Feeding Flaxseed and Lupins during the Transition Period in Dairy Cows: Effects on Production Performance, Fertility and Biochemical Blood Indices.

Flaxseed and lupin seed were offered as an alternative dietary approach in dairy cows, through the partial substitution of soybean meal. Milk production and fertility traits were investigated. A total of 330 animals were allocated into two groups, treated ( = 176) and control ( = 154).

The impact of cryopreservation on both sperm HPV-negative and positive subtypes.

It is well known that various human papillomavirus (HPV) genotypes are present in semen specimens. Also, it has been demonstrated that sperm parameters are negatively affected when HPV infection is present in the sperm sample. Besides all these, the effect of cryopreservation on HPV sensitivity and resistance is not known.

Oviductal epithelial cells transcriptome and extracellular vesicles characterization during thermoneutral and heat stress conditions in dairy cows.

In this study, the transcriptome of oviductal epithelial cells and certain characteristics of their extracellular vesicles of dairy cows were described under thermoneutral and heat stress conditions. Twenty cows were compared in springtime at THI = 65.6 ± 0.

The Effects of Heat Shock Protein 70 Addition in the Culture Medium on the Development and Quality of In Vitro Produced Heat Shocked Bovine Embryos.

The aims of the present study were to examine the effects of HSP70 addition in the in vitro culture medium of day 3 embryos on their developmental competence and quality. Bovine oocytes ( = 1442) were in vitro matured, inseminated and cultured for the first two days according to standardized methods. The presumptive zygotes were randomly allocated in three experimental groups: Control, C (embryos cultured at 39 °C throughout the culture period), group C41 (temperature was raised to 41 °C from the 48th to 72nd h post insemination (p.

Age, gestational and heat stress effects on ghrelin secretion in dairy cattle.

It is known that heat stress decreases dry matter intake in cattle with impacts on milk production and fertility. Ghrelin is an orexigenic hormone with suppressive effects on reproduction. In this study, we investigated the effects of heat stress and gestational status on ghrelin secretion and its possible associations with DMI in Holstein cattle.

Developmental competence of heat stressed oocytes from Holstein and Limousine cows matured in vitro.

The negative effects of heat stress on dairy cattle's fertility have been extensively studied, but the relevant knowledge for beef cattle is rather limited. The aims of this study were to investigate the effects of HS during in vitro maturation on the developmental potential of oocytes derived from Limousine and Holstein cows and to estimate the effect of the differential gene expression of important genes in oocytes, cumulus cells and blastocysts in the growth competence between the breeds. In seven replicates, cumulus oocyte complexes from Holstein and Limousine cows were matured for 24 hr at 39°C (controls C; Hol_39, Lim_39) or at 41°C from hour 2 to hour 8 of IVM (treated T; Hol_41, Lim_41), fertilized, and presumptive zygotes were cultured for 9 days at 39°C.

Heat Shock Protein 70 Improves In Vitro Embryo Yield and Quality from Heat Stressed Bovine Oocytes.

Heat shock protein 70 (HSP70) is a chaperon that stabilizes unfolded or partially folded proteins, preventing inappropriate inter- and intramolecular interactions. Here, we examined the developmental competence of in vitro matured oocytes exposed to heat stress with or without HSP70. Bovine oocytes were matured for 24 h at 39 °C without (group C39) or with HSP70 (group H39) and at 41 °C for the first 6 h, followed by 16 h at 39 °C with (group H41) or without HSP70 (group C41).

Early embryo losses, progesterone and pregnancy associated glycoproteins levels during summer heat stress in dairy cows.

Objectives of this study were to characterize the effects of heat stress on pregnancy associated glycoproteins (PAG) and progesterone and its involvement in embryo survival. In trial 1, blood samples collected from days 29 to 36 post insemination were examined for the comparison of PAG concentrations between winter (n = 3721) and summer (n = 2388). In trial 2, embryo losses were assessed in winter (n = 144) and in summer (n = 133), in days 31 or 32 of pregnancy.

A study on stress response and fertility parameters in phenotypically thermotolerant and thermosensitive dairy cows during summer heat stress.

It is well documented that heat stress (HS) causes subfertility in dairy cows. However, during the last ten years we have been observing that, under high temperature-humidity index (THI ≥ 75), despite the overall reduced fertility, some cows conceive at the first artificial insemination (AI). Here, we examined distinctive features of cows with conserved fertility under severe HS.

Short term temperature elevation during IVM affects embryo yield and alters gene expression pattern in oocytes, cumulus cells and blastocysts in cattle.

