Egyes metabolikus és hormonális jellemzők alakulása ellés után és hatása az első ovuláció időpontjára valamint az asszisztált reprodukciós technológiák eredményességére anyajuhokban = The changes of certain metabolic and endocrine characteristics postpartum and its effect to the day of first ovulation and the efficiency of assisted reproductive technologies in ewes

A vizsgálatok keretében a szezonnak, fotóperiódusnak és a metabolikus állapotnak az ellés után jelentkező első ivarzás/ovuláció idejére gyakorolt hatását vizsgáltuk intenzíven tejelő, nem szoptató Awassi juhokban. Az eredmények azt jelzik, hogy körülményeink között (kontinentális zóna) az Awassi juhok petefészkének aktivitása szezonálissá válik és az ellés utáni első ivarzás/ovuláció az ősszel ellett, nem szoptató anyákban nagyon korán megtörténhet, még azelőtt, hogy a méh teljes involuciója befejeződhetne. A plazma metabolitok és metabolikus hormonok szintje a vizsgált időszakban mindvégig a fiziológiás tartományban maradt; az intenzív tejtermelés sem borította fel a metabolikus egyensúlyt. A fénykiegészítés késleltetheti az ellés után jelentkező első ivarzás/ovuláció jelentkezésének idejét. A tenyész szezonon kívül alkalmazott melatonin kezelésnek a spermiumokra, a here endokrin funkciójára és az IGF-I szintre kifejtett hatását is vizsgáltuk Awassi tenyész kosokban. A vizsgálatok eredményei azt jelzik, hogy a melatonin javíthatja a here tesztoszteron termelését, de nincs hatással a spermiumtermelésre és az IGF-I szintre. | The influence of the season, photoperiod and metabolic status on the time of the first postpartum ovulation in lactating, non-suckled dairy Awassi ewes was studied. Trials were conducted in a commercial Awassi flock, where lambs are weaned immediately after birth. It was found that ovarian function of Awassi population became seasonal under temperate continental weather and the first postpartum ovulation of non-suckling, autumn-lambing dams may happen very early, even before the completion of uterine involution. Plasma metabolites and metabolic hormones were in physiological range in the periparturian period; the metabolic balance was not turned by the intensive milk production. Additional lightening may retard the time of first postpartum ovulation. The effect of melatonin treatment applied out of the breeding season on semen characteristics, endocrine function of testicles and baseline level of IGF-I in Awassi rams were also studied. It was found that melatonin treatment may improve testicular testosterone production but does not influence semen parameters and IGF-I level

Postpartalni nastavak ciklične funkcije jajnika, prvi estrus i ponovno oplođenje i njihov odnos prema metabolizmu energije kod visoko-mlečnih krava

