DSpace Coleção: Artigo em periódico indexado (CNPGC)

Management practices for the control of Haematobia irritans, Dermatobia hominis, and Cochliomyia hominivorax in cattle across Latin America: a sustainable, collective approach.

2026-01-01T00:00:00Z

Título: Management practices for the control of Haematobia irritans, Dermatobia hominis, and Cochliomyia hominivorax in cattle across Latin America: a sustainable, collective approach. Autoria: RODRIGUEZ-VIVAS, R. I.; CUTOLO, A. A.; BARROS, A. T. M. de; CUORE, U. D.; MOLENTO, M. B.; LÓPEZ-OSORIO, S.; RODRIGUES, D. S.; SPINA, M.; BORGES, F. A.; LOPES, W. D. Z.; PULIDO-MEDELLIN, M. O.; FIEL, C. A.; COSTA-JUNIOR, L. M.; ANZIANI, O. S.; SAN MARTÍN, L. M.; SABATINI, G. A. Conteúdo: ABSTRACT - Bovines are suitable hosts and can be affected by fly infestations. Flies pose a significant threat to cattle livestock in Latin America (LA), causing substantial economic repercussions to animal production (reduced productivity, veterinary expenses, and decreased animal welfare) and damage to human health. The most important flies affecting cattle in Argentina, Brazil, Colombia, Mexico, and Uruguay are Haematobia irritans, Dermatobia hominis, and Cochliomyia hominivorax. Due to production losses and the consequent economic costs associated with these flies, control measures must be implemented, primarily relying on insecticidal products. However, decision-making for preventing and treating animals with insecticides varies due to differences in environmental conditions across countries and regions, production systems, animal populations, infestation levels, animal welfare, and the prevalence of myiasis, among other factors. Although insecticides remain the most effective option for fly control in cattle, resistant populations have developed, rendering them less effective. To overcome fly resistance to insecticides, non-chemical (mechanical, environmental, biological, and genetic) methods are being integrated into alternative control and eradication strategies. The use of integrated livestock fly control contributes to safeguarding animal, public, and environmental health. This review is designed to support individuals and institutions, both civil and governmental, addressing the ongoing challenge posed by flies affecting livestock.

One or two cyclicity inductions on TAI pregnancy rate and pregnancy loss in precocious Nellore heifers.

2025-01-01T00:00:00Z

Título: One or two cyclicity inductions on TAI pregnancy rate and pregnancy loss in precocious Nellore heifers. Autoria: TAVEIRA, A. A. R.; SILVA, L. G. da; SILVA, L. G. da; MASCHARELLO, J.; FERREIRA, L. C. L.; NOGUEIRA, E. Conteúdo: ABSTRACT - The objective was to evaluate the pregnancy rate and pregnancy loss of precocious Nellore heifers submitted to one or two previous cyclicity inductions to TAI (timed artificial insemination). A total of 572 Nellore nulliparous aged 12 to 14 months-old were used, divided into two treatments: on D-50, T1- one cyclicity induction (n = 313): 1 ml of 0.9% NaCl and T2- two cyclicity induction (n = 259): 1 ml of injectable progesterone. From that date, the two groups received the same management as follows: On D-26, oral supply of 2.28 g/head/ day (MGA® PREMIX) for twelve days and on D-12, IM application 0.6 mg of estradiol cypionate (E.C.P.®) in all. Subsequently carried out the TAI protocol and pregnancy diagnosis was performed on D41 and pregnancy confirmed on D101. The uterus and ovary were evaluated in D-50, D-26, and D0. There was no difference in pregnancy rate and pregnancy loss (P > 0.05), besides in T2, better grades of uterine and ovarian scores were observed between the beginning of cyclicity induction and D0 (P < 0.05). The two-induction group had better uterus and ovary scores, which did not interfere with pregnancy and pregnancy loss rates. RESUMO - O objetivo foi avaliar a taxa de prenhez e perda de prenhez de novilhas Nelore precoces submetidas a uma ou duas induções prévias à IATF (inseminação artificial em tempo fixo). Foram utilizadas 572 nulíparas nelore com idade entre 12 e 14 meses de idade, divididas em dois tratamentos: no D-50, T1- uma indução (n = 313): 1 ml de NaCl 0,9% e T2- duas induções (n = 259): 1 ml de progesterona injetável. A partir dessa data, os dois grupos receberam o mesmo manejo: no D-26, administração oral de 2,28 g/cabeça/dia (MGA® PREMIX) por doze dias e no D-12, aplicação IM de 0,6 mg de cipionato de estradiol (E.C.P.®) em todos. Posteriormente foi realizado o protocolo de IATF e o diagnóstico de gestação foi realizado no D41 e a gestação confirmada no D101. O útero e o ovário foram avaliados em D-50, D-26 e D0. Não houve diferença na taxa de prenhez e perda gestacional (P > 0,05), apesar de observadas melhores notas dos escores uterino e ovariano entre o início da indução e o D0 no tratamento T2 (P < 0,05). O grupo das duas induções teve melhor desenvolvimento de útero e ovário, não interferindo na taxa de prenhez e perda gestacional.

