Effect of immunocastration on behaviour and blood parameters (cortisol and testosterone) of Holstein bulls

To evaluate the effect that immunocastration has on behaviour, testosterone and cortisol levels of feedlot Holstein bulls, 720 intact animals aged between 7 and 8 months, weighing 232±1.19 kg were randomly assigned to two treatments: immunocastration using the Bopriva vaccine and a placebo (360 animals per treatment). The bulls were slaughtered at day 239 of treatment. Animals were vaccinated on days 1, 21, 101, and 181, and on those same days testosterone levels were measured; while cortisol, glucose and creatin kinase measurements were done on day 181 and during exanguination at slaughter. Sexual, aggressive and social behaviours were evaluated and it was found that intact bulls showed a higher average of head butts, mounting, threats, flehmen sign and sniffing (P<0.05), no differences were found for vocalisations, lowering of the head and grooming (P>0.05). Testosterone levels in intact bulls remained at 0.47ng/mL throughout the study, however, by day 181 differences (P<0.05) were observed in immunised bulls, with values of 0.22ng/mL. At slaughter, testosterone levels were 0.21 ± 0.06 ng/mL in immunocastrated bulls and 0.54 ± 0.06 ng/mL in the placebo group. The use of immunocastration with Bopriva has shown to be effective to reduce testosterone, sexual and aggressive behaviours on Holstein bulls

Effects of immunocastration performed at two live weights on the growth physiology, temperament and testicular development of feral beef bulls

The aim of this study was to examine the effect of administering an anti-gonadotropin-releasing hormone vaccine (Improvac®, developed for pigs) on the performance, temperament, testicular development, and hormone and metabolite profiles of feral bulls (Bos taurus) vaccinated at two different live weights (LW). In all, 16 Serrana de Teruel animals were involved in this 2 x 2 factorial design using the factors LW (LIGHT vs. HEAVY) and vaccine treatment (control, C vs. vaccinated, VA). All animals received the same diet (ad libitum concentrate plus straw) over a 164-day fattening period. Temperament was assessed using chute and flight speed tests. Testicular diameter and subcutaneous fat thickness were recorded. Testosterone, IGF-1, urea, NEFA, and creatinine profiles were analyzed. Bull weight gain was reduced in VA compared to C animals, regardless of the initial LW. The vaccine did not affect the temperament tests, subcutaneous fat thickness or NEFA and creatinine concentrations and had minor effects on linear body measures. The vaccine inhibited testicular growth, reduced plasma testosterone to residual levels, and increased urea concentrations. LIGHT-C animals exhibited increased mean plasma IGF-1 concentrations compared to LIGHT-VA animals. In conclusion, vaccination reduced bull growth and sexual development irrespective of LW at immunization

Immunization against Gonadotropin-Releasing Hormone in Female Beef Calves to Avoid Pregnancy at Time of Slaughter

Precociousness of heifers kept in mixed beef herds with young and adult bulls leads to unwanted pregnancies. Inbreeding, premature calving followed by dystocia and a high stillbirth rate are the consequences. As an alternative, such heifers are slaughtered during the resulting pregnancy. The slaughtering of pregnant animals is an ethical problem, which is strongly criticized by consumers and animal welfare organizations. Therefore, the aim of this study was to postpone puberty in female beef calves housed in Swiss mixed herds to avoid pregnancy until scheduled slaughter at 11 months of age. We used a vaccine (Improvac®) that induces antibody production against sexual hormones, thereby suppressing the reproductive cycle. Monthly progesterone analysis in blood was performed to decide whether the cycle had already started. The results proved, that vaccinated female beef were not coming in heat until 11 months of age compared to the unvaccinated control group, which came in heat earlier. In conclusion, vaccination with Improvac® is an animalfriendly, non-invasive and reliable method to avoid early pregnancy in heifers as well as the slaughter of pregnant cattle

Effects of surgical castration, immunocastration and homeopathy on the performance, carcass characteristics and behaviour of feedlot-finished crossbred bulls

