ADDITIVES USED IN EXTENDERS TO IMPROVE THE FREEZABILITY OF RAM SEMEN IN RECENT YEARS: a mini review

Abstract

A b s t r a c tOne of the most important reasons why artificial insemination does not spread as much in cattle as sheep is that ram sperm is highly fragile against cryodamage and consequently the optimum fertility results can not be obtained from cervical inseminations compared to laparoscopic insemination. To establish an ideal ram sperm freezing model, many studies have been carried out for more than 60 years and various methods have been tested by making great efforts. One of the topics where these tests have been done intensively in recent years are additives used in freezing extenders in order to increase the tolerance of sperm against oxidative stress in frozen-thawed ram semen. In this review, covering the studies carried out between the years 2000-2016, we have mostly compiled the additives used in ram semen freezing media which have given better results compared to others supplements. It is understood that, usually, seminal plasma and proteins, thiol compounds, enzymatic antioxidants, sugars, fatty acids and vitamins have been studied as additive agents in recent years. As a result, this review suggests us that further studies are needed to explore the novel techniques and new additives, and their combinations should be tested in different doses in order to install an ideal cryopreservation template for ram semen. Furthermore, even though addition of various compounds to freezing media have improved freezability of ram semen in experimental conditions, anyway these results must be confirmed in field studies. Therefore, the value of sperm which potential fertility is predicted from laboratory survey must be compared with conception or lambing rates.Keywords: ram semen, additives, freezability, extender While the basic techniques related to sperm freezing have done positive effects and important advances mostly on dairy cattle husbandry, any remarkable success has not been provided in sheep. Substantially, these matter is caused mainly by from two reasons following as: i] intolerance of ram sperm against cryopreservation, ii] the physiological and anatomic factors in sperm transport. It is well known subject for a long time that freezing and thawing of ram sperm have caused significant membran and genetic damage [1]. As cervical insemination has given poor fertility results compared to laparascopic inseminations, artificial insemination with frozen semen has not become widespread in sheep husbandry [2]. On the other hand, the expenses of ram semen freezing are almost 20 times more than those of bull semen freezing cost [3]. В Recently, investigators have focused mostly on especially composition, determination of in vivo properties and effects of different cryoprotectants, antioxidants and specific supplements in sperm freezing [4].We understood from literature documented here, no comprehensive review of the researches on frozen ram sperm has been found from that date into the past 16 years. During 2000s, the attentions of researchers have mostly concentrated on additives for improving membrane repair and ...

Sığır Serum Albumini İlave Edilmiş Lesitin Bazlı Sulandırıcı İle Sulandırılan Koç Spermasının Dondurma-Çözdürme Sonrası Uzun Süreli İnkübasyon Direnci

“…These restrictive effects provoke to decrease of motility, viability, mitochondrial membrane function, DNA integrity and fertilizing ability of spermatozoa [11,12,16] . Various supplements were tested to minimize the adverse effect of cryopreservation [5][6][7][8][9][10][11][12]14,16,28] . Bovine serum albumin is one of the attempted supplements, because of a good amino acid profile and protective functions [17,21] .…”

“…Therefore, the success of semen cryopreservation depends on minimizing the adverse effects and maintaining the post-thaw semen quality [1,5] . There are a lot of research, aim of which was to increase success of ram semen cryopreservation with different procedures and additives [6][7][8][9][10] .…”

Endi̇kasyon Dişi (Off-Label) İlaç Kullanimindan Doğan Zararlardan İlaç Üreti̇ci̇si̇ni̇n Ve Heki̇mi̇n Hukuki̇ Sorumluluğu

“…Hekim, İlacın Endikasyon Dışı Kullanımını Önermekte Kusurlu Olmalıdır. Hekim, hekimlik sözleşmesinin kendisine yüklediği yükümlülükleri kusurlu olarak ihlal etmiş olmalıdır 138 . Sorumluluğun sübjektif unsuru olan kusur, hukuka aykırı bir davranışta bulunan kişiye ilişkin olarak yürütülen bir değer yargısı olup, kişinin, zararlı sonucu önlemek için gerekli iradeyi göstermemiş olması nedeniyle kınanmasını ifade eder 139 .…”