Određivanje optimalne veličine folikula za dobivanje najkvalitetnijih oocita za in vitro oplodnju

The aim of this study was to determinate optimal follicular size for collection of high quality oocytes, and the subsequent capacity of the oocyte to mature and be fertilized and to develop in vitro. The ovaries of dairy cows were cut out immediately after slaughter and transported within one hour. The follicles were separated and divided into three groups according to diameter, i.e. small (3-5 mm), medium-size (6-9 mm), large (10-20 mm). Quality grading (A, B, C, D) of the oocytes was performed on the basis of cumulus cell development and homogeneity of cytoplasm. A total of 284 COCs were aspirated from 123 ovaries. Among 143 COCs, 236 were grades A and B and 48 were grades C and D. The maturation rate of the oocytes from medium size follicles A and B grade was 56.01% better than C and D grade. Only A and B graded oocytes were fertilized in vitro with 1×106 sperm/mL using Fert-TL, with 0.3% BSA, 22 μg/mL sodium pyruvate, 10 μg/mL heparin. The cleavage rate in the small follicle oocytes was significantly lower (35.89%) than in the medium-size follicle oocytes (56.41%), and a similar trend was observed in the morula development rates, independent of the oocyte grade. Good quality oocytes received from medium size follicles, and oocytes with more than three complete layers of cumulus cells (Grades A and B) have better competence for in vitro maturation and cleavage.Cilj ovoga istraživanja bio je odrediti optimalnu veličinu folikula kako bi se prikupile oocite visoke kvalitete s obzirom na visoki kapacitete za sazrijevanje, oplodnju i razvoj in vitro. Jajnici krava mliječne pasmine izrezani su odmah nakon klanja i prevezeni unutar sat vremena. Folikuli su izdvojeni i podijeljeni u tri skupine s obzirom na njihov promjer: u skupinu malih folikula (3 - 5 mm), skupinu folikula srednje veličine (6 - 9 mm) i skupinu velikih folikula (10 - 20 mm). Stupnjevanje kvalitete oocita (A, B, C, D) učinjeno je na temelju razvoja kumulusnih stanica i homogenosti citoplazme. Aspirirane su ukupno 284 kumulusne oocite iz 123 jajnika. Od ukupno 284 kumulusne oocite njih 236 bilo je A i B-stupnja, a 48 ih je bilo C i D-stupnja. Sazrijevanje oocita iz skupine folikula srednje veličine A i B-stupnja bilo je 56,01 % bolje od onih stupnja C i D. Samo su oocite A i B-stupnja oplođene in vitro s 1×106 sperme po mililitru uz upotrebu Fert-TL-a, s 0,3 % Bovine Serum Albumin-a, 22 μg/mL natrijeva piruvata i 10 μg/mL heparina. Brazdanje oocita dobivenih iz folikula male veličine bilo je znakovito niže (35,89 %) nego u skupini folikula srednje veličine (56,41 %), a slično je uočeno i u razvoju morula, neovisno o kvaliteti oocita. Zaključeno je da oocite dobre kvalitete dobivene u skupini folikula srednje veličine, oocite s više od tri cjelovita sloja kumulusnih stanica (stupnjevi A i B) imaju veće šanse za sazrijevanje in vitro i brazdanje

Superovulacijski odgovor prvog dana liječenja i njegova povezanost s veličinom i položajem jajnika kod visokoproizvodnih mliječnih krava.

