot-finished steers submitted to energy supply patterns / Comportamento ingestivo de novilhos terminados em confinamento submetidos a padrões de fornecimento de energia

This study aimed to verify the effects of supplying different energy patterns on ingestive behavior of feedlot-finished cattle. Twenty-seven pure and crossbred Charolais or Nellore steers with an initial average age and weight of 22 months and 252.8 kg, respectively, were used. Three treatments were carried out, two of them with an increasing rate of concentrate in the diet during the finishing period (IT5 and IT10) and one with constant roughage to concentrate ratio (CT). The experimental design was a completely randomized design with three treatments, five periods, and nine replications. Feeding time was higher for CT (4.31 hours) when compared to IT5 (3.85 hours). Steers from the treatment IT10 remained longer in lying leisure (8.14 hours) when compared to the treatment CT (7.24 hours). A superiority of chewing per ruminated bolus was observed in IT10 (58.59 seconds) when compared to IT5 (54.11 seconds) whereas a higher number of ruminated bolus was observed in TC5 (534.68 ruminated bolus day−1) when compared to IT10 (473.77 ruminated bolus day−1). Animals from CT presented a higher dry matter intake (9.54 kg day−1) than those from IT10 (8.63 kg day−1). Steers from CT and IT5 showed a higher NDF intake (3.63 and 3.58 kg NDF day−1, respectively) when compared to IT10 (3.29 kg NDF day−1). The constant energy pattern increases feeding time and dry matter intake. The one of less vigorous growth increases the number of bolus ruminated per day, while the one of more vigorous growth increases idle time and chews per bolus and decreases the intake of neutral detergent fiber.

O objetivo foi verificar os efeitos do fornecimento de diferentes padrões de energia no comportamento ingestivo de bovinos terminados em confinamento. Foram utilizados 27 novilhos, puros e cruzados das raças Charolês ou Nelore com idade e peso médios iniciais respectivos de 22 meses e 252,8 kg. Utilizaram-se três tratamentos, sendo dois com taxa crescente da participação do concentrado ao longo do período de terminação (TC5 e TC10) e um com relação volumoso:concentrado constante (TC). O delineamento experimental foi o inteiramente casualizado, com três tratamentos, cinco períodos e nove repetições. O tempo de alimentação foi maior para o TC (4,31 horas) em relação ao TC5 (3,85 horas). Os novilhos do tratamento TC10 permaneceram mais tempo em ócio deitado (8,14 horas) em relação aos do tratamento TC (7,24 horas). Houve superioridade do tempo de mastigadas por bolo ruminado do TC10 (58,59 segundos) em relação ao TC5 (54,11 segundos) e maior número de bolos ruminados do TC5 (534,68 bolos ruminados por dia) em relação ao TC10 (473,77 bolos ruminados por dia). O TC apresentou maior consumo de matéria seca (9,54 kg dia-1) que o TC10 (8,63 Kg dia-1). O TC e TC5 demonstraram maiores consumos de FDN (3,63 e 3,58 kg de FDN dia-1, respectivamente) que o TC10 (3,29 kg de FDN dia-1). O padrão constante de energia aumenta o tempo de alimentação e consumo de matéria seca, o de crescimento menos acentuado aumenta o número de bolos ruminados por dia, enquanto o crescimento mais acentuado aumenta os tempos de ócio deitado e mastigadas por bolo e diminui o consumo de fibra em detergente neutro.

Performance and ingestive and social behavior of young cattle with different sexual conditions supplemented in Aruana pasture / Desempenho, comportamento ingestivo e social de bovinos jovens com diferentes condições sexuais suplementados em pastagem de Aruana

This study was conducted aiming at measuring the performance and behavior of beef cattle surgically castrated, immunocastrated or non-castrated, finished at 18 months old in Aruana pasture and with energy supplementation. Thirty-nine male bovines with an initial average body weight and age of 284.1 ± 31.4 kg and 14 months old, respectively, were used. The bromatological composition analysis and productive parameters of the pasture did not differ between treatments. The performance of young cattle was not changed by the sexual condition. When evaluating the agonistic behavior, the non-castrated bovine presented a higher number of activities, such as threats and fights, in relation to those immunocastrated. The time spent on the feeder by non-castrated young cattle (56.20 minutes) was higher than that observed for surgically castrated or immunocastrated (41.43 and 32.38 minutes, respectively). The combination between the correct management of Aruana pasture and use of supplementation showed to be promising for finishing bovines. Both surgically castrated and immunocastrated steers demonstrated to be equivalents in the performed evaluations. Therefore, if the farmer chooses castration, the use of immunocastration is suggested. This practice is less invasive, preserves animal welfare more than surgical castration, and has a lower cost.

