Ovsynch i njegove modifikacije u kontroli reprodukcije i liječenju određenih neplodnosti u mliječnih krava- kada i zašto?

In order to optimise reproductive performance and thus production, it is now impossible to control the reproduction of dairy cows without the use of hormones. Due to the characteristics of dairy cows, the use of hormones not only reduces the need for visual heat detection and thus the number of undetected cows in heat, but also prevents certain problems associated with intensive production and its negative effects on reproduction. Ovsynch, as a planned combination of GnRH and PGF2α that allows artificial insemination at the optimal time without the need to control ovaries and uterus, once offered solutions to these problems, but over time its shortcomings were recognised. Therefore, pre-synchronisation protocols have been developed to create optimal conditions for Ovsynch and allow for the best outcome. In addition to pre-synchronisation, Ovsynch and its modifications can also be used in the resynchronisation of inseminated and sonographically diagnosed non-pregnant cows as soon as possible, improving farm efficiency. The addition of progesterone implants also further improves the performance of Ovsynch-based protocols. In addition to controlling reproduction, Ovsynch and its modifications have also proven successful in treating certain forms of infertility in dairy cows, such as anovulatory conditions and cystic ovarian disease. This paper presents the possibilities of using the Ovsynch protocol and its various modifications, and their advantages and disadvantages.Da bi se optimizirala reproduktivna učinkovitost, a samim time i proizvodnja mlijeka, danas je nemoguće zamisliti kontrolu reprodukcije mliječnih krava bez uporabe hormona. Zbog osobitosti mliječnih krava, uporabom hormona smanjuje se potreba za vizualnim opažanjem estrusa i na taj način broj nedetektiranih krava u estrusu, ali se i sprečavaju određeni problemi vezani za intenzivnu proizvodnju i njihov negativan utjecaj na reprodukciju. Ovsynch je kao planirana kombinacija GnRH i PGF2α koja omogućuje umjetno osjemenjivanje u optimalno vrijeme bez potrebe za kontrolom jajnika i maternice, svojevremeno ponudio rješenje vezano za ove probleme, ali s vremenom su uočeni i njegovi nedostatci. Stoga su se razvili i presinkronizacijski protokoli koji omogućavaju optimalne preduvjete za Ovsynch i omogućuju njegov najbolji rezultat. Osim u presinkronizaciji, Ovsynch i njegove modifikacije mogu se koristiti i u resinkronizaciji osjemenjenih i potom, čim prije, dijagnosticiranih negravidnih krava, čime se poboljšava učinkovitost farme. Dodavanje progesteronskih implantanata dodatno poboljšava i uspješnost protokola koji se baziraju na Ovsynchu. Osim u kontroli reprodukcije, Ovsynch i njegove modifikacije su se pokazale uspješnima i u liječenju određenih neplodnosti u mliječnih krava, poput anovulatornih stanja i cistične bolesti jajnika. U ovom će radu biti prikazane mogućnosti uporabe Ovsynch protokola i njegovih različitih modifikacija, zajedno s njihovim prednostima i nedostatcima

Application of GnRH and PGF for Estrus Induction and Synchronization of Ovulation in Dairy Cows

