52 research outputs found
Az "ĂłvodásĂtási" rendszer stresszhatásának vizsgálata a fiaztatĂłban Ă©s az utĂłnevelĹ‘ben a bĂ©lsár kortizolszint meghatározásával
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 keretĂ©ben a szezonnak, fotĂłperiĂłdusnak Ă©s a metabolikus állapotnak az ellĂ©s után jelentkezĹ‘ elsĹ‘ ivarzás/ovuláciĂł idejĂ©re gyakorolt hatását vizsgáltuk intenzĂven tejelĹ‘, nem szoptatĂł Awassi juhokban. Az eredmĂ©nyek azt jelzik, hogy körĂĽlmĂ©nyeink között (kontinentális zĂłna) az Awassi juhok petefĂ©szkĂ©nek aktivitása szezonálissá válik Ă©s az ellĂ©s utáni elsĹ‘ ivarzás/ovuláciĂł az Ĺ‘sszel ellett, nem szoptatĂł anyákban nagyon korán megtörtĂ©nhet, mĂ©g azelĹ‘tt, hogy a mĂ©h teljes involuciĂłja befejezĹ‘dhetne. A plazma metabolitok Ă©s metabolikus hormonok szintje a vizsgált idĹ‘szakban mindvĂ©gig a fiziolĂłgiás tartományban maradt; az intenzĂv tejtermelĂ©s sem borĂtotta fel a metabolikus egyensĂşlyt. A fĂ©nykiegĂ©szĂtĂ©s kĂ©sleltetheti az ellĂ©s után jelentkezĹ‘ elsĹ‘ ivarzás/ovuláciĂł jelentkezĂ©sĂ©nek idejĂ©t. A tenyĂ©sz szezonon kĂvĂĽl alkalmazott melatonin kezelĂ©snek a spermiumokra, a here endokrin funkciĂłjára Ă©s az IGF-I szintre kifejtett hatását is vizsgáltuk Awassi tenyĂ©sz kosokban. A vizsgálatok eredmĂ©nyei azt jelzik, hogy a melatonin javĂthatja a here tesztoszteron termelĂ©sĂ©t, de nincs hatással a spermiumtermelĂ©sre Ă©s 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
Effect of feeding different oils on plasma corticosterone in broiler chickens
A study was conducted to examine the effects of different oils on the plasma corticosterone concentrations of broiler chickens fed ad libitum or deprived of feed for 24 hours. A total of 36 Ross broilers were randomly assigned to one of three dietary treatments at 10 days of age and fed a grower diet supplemented with 60 g/kg soybean oil (rich in linoleic acid, C18:2n–6), linseed oil (rich in a-linolenic acid, C18:3n–3) or fish oil (rich in C14:0, C16:0, C16:1n–7, C20:1n–9; eicosapentaenoic acid and docosahexaenoic acid, EPA, C20:5n–3 and DHA, C22:6n–3), respectively, for 18 days. Dietary supplementation of fish oil resulted in lower (P < 0.05) baseline plasma corticosterone levels of chickens fed ad libitum for 18 days compared to soybean and linseed oil supplementations. Feed deprivation for 24 h induced a significant (P < 0.05) increase in corticosterone concentration in every treatment group compared to the ad libitum-fed birds. The hormone levels of feed-deprived birds did not differ significantly among groups fed diets supplemented with different oils
A növekedĂ©si hormon genotĂpus (AluI polimorfizmus) hatása egyes metabolikus Ă©s hormonális jellemzĹ‘k ellĂ©s utáni alakulására, valamint az elsĹ‘ ovuláciĂł idĹ‘pontjára holstein frĂz 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 genotĂpusnak (AluI-polimorfizmus) az ellĂ©s után fellĂ©pĹ‘ energiahiányos állapot dekompenzálĂłdásával (ketĂłzis) Ă©s a szaporodási mutatĂłk alakulásával mutatott összefĂĽggĂ©seit vizsgálták tejhasznosĂtásĂş (holstein frĂz) tehenekben, illetve ĂĽszĹ‘kben. MegállapĂtásaik: (1) Az egyes genotĂpusok eloszlása: LL kb. 80-85 %, LV kb. 10-15 %, VV legfeljebb 2-3 %. (2) Nem volt kimutathatĂł jelentĹ‘sebb közvetlen befolyása az ellĂ©s elĹ‘tti napokban biztosĂtott kĂĽlönbözĹ‘ energiaszintű takarmányozásra adott metabolikus Ă©s endokrin válaszra, a hasnyál-mirigy inzulin termelĂ©sĂ©re, a plazma NEFA, BHB, inzulin Ă©s IGF-I ellĂ©s utáni plazma-koncentráciĂłjára, továbbá a tejtermelĂ©s nagyságára. (3) NagyszámĂş állaton vizsgálva kimutathatĂł az STH polimorfizmus összefĂĽggĂ©se az ellĂ©stĹ‘l az elsĹ‘ ovuláciĂłig eltelĹ‘ idĹ‘tartam hosszával, Ă©s/vagy az ellĂ©s utáni elsĹ‘ 30 napon bekövetkezĹ‘ kondĂciĂłpont-csökkenĂ©s mĂ©rtĂ©kĂ©vel. (4) Munkánk során ? a V hordozĂłk alacsony számaránya miatt ? szándĂ©kaink ellenĂ©re nem sikerĂĽlt ugyan megnyugtatĂł számĂş adat birtokába jutnunk, valĂłszĂnű azonban, hogy az STH genotĂpusnak nincs közvetlen hatás a luteinizáciĂłnak a posztovuláciĂłs P4-szintemelkedĂ©s ĂĽtemĂ©ben megnyilvánulĂł intenzitására sem. Az STH polimorfizmus Ă©s az állat metbolikus, továbbá szaporodási jellemzĹ‘inek tisztázásához azonban mĂ©g további vizsgálatok szĂĽksĂ©gesek. | 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
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
Bacteriological recovery after intramuscular or intracisternal spiramycin-based drying-off therapy
Systemic (intramuscular, IM) vs. local (intracisternal, IC) routes of spiramycin-based drying-off therapy were compared for efficacy on 65 Staphylococcus aureus infected udder quarters of 38 dairy cows. Single-dose (30,000 IU/kg) IM treatment (single IM group) resulted in a similarly low bacteriological recovery rate (14%) as seen in the untreated controls (18%). IM treatment (30,000 IU/kg) on 4 consecutive days (4 IM group) resulted in significantly higher quarter-based recovery rates than that in the single IM group. The bacteriological recovery rates obtained in the intracisternal and 4 IM groups were quite similar but remained below 50%. Based on these findings as well as on the high cost of the repeated intramuscular treatment regime there is no reason to give extra preference to the systemic application of spiramycin at drying off in the practice