Prevalence and morphological appearance of sperm nuclear defects using feulgen reaction in beef Bulls.

2025-01-01T00:00:00Z

Título: Prevalence and morphological appearance of sperm nuclear defects using feulgen reaction in beef Bulls. Autoria: FERNANDES, C. E.; ZART, A. L.; MARTINS, J. C. de A.; OKO, R.; SUTOVSKY, P.; NOGUEIRA, E. Conteúdo: ABSTRACT - The objective of this study was to assess the prevalence and compare the morphological aspects of sperm nuclei abnormalities in beef bulls submitted to breeding soundness evaluation (BSE). Semen samples were collected by electroejaculation from 649 beef bulls (Bos indicus, n = 515 and Bos indicus × Bos taurus crossbreed, n = 134) ranging from 2 to 12 years of age. Following a clinical evaluation and semen assessment, a slide was prepared with fresh semen and stained by using the Feulgen-stain for the purpose of evaluating sperm and nuclear morphology. Abnormal sperm nuclei were classified into three categories: A, multiple vacuoles in a pouch-like formation; B, a single vacuole such as the nuclear crater/diadem defect; and C, abnormal chromatin condensation. In accordance with the BSE criteria, the animals were classified as either satisfactory or unsatisfactory potential breeders. The prevalence of nuclear defects was comparable between satisfactory bulls of both genotypes. Unsatisfactory Bos indicus bulls exhibited a higher frequency of A and B nuclear defect categories. A category presented an odds ratio of 7.14 (0.012) for unsatisfactory bulls. A low percentage of the C category (2.3%) was observed in both BSE classifications. Vacuoles or craters were predominantly observed in the post-acrosomal and mid-subacrosomal regions, with minimal occurrence in the apical ridge region. Our findings provide the baseline for nuclear defects in B. indicus and its crossbreeds. The Feulgen reaction thus enables a simple yet comprehensive analysis of nuclear sperm head defects during BSE. In addition, stain retention facilitates a practical evaluation and an accurate account of the nuclear lesion types.

Comparison between recombinant bovine somatotropin and equine chorionic gonadotropin in timed artificial insemination protocols in Bos indicus cows under low body condition score.

