Fertility after Artificial Insemination Using a Soybean-Based Semen Extender in Sheep

Abstract

Abstract. The present study aimed to compare the fertility of ewes intrauterinally inseminated with frozen-thawed semen using a soybean-based semen extender (AndroMed) with those of ewes intrauterinally inseminated with frozenthawed semen using a Tris-based extender containing either egg yolk or BSA. Suffolk ewes (n=104) were treated with an intravaginal sponge containing 40 mg fluoroprogesterone acetate (FGA) for 12 days and an intramuscular injection of 500 IU equine chorionic gonadotropin to induce estrus and ovulation during the non-breeding season (July, 2007). Intrauterine insemination was carried out 40-46 h after removal of the FGA sponge (n=90), regardless of the incidence of estrus. The pregnancy rates were not significantly different among the semen extenders containing egg yolk (64.5%) or BSA (58.6%) and AndroMed extender (56.7%). The lambing rates (64.5, 55.2 and 56.7% for the semen extenders containing egg yolk, BSA and AndroMed, respectively) and prolificacy (1.59 to 1.75) were also not significantly different. The present results indicate that an egg yolk-containing semen extender can be replaced with the non-animal derived extender AndroMed, which could be used for intrauterine insemination using frozen-thawed ram semen without reducing fertility. Key words: Artificial insemination, Fertility, Semen extender, Sheep (J. Reprod. Dev. 54: [286][287][288][289] 2008) gg yolk-based semen extenders have been widely utilized for cryopreservation of semen from farm animals including sheep [1][2][3]. However, it is not always easy to prepare semen extenders consistent with quality standards because of the individual quality differences inherent in egg yolk due to the numbers of days after laying and the storage period. Also, addition of egg yolk reduces the acrosome integrity of goat spermatozoa [4], and high egg yolk concentrations reduce the post-thawing viability of ejaculated spermatozoa in several species, such as goats [5], rams [1] and water buffaloes [6]. Furthermore, there has been movement recently to eliminate all animal ingredients, including egg yolk, milk or bovine serum albumin (BSA), in order to design a defined semen extender. Removal of chicken egg yolk from semen extenders would provide several advantages, such as improved consistency in the components of semen extenders and elimination of hygienic risks. Therefore, development of a synthetic semen extender free of animal sources has been desired. A soybean lecithin-based extender (AndroMed; Minitub, Tiefenbach, Germany) has been developed and utilized for bovine [7][8][9] and mountain gazelle semen [10]. Fresh and frozen ram semen diluted with a synthetic semen extender, AndroMed, has been inseminated with satisfactory fertility results in Norway (Paulenz H.: personal communication).Low fertility (20-30%) in ewes inseminated with frozen semen into the cervical orifice, an ordinal deposition site for artificial insemination (AI) in sheep, has not been applied fully on the field, except for intrauterine AI using laparoscopy (60-80% in...

Effect of Egg Yolk and Soybean Lecithin on Tris-Based Extender in Post-Thaw Ram Semen Quality and in vitro Fertility

“…Spermatozoa that are morphologically defective or have poor motility tend to have low success rate of oocyte fertilization. The decreased fertility rates of the L1, L3 and L6 groups compared to those observed in sperm that were frozen with egg yolk are consistent with findings from other authors [17,[19][20][21] . Those authors have observed a deleterious effect or a reduction in the fertility of semen frozen in the presence of soybean lecithin.…”

“…Most semen extenders contain egg yolk and skim milk as sources of lipoprotein that protects sperm cells from cold shock and other damage [9,10] . However, the possible disadvantages of using egg yolk, including its potential to be a cause of allergic reactions, the risk of bacterial contamination and its variable effect on semen have been ÜSTÜNER, ALÇAY, NUR SAĞIRKAYA, SOYLU Effect of Egg Yolk and Soybean ... reported [7,9,11,17] . On the other hand, soybeans contain a high component of low-density lipoprotein, e.g., lecithin or egg yolk-like lecithin [5] .…”

“…However, there are conflicting reports concerning the beneficial effect of lecithin [5,[17][18][19]21] . Increased lecithin concentrations in freezing media positively affect bull [7,11,25] and stallion [21] sperm fertility rates.…”

Comparison of various semen extenders and addition of prostaglandin F2 on pregnancy rate in cows

“…The first to find the AndroMed ® extender preferable were Aires et al (2003). In accord with the present findings, others confirmed this assessment for various ruminant species (Herold et al, 2003;Amirat et al, 2005;Janett et al, 2005;Akhter et al, 2010;Mohan and Atreja, 2014;Chelucci et al, 2015), although for sheep semen there are also controversial assessments (Fukui et al, 2008;Emamverdi et al, 2013). Many insemination organizations are hesitant to switch from the customary egg yolk to a phytoextender, because they are concerned that the latter may not be compatible with semen from all bulls and that, with the recently recommended substantial extension of the pre-freezing equilibration time, egg yolk seems to be indispensable.…”

Efeito da utilização de diferentes diluidores para a produção in vitro de embriões bovinos

“…Ele já foi testado por alguns pesquisadores (Muino et al, 2007), quando foi provada a viabilidade do uso desses para a congelação espermática (Janett et al, 2005). No entanto, outros autores não encontraram resultados positivos em relação à crioproteção espermática com o uso de diluidores livres de proteína animal (Nothling et al, 2007;Fukui et al, 2008).…”