Objetivou-se mensurar o desempenho e comportamento de bovinos de corte, castrados cirurgicamente, imunocastrados ou não castrados, terminados aos 18 meses em pastagem de Aruana, recebendo suplementação energética. Foram utilizados trinta e nove bovinos machos, com peso corporal e idade iniciais médios de 284,1 ± 31,4 kg e 14 meses, respectivamente. A análise da composição bromatológica e os parâmetros produtivos da pastagem não diferiram entre tratamentos. O desempenho dos novilhos não foi alterado pela condição sexual (P > 0,05). Ao avaliar o comportamento agonístico, verifica-se que os não castrados apresentaram maior número de atividades, como ameaças e brigas, em relação aos imunocastrados. O tempo de permanência no comedouro dos não castrados (56,20 minutos) foi superior ao detectado para castrados cirurgicamente ou imunocastrados (41,43 e 32,38 minutos), respectivamente. A combinação entre o correto manejo da pastagem de Aruana e o uso de suplementação se mostrou promissora para a terminação de bovinos. Quando compara-se os novilhos castrados cirurgicamente e os imunocastrados ambos demostraram ser equivalentes nas condições do presente estudo. Portanto, se o produtor optar pela castração sugere-se a imunização contra o fator de liberação de gonatrofinas. Essa prática é menos invasiva, preserva o bem-estar animal mais do que a castração cirúrgica e tem menor custo.

Desempenho e qualidade de carcaça de suínos machos castrados, fêmeas e machos imunocastrados de diferentes potenciais genéticos / Performance and carcass quality of castrated males, females and immunocastrated male pigs from different genetic potentials

Considerando o crescimento da imunocastração de suínos no Brasil e a carência de informações de seu efeito nas diferentes linhagens e cruzamentos comerciais, objetivou-se com este estudo avaliar o desempenho e a qualidade de carcaça de suínos de 70 a 150 dias de diferentes categorias sexuais e diferentes origens genéticas. Os machos reprodutores utilizados foram o PIET (com predominância da genética Pietrain) e o DLPH (proporção semelhante de Hampshire, Duroc, Large White, Pietrain). Foram utilizados 20 animais de cada categoria, com peso médio inicial de 25,0 kg alojados em baias de piso de concreto. Foi utilizado um delineamento experimental em blocos casualizados em arranjo fatorial 3 x 2 (três categorias sexuais fêmeas, machos castrados e machos imunocastrados - e duas origens genéticas), totalizando seis tratamentos e cinco repetições, com dois animais por baia (parcela experimental). Os suínos DLPH apresentaram menor (P<0,05) consumo de ração e conversão alimentar durante a fase de crescimento. Machos imunocastrados apresentaram melhor (P<0,05) desempenho na fase de terminação. Não houve influência (P>0,05) da origem genética sobre as características de carcaça, já o rendimento de carcaça de fêmeas foi superior (P<0,05) ao de machos imunocastrados.(AU)

Considering the growth of pig immunocastration in Brazil and the lack of information on its effects in the different lineages and commercial crosses, this study aimed to evaluate the performance and quality of pork carcass from 70 to 150 days of different sexual categories and different genetic origins. The breeding males used were PIET (predominantly Pietrain genetics) and DLPH (similar proportion of Hampshire, Duroc, Large White, Pietrain). Twenty animals of each category were used, with initial mean weight of 25.0 kg housed in concrete floor bays. A randomized block design in a 3 x 2 factorial arrangement (three sex categories - females, castrated males and immunocastrated males - and two genetic origins) was used, totaling six treatments and five replications, with two animals per bay (experimental plot). DLPH pigs presented lower (P <0.05) feed intake and feed conversion during the growth phase. Immunocastrated males showed better (P <0.05) performance in the finishing phase. There was no influence (P> 0.05) of the genetic origin on the carcass traits and the carcass yield of females was higher (P <0.05) than that of the immunocastrated males.(AU)

Desempenho e qualidade de carcaça de suínos machos castrados, fêmeas e machos imunocastrados de diferentes potenciais genéticos / Performance and carcass quality of castrated males, females and immunocastrated male pigs from different genetic potentials