In the last few decades a continuous increase was observed in average milk production of dairy cows all over the world. Simultaneously, however, a dramatic decrease was seen in reproductive performance. This tendency is attributed to the increased incidence of bacterial complications in uterine involution, as well as to the high occurrence of ovarian malfunctions in the postpartum period. The aim of this paper is to review the physiology and pathology of the latter, really complex phenomenon. The nutritional basis of this process, that the requirements of high-producing dairy cows shift abruptly after parturition as the daily milk yield rapidly increases and the ensuing negative energy balance (NEB) will extend 10-12 weeks. In the context of the high genetic merit dairy cow, the pp NEB is the difference between the dietary intake of utilizable energy and the expenditure of energy for body mass maintenance and milk synthesis. In principle, it is a physiological phenomenon, which may, however, result in more or less severe disorders in both the metabolism and reproduction and so it may lead to great economic losses in modern dairy practice [112]. In the first 3-4 weeks after calving the NEB is highly correlated with both milk yield and the interval to first ovulation. Because the number of ovulatory estrous cycles preceding the insemination (AI) has been shown to influence the conception rate, the length of the pp interval to first ovulation provides an important parameter for assessing the effect of NEB on reproductive performance [19, 20].U proteklih nekoliko decenija uočeno je stalno povećanje prosečne proizvodnje mleka kod mlečnih krava širom sveta. U isto vreme, međutim, zapaženo je dramatično smanjenje reproduktivnih rezultata. Ova tendencija je pripisana povećanom pojavljivanju bakterijskih komplikacija tokom involucije uterusa, kao i velikom broju disfunkcija jajnika u postpartalnom periodu. Cilj ovoga rada je da se razmotri fiziologija i patologija ove druge pojave, tog zaista kompleksnog fenomena. Nutriciona osnova ovog procesa je da se potrebe visoko mlečnih krava naglo promene posle partusa kada se dnevni prinos mleka naglo povećava, a posledični negativni energetski bilans se produžava na 10 do 12 sedmica. U kontekstu visoke genetske vrednosti mlečnih krava, postpartalni negativni energetski bilans je razlika između dijetetskog unosa iskoristive energije i potrošnje energije za održavanje telesne mase i sinteze mleka. U principu, to je fiziološki fenomen koji, međutim, može da rezultira u manje ili više teškim poremećajima kako u metabolizmu, tako i u reprodukciji, i tako može da dovede i do velikih finansijskih gubitaka u savremenoj proizvodnji mleka [112]. U prvih tri do četiri sedmice posle teljenja, negativni energetski bilans je u visokoj korelaciji i sa prinosom mleka i intervalom do prve ovulacije. Zbog toga što je ukazano da broj ovulatornih estrusnih ciklusa, koji prethode inseminaciji, utiče na stepen koncepcije, dužina postpartalnog intervala do prve ovulacije obezbeđuje važan parametar za procenu efekta negativnog energetskog bilansa na reproduktivne rezultate [19, 20]

A növekedési hormon genotípus (AluI polimorfizmus) hatása egyes metabolikus és hormonális jellemzők ellés utáni alakulására, valamint az első ovuláció időpontjára holstein fríz tehenekben = The influence of STH genotype (AluI polymorphism) on certain metabolic and endocrine characteristics, and the day of first ovulation in postpartum Holstein Friesin cows

Az STH genotípusnak (AluI-polimorfizmus) az ellés után fellépő energiahiányos állapot dekompenzálódásával (ketózis) és a szaporodási mutatók alakulásával mutatott összefüggéseit vizsgálták tejhasznosítású (holstein fríz) tehenekben, illetve üszőkben. Megállapításaik: (1) Az egyes genotípusok eloszlása: LL kb. 80-85 %, LV kb. 10-15 %, VV legfeljebb 2-3 %. (2) Nem volt kimutatható jelentősebb közvetlen befolyása az ellés előtti napokban biztosított különböző energiaszintű takarmányozásra adott metabolikus és endokrin válaszra, a hasnyál-mirigy inzulin termelésére, a plazma NEFA, BHB, inzulin és IGF-I ellés utáni plazma-koncentrációjára, továbbá a tejtermelés nagyságára. (3) Nagyszámú állaton vizsgálva kimutatható az STH polimorfizmus összefüggése az elléstől az első ovulációig eltelő időtartam hosszával, és/vagy az ellés utáni első 30 napon bekövetkező kondíciópont-csökkenés mértékével. (4) Munkánk során ? a V hordozók alacsony számaránya miatt ? szándékaink ellenére nem sikerült ugyan megnyugtató számú adat birtokába jutnunk, valószínű azonban, hogy az STH genotípusnak nincs közvetlen hatás a luteinizációnak a posztovulációs P4-szintemelkedés ütemében megnyilvánuló intenzitására sem. Az STH polimorfizmus és az állat metbolikus, továbbá szaporodási jellemzőinek tisztázásához azonban még további vizsgálatok szükségesek. | The interrelations of STH (Alu-I) genotype with decompensation of postpartum negative energy balance (hyperketonaemia, ketolactia kenonuria) as well as with reproduction were studied in dairy cows (Exp. 1-4) and heifers (Exp. 5). The main observations: (1) The incidence of various genotypes in the studied herds: LL: about 80-85 %, LV: about 10-15 %, VV: max. 2-3 %. (2) The STH genotype did not have direct influence on the endocrine and metabolic response on different levels of energy supply in the pre-calving period, the pancreatic insulin production, the plasma levels of NEFA, BHB, insulin and IGF-I in the postpartum period, furthermore on the milk production. (3) Hen it was studied in large number of animals, there were interrelations between the STH genotype, the degree of body condition loss and the duration of postpartum acyclicity / time of the first postpartum ovulation. (4) Although in this trial ? due to the low rate of valin carriers (LV+VV genotypes) ? we could not get clear improvement, but it is almost sure that the STH genotype do not have any direct effects on the luteinisation, represented by the post-ovulatory rise of plasma progesterone levels. However, also further studies are required for the clarification of physiological details in interrelationships of STH genotypes, metabolism and reproduction

