Efficacy of feeding cow colostrum to newborn lambs

In the present study the efficacy of feeding cow colostrum to newborn lambs was investigated. Seventy two newborn lambs were divided into 6 groups and were fed as follows: groups 1 to 3 received 4 meals of 1st or 2nd or unknown milking cow colostrums (UMCC) in 18 h, group 4 received 6 ml of a commercial cow colostrum replacer and 2 meals of UMCC, group 5 received 4 meals of ewe colostrum, and group 6 lambs were allowed to be nourished by their dams. Blood samples were collected at 24 h, 1st, 2nd, 3rd and 4th week after birth. Total proteins and albumin concentrations and gamma-Glutamyl-Transferase activity (gamma-GT) were assayed spectophotometrically, while globulin concentration was calculated from the related data. Significant differences (P < 0.05) among groups were observed at 24 h after birth for all parameters: differences in total globulins and gamma-GT activity were non-detectable at 4th week. At 4th week of age, no differences were detected in almost all parameters measured between lambs that received artificially ewe or cow colostrum. Our data imply that cow colostrum could be a good replacer of ewe colostrum as concerns passive immunity in cases where ewe colostrum physically cannot or it is not advisable to be used. (C) 2012 Elsevier B.V. All rights reserved

Prevalence of Coxiella burnetii antibodies in bulk milk and blood serum and associations with reproductive indices in cow dairy herds of Central Northern Greece

For the first time in Greece, we investigated the prevalence of Coxiella burnetii antibodies in milk and sera from dairy cattle herds located at central and northern parts of the country. Eighty herds were initially voluntary enrolled in the study and a bulk milk sample from each farm was assayed by ELISA for C. burnetii antibodies. According to antibody titre, herds were classified into 5 categories: negative and grades 1,2,3 and 4 (ascending scale). To assess the prevalence within farms, two herds from each category were selected and blood samples were collected for antibody assessment. In these herds, some reproductive indices were compared between farms; in addition, comparisons were made in paired seropositive and seronegative animals from one grade 3 herd. Twenty three herds (35%) were found positive, 21 being in categories 3 and 4. The prevalence of seropositive animals between herds varied from 4.9 to 46.3%, even from farms initially characterized as negative, some positive animals were detected. Between farms, no differences were detected in the abortion rate or in the mean number of artificial inseminations (AI) per pregnancy. Some differences were found in other reproductive indices that were impossible to be biologically interpreted under the light of C. burnetii level of infection. From the results presented here, we infer that C. burnetii infection is likely asymptomatic in dairy cows causing minimal -if any- economic losses to farmers. However, since the disease is a zoonotic one, its spread can easily occur, a systematic surveillance, in all ruminant species, for the restriction or eradication of the disease should be undertaken in national level

Ultrasonographic findings of the corpus luteum and the gravid uterus during heat stress in dairy cattle

The objectives of this study were to assess alterations in, echogenic appearance, size and blood flow in the corpus luteum, the placentomes and the blood flow in umbilical and uterine arteries that heat stress can cause in cooled pregnant dairy cows. Pregnant cows were allocated in two groups and the gravid uteri, along with the ipsilateral corpora lutea were examined during the winter (group W, n = 9) or the summer (group S, n = 10). The grey-scale ultrasound and colour flow imaging of the corpus luteum and placentome were performed. In addition, the umbilical and uterine artery diameters and haemodynamic parameters in the vessels were calculated. At the time of ultrasonographic examination, cortisol concentrations were higher, and progesterone levels tended to be lower in group S compared to group W. The grey-scale ultrasound evaluation of corpora lutea and placentomes was lower in group S compared to group W. The diameter of umbilical artery and the blood volume in the vessel were less in group S than in group W. We infer that heat stress affects foetal blood supply and possibly the structure of placentomes and corpora lutea, but it differently affects the blood flow characteristics in the umbilical and uterine arteries. © 2021 Wiley-VCH Gmb

A study on ghrelin and LH secretion after short fasting and on ghrelin levels at perioestrual period in dairy cattle