Considerando o crescimento da imunocastração de suínos no Brasil e a carência de informações de seu efeito nas diferentes linhagens e cruzamentos comerciais, objetivou-se com este estudo avaliar o desempenho e a qualidade de carcaça de suínos de 70 a 150 dias de diferentes categorias sexuais e diferentes origens genéticas. Os machos reprodutores utilizados foram o PIET (com predominância da genética Pietrain) e o DLPH (proporção semelhante de Hampshire, Duroc, Large White, Pietrain). Foram utilizados 20 animais de cada categoria, com peso médio inicial de 25,0 kg alojados em baias de piso de concreto. Foi utilizado um delineamento experimental em blocos casualizados em arranjo fatorial 3 x 2 (três categorias sexuais – fêmeas, machos castrados e machos imunocastrados - e duas origens genéticas), totalizando seis tratamentos e cinco repetições, com dois animais por baia (parcela experimental). Os suínos DLPH apresentaram menor (P0,05) da origem genética sobre as características de carcaça, já o rendimento de carcaça de fêmeas foi superior (P<0,05) ao de machos imunocastrados.

Considering the growth of pig immunocastration in Brazil and the lack of information on its effects in the different lineages and commercial crosses, this study aimed to evaluate the performance and quality of pork carcass from 70 to 150 days of different sexual categories and different genetic origins. The breeding males used were PIET (predominantly Pietrain genetics) and DLPH (similar proportion of Hampshire, Duroc, Large White, Pietrain). Twenty animals of each category were used, with initial mean weight of 25.0 kg housed in concrete floor bays. A randomized block design in a 3 x 2 factorial arrangement (three sex categories - females, castrated males and immunocastrated males - and two genetic origins) was used, totaling six treatments and five replications, with two animals per bay (experimental plot). DLPH pigs presented lower (P 0.05) of the genetic origin on the carcass traits and the carcass yield of females was higher (P <0.05) than that of the immunocastrated males.

Desempenho, características de carcaça e qualidade de carne de suínos sob castração cirúrgica ou imunológica / Performance, carcass characteristics and meat quality of pigs under surgical or immunological castration

Objetivou-se avaliar o desempenho e características da carcaça de cordeiros Santa Inês terminados a pasto e suplementados com blocos multinutricionais (BMs). Foram utilizados 20 cordeiros inteiros, sendo 10 do biótipo Santa Inês Tradicional e 10 Santa Inês Moderno. Estes foram distribuídos em um delineamento inteiramente casualizado, onde permaneceram até atingirem a idade para abate de 264 dias. Apesar de possuírem biótipos distintos, os ovinos não diferiram estatisticamente para variáveis de desempenho, características quantitativas, qualitativas, morfometria, biometria, somente a variável de rendimento de paleta apresentou-se superior para o biótipo moderno em 19,75% enquanto que para o tradicional foi de 19,18%. Observou- se um consumo crescente de bloco multinutricional pelos cordeiros até aos 56 dias de experimento, atingindo no máximo 0,240g/animal/dia, mas aos 84 dias houve um declínio para 0,198g/animal/dia. O ganho de peso médio diário (GPMD) foi de 144,22 e 146,67 para o biótipo tradicional e o moderno respectivamente, bem como o peso final (PF) que foi de 32,26 e 32,66kg para cada biótipo. A tipificação da carcaça dos animais é moderada, sendo, portanto uma carcaça magra. A margem bruta de lucro foi de 78 reais/animal. Apesar das diferenças biotípicas os cordeiros da raça Santa Inês terminados a pasto e suplementados com blocos multinutricionais apresentam carcaças com características semelhantes.(AU)

The objective of this study was to evaluate the performance and carcass characteristics of Santa Inês lambs fed pasture supplemented with multinutritional blocks (MB). Twenty whole lambs were used, 10 of the Santa Inês Tradicional and 10 Santa Inês Moderno biotypes. These were distributed in a completely randomized design, where they remained until reaching the slaughtering age of 264 days. Although they had different biotypes, sheep did not differ statistically for performance variables, quantitative, qualitative, morphometry, biometrics, only the palette yield variable was higher for the biotype in 19. 75%, while for the traditional one it was 19. 18%. Increasing use of the multinutritional block was observed by lambs up to 56 days of experiment, reaching a maximum of 0.240g/animal/day, but at 84 days there was a decline to 0.198g/animal/day. The average daily gain (ADG) was 144.22 and 146.67 for the traditional and modem biotypes, respectively, and the final weight (FW) was 32. 26 and 32. 66kg for each biotype. The carcass of the animals is moderate and therefore a lean carcass. The gross profit margin was 78 reais/animal. Despite the biotypic differences, the Santa Inês lambs fed pasture and supplemented with multinutritional blocks showed similar carcass characteristics.(AU)