Szabályozási mechanizmusok az állatorvosi alapkutatásban: a molekulától a szervrendszerekig = Regulatory mechanism in basic veterinary science: from molecules to organ systems

Az energia-metabolizmus szabályozásának hormonális és neuromorfológiai vizsgálatai szerint szarvasmarhában a lokálisan termelt leptin a tőgy és a járulékos nemi mirigyek működését szabályozza. Negatív energia-egyensúlyban a szénhidrátok hatására nő a T3 szint, növelve a helyi leptin termelést. Bizonyítottuk, hogy a csökkenő energiaszinten takarmányozott baromfiban kialakuló alacsony T3 szint nemcsak a megnövekedett májbeli hormon inaktiválás, hanem a hormon aktiválás csökkenésének is a következménye. Orexigén és anorexigén neuropeptidek rostrocaudalis megoszlását és denzitásbeli változásait vizsgálva patkányok lateralis septumában (LS) megállapítottuk, hogy a LS peptiderg rendszerei egyaránt érzékenyen reagálnak az éhezés, és egyes gonadális hormonok hatására is. Az endothelsejtek egyes strukturális és IgG homeosztázisban résztvevő génjének expressziós elemzése alapján megállapítottuk, hogy a bFcRn nehézlánc promotere több NFkB transzkripciós kötőhelyet is tartalmaz, ill. a LPS kezelés hatására mind in vitro, mind in vivo emelkedik e gén expresszió mértéke. A dystroglycan expresszió hatását vizsgálva az endothel sejtekre megállapítottuk, hogy a DAPC a vizsgált sejttípusokban befolyásolja a sejt és az extracelluláris mátrix kölcsönhatását. Normal és negativ energiaegyensúlyban lévő kérődzőkben végzett molekuláris szintű vizsgálatok arra utalnak, hogy ketózis esetén az endometrium sejtjei kisebb arányban pusztulnak el apoptosissal, ami fokozza a necrosis veszélyét. | According to the hormonal and neuromorphologic aspects of the regulation of energy metabolism the locally produced leptin affects bovine milk production and has local regulatory effect on the male accessory glands. Carbohydrates increase the T3 level, which increases local leptin production in cows with negative energy balance. In pultry the decreased circulatory T3 in restricted feed intake, is not only the consequence of an increased hepatic hormone inactivation, but also of a decreased D2 activity. Examining the rostrocaudal distribution and density changes of orexigenic and anorexigenic neuropeptides in the lateral septum (LS) of rats, we found that the peptiderg systems of the LS react with marked neurochemical changes not only to food deprivation, but also to the effect of certain gonadal hormones. Studies on the gene expression of certain structure genes and genes influencing IgG homeostasis revealed, that bFcRn has several NFkB transcriptional binding sites in its promoter and is upregulated after LPS treatment both in vitro and in vivo. Investigating the role of the expression of dystroglycan in the adhesive properties of endothel cells, we confirmed the role of DAPC in the interaction of the cell types we used with the extracellular matrix. Molecular level investigations of ruminants in normal and in negative energy balance, led showed that in case of ketosis the cells of endometrium will die in smaller proportion by apoptosis which increases the risk of necrosis

Subsequent effect of subacute T-2 toxicosis on spermatozoa, seminal plasma and testosterone production in rabbits