The aim of this study was to evaluate total weight gain, carcass yield, rib-eye area, marbling, subcutaneous fat thickness, frequencies of mounting, excitement, dominance behaviour and serum testosterone concentration in feedlot-finished non-castrated bulls, surgically castrated bulls, immunocastrated bulls and bulls treated with homeopathy. The study involved 52 calves, Holstein-Zebu, 20±3 months old, in a completely randomised design divided into four treatments of 13 animals: non-castrated, surgically castrated, immunocastrated and non-castrated with homeopathy. Analysis of variance was performed, and the Tukey test was applied (P<0.05). The Pearson correlation coefficient was estimated and principal components analysis was performed. The castrated animals had lower total weight gain and carcass yield than the animals in the remaining treatment groups. The immunocastrated bulls had a greater subcutaneous fat thickness than the non-castrated bulls. The castrated bulls exhibited lower frequencies of mounting, excitement and dominance behaviour than the animals in the remaining treatment groups. Testosterone levels were lower in the castrated animals. Principal components analysis revealed a moderate magnitude and sharpness in the differentiation of the castrated animals. It was concluded that the immunocastrated animals were similar in performance to the non-castrated animals, while the carcass finish characteristics of the immunocastrated animals were similar to the castrated animals. The castrated animals had lower productive performance than the animals in the remaining treatment groups. The homeopathy animals had performance and carcass finish characteristics similar to the non-castrated animals. Homeopathy and immunocastration did not reduce sodomy and dominance behaviours

Effect of the biological castration vaccine (Improvac®) on sex hormones and reproductive organs of pigs in Vietnam

The Improvac® vaccine has been shown to improve growth performance, meat quality, and sexual behavior in swine herds in several countries. This study initially investigated the ability of this vaccine to control sex hormones and the development of reproductive organs in Vietnamese crossbred pigs (Yorkshire – Landrace x Duroc). A total of 45 male piglets were randomly divided into three groups: vaccinated at 12 and 18 weeks old, surgically castrated males at 7 days old, and entire males. Meanwhile, 40 female piglets were randomly assigned to one of two groups: those vaccinated at 12 and 16 weeks of age or entire females. Serum from experimental pigs was collected monthly before and after vaccination until slaughter (25 weeks of age). At the time of slaughter, reproductive organs were obtained to assess changes at the macroscopic and microscopic features. Anti-GnRH antibodies in the immunized male and female pigs increased dramatically and remained for several weeks following a booster shot, while serum levels of sex hormones were significantly lower than in the entire group (P<0.05). In addition, the reproductive organs of the immunized groups were negatively affected compared to the control groups. The male vaccinated group showed a significant reduction in the size of reproductive organs and irreversible disruption of spermatogenesis and testicular structure. The ovary and reproductive organs in the immunized female group revealed degradation in the size and ovarian follicle development. Taken together, the Improvac® vaccine can decrease sex hormones, thereby disrupting the development of reproductive organs in vaccinated male and female pigs

Meta-análise da técnica de imunocastração (anti-GnRH) para bovinos machos em fase de terminação

The objective of this work was to analyze the effects of immunocastration on the performance and carcass quality of steers in the finishing phase, compared with non-castration and surgical castration. Data from ten studies with records of 1,261 male bovines were analyzed. The studies included in the meta-analysis necessarily contained treatments with immunocastration specifically against the gonadotropin-releasing hormone. Each study was considered as a random effect in the statistical model used. The data were tested for homogeneity of variances and residue normality, and then subjected to the analysis of variance. Means were compared by Student’s t-test. Non-castrated steers showed greater daily weight gain, feed efficiency, slaughter and hot carcass weights, and loin eye area, besides lower fat thickness than surgically-castrated animals and the lowest a* and b* meat coloration values. Overall, immunocastrated steers were inferior to the non-castrated ones, but superior to those surgically-castrated. Immunocastrated steers present performance and carcass traits superior to those of surgically-castrated animals, but similar meat quality.O objetivo deste trabalho foi analisar os efeitos da imunocastração sobre o desempenho e a qualidade de carcaça de novilhos em terminação, em comparação à não castração e à castração cirúrgica. Analisaram-se dados de dez estudos, com registros de 1.261 bovinos machos. Os estudos incluídos na meta-análise continham, necessariamente, tratamentos com imunização ativa contra o hormônio liberador de gonadotrofinas. Cada estudo foi considerado como efeito aleatório no modelo estatístico utilizado. Os dados foram testados quanto à homogeneidade de variâncias e à normalidade dos resíduos, e, posteriormente, submetidos à análise de variância. As médias foram comparadas pelo teste t de Student. Os novilhos não castrados apresentaram maiores ganho de peso diário, eficiência alimentar, pesos ao abate e de carcaça quente, e área de olho de lombo, além de menor espessura de gordura que os castrados cirurgicamente e menores valores de a* e b*, para coloração da carne. No geral, os novilhos imunocastrados foram inferiores aos não castrados, mas superiores aos castrados cirurgicamente. Novilhos submetidos à imunocastração apresentam características de desempenho e de carcaça superiores aos castrados cirurgicamente, mas qualidade de carne similar

Efeitos do uso da castração imunológica no epitélio seminífero de machos bubalinos.