Desempenho, características de carcaça e qualidade de carne de suínos sob castração cirúrgica ou imunológica / Performance, carcass characteristics and meat quality of pigs under surgical or immunological castration

Objetivou-se avaliar o desempenho e características da carcaça de cordeiros Santa Inês terminados a pasto e suplementados com blocos multinutricionais (BMs). Foram utilizados 20 cordeiros inteiros, sendo 10 do biótipo Santa Inês Tradicional e 10 Santa Inês Moderno. Estes foram distribuídos em um delineamento inteiramente casualizado, onde permaneceram até atingirem a idade para abate de 264 dias. Apesar de possuírem biótipos distintos, os ovinos não diferiram estatisticamente para variáveis de desempenho, características quantitativas, qualitativas, morfometria, biometria, somente a variável de rendimento de paleta apresentou-se superior para o biótipo moderno em 19,75% enquanto que para o tradicional foi de 19,18%. Observou- se um consumo crescente de bloco multinutricional pelos cordeiros até aos 56 dias de experimento, atingindo no máximo 0,240g/animal/dia, mas aos 84 dias houve um declínio para 0,198g/animal/dia. O ganho de peso médio diário (GPMD) foi de 144,22 e 146,67 para o biótipo tradicional e o moderno respectivamente, bem como o peso final (PF) que foi de 32,26 e 32,66kg para cada biótipo. A tipificação da carcaça dos animais é moderada, sendo, portanto uma carcaça magra. A margem bruta de lucro foi de 78 reais/animal. Apesar das diferenças biotípicas os cordeiros da raça Santa Inês terminados a pasto e suplementados com blocos multinutricionais apresentam carcaças com características semelhantes.

The objective of this study was to evaluate the performance and carcass characteristics of Santa Inês lambs fed pasture supplemented with multinutritional blocks (MB). Twenty whole lambs were used, 10 of the Santa Inês Tradicional and 10 Santa Inês Moderno biotypes. These were distributed in a completely randomized design, where they remained until reaching the slaughtering age of 264 days. Although they had different biotypes, sheep did not differ statistically for performance variables, quantitative, qualitative, morphometry, biometrics, only the palette yield variable was higher for the biotype in 19. 75%, while for the traditional one it was 19. 18%. Increasing use of the multinutritional block was observed by lambs up to 56 days of experiment, reaching a maximum of 0.240g/animal/day, but at 84 days there was a decline to 0.198g/animal/day. The average daily gain (ADG) was 144.22 and 146.67 for the traditional and modem biotypes, respectively, and the final weight (FW) was 32. 26 and 32. 66kg for each biotype. The carcass of the animals is moderate and therefore a lean carcass. The gross profit margin was 78 reais/animal. Despite the biotypic differences, the Santa Inês lambs fed pasture and supplemented with multinutritional blocks showed similar carcass characteristics.

Effect of immunocastration with Bopriva on carcass characteristics and meat quality of feedlot Holstein bulls.

To evaluate the effect of immunocastration on carcass and meat characteristics, Holstein bulls aged between 7 and 8months with a live weight of 232±1.19kg were given two separate treatments, placebo (intact bulls) versus Bopriva, and then slaughtered after approximately 239days of fattening. While the testosterone levels in intact bulls remained at 0.42ng/ml throughout the study, by day 181, differences (P<0.05) were observed in immunized bulls, with values of 0.21ng/ml. The carcasses of animals treated with Bopriva recorded both a higher hot carcass weight (HCW) and a cold carcass weight (CCW), as well as higher dorsal fat density, marbling and KPH (P<0.05); however, no differences (P>0.05) were observed in the Longissimus lumborum area. No significant differences (P>0.05) were recorded between the treatments for pH, L*, a*, b* C* and H*. The carcasses of the animals treated with Bopriva were heavier, with higher dorsal fat density and marbling score.