The aim of this research was to determine the relation between the size of ovaries, their topographic position, ovarian structures (follicles (F) and corpora lutea (CL)) before superovulatory treatment and the superovulatory response and embryo yield. Holsteinized dairy cows (32) were treated for superovulation with Pluset® (Laboratorios Calier, S.A., Barselona, Spain). On Day 1 of the superovulatory treatment and during the procedure to recover the embryos, we examined the ovaries of donors with an ultrasound scanner. The ovaries were divided into 3 groups according to their size. Group 1 ovaries (1112.0 mm2) were 25 % larger than Group 2 ovaries, the area of which varied from 668.0 to 1112.0 mm2 (mean, 890.0 mm2 ± 25 %). After superovulation, the mean area of the right side ovaries (RSO) (3147.61 ± 106.6 mm2) was by 27.3 % (P0.05) compared with the LSO. The most intense response to the superovulatory treatment by ovary size was observed in Group 1 ovaries: the RSO increased by 5.5 times and the LSO by 4.8 times, but according to the absolute measure, the greatest increase was observed in Group 3, where ovaries on both sides increased 2.4 times. According to the number of CL, Group 1 RSO donors showed a 2.3 times (P1112,0 mm2) više od 25 % veći od jajnika skupine 2. Nakon postupka superovulacije, srednja veličina (3147,61 ± 106,6 mm2) desnih jajnika (DJ) bila je 27,3 % (P0,05) u usporedbi sa LJ. Najintenzivniji superovulacijski odgovor s obzirom na veličinu jajnika opažen je u skupini 1: kod DJ povećanje je bilo 5,5, a kod LJ 4,8 puta, ali s obzirom na apsolutne mjere, najveći porast opažen je u skupini 3 u kojoj su jajnici s obje strane povećani 2,4 puta. S obzirom na broj CL, skupina 1 DJ davateljica pokazala je 2,3 puta (P<0,05) slabiji superovulacijski odgovor u usporedbi sa skupinom 3 DJ davateljica. Broj dobivenih embrija (9,8 ± 2,2) bio je 3,6 puta (P<0,05) veći među davateljicama 3 DJ skupine prije superovulacije u usporedbi sa davateljicama skupine 1 DJ (2,7 ± 0.5). Kod krava skupine 3 DJ, broj prenosivih embrija (6,3 ± 0,6) bio je 3,2 puta (P<0,05) veći u usporedbi s kravama davateljicama skupine 1 DJ (2,0 ± 0,3). Žuta tijela u DJ su pokazala signifikantni utjecaj od 85 % (P<0,05) na dobivanje embrija u usporedbi sa samo 30 % (P<0,05) u LJ

Prevalencija kliničkog metritisa i pokazatelji plodnosti u krava liječenih slabijim laserskim zračenjem i antibioticima u postpartalnom razdoblju.

The aim of the study was to compare the efficiency of low-intensity laser (LIL) irradiation, antibiotic injections and a combination of both methods in the prophylaxis and treatment of metritis in cows. Examinations were carried out on 290 freshly calved cows with a rectal temperature on the second day after parturition above 38.9 C. Cows from group I (n = 95) were given an intramuscular injection of ceftiofur hydrochloride (600 mg) for three days, commenced from the second day after parturition. Group II consisted of 55 cows, the sacroiliac area of which was irradiated for 10 days consecutively with LIL. Group III (n = 65) were given an intramuscular 600mg injection of ceftiofur for three days and the sacroiliac area was irradiated 10 times consecutively, once a day with LIL. The control group IV (n = 55) were not given antibiotics or laser irradiation. A number of cows, ranging from 57.1% (group III a) to 65% (group IV), developed clinical metritis, which was treated with antiseptics. The longest recovery time from metritis (21 ± 6.12 d) was found in the IV group. Cows from group III recovered from metritis 11.5 days more quickly than the cows from the IV (negative control) group (P<0.05) and 4 days more quickly than cows from the I (positive control) group. Fertility indices such as: calving-first insemination, service period, conception rate, insemination index and the calving-pregnancy period, were better in cows treated prophylactically with the combined method (antibiotic and LIL physiotherapy) in comparison to the other groups.U radu se uspoređuje učinkovitost slabijeg laserskog zračenja, primjene antibiotika i kombinacije obiju metoda u profilaksi i liječenju metritisa u krava. Istraživanje je bilo provedeno na 290 netom oteljenih krava s rektalnom temperaturom višom od 38,9 °C drugog dana nakon teljenja. Kravama I. skupine (n = 95) intramuskularno je bio primijenjen ceftiofur hidroklorid (600 mg) tijekom tri dana, počevši drugog dana nakon teljenja. U II. skupini bilo je 55 krava koje su bile zračene laserskim zračenjem u sakroilijačnom području tijekom 10 uzastopnih dana. Kravama III. skupine (n = 65) intramuskularno je bio primijenjen ceftiofur hidroklorid (600 mg) tijekom tri dana, a bile su zračene laserskim zračenjem u sakroilijačnom području tijekom 10 uzastopnih dana jedanput dnevno. Kontrolna skupina IV (n = 55) nije dobivala antibiotik niti je bila zračena. U određenog broja krava, od 57,1% (skupina IIIa) do 65% (skupina IV), razvio se klinički metritis, koji je bio liječen antisepticima. Najduže vrijeme oporavka od metritisa (21 ± 6,12 d) ustanovljeno je u skupini IV. Krave skupine III oporavile su se od metritisa za 11,5 dana brže od krava IV. (negativne kontrolne) skupine (P<0,05) i četiri dana brže od krava I. (pozitivne kontrolne) skupine. Pokazatelji plodnosti poput prvoga osjemenjivanja nakon teljenja, servisnog perioda, stope začeća, indeksa osjemenjivanja i razdoblja od teljenja do bređosti bili su bolji u krava kojima je bio profilaktički primijenjen antibiotik u kombinaciji s laserskim zračenjem u usporedbi s drugim skupinama

