Evaluation of cervical mucus and reproductive efficiency of seasonally anovular dairy goats after short-term progestagen-based estrous induction protocols with different gonadotropins

Abstract

The use of three different gonadotropins was tested for estrous induction in dairy goats during the non-breeding season. All does received an injection of 30 μg of d-cloprostenol and intravaginal sponges containing 60mg of medroxyprogesterone acetate (MAP) for 6 d plus 20 IU of porcine FSH (pFSH), 200 IU of eCG or 250 IU of hCG 24h before sponge removal. In Experiment 1 (n=24), ovarian ultrasound parameters were recorded and cervical mucus was evaluated daily for 5 d after sponge removal or until ovulation. In Experiment 2 (n=80), reproductive efficiency of artificially inseminated or naturally mated does was assessed. The mean interval from sponge removal to ovulation (73.5±23.7 h), number of ovulations (1.6±0.7) and ovulatory follicle diameter (7.2±0.8 mm) did not vary (P >0.05) among the three groups. At ovulation, cervical mucus had crystalline-striated to striated (22.2%), striated to striated-caseous (72.2%) and striated-caseous to caseous (5.6%) appearance. The largest follicle diameter was greater (P <0.05) in does with crystalline (6.7±1.4 mm), crystalline-striated (7.2±1.1 mm) or striated (7.3±1.3 mm) mucus than in those with striated-caseous (5.3±1.4 mm) or caseous (4.5±1.1 mm) mucus. Percentage of animals exhibiting estrus (92.5%) and conception rate (60.8%) were similar (P >0.05) among the three gonadotropins groups. Results of this study support the use of eCG (200 IU), hCG (250 IU) and pFSH (20 IU) for the estrous induction protocols in dairy goats during the non-breeding season. Cervical mucus evaluation can be used as an additional method to determine the optimal time for artificial insemination in goats.

Combined treatment with oestradiol benzoate, d‐cloprostenol and oxytocin permits cervical dilation and nonsurgical embryo recovery in ewes

“…All ewes received two doses of 37.5 μg of d‐cloprostenol (Prolise ® , Tecnopec, São Paulo, Brazil)/by latero‐vulvar route 7 days apart (Fonseca et al., ). After the second cloprostenol injection, the ewes were checked for oestrus every 12 hr and ewes in oestrus were mated with fertile rams (1:4 ram to ewes ratio) throughout the duration of the oestrous period (two to three times according to mounting acceptance).…”

Luteal function in cyclic goats treated with human chorionic gonadotropin administered by intramuscular or intravaginal routes at the time of artificial insemination

“…injections of 30 μg of d-cloprostenol (Prolise®, Tecnopec LTDA, São Paulo, Brazil) were given 7.5 days apart (Bonato et al, 2019), with the administration of the first dose on a random day of the estrous cycle. Artificial insemination (AI) was performed 60 h after the application of the second dose of d-cloprostenol (Bonato et al, 2019) by the Embrapa® transcervical technique (Fonseca et al, 2017), using a Collin speculum (sizes 0-3). The speculum was opened in the centre of the vagina, and with the help of a flashlight, the cervical opening was positioned.…”

From reproductive technologies to genome editing in small ruminants: an embryo s journey

“…Estrus, LH peak and ovulation occur approximately 30, 40 and 60 h after device removal, respectively (goats: Menchaca et al ., 2007a ; Vilariño et al ., 2011 ; sheep: Vilariño et al ., 2010 , 2013 ). The pregnancy rate obtained with the short-term protocol associated with FTAI, and associated with natural mating or conventional artificial insemination, has been previously published in several reports in sheep and goats ( Ungerfeld and Rubianes, 1999 ; Menchaca and Rubianes 2004 , 2007 ; Fonseca et al ., 2005 , 2017 ). In addition, we have recently generated new information on large-scale FTAI programs on more than 13,000 ewes (Menchaca, 2018; IRAUy, Montevideo, Uruguay; unpublished results).…”