RESUMO

This study aimed to assess the sperm quality and number of colony-forming units (CFU mL-1) in extended boar semen stored at low temperatures with or without antibiotics. Normospermic ejaculates (n = 34) were diluted in split samples with Androstar® Premium with or without antibiotics (ampicillin and apramycin sulfate). The extended semen doses were stored for 120 h under three storage temperatures (5, 10, and 17 °C). Variables were analyzed as repeated measures using the GLIMMIX procedure, in a factorial design. The extended semen doses under low-temperature storage (5 and 10 °C) had total motility above 75% throughout the storage. The interaction antibiotic × temperature was significant for total (P = 0.004) and progressive motility (P = 0.005). In extended boar semen doses with antibiotics, the total and progressive motility increased as the storage temperature increased (80.2%, 84.5%, and 89.1%; 70.5%, 76.0%, and 82.9% for total and progressive motility at 5, 10, and 17 °C, respectively; P < 0.05). In extended semen doses without antibiotics, the total and progressive motility were lower when stored at 5 °C than at 10 °C and 17 °C (81.8%, 85.4% and 86.6% and 71.9%, 76.7%, 78.9% for total and progressive motility at 5, 10, and 17 °C, respectively; P < 0.05). After the thermoresistance test, total and progressive motility of doses with antibiotics were higher at 17 °C than 5 °C (P < 0.05); however, they were not affected (P > 0.05) by storage temperature in extended semen doses without antibiotics. The number of CFU mL-1 was lower in extended semen doses without antibiotics stored at 5 and 10 °C than at 17 °C (P < 0.05); however, in extended semen doses with antibiotics, no effect of storage temperature was observed (P > 0.05). The bacterial load was greater in extended semen without antibiotics than with antibiotics, regardless of the storage temperature (P < 0.05). The acrosome and sperm membrane integrity were not influenced (P > 0.05) by using antibiotics. A higher percentage of normal acrosomes was observed as the storage temperature increased (93.6%, 94.3%, and 96.8% at 5, 10, and 17 °C, respectively; P < 0.0001). The membrane integrity was higher (P < 0.0001) in extended semen doses stored at 17 °C than at 10 or 5 °C. The pH rose throughout the storage in all the treatments, except in extended semen doses stored at 17 °C without antibiotics, in which a decrease in the pH occurred at 120 h (P < 0.05). Although the sperm quality being negatively affected by low temperatures, the storage of extended boar semen doses at 5 °C is possible since the sperm viability in vitro was maintained for up to 5 days, fulfilling the requirements of semen quality to be used in artificial insemination. Nevertheless, the use of extended semen doses without antibiotics requires the optimization of hygiene procedures during semen dose processing.

Assuntos

RESUMO

The aim of this study was to verify the influence of the degree of bacterial contamination of boar ejaculate and semen extender on the quality of semen doses. The experiment was conducted in four boar studs, from which raw semen and two semen doses from each ejaculate were collected to evaluate the number of colony-forming units (CFU), pH, sperm morphology and motility. Extender samples were also evaluated for CFU. Ejaculates that had higher levels of contamination (> 220 CFU mL-1) resulted in semen doses with a greater degree of bacterial contamination but with no reduction in motility or alteration in pH. When the semen doses were classified according to the degree of contamination of the extender, a decrease in motility was observed after 108 and 168 h of storage (P < 0.05) in the group whose extender had ≥14,000 CFU mL-1 versus the group whose extender had ≤ 330 CFU mL-1. The pH remained stable during 168 h of storage in semen doses with extender that had lower contamination levels, but decreased from 7.2 to 6.0 between 24 and 168 h of storage (P < 0.05) in the group with extender that had higher levels of contamination. A higher number of abnormal acrosomes (P < 0.05)was observed after 168 h of storage in the semen doses whose extender was highly contaminated. The production of semen doses with low bacterial contamination and high sperm cell viability will only be possible with a strict hygienic control in semen processing, primarily with respect to the extender, combined with minimal contamination during collection.(AU)

