Animal Reproduction (AR)
Animal Reproduction (AR)

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

Laiara Fernandes Rocha; Ana Lúcia Almeida Santana; Rosiléia Silva Souza; Mariana Machado-Neves; José Carlos Oliveira Filho; Emilly Sabrina Cotrim dos Santos; Monna Lopes de Araujo; Taís Borges da Cruz; Larissa Pires Barbosa

Downloads: 0
Views: 53


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.


immunocastration, lambs, testicular morphometry


Amann RP, Almquist JO. Reproductive capacity of dairy bulls. VIII. Direct and indirect measurement of testicular sperm production. J Dairy Sci. 1962;45(6):774-81.

Amann RP. Reproductive capacity of dairy bulls. III. The effect of ejaculation frequency, unilateral vasectomy, and age on spermatogenesis. Am J Anat. 1962;110(1):49-67. PMid:13860859.

Amatayakul-Chantler S, Hoe F, Jackson JA, Roca RO, Stegner JE, King V, Howard R, Lopez E, Walker J. Effects on performance and carcass and meat quality attributes following immunocastration with the gonadotropin releasing factor vaccine Bopriva or surgical castration of Bos indicus bulls raised on pasture in Brazil. Meat Sci. 2013;95(1):78-84. PMid:23665362.

Bielli A, Katz H, Pedrana G, Gastel MT, Morana A, Castrillejo A, Lundeheim N, Forsberg M, Rodriguez-Martinez H. Nutritional management during fetal and postnatal life, and the influence on testicular stereology and Sertoli cell numbers in Corriedale ram lambs. Small Rumin Res. 2001;40(1):63-71. PMid:11259877.

Castro ACS, Berndtson WE, Cardoso FM. Cinética e quantificação da espermatogênese: bases morfológicas e suas aplicações em estudos da reprodução de mamíferos. Rev Bras Reprod Anim. 1997;21(1):25-34.

Costa DS, Henry MRGM, Paula TAR. Espermatogênese de catetos (Tayassu tajacu). Arq Bras Med Vet Zootec. 2004;56(1):46-51.

Costa DS. Análise morfofuncional da Espermatogênese e características seminais de Catetos (Tayassu tajacu) [tese]. Belo Horizonte: Universidade Federal de Minas Gerais UFMG; 2001.

De Rooij DG, Lok D. Regulation of the density of spermatogonia in the seminiferous epithelium of the Chinese hamster: II. Differentiating spermatogonia. Anat Rec. 1987;217(2):131-6. PMid:3578833.

Egu UN. Effect of Gonadotrophin (Pergonal Ž) on daily sperm output, gonadal and extragonadal sperm reserves of mature Yankasa Rams in Eastern Nigeria. J Agric Sci Pract. 2017;2(1):1-17.

França LR, Russell LD. The testis of domestic animals. In: Regadera J, Martinez-Garcia F, editors. Male reproduction: a multidisciplinary overview. Madrid: Churchill Livingstone; 1998. p. 197-219.

França LR, Ye SJ, Ying L, Sandberg M, Russell LD. Morphometry of rat germ cells during spermatogenesis. Anat Rec. 1995;241(2):181-204. PMid:7710135.

Han X, Gu L, Xia C, Feng J, Cao X, Du X, Zeng X, Song T. Effect of immunization against GnRH on hypothalamic and testicular function in rams. Theriogenology. 2015a;83(4):642-9. PMid:25433833.

Han Y, Liu G, Jiang X, Ijaz N, Tesema B, Xie G. KISS1 can be used as a novel target for developing a DNA immunocastration vaccine in ram lambs. Vaccine. 2015b;33(6):777-82. PMid:25562792.

Hochereau-de-Reviers MT, Lincoln GA. Seasonal variation in the histology of the testis of the red deer, Cervus elaphus. J Reprod Fertil. 1978;54(2):209-13. PMid:722668.

SPSS. IBM SPSS Statistics for Windows, Version 23.0. Armonk, NY: IBM Corp; 2015.

Johnson L, Varner DD, Roberts ME, Smith TL, Keillor GE, Scrutchfield WL. Effíciency of spermatogenesis a comparative approach. Anim Reprod Sci. 2000;60-61:471-80. PMid:10844217.

Kerr JB, Millar M, Maddocks S, Sharpe RM. Stage‐dependent changes in spermatogenesis and Sertoli cells in relation to the onset of spermatogenic failure following withdrawal of testosterone. Anat Rec. 1993;235(4):547-59. PMid:8385423.

Kilgour RJ, Pisselet C, Dubois MP, Courot M. Ram lambs need FSH for normal testicular growth, Sertoli cell numbers and onset of spermatogenesis. Reprod Nutr Dev. 1998;38(5):539-50. PMid:9923006.