Pannon White (n512) male rabbits (weight: 4050 to 4500 g, age: 9 months) received 2ml of a suspension containing purified T-2 toxin by gavage for 3 days. The daily toxin intake was 4 mg/animal (0.78 to 0.99 mg/kg body weight (BW)). Control animals (n512) received toxin-free suspension for 3 days. Since a feed-refusal effect was observed on the second day after T-2 administration, a group of bucks (n510) were kept as controls (no toxin treatment) but on a restricted feeding schedule, that is, the same amount of feed was provided to them as was consumed by the exposed animals. On day 51 of the experiment (i.e. 48 days after the 3-day toxin treatment), semen was collected, and pH, concentration, motility and morphology of the spermatozoa, as well as concentration of citric acid, zinc and fructose in the seminal plasma, were measured. After gonadotropinreleasing hormone (GnRH) analogue treatment, the testosterone level was examined. One day of T-2 toxin treatment dramatically decreased voluntary feed intake (by 27% compared to control, P,0.05) and remained lower ( P,0.05) during the first 2 weeks after the withdrawal of the toxin. BW of the contaminated rabbits decreased by 88% on days 17 and 29 compared to controls ( P,0.05). No effect of toxin treatment was detected on pH and quantity of the semen or concentration of spermatozoa. The ratio of spermatozoa showing progressive forward motility decreased from 65% to 53% in the semen samples of toxin-treated animals compared to controls ( P.0.05). The ratio of spermatozoa with abnormal morphology increased ( P,0.05) in the ejaculates collected from the toxin-treated animals. T-2 toxin applied in high doses decreased the concentration of citric acid in seminal plasma ( P,0.05). No effect of T-2 toxin on the concentrations of the other seminal plasma parameters (fructose and zinc) was observed. T-2 toxin decreased the basic testosterone level by 45% compared to control ( P,0.01) and resulted in lower ( P,0.05) GnRH-induced testosterone concentration. Feed restriction, that is, less nutrient intake, resulted in more morphologically abnormal spermatozoa in the semen, but it did not cause significant loss in BW, motility of the spermatozoa, composition of the seminal plasma or testosterone concentration – its effect needs further examination