2025-01-01T00:00:00Z

Título: Comparison between recombinant bovine somatotropin and equine chorionic gonadotropin in timed artificial insemination protocols in Bos indicus cows under low body condition score. Autoria: GASSENFERTH, G.; VALLE, V. M.; SOUZA, F. A.; GOMES, M. G. T.; GASSENFERTH JUNIOR, A.; ROSA, G. V. A.; BRAGATO, A.; NOGUEIRA, E.; KOZICKI, L. E. Conteúdo: ABSTRACT - This study aimed to evaluate the efficiency of recombinant bovine somatotropin (rbST) on pregnancy rate (PR), dominant follicle diameter (DFD) pre-ovulatory follicle diameter (DFPO), and follicular growth rate (FGR) in Bos indicus cows with low body condition score (BCS; mean = 2.3) subjected to fixed-time artificial insemination (FTAI) protocols. The females were divided into four groups: rbST group day zero (GbSTd0; n=31) received a progesterone (P4) intravaginal device + estradiol benzoate + rbST on d0 of the protocol; on d8, P4 was removed and PGF2 + estradiol cypionate were administered; on d10, FTAI was performed; GbSTd8; n=31) received the same treatment as GbSTd0, except rbST administration on d8; the control group (GC; n=42) received the same treatment as GbSTd0 but without rbST; equine chorionic gonadotropin group (eCGG; n=46) received the same treatment as GC + eCG on d8. Ovarian follicles were evaluated by ultrasonography (US) on d0, d8, and d10 of the protocols. PRs (at d35) and FGR between d8 and d10 of the protocol were calculated. PRs resulted 16.1%, 19.4%, 30.9%, and 43.4% in GbSTd0, GbSTd8, GC, and GeCG, respectively. eCGG PR differed significantly (P<0.05) from rbST groups but not to the GC; no difference was observed between rbST groups and GC. eCGG resulted in larger DFPO (11.2±1.5 vs. 9.6±0.5 in GbSTd0; 9.9±0.8 in GbSTd8; 10.1±1.3 in GC; P=0.0001) and greater FGR (2.20±1.03 vs. 0.93±0.50 in GbSTd0; 0.94±0.52 in GbSTd8; 1.17±0.64 in GC) (P<0.0001). It was concluded that rbST groups resulted in lower PR, FGR, and DFPO compared to eCGG in cows with reduced BCS; therefore, eCG is recommended for use in cows with low BCS in FTAI programs. RESUMO - O estudo objetivou verificar a eficiência da somatotrofina recombinante bovina (rbST) sobre a taxa de prenhez (TP), o diâmetro do folículo dominante (DFD) e do pré-ovulatório (DFPO) e a taxa de crescimento folicular (TCF) de vacas Bos indicus com baixo escore corporal (ECC médio=2,3) submetidas a protocolos de inseminação artificial em tempo fixo (IATF). As fêmeas foram distribuídas em quatro grupos: grupo bST dia zero (GbSTd0; n=31) recebeu, no d0 do protocolo, um dispositivo intravaginal com progesterona (P4) + benzoato de estradiol + rbST; no d8, houve a remoção da P4 e foi aplicado PGF2 + cipionato de estradiol; no d10, executou-se a IATF; GbSTd8 (n=31) recebeu idêntico tratamento ao GbSTd0, exceto a aplicação da rbST no d8; grupo controle (GC; n=42) recebeu o idêntico tratamento ao GbSTd0, exceto a não aplicação da rbST; grupo gonadotrofina coriônica equina (GeCG;n=46) recebeu idêntico tratamento ao GC + eCG no d8. Os folículos ovarianos foram avaliados por exames de ultrassonografia (US) em d0, d8 e d10 dos protocolos. Foram calculadas as TPs (no d35) e a TCF entre d8 e d10 do protocolo. As TPs resultaram respectivamente em 16,1%; 19,4%; 30,9% e 43,4% nos GbSTd0, GbSTd8, GC e GeCG. As TPs do GeCG mostraram diferença (P<0,05) em relação aos grupos da rbST, mas não ao GC; não houve diferença entre os grupos rbST e o GC. A eCG resultou em maior DFPO (11,2±1,5 vs. 9,6±0,5 do GbSTd0; 9,9±0,8 do GbSTd8 e 10,1±1,3 do GC; P=0,0001) e maior TCF (2,20±1,03 vs. 0,93±0,50 do GbSTd0; 0,94±0,52 do GbSTd8, 1,17±0,64 do GC) (P<0,0001). Concluiu-se que os grupos rbST resultaram em menor TP, TCF e DFPO que a eCG, em vacas com reduzido escore ECC; recomenda-se o emprego da eCG em vacas com baixo ECC em programas de IATF.