Uzgajivači mliječnih goveda u svojim krdima redovito koriste postupak umjetnog osjemenjivanja. U današnje se vrijeme tradicionalna metoda detekcije estrusa promatranjem pokazala vremenski vrlo neučinkovitom zato što se javlja tendencija za povećanjem broja životinja u stadu, kod krava se sve češće javlja tiho gonjenje ili znakovi estrusa budu slabo izraženi. Kako bi se smanjila potreba za vizualnom detekcijom estrusa sve se češće koriste hormonalni protokoli koji omogućavaju sinkronizaciju velikog broja životinja i vremenski tempirano umjetno osjemenjivanje. Najčešći korišteni hormonalni protokol koji koristi GnRH i PGF2α naziva se Ovsynch. U tom se protokolu u bilo kojoj fazi ciklusa aplicira GnRH, sedam dana nakon toga slijedi aplikacija PGF2α, dva dana kasnije druga aplikacija GnRH te vremenski tempirano umjetno osjemenjivanje uslijedi 8-24 sata nakon posljednje aplikacije GnRH. Nedostatak ovog protokola je taj što životinje različito mogu odgovoriti na hormonalni tretman. Tako na primjer Ovsynch protokol pokazuje lošije rezultate kod junica i kod krava s tri folikularna vala. Ovom se problemu pokušava doskočiti različitim modifikacijama originalnog Ovsynch protokola. Tako je na primjer razvijen Double Ovsynch protokol koji pokazuje bolje rezultate kod junica ili Ovsynch protokol uz suplementaciju progesterona koji se češće koristi kod anestričnih krava ili krava s cističnim jajnicima. Kako bi se povećala stopa sinkronizacije unutar stada koriste se presinkronizacijski protokoli koji zbog duljeg trajanja homogenije sinkroniziraju stado. Resinkronizacijski protokoli koriste se kod krava koje nisu postale gravidne nakon prethodnog osjemenjivanja. Takvi protokoli omogućavaju brzo ponovno osjemenjivanje negravidnih krava. Nadalje, primjena navedenih hormona uspješno se koristi i u liječenju određenih stanja neplodnosti u mliječnih krava.Dairy cattle breeders regularly use the process of artificial insemination in their herds. Nowadays, the process of visual heat detection has proven to be very time consuming because there is tendency to increase the number of animals in herds. Furthermore, silent estrus is more often observed and sings of estrus are becoming weaker. In order to reduce the need for visual detection of estrus, hormonal protocols are increasingly used, which enable the synchronization of a large number of animals and timed artificial insemination. Most commonly used hormonal protocol that uses GnRH and PGF2α is called Ovsynch. In this protocol, GnRH is applied at any stage of the cycle, followed by PGF2α application seven days after, and another GnRH application two days after the application of second GnRH. Timed artificial insemination is preformed 8-24 hours after the second GnRH application. The disadvantage of this protocol is that animals respond differently to hormonal treatment. Thus, for example, the Ovsynch protocol shows poorer results in heifers and in cows with cycles with three follicular waves. Various modifications of the original Ovsynch protocol are attempted to resolve this problem. For example, the Double Ovsynch protocol was developed, which shows better results in heifers. Another modification is supplementation of Ovsynch protocol with progesterone, which is more commonly used in anestric cows or cows with cystic ovaries. In order to increase the synchronization rate within the herd, presynchronization protocols are used, which, due to their longer duration, synchronize the heard more homogeneously. Resynchronization protocols are used in cows that have not become pregnant after previous insemination. Such protocols allow rapid reinsemination of non-pregnant cows. Furthermore, these hormons are effective in treatment of some fertility-related problems in dairy cows

Application of GnRH and PGF for Estrus Induction and Synchronization of Ovulation in Dairy Cows