Role of adrenocortical system in occurrence of ketosis in high-yield dairy cows

From the very onset of lactation, the requirements of the mammary gland have an advantage over the requirements of other organic systems, even in the case of clinically exhibited ketosis. In hypoglycemic, ketotic cows, the mammary gland utilizes glucosis approximately in the same degree as the mammary gland of cows with normal glycemia. This indicates that the regulatory role of hormones can have primary importance in the earliest phase of lactation, when metabolic processes are on the very brink of a ketotic state. That is why it is believed that, in conditions of a great burdening of the metabolism, inadequate activity by the adrenocortical system presents one of the primary factors in the etiopathogenesis of ketosis in dairy cows. It is still an open issue whether hypof unction of the adrenal cortex is a direct cause of this disorder, or whether its activity is a consequence of insufficient stimulation by ACTH. In ketotic cows, average concentrations of cortisol have been established in ketotic cows, from 23.98 nmol/l in blood serum, and it is approximately the same as in healthy cows in the corresponding phase of lactation. However, the vast range of individual values largely makes it difficult to make a correct evaluation of the functional state of the adrenal cortex of ketotic cows. On the grounds of individual figures, in 26% diseased cows cortisol concentration in blood serum is from 1.38 to 16.55 nmol/l, in 37% it is from 16.55 to 27.59 nmol/l, and in 37 percent it is over 27.59 nmol/l. This indicates that cows with clinical symptoms of ketosis can be divided into those with low, medium, or high values of cortisol concentration in blood serum. Following the stimulation of the adrenal cortex with ACTH, the individual differences in serum cortisol concentration are considerably decreased. The ratio between the lowest and the highest values of cortisol concentration before the application of ACTH is 1:6, while it is only 1:1.5 four hours following application. After that, the values again take on the starting characteristics, and 24 hours after the application of ACTH they return to the starting values, and the ratio between the individual values is 1:8. It seems that the function of the adrenal cortex has been preserved in cows with clinical symptoms of ketosis and it is capable of reacting fully to stimulation with corticotropin. The cortisolemia values indicate, primarily, that there are big individual differences regarding the regulation of the degree of activity of the adrenal cortex, so that it is possible that, in the ketotic state, it is rather a case of uncoordinated activities of the adrenal cortex with the organism requirements imposed by the mammary gland, than that it is a matter of its hypofunction. .Od samog početka laktacije potrebe mlečne žlezde imaju prednost u odnosu na potrebe drugih organskih sistema, čak i u slučaju klinički ispoljene ketoze. Kod hipoglikemičnih, ketoznih krava, mlečna žlezda koristi glikozu u približno istom obimu kao i mlečna žlezda krava sa normalnom glikemijom. To ukazuje da u najranijoj fazi laktacije, kada su metabolički procesi na samoj granici ketoznog stanja, regulatorna uloga hormona može da ima prvostepeni značaj. Zbog toga se smatra da u uslovima velikog opterećenja metabolizma neadekvatna aktivnost adrenokortikalnog sistema predstavlja jedan od primarnih činilaca u etiopatogenezi ketoze mlečnih krava. Još uvek je otvoreno pitanje da li je hipofunkcija kore nadbubrega neposredan uzrok ovog poremećaja ili je njena aktivnost posledica nedovoljne stimulacije ACTH. Kod ketoznih krava je utvrđeno da je prosečna koncentracija kortizola od 23,98 nmol/l u krvnom serumu i približno je ista kao i kod zdravih krava u istoj fazi laktacije. Međutim, veliki raspon pojedinačnih vrednosti, u velikoj meri otežava pravilnu procenu funkcionalnog stanja kore nadbubrega kod ketoznih krava. Na osnovu pojedinačnih podataka kod 26 posto obolelih krava koncentracija kortizola u krvnom serumu je od 1,38 do 16,55 nmol/l, kod 37posto od 16,55 do 27,59 nmol/l, a kod 37 posto više od 27,59 nmol/l. To ukazuje da se krave sa kliničkim simptomima ketoze mogu da svrstaju na one sa niskim, srednjim i visokim vrednostima koncentracije kortizola u krvnom serumu. Nakon stimulisanja kore nadbubrega sa ACTH znatno se smanjuju pojedinačne razlike u koncentraciji serumskog kortizola. Odnos između najniže i najviše vrednosti koncentracije kortizola pre aplikovanja ACTH je 1:6, a četiri časa posle aplikacije je samo 1:1,5. Zatim, vrednosti ponovo poprimaju početna obeležja i nakon 24 časa od primene ACTH vraćaju se na početne vrednosti, a raspon pojedinačnih vrednosti je 1:8. Po svemu sudeći očuvana je funkcija kore nadbubrega kod krava sa kliničkim simptomima ketoze i u stanju je da u potpunosti reaguje na stimulaciju kortikotropinom. Vrednosti kortizolemije ukazuju, pre svega, da postoje velike pojedinačne razlike u pogledu regulacije stepena aktivnosti kore nadbubrega, tako daje moguće da se u ketoznom stanju više radi o neusklađenoj aktivnosti kore nadbubrega prema potrebama organizma koje nameće mlečna žlezda, nego što se radi o njenoj hipofunkciji.