Kumi-Diaka J, Osori DIK, Njoku CO, Ogwu D. Quantitative estimation of spermatogenesis in bulls (Bos indicus) in a tropical environment of Nigeria. Vet Res Commun. 1983;6(3):215-22. PMid:6880012.

Lents MP, Barbosa LP, Santana ALA, Pinheiro EEG, Mugabe LC, Biscarde CEA, Kiya CK, Machado WM, Souza RS. Immunocastration of goats using anti-gonadotrophin releasing hormone vaccine. Theriogenology. 2018;114:7-13. PMid:29574307.

Martins JM, Souza CEA, Campos ACN, Aguiar GV, Lima ACB, Araújo AA, Neiva JNM, Moura AAA. Biometria do trato reprodutor e espermatogênese em ovinos sem padrão racial definido (SPRD). Arch Zootec. 2008;57(220):553-6.

Morais ACT, Barbosa LP, Neves MM, Matta SLP, Morais DB, Melo BES. Parâmetros morfofisiológicos testiculares de camundongos (Mus musculus) suplementados com geleia real. Arq Bras Med Vet Zootec. 2009;62(1):110-8.

Morais DB, Barbosa LP, Melo BES, Matta SLP, Neves MM, Balarini MK, Rodrigues MV. Microscopia e morfometria de componentes tubulares de testículos de coelhos suplementados com geleia real. Arq Bras Med Vet Zootec. 2012;64(4):810-6.

Nazari-Zenouz F, Moghaddam G, Hamidian G, Ashrafi J, Rafat SA, Qasemi-Panahi B. Postnatal testicular development and testosterone changes in Ghezel ram lambs. Small Rumin Res. 2016;141:70-6.

Needham T, Lambrechts H, Hoffman LC. Castration of male livestock and the potential of immunocastration to improve animal welfare and production traits: invited review. S Afr J Anim Sci. 2017;47(6):731-42.

Paula TAR. Avaliação histológica e funcional do testículo de capivaras adultas (Hydrochoerus hydrochaeris) [tese]. Belo Horizonte: Universidade Federal de Minas Gerais; 1999.

Santos JD, Eufrasio RO, Pinheiro GF, Alves FR, Carvalho MAM, Machado AAN Jr. Influência da estação do ano sobre a estrutura testicular em ovinos explorados no sul do Estado do Piauí. Pesq Vet Bras. 2015;35(11):933-9.

Sarti P, Paula TAR, Polli GO, Souza TD, Araújo GR. Morfofisiologia do tecido intertubular e das células de Leydig de jaguatirica (Leopardus pardalis) adulta. Arq Bras Med Vet Zootec. 2011;63(5):1060-5.

Sousa FML, Lobo CH, Menezes ESB, Rego JPA, Oliveira RV, Lima-Souza AC, Fioramonte M, Gozzo FC, Pompeu RCFF, Cândido MJD, Oliveira JT, Moura AA. Parameters of the reproductive tract, spermatogenesis, daily sperm production and major seminal plasma proteins of tropically adapted morada nova rams. Reprod Domest Anim. 2014;49(3):409-19. PMid:24716618.

Tesema B, Zhao JY, Jiang XP, Liu G, Han Y, Wassie T. Kisspeptin recombinant oral vaccine: a master gene vaccine inhibiting the reproductive physiology and behavior of ram lambs. Vaccine. 2019;37(32):4630-6. PMid:29097006.

Thompson DL Jr. Immunization against GnRH in male species (comparative aspects). Anim Reprod Sci. 2000;60-61:459-69. PMid:10844216.

Ülker H, Küçük M, Yilmaz A, Yoruk M, Arslan L, DeAvila DM, Reeves JJ. Changes in testicular development, ultrasonographic and histological appearance of the testis in buckkids immunized against LHRH using recombinant LHRH fusion protein. Reprod Domest Anim. 2009;44(1):37-43. PMid:18507800.

Vyas NY, Raval MA. Aphrodisiac and spermatogenic potential of alkaloidal fraction of Hygrophila spinosa T. Ander in rats. J Ethnopharmacol. 2016;194:947-53. PMid:27989878.

Walker WH, Cheng J. FSH and testosterone signaling in Sertoli cells. Reproduction. 2005;130(1):15-28. PMid:15985628.

Xu M, Xu C, Liu F, Shen X, Meng J, Chen H, Yang J, Zhou P, Gao R, Gan S. Effects of active immunization with newly modified GnRH peptides on spermatogenesis and production performance of Holstein bulls. Biol Reprod. 2018;99(2):461-72. PMid:29272345.

Young KA, Nelson RJ. Mediation of seasonal testicular regression by apoptosis. Reproduction. 2001;122(5):677-85. PMid:11690527.

Submitted date:

Accepted date:

62974a79a953950c6a6b4982 animreprod Articles
Links & Downloads

Anim Reprod

Share this page
Page Sections