Uzgajivači mliječnih goveda u svojim krdima redovito koriste postupak umjetnog osjemenjivanja. U današnje se vrijeme tradicionalna metoda detekcije estrusa promatranjem pokazala vremenski vrlo neučinkovitom zato što se javlja tendencija za povećanjem broja životinja u stadu, kod krava se sve češće javlja tiho gonjenje ili znakovi estrusa budu slabo izraženi. Kako bi se smanjila potreba za vizualnom detekcijom estrusa sve se češće koriste hormonalni protokoli koji omogućavaju sinkronizaciju velikog broja životinja i vremenski tempirano umjetno osjemenjivanje. Najčešći korišteni hormonalni protokol koji koristi GnRH i PGF2α naziva se Ovsynch. U tom se protokolu u bilo kojoj fazi ciklusa aplicira GnRH, sedam dana nakon toga slijedi aplikacija PGF2α, dva dana kasnije druga aplikacija GnRH te vremenski tempirano umjetno osjemenjivanje uslijedi 8-24 sata nakon posljednje aplikacije GnRH. Nedostatak ovog protokola je taj što životinje različito mogu odgovoriti na hormonalni tretman. Tako na primjer Ovsynch protokol pokazuje lošije rezultate kod junica i kod krava s tri folikularna vala. Ovom se problemu pokušava doskočiti različitim modifikacijama originalnog Ovsynch protokola. Tako je na primjer razvijen Double Ovsynch protokol koji pokazuje bolje rezultate kod junica ili Ovsynch protokol uz suplementaciju progesterona koji se češće koristi kod anestričnih krava ili krava s cističnim jajnicima. Kako bi se povećala stopa sinkronizacije unutar stada koriste se presinkronizacijski protokoli koji zbog duljeg trajanja homogenije sinkroniziraju stado. Resinkronizacijski protokoli koriste se kod krava koje nisu postale gravidne nakon prethodnog osjemenjivanja. Takvi protokoli omogućavaju brzo ponovno osjemenjivanje negravidnih krava. Nadalje, primjena navedenih hormona uspješno se koristi i u liječenju određenih stanja neplodnosti u mliječnih krava.Dairy cattle breeders regularly use the process of artificial insemination in their herds. Nowadays, the process of visual heat detection has proven to be very time consuming because there is tendency to increase the number of animals in herds. Furthermore, silent estrus is more often observed and sings of estrus are becoming weaker. In order to reduce the need for visual detection of estrus, hormonal protocols are increasingly used, which enable the synchronization of a large number of animals and timed artificial insemination. Most commonly used hormonal protocol that uses GnRH and PGF2α is called Ovsynch. In this protocol, GnRH is applied at any stage of the cycle, followed by PGF2α application seven days after, and another GnRH application two days after the application of second GnRH. Timed artificial insemination is preformed 8-24 hours after the second GnRH application. The disadvantage of this protocol is that animals respond differently to hormonal treatment. Thus, for example, the Ovsynch protocol shows poorer results in heifers and in cows with cycles with three follicular waves. Various modifications of the original Ovsynch protocol are attempted to resolve this problem. For example, the Double Ovsynch protocol was developed, which shows better results in heifers. Another modification is supplementation of Ovsynch protocol with progesterone, which is more commonly used in anestric cows or cows with cystic ovaries. In order to increase the synchronization rate within the herd, presynchronization protocols are used, which, due to their longer duration, synchronize the heard more homogeneously. Resynchronization protocols are used in cows that have not become pregnant after previous insemination. Such protocols allow rapid reinsemination of non-pregnant cows. Furthermore, these hormons are effective in treatment of some fertility-related problems in dairy cows

Facial neuromuscular junctions and brainstem nuclei are the target of tetanus neurotoxin in cephalic tetanus

Cephalic tetanus (CT) is a severe form of tetanus that follows head wounds and the intoxication of cranial nerves by tetanus neurotoxin (TeNT). Hallmarks of CT are cerebral palsy, which anticipates the typical spastic paralysis of tetanus, and rapid evolution of cardiorespiratory deficit even without generalized tetanus. How TeNT causes this unexpected flaccid paralysis, and how the canonical spasticity then rapidly evolves into cardiorespiratory defects remain unresolved aspects of CT pathophysiology. Using electrophysiology and immunohistochemistry, we demonstrate that TeNT cleaves its substrate VAMP within facial neuromuscular junctions and causes a botulism-like paralysis overshadowing its canonical spasticity. Meanwhile, TeNT spreads among brainstem neuronal nuclei and, as shown by an assay to monitor the ventilation ability of CT mice, it harms essential functions like respiration. A partial axotomy of the facial nerve revealed a still-unknown ability of TeNT to undergo intra-brainstem diffusion, which allows the toxin to spread onto brainstem nuclei devoid of direct peripheral efferents. Other showing a mechanism possibly involved in the transition from local to generalized tetanus, these findings suggest that patients with idiopathic facial nerve palsy should be immediately considered for CT and treated with antisera to block the potential progression of a life-threatening form of tetanus