Uloga adrenokortikalnog sistema u nastanku ketoze visoko-mlečnih krava

From the very onset of lactation, the requirements of the mammary gland have an advantage over the requirements of other organic systems, even in the case of clinically exhibited ketosis. In hypoglycemic, ketotic cows, the mammary gland utilizes glucosis approximately in the same degree as the mammary gland of cows with normal glycemia. This indicates that the regulatory role of hormones can have primary importance in the earliest phase of lactation, when metabolic processes are on the very brink of a ketotic state. That is why it is believed that, in conditions of a great burdening of the metabolism, inadequate activity by the adrenocortical system presents one of the primary factors in the etiopathogenesis of ketosis in dairy cows. It is still an open issue whether hypof unction of the adrenal cortex is a direct cause of this disorder, or whether its activity is a consequence of insufficient stimulation by ACTH. In ketotic cows, average concentrations of cortisol have been established in ketotic cows, from 23.98 nmol/l in blood serum, and it is approximately the same as in healthy cows in the corresponding phase of lactation. However, the vast range of individual values largely makes it difficult to make a correct evaluation of the functional state of the adrenal cortex of ketotic cows. On the grounds of individual figures, in 26% diseased cows cortisol concentration in blood serum is from 1.38 to 16.55 nmol/l, in 37% it is from 16.55 to 27.59 nmol/l, and in 37 percent it is over 27.59 nmol/l. This indicates that cows with clinical symptoms of ketosis can be divided into those with low, medium, or high values of cortisol concentration in blood serum. Following the stimulation of the adrenal cortex with ACTH, the individual differences in serum cortisol concentration are considerably decreased. The ratio between the lowest and the highest values of cortisol concentration before the application of ACTH is 1:6, while it is only 1:1.5 four hours following application. After that, the values again take on the starting characteristics, and 24 hours after the application of ACTH they return to the starting values, and the ratio between the individual values is 1:8. It seems that the function of the adrenal cortex has been preserved in cows with clinical symptoms of ketosis and it is capable of reacting fully to stimulation with corticotropin. The cortisolemia values indicate, primarily, that there are big individual differences regarding the regulation of the degree of activity of the adrenal cortex, so that it is possible that, in the ketotic state, it is rather a case of uncoordinated activities of the adrenal cortex with the organism requirements imposed by the mammary gland, than that it is a matter of its hypofunction. .Od samog početka laktacije potrebe mlečne žlezde imaju prednost u odnosu na potrebe drugih organskih sistema, čak i u slučaju klinički ispoljene ketoze. Kod hipoglikemičnih, ketoznih krava, mlečna žlezda koristi glikozu u približno istom obimu kao i mlečna žlezda krava sa normalnom glikemijom. To ukazuje da u najranijoj fazi laktacije, kada su metabolički procesi na samoj granici ketoznog stanja, regulatorna uloga hormona može da ima prvostepeni značaj. Zbog toga se smatra da u uslovima velikog opterećenja metabolizma neadekvatna aktivnost adrenokortikalnog sistema predstavlja jedan od primarnih činilaca u etiopatogenezi ketoze mlečnih krava. Još uvek je otvoreno pitanje da li je hipofunkcija kore nadbubrega neposredan uzrok ovog poremećaja ili je njena aktivnost posledica nedovoljne stimulacije ACTH. Kod ketoznih krava je utvrđeno da je prosečna koncentracija kortizola od 23,98 nmol/l u krvnom serumu i približno je ista kao i kod zdravih krava u istoj fazi laktacije. Međutim, veliki raspon pojedinačnih vrednosti, u velikoj meri otežava pravilnu procenu funkcionalnog stanja kore nadbubrega kod ketoznih krava. Na osnovu pojedinačnih podataka kod 26 posto obolelih krava koncentracija kortizola u krvnom serumu je od 1,38 do 16,55 nmol/l, kod 37posto od 16,55 do 27,59 nmol/l, a kod 37 posto više od 27,59 nmol/l. To ukazuje da se krave sa kliničkim simptomima ketoze mogu da svrstaju na one sa niskim, srednjim i visokim vrednostima koncentracije kortizola u krvnom serumu. Nakon stimulisanja kore nadbubrega sa ACTH znatno se smanjuju pojedinačne razlike u koncentraciji serumskog kortizola. Odnos između najniže i najviše vrednosti koncentracije kortizola pre aplikovanja ACTH je 1:6, a četiri časa posle aplikacije je samo 1:1,5. Zatim, vrednosti ponovo poprimaju početna obeležja i nakon 24 časa od primene ACTH vraćaju se na početne vrednosti, a raspon pojedinačnih vrednosti je 1:8. Po svemu sudeći očuvana je funkcija kore nadbubrega kod krava sa kliničkim simptomima ketoze i u stanju je da u potpunosti reaguje na stimulaciju kortikotropinom. Vrednosti kortizolemije ukazuju, pre svega, da postoje velike pojedinačne razlike u pogledu regulacije stepena aktivnosti kore nadbubrega, tako daje moguće da se u ketoznom stanju više radi o neusklađenoj aktivnosti kore nadbubrega prema potrebama organizma koje nameće mlečna žlezda, nego što se radi o njenoj hipofunkciji.