Effect of low-dose zearalenone exposure on luteal function, follicular activity and uterine oedema in cycling mares
The effect of 10-day zearalenone administration starting 10 days after ovulation was studied in 6 cycling trotter mares in the summer period. After an entire oestrous cycle (Cycle 1), mares were given 7 mg purified zearalenone per os daily (1 mg/ml in ethyl alcohol) beginning on Day 10 of Cycle 2. Toxin exposure was continued until the subsequent ovulation. Luteal function and follicular activity were monitored daily by rectal palpation, ultrasonography and blood sampling for progesterone. During toxin exposure, all animals were in good physical condition. The toxin had no effect on the length of the interovulatory intervals, luteal and follicular phases. It did not influence significantly the plasma progesterone profiles (logistic curve parameters A1 to A6), the follicular activity (growth rate, maximum size of the ovulatory follicles, maximum number and the time of first increase in the number of large follicles) and the uterine oedema. It is concluded that in cyclic mares the methods used in this study could not detect any adverse effect of zearalenone (administered at a low dose similar to natural exposure) on reproduction
Heart rate, heart rate variability, faecal glucocorticoid metabolites and avoidance response of dairy cows before and after changeover to an automatic milking system
The heart rate variability (HRV) parameters of dairy cows were monitored during parlour (PARL) and the later installed automatic (AMS) milking on a small-scale commercial dairy farm in Hungary. The aim of the study was to assess stress in relation to the type of milking and the frequency of human interaction. Parlour milking involved regular moving and crowding of the animals with frequent human interaction, which were much less frequent in automatic milking. The first phase of the study was conducted prior to the changeover [n = 27] and the second two months afterwards [n = 19 (of the cows from the first phase)]. Heart rate (HR) was recorded by the Polar RS800 CX recording system. HRV parameters indicative of sympathovagal balance were calculated for periods of lying and standing in the barn, waiting before milking and milking, respectively. Morning and evening faecal glucocorticoid concentrations were also measured. Fear of humans was tested by an avoidance distance test. Baseline HRV parameters showed no difference (P > 0.05) between the two systems. In the periods before, during and after milking a higher sympathetic tone was detected in cows in the PARL phase. Mean faecal glucocorticoid concentrations were higher at the time of parlour milking. The avoidance distance did not differ between the two phases. The results suggest that automatic milking might be less stressful for cows than parlour milking, possibly due to the shorter duration of restraint after milking and the less frequent human interaction
Peripheral circulating insulin-like growth factor-I and -II in cattle
Interrelationships between circulating concentrations of the insulin-like growth factors (IGF-I and IGF-II) were investigated in 235 blood samples taken from 145 healthy beef or dairy calves, bulls and cows of different breeds and ages. Autoradiography of Western ligand blots indicated different IGF binding protein (IGFBP) profiles between sera from different categories of cattle. Each IGF radioimmunoassay was validated by determining the effects of IGFBPs, ligand and contraligand, as well as serial dilution and comparison with results obtained after molecular sieve chromatography in acid. In female cattle mean values for IGF-I varied from 5.1 nmol/l in postparturient Holstein cows to 18.5–20.5 nmol/l in growing beef heifers, while mean IGF-II concentrations ranged from 30.0 nmol/l in the cows to 14.7–15.7 nmol/l in the beef heifer calves. In male cattle mean serum IGF-I ranged widely from 8.2 nmol/l in 1-day-old Holstein calves to 67.4 nmol/l in 16-month-old Simmental-type bulls. Mean IGF-II concentrations decreased from 22.9 nmol/l in 1-day-old Holstein bull calves to 11.9 nmol/l in 12-month-old beef bulls. Thus, total molar IGF concentrations were fairly stable in female cattle (24.7–35.1 nmol/l) but extended from 27.3 nmol/l to 81.8 nmol/l in the male cattle. The tendency for a reciprocal relationship between serum concentrations of these growth factors was most obvious in the periparturient cows
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