O procedimento de imunocastração vem sendo utilizado como técnica alternativa amplamente favorável ao bem-estar animal, por ser indolor, pouco invasiva e com eficácia semelhante à da castração cirúrgica, que causa maior estresse aos animais, principalmente quando realizada de forma inadequada. A imunocastração estimula a produção de anticorpos contra o Hormônio Liberador de Gonadotrofina (GnRH), bloqueando temporariamente a produção da testosterona pelas gônadas masculinas e consequetemente a espermatogênese. Por causa da escassez de informações sobre este procedimento em touros bubalinos, o estudo teve como objetivo analisar os possíveis efeitos da imunocastração no testículo desses animais. Vinte touros bubalinos, com idade entre 4 a 6 anos, oriundos da ilha do Marajó – PA, foram avaliados e divididos aleatoriamente em dois grupos composto por dez animais no grupo controle (GC) e dez do grupo imunocastrado (GIM). O produto utilizado foi a vacina anti-GnRH Bopriva ® (Zoetis, SP, Brasil). O GIM recebeu duas doses de 1,0ml contendo 400μg da vacina Bopriva ® com intervalo de 60 dias e o grupo controle recebeu 1,0 ml de solução fisiológica. Após 14 dias da última dose, os animais foram abatidos para consumo e foi coletado os 20 pares de testículos para analises de parâmetros macroscópicos como: comprimento, largura, circunferência e peso. Além disso, foi realizada a retirada de fragmentos do parênquima testicular na porção medial para confecção de lâminas histológicas. Para comparação dos dados foi aplicado o teste t de Student considerando a significância com p<0,05 e intervalo de confiança de 95%. Foi observado diferença significativa entre os dois grupos para grupos para peso (direito p<0001; esquerdo p≤ 0,0001), circunferência (direito p<0,0001; esquerdo p<0,0001), largura (somente lado direito p<0,0372) e comprimento (direito p≤ 0,0013; esquerdo p<0,0437). Na avaliação microscópica, os animais do GC não apresenteram alterações. Nos animais do GIM houve degeneração em todas as amostras, sendo visualizado descamação, tortuosidade e espessamento da membrana basal do túbulo seminífero, assim como vacuolização e atrofia das células de Sertoli. Foi observado também uma redução do número de células de Leydig, núcleos picnóticos e azoospermia. Conclui-se vacina anti-GnRH pode comprometer a fertilidade de búfalos, provavelmente pela supressão da função testicular. A provável supressão na função testicular foi demostrada através da análise das alterações macroscópicas e degeneração e atrofia testicular a nível histológico observadas em animais imunocastrados.The immunocastration procedure has been used as an alternative technique that is widely favorable to animal welfare, as it is painless, little invasive and with similar effectiveness to surgical castration, which causes greater stress to animals, especially when performed improperly. Immunocastration stimulates the production of antibodies against the Gonadotropin Releasing Hormone (GnRH), temporarily blocking the production of testosterone by the male gonads and consequently spermatogenesis. Due to the scarcity of information about this procedure in buffalo bulls, the study aimed to analyze the possible effects of immunocastration on the testis of these animals. Twenty buffalo bulls, aged 4 to 6 years, from the island of Marajó - PA, were evaluated and randomly divided into two groups consisting of ten animals in the control group (CG) and ten in the immunocastrated group (GIM). The product used was the Bopriva ® anti-GnRH vaccine (Zoetis, SP, Brazil). The GIM received two doses of 1.0 ml containing 400μg of the Bopriva ® vaccine with an interval of 60 days and the control group received 1.0 ml of saline solution. Fourteen days after the last dose, the animals were slaughtered for consumption and the 20 pairs of testicles were collected for analysis of macroscopic parameters such as: length, width, circumference and weight. In addition, fragments of the testicular parenchyma were removed from the medial portion to make histological slides. For data comparison, Student's t test was applied considering significance with p<0.05 and 95% confidence interval. A significant difference was observed between the two groups for groups for weight (right p<0001; left p≤ 0.0001), circumference (right p<0.0001; left p<0.0001), width (only right-side p< 0.0372) and length (right p≤ 0.0013; left p<0.0437). In the microscopic evaluation, the animals of the CG did not present alterations. In the animals from the GIM, there was degeneration in all samples, with desquamation, tortuosity and thickening of the basement membrane of the seminiferous tubule being visualized, as well as vacuolation and atrophy of Sertoli cells. A reduction in the number of Leydig cells, pyknotic and azoosperm nuclei was also observed. It is concluded that anti-GnRH vaccine may compromise fertility in buffaloes, probably by suppressing testicular function. Probable suppression of testicular function was demonstrated through the analysis of macroscopic changes and testicular degeneration and atrophy at the histological level observed in immunocastrated animals