Factors affecting expression of estrus in dairy cows with high milk yields

The objectives of this study were to define the effect of the milk progesterone (P4) concentration on estrus expression in dairy cows with high milk yield and to identify the effect of milk yield and parity on the milk P4 concentration and cow’s pregnancy after artificial insemination (AI). In this study, 48 clinically healthy cows without reproduction disorders, on day 90-100 after calving were used. At the beginning of estrus and 12 hours after the beginning of estrus, the milk P4 concentration in dairy cows with high milk yield (group 3) was higher than in group 2 (33.66; 22.36%) and in group 1 (51.60; 65.26%) (P 0.05) and the first (28.28%; P < 0.01) lactation ones (28.28%; P < 0.01). The milk P4 concentration at the beginning of estrus and 12 hours after the beginning of estrus in pregnant and non-pregnant cows was 2.58 and 3.32; 4.20 and 5.00 ng/ml, respectively (P < 0.001). As a result, it was concluded that high progesterone concentration affected the expression of estrus and pregnancy results in dairy cows, and the measuring of progesterone concentration in milk can be used as a non-invasive method to provide detailed information about fertility in high milk yield cows

The Effect of Supplementation of Rumen-Protected Choline on Reproductive and Productive Performances of Dairy Cows

We aimed to evaluate the effects of organic herbal preparations containing rumen-protected choline (RPC) in dairy cow milk&rsquo;s BHB and progesterone (P4) concentration changes, reproduction, and production performances. Cows were divided into the following two groups: The CHOL (n = 60) cow diet was supplemented with 10 g/day RPC from 20 days pre-calving to 20 days post-calving, and CONT (n = 60) were fed a conventional diet. BHB and P4 concentrations were measured at 5&ndash;64 DIM and 21&ndash;64 DIM, respectively, with DelPro 4.2. BHB was lower in the CHOL group at 5&ndash;64 DIM than CONT p &gt; 0.05. The first post-calving P4 peak, p &lt; 0.001, was determined earlier in the CHOL group, and the P4 profile during 21&ndash;64 DIM was similar, p &gt; 0.05. The insemination rate was lower, and the interval between calvings was shorter. The first insemination time was earlier in the CHOL group, p &lt; 0.05. Milk yield was higher in the CHOL group at 21&ndash;64 DIM, p &gt; 0.05. The CHOL group had more fat in their milk at 31&ndash;60 DIM, p &lt; 0.05. There were no significant differences in protein and SCC between the groups, p &gt; 0.05. Based on our results, we concluded that the supplementation of RPC pre- and post-calving had statistically significant effects on the first peak of P4, and benefited the reproduction performances, milk yield, and milk fat during the early postpartum period

Inline changes in lactate dehydrogenase, milk concentration according to the stage and number of lactation periods, including the status of reproduction and milk yield in dairy cows