In two experiments, we studied (a) the changes of LH secretion in heifers under different feeding schedules and (b) total ghrelin concentration at oestrus in cows and heifers. In experiment one, synchronized heifers were allocated in three groups (R, regularly fed controls; F, fasted; and F-F fasted-fed). One day after the completion of the oestrous induction protocol, group F and F-F animals stayed without feed for 24 hr; thereafter, feed was provided to R and F-F cattle; 2 hr later, GnRH was administered to all animals. Blood samples were collected for ghrelin, progesterone, LH and cortisol concentrations. Fasting caused increased ghrelin concentrations in groups F and F-F, while in response to GnRH, LH surge was significantly attenuated in groups F and F-F compared to R. In experiment 2, lactating cows and heifers were used. On day 9 of a synchronized cycle, PGF2α was administered, and blood samples were collected twice daily until the third day after oestrus and analysed for progesterone, estradiol, ghrelin, glucose and BHBA concentrations. No difference was recorded between groups in steroids and BHBA concentrations. In comparison to mid-luteal values, ghrelin concentrations significantly increased at perioestrual period in cows, but not in heifers. This study provides evidence that starving-induced elevated ghrelin concentrations can have suppressing effect on LH secretion, even after ghrelin's restoration to basal values and that during oestrus, ghrelin secretion is differently regulated in cows and heifers, likely being independent from oestradiol concentrations. Further research is required to identify the determining factors that drive the different regulation of ghrelin secretion in cows and heifers. © 2018 Blackwell Verlag Gmb

Relationship between oocyte maturation and the activity of two glycosidases beta-N-acetyloglucosaminidase (NAGASE), alpha-mannosidase (alpha-MAN) in bovine follicular fluid

International audienc

Association between two glycosidases activity (α-mannosidase and β-N-acetyloglucosaminades) and in vitro fertilizing capacity of bovine oocytes

National audienc

Daily supplementation with ghrelin improves in vitro bovine blastocysts formation rate and alters gene expression related to embryo quality

Ghrelin is a gastric peptide having regulatory role in the reproductive system functionality, acting mainly at central level. Because the expression of ghrelin system (ghrelin and its receptor) has been detected in the bovine ovary, the objectives of the present study were to investigate whether ghrelin can affect the developmental potential of in vitro-produced embryos, and to test their quality in terms of relative abundance of various genes related to metabolism, apoptosis and oxidation. In the first experiment, in vitro-produced zygotes were cultured in the absence (control [C]) and in the presence of three concentrations of acylated ghrelin (200 pg/mL [Ghr200], 800 pg/mL [Ghr8001; and 2000 pg/mL [Ghr2000]); blastocyst formation rates were examined on Days 7, 8, and 9. In the second experiment, only the 800 pg/mL dose of ghrelin was used. Zygotes were produced as in experiment 1 and 24 hours post insemination they were divided into 4 groups; in two groups (C; without ghrelin; Ghr800 with ghrelin), embryos were cultured without medium replacement; in the remaining two groups (Control N and GhrN), the culture medium was daily renewed. A pool of Day-7 blastocysts were snap frozen for relative mRNA abundance of various genes related to metabolism, oxidation, implantation, and apoptosis. In experiment 3, embryos were produced as in experiment 2, but in the absence of serum (semi-defined culture medium). In experiment 1, no differences were detected between C, Ghr200, and Ghr2000, although fewer blastocysts were produced in group Ghr800 compared with C. In experiment 2, the lowest blastocysts yield was found in Ghr800, whereas daily renewal of ghrelin (Ghr800N) resulted to increased blastocysts formation rate, which on Day 7 was the highest among groups (P < 0.05). In experiment 3, ghrelin significantly suppressed blastocysts yield. Significant differences were detected in various relative mRNA abundance, giving an overall final notion that embryos produced in the presence of ghrelin were of better quality than controls. Our results imply a specific role of ghrelin in early embryonic development; however, the specific mode of its action needs further investigation. (C) 2014 Elsevier Inc. All rights reserved