O objetivo desse estudo foi verificar a influência do grau de contaminação bacteriana do ejaculado do macho suíno e do diluente na qualidade das doses inseminantes. O estudo foi conduzido em quatro centrais de inseminação, onde foram colhidas amostras de sêmen fresco e duas doses inseminantes produzidas a partir de cada uma das referidas amostras de sêmen. As amostras foram avaliadas quanto ao número de Unidades Formadoras de Colônia (UFC) de bactérias mesófilas totais e coliformes, pH, morfologia espermática e motilidade. As amostras de diluente também foram avaliadas quanto ao número de bactérias mesófilas. Ejaculados que apresentaram grau mais elevado de contaminação bacteriana ( > 220 UFC mL-1) resultaram em doses inseminantes com maior nível de contaminação bacteriana, porém não houve redução de motilidade ou alteração de pH. Quando as doses inseminantes foram classificadas de acordo com a contaminação do diluente, um decréscimo na motilidade foi observado após 108 e 168 horas de armazenamento (P < 0,05) no grupo em que o diluente apresentava ≥14.000 UFC mL-1 se comparado com o observado no grupo cujo diluente apresentava ≤ 330 UFC mL-1. O pH permaneceu estável durante as 168 h de armazenamento em doses inseminantes que apresentavam diluentes com menor nível de contaminação, mas diminuiu de 7,2 para 6,0 entre 24 e 168 h de armazenamento (P < 0,05), no grupo com diluente que apresentava o maior nível de contaminação. Um número maior de acrossomas anormais (P < 0,05) foi observado após 168 h de armazenamento em doses inseminantes cujo diluente era altamente contaminado. A produção de doses inseminantes com baixa contaminação bacteriana e alta viabilidade de células espermáticas só é possível com um estrito controle de higiene durante o processamento do sêmen, principalmente no que se refere ao diluente, combinado com uma contaminação mínima durante a coleta do sêmen.(AU)

Assuntos

RESUMO

The aim of this study was to verify the influence of the degree of bacterial contamination of boar ejaculate and semen extender on the quality of semen doses. The experiment was conducted in four boar studs, from which raw semen and two semen doses from each ejaculate were collected to evaluate the number of colony-forming units (CFU), pH, sperm morphology and motility. Extender samples were also evaluated for CFU. Ejaculates that had higher levels of contamination (> 220 CFU mL-1) resulted in semen doses with a greater degree of bacterial contamination but with no reduction in motility or alteration in pH. When the semen doses were classified according to the degree of contamination of the extender, a decrease in motility was observed after 108 and 168 h of storage (P < 0.05) in the group whose extender had ≥14,000 CFU mL-1 versus the group whose extender had ≤ 330 CFU mL-1. The pH remained stable during 168 h of storage in semen doses with extender that had lower contamination levels, but decreased from 7.2 to 6.0 between 24 and 168 h of storage (P < 0.05) in the group with extender that had higher levels of contamination. A higher number of abnormal acrosomes (P < 0.05)was observed after 168 h of storage in the semen doses whose extender was highly contaminated. The production of semen doses with low bacterial contamination and high sperm cell viability will only be possible with a strict hygienic control in semen processing, primarily with respect to the extender, combined with minimal contamination during collection.

O objetivo desse estudo foi verificar a influência do grau de contaminação bacteriana do ejaculado do macho suíno e do diluente na qualidade das doses inseminantes. O estudo foi conduzido em quatro centrais de inseminação, onde foram colhidas amostras de sêmen fresco e duas doses inseminantes produzidas a partir de cada uma das referidas amostras de sêmen. As amostras foram avaliadas quanto ao número de Unidades Formadoras de Colônia (UFC) de bactérias mesófilas totais e coliformes, pH, morfologia espermática e motilidade. As amostras de diluente também foram avaliadas quanto ao número de bactérias mesófilas. Ejaculados que apresentaram grau mais elevado de contaminação bacteriana ( > 220 UFC mL-1) resultaram em doses inseminantes com maior nível de contaminação bacteriana, porém não houve redução de motilidade ou alteração de pH. Quando as doses inseminantes foram classificadas de acordo com a contaminação do diluente, um decréscimo na motilidade foi observado após 108 e 168 horas de armazenamento (P < 0,05) no grupo em que o diluente apresentava ≥14.000 UFC mL-1 se comparado com o observado no grupo cujo diluente apresentava ≤ 330 UFC mL-1. O pH permaneceu estável durante as 168 h de armazenamento em doses inseminantes que apresentavam diluentes com menor nível de contaminação, mas diminuiu de 7,2 para 6,0 entre 24 e 168 h de armazenamento (P < 0,05), no grupo com diluente que apresentava o maior nível de contaminação. Um número maior de acrossomas anormais (P < 0,05) foi observado após 168 h de armazenamento em doses inseminantes cujo diluente era altamente contaminado. A produção de doses inseminantes com baixa contaminação bacteriana e alta viabilidade de células espermáticas só é possível com um estrito controle de higiene durante o processamento do sêmen, principalmente no que se refere ao diluente, combinado com uma contaminação mínima durante a coleta do sêmen.

Assuntos