Comparación de la castración quirúrgica al nacimiento versus inmunocastration sobre las características de la canal y carne en machos Holstein

El objetivo fue comparar el efecto de la castración quirúrgica al nacimiento vs immunocastración, sobre las características de la canal y carne en machos Holstein en engorda; se utilizaron 720 machos Holstein aproximadamente de 7 a 8 meses de edad con peso inicial de 240.82 kg. Se formaron 2 tratamientos con 4 corrales de 90 animales en cada uno: toros castrados quirúrgicamente que fueron castrados 24 h después del nacimiento y toros inmunocastrados vacunados con Bopriva aplicando cuatro dosis, al día 1, 21, 101 y 181 de engorda. Se tomaron pesos individuales en cada vacunación. Los animales se sacrificaron a los 242 días de engorda. A partir de la segunda vacunación se observaron diferencias (P0.05) entre tratamientos mientras que los valores de b*, C* y H* fueron más altos (P<0.05) en los animales inmunocastrados. Para fines de producción, el sacrificar los machos Holstein al nacimiento, se obtienen animales más pesados y con mejores características en la canal; sin embargo es importante evaluar el impacto del bienestar animal por la castración al nacimiento

Effects of an injectable zinc solution at weaning as an alternative castration method in beef cattle

Two experiments were conducted to investigate a 1 mL intratesticular zinc (100 mg Zn) injection administered into each testicle at weaning (Z) and its effects on growth, health, behavior and testosterone. In the first experiment, beef bulls were assigned randomly to treatment at birth: 1) surgically castrated at birth (S; n = 37) or 2) Z (n = 37). Testicular thickness differed by day (P \u3c 0.01) for Z. Testosterone concentrations were greater in Z by d 77 and remained so through d 280 (P = 0.02) compared to S. Zinc injected calves were heavier at the trail’s conclusion (P ≤ 0.04), had greater ADG overall (P \u3c 0.01), heavier hot carcass weight (P = 0.01), and greater lean muscle area (P = 0.01) compared to S; but a lower marbling score (P \u3c 0.01). Yield Grade, dressed carcass yield and fat thickness were similar (P ≥ 0.14). Zinc injected calves had greater haptoglobin (Hp) concentrations (P \u3c 0.01). Zinc injected calves had greater concentrations of white blood cells on d 1 and 2 and greater concentrations and proportions of neutrophils on d 1, 2 and 3 (P \u3c 0.01). Conversely, S had a greater percentage of lymphocytes on d 1, 2 and 3 and a lower ratio of neutrophils to lymphocytes during that same time (P \u3c 0.01). Zinc injected calves spent more time on their side or sternum on d 1 and more time on their side on d 2 while S spend more time standing during that time (P \u3c 0.01). During d 3, 4, 5, and 6, Z stood more while S laid on their sternum (P \u3c 0.01). In trail 2, beef bulls were allocated randomly to treatment one week post weaning: 1) banded (B; n = 42) or 2) Z (n = 39). Body weights were similar (P ≥ 0.39) but ADG improved for Z compared to B (P = 0.05). Testosterone concentrations were greater in Z compared to B (P ≤ 0.02). Testicular width in Z differed by d (P \u3c 0.01). Zinc castrated calves spent more time on their side compared to B one day post castration (P = 0.03) until d 3 and 4 where B spent more time on their side (P ≤ 0.02). Banded calves stood more the first two days (P ≤ 0.01). On days 3, 4, 5, and 6, Z stood more (P ≤ 0.01) while B were on their sternum (P ≤ 0.03). Banded calves had lower Hp concentrations compared to Z (P ≤ 0.01). Total white blood cell concentrations, proportions and concentrations of neutrophils, and proportion of lymphocytes were greater in Z compared to B on d 1, 2, and 3 (P ≤ 0.01). There was no interaction between treatments over time for IL1β, IL6, and TNFα expression (P ≥ 0.83). The findings in both studies indicate that intratesticular Zn injections at weaning can improve growth performance and some carcass attributes but produce a heightened inflammatory and immune response and cause discomfort. Injecting zinc, as formulated and administered in these trails, does not result in complete castration of beef calves at this age and therefore cannot be considered a true castration alternative