The aim of the present study was to investigate inline lactate dehydrogenase (LDH) dynamic changes based on different cow factors – different number and stages of lactation, milk yield, and the status of reproduction in clinically healthy dairy cows. In the Herd Navigator system, LDH activity levels (μmol/min per litre) were measured using dry-stick technology. A total of 378 cows were selected. According to their reproductive status, the cows were classified as belonging to the following groups: Fresh (1 – 44 days after calving); Open (45 – 65 days after calving); Inseminated (1 – 35 days after insemination); Pregnant (35 – 60 days after insemination and pregnant). According to their productivity, the cows were classified into the following groups: 35 kg/day. The cows were milked with a DeLaval milking robot (DeLaval Inc. Tumba Sweden) in combination with a Herd Navigator analyser (Lattec I/S. Hillerød Denmark). In conclusion inline dynamic changes in the milk LDH concentration may increase together with the rise in the lactation period frequency. The highest LDH level determinated in the group of the fresh cows ranged from 5 to 10 DIM, while the highest LDH concentration level was found in the fresh cow milk. Thus, there was a positive relationship between the milk concentration of LDH and the milk yield

Ruminating, Eating, and Locomotion Behavior Registered by Innovative Technologies around Calving in Dairy Cows

The hypothesis for this study was that there are correlations between ruminating, eating, and locomotion behavior parameters registered by the RumiWatch sensors (RWS) before and after calving. The aim was to identify correlations between registered indicators, namely, rumination, eating, and locomotion behavior around the calving period. Some 54 multiparous cows were chosen from the entire herd without previous calving or other health problems. The RWS system recorded a variety of parameters such as rumination time, eating time, drinking time, drinking gulps, bolus, chews per minute, chews per bolus, activity up and down time, temp average, temp minimum, temp maximum, activity change, other chews, ruminate chews, and eating chews. The RWS sensors were placed on the cattle one month before expected calving based on service data and removed ten days after calving. Data were registered 10 days before and 10 days after calving. We found that using the RumiWatch system, rumination time was not the predictor of calving outlined in the literature; rather, drinking time, downtime, and rumen chews gave the most clearcut correlation with the calving period. We suggest that using RumiWatch to combine rumination time, eating time, drinking, activity, and down time characteristics from ten days before calving, it would be possible to construct a sensitive calving alarm; however, considerably more data are needed, not least from primiparous cows not examined here

The Association between Blood Β-Hydroxybutyric Acid Concentration in the Second Week of Lactation and Reproduction Performance of Lithuanian Black and White Cows

Hyperketonemia is a very common metabolic state in dairy cows, which result in lower milk production, impaired fertility, and increased frequency of other diseases. In this study, we aimed to determine the influence of season, parity, and milk yield of cows on beta-hydroxybutyrate (BHB) concentration in the second week of lactation (WK 2) and establish the relationship between BHB concentration in WK 2 and reproduction performance traits such as insemination rate and first insemination day of Lithuanian Black and White dairy cows. The study included clinically healthy Lithuanian Black and White cows (n = 692). Blood BHB concentration was measured using capillary blood samples collected after morning milking when cows were 7–10 DIM. The impact of WK 2 blood BHB concentration on the insemination rate and first insemination day were investigated. The effect of BHB was evaluated according to the season, parity, and milk yield per lactation (305 DIM). Significant differences were observed in BHB concentration in WK 2 due to season and parity, but no statistically significant differences were observed for milk yields (305 d). Increased blood BHB concentration in WK 2 negatively affected insemination rate (p < 0.001) and first insemination day (p < 0.001). The study findings indicate that BHB concentration in WK 2 depends on season and parity, while the milk yield is not associated with BHB concentration. High BHB concentration in WK 2 increases insemination rate and delays the first insemination day for high milk-yielding Lithuanian Black and White dairy cows

The Association between Charolais Cows’ Age at First Calving, Parity, Breeding Seasonality, and Calf Growing Performance

The objective of this study was to evaluate the impact of cows’ calving ages and newborn calf body weight on the pre-weaning growth rates of calves under the farming conditions of a northeastern European country. The females were purebred Charolais cows that calved between 2019 and 2022. A total of 130 calves (bulls = 76; heifers = 54) were observed during the evaluation. The investigation showed that, based on gender, bulls had a 4.28% higher birth weight than heifers (p p p p p p p p < 0.05)