Conception rate of artificially inseminated Holstein cows affected by cloudy vaginal mucus, under intense heat conditions

Abstract

-The objective of this work was to obtain prevalence estimates of cloudy vaginal mucus in artificially inseminated Holstein cows raised under intense heat, in order to assess the effect of meteorological conditions on its occurrence during estrus and to determine its effect on conception rate. In a first study, an association was established between the occurrence of cloudy vaginal mucus during estrus and the conception rate of inseminated cows (18,620 services), raised under intense heat (mean annual temperature of 22°C), at highly technified farms, in the arid region of northern Mexico. In a second study, data from these large dairy operations were used to assess the effect of meteorological conditions throughout the year on the occurrence of cloudy vaginal mucus during artificial insemination (76,899 estruses). The overall rate of estruses with cloudy vaginal mucus was 21.4% (16,470/76,899; 95% confidence interval = 21.1-21.7%). The conception rate of cows with clean vaginal mucus was higher than that of cows with abnormal mucus (30.6 vs. 22%). Prevalence of estruses with cloudy vaginal mucus was strongly dependent on high ambient temperature and markedly higher in May and June. Acceptable conception rates in high milk-yielding Holstein cows can only be obtained with cows showing clear and translucid mucus at artificial insemination.Index terms: dairy cattle, heat stress, reproductive efficiency, seasonal pattern, subclinical endometritis, uterine infection. Taxa de concepção de vacas Holandesas inseminadas artificialmente e afetadas por muco vaginal turvo, sob condições de intenso calorResumo -O objetivo deste trabalho foi obter estimativas de prevalência de muco vaginal turvo durante o estro em vacas Holandesas criadas sob intenso calor, para avaliar o efeito das condições climáticas sobre sua ocorrência durante o estro e determinar seu efeito sobre a taxa de concepção. Em um primeiro estudo, foi estabelecida a associação entre a ocorrência de muco vaginal turvo durante o estro e a taxa de concepção de vacas inseminadas (18.620 serviços), criadas sob intenso calor (temperatura média anual de 22°C), em fazendas altamente tecnificadas, na região árida do norte do México. Em um segundo estudo, os dados desses grandes estábulos leiteiros foram utilizados para avaliar o efeito das condições climáticas, ao longo do ano, na ocorrência de muco vaginal turvo durante a inseminação artificial (76.899 cios). A taxa global de cios com muco vaginal turvo foi de 21,4% (16.470/76.899; intervalo de confiança de 95% = 21,1-21,7%). A taxa de concepção das vacas com muco vaginal límpido foi maior que a de vacas com muco anormal (30,6 vs. 22%). A prevalência de estros com muco vaginal turvo foi fortemente dependente de elevada temperatura ambiente, e significativamente maior em maio e junho. Taxas de concepção aceitáveis de vacas Holandesas com elevada produção de leite somente são obtidas em vacas que apresentem muco translúcido durante a inseminação artificial.Termos para indexação: gado leiteiro, estresse por calor,...

Physical Traits of Vaginal Mucus Discharge and Their Relations to Conception Rate of Egyptain Baladi Cows

“…Similar results were reported by Lim et al (2014) who found that the conception rate was 67.3% for dairy cows that had transparent vaginal mucus and Bhat et al (2015) found that the conception rate was 94.1% for cows that had transparent vaginal mucus and reported similar trend. In addition, Mellado et al (2015) suggested that the conception rate from the first service with transparent mucus was higher (31.9%) than turbid mucus (22.3%) in cows. Parikh et al (2018) reported that cows with clear mucus had higher conception rate.…”

“…Physical properties of vaginal mucus discharge have direct bearing on the fertility status of the animals (Panchal et al, 1994 andRangnekar et al, 2002). Many researchers investigated the relationships between properties of cervical mucus during estrus phase and conception rate in cattle (Madkar et al, 2015, Mellado et al, 2015and Bernardi et al, 2016. Cervical mucus properties as an indicator of the female hormonal condition also play a vital role in conception rate (Benbia et al, 2011).…”