Heat stress causes subfertility in cattle by inducing alterations in steroidogenic capacity, follicular function and ovulation defects, which eventually negatively affect oocyte quality and embryo survival. Here, the effects of short, moderate temperature elevation during IVM, on embryo yield, and on the expression of various genes was evaluated. In 8 replicates, cumulus oocyte complexes (COCs) were matured for 24 h at 39 °C (controls n = 605) or at 41 °C from hour 2 to hour 8 of IVM (treated, n = 912), fertilized, and presumptive zygotes were cultured for 9 days at 39 °C.

Clinical, Ultrasonographic, Bacteriological, Cytological and Histopathological Findings of Uterine Involution in Ewes with Uterine Infection.

The objectives of the study were (a) to study the characteristics of uterine involution in ewes that had developed subclinical uterine infection in the immediately post-partum period and (b) to evaluate effects of the infection in the subsequent reproductive performance of ewes. Uterine infection was induced in ewes (I, n = 10) by intrauterine inoculation of ; uninoculated controls were included (C, n = 12). Animals were examined at regular intervals before and post-inoculation.

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.

The In Vitro Impact of the Herbicide Roundup on Human Sperm Motility and Sperm Mitochondria.

Toxicants, such as herbicides, have been hypothesized to affect sperm parameters. The most common method of exposure to herbicides is through spraying or diet. The aim of the present study was to investigate the effect of direct exposure of sperm to 1 mg/L of the herbicide Roundup on sperm motility and mitochondrial integrity.

Effects of pregnancy and short-lasting acute feed restriction on total ghrelin concentration and metabolic parameters in dairy cattle.

The aims of this study were: to compare total ghrelin concentration throughout pregnancy between lactating cows and heifers, and to study the response to acute feed restriction in pregnant or non-pregnant heifers. Blood samples were collected each month of pregnancy from cows (n = 5) and heifers (n = 5) and analyzed for total ghrelin concentration. Compared to pre-conception values, ghrelin concentrations tended to be greater during 3rd month of pregnancy in heifers, whereas they were higher in the 7th, 8th and 9th months in lactating cows, but no difference was detected between lactating cows and heifers.

Effects of ghrelin on activation of Akt1 and ERK1/2 pathways during in vitro maturation of bovine oocytes.

The purpose of this study was to investigate the possible molecular pathways through which ghrelin accelerates in vitro oocyte maturation. Bovine cumulus-oocyte complexes (COCs), after 18 or 24 h maturation in the absence or the presence of 800 pg ml-1 of acylated ghrelin were either assessed for nuclear maturation or underwent in vitro fertilization in standard media and putative zygotes were cultured in vitro for 8 days. In a subset of COCs the levels of phosphorylated Akt1 and ERK1/2 (MAPK1/3) were assessed at the 0th, 6th, 10th, 18th and 24th hours of in vitro maturation (IVM).

Urokinase-type plasminogen activator does not affect in vitro bovine embryo development and quality.

The effects of modification of the in vitro embryo culture media (IVC) with the addition of urokinase-type plasminogen activator (u-PA) on the yield and/or quality of bovine embryos were examined in two experiments. In Experiment 1, denuded embryos were cultured in semi-defined synthetic oviductal fluid (SOF) for seven days, while in Experiment 2 embryos were co-cultured with cumulus cell monolayer in a serum-containing SOF medium. Plasminogen activator activity (PAA) and plasminogen activator inhibition (PAI) were determined in all spent IVC media.

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 [Ghr800]; and 2000 pg/mL [Ghr2000]); blastocyst formation rates were examined on Days 7, 8, and 9.

Human ghrelin decreases pituitary response to GnRH in superovulated ewes.

In addition to its metabolic role, ghrelin has been found to suppress luteinizing hormone secretion in many species acting mainly at the hypothalamic level. The objectives of the present study were to test the hypothesis that besides its effects on the hypothalamic level, ghrelin exerts a direct action on the pituitary. Twelve cycling ewes were synchronized, using progestagen intravaginal sponges and superovulated using eCG.

Association between physical properties of cervical mucus and ovulation rate in superovulated cows.

Possible associations between certain physical properties of cervical mucus (CM) and ovulation rate were studied in 21 superovulated Holstein cows. In CM samples collected at the beginning of estrus (0 h) and in 4 h intervals for the following 24 h, the pH, the spinnbarkeit (spinability), and the crystallization value were measured. Blood samples, collected at the same time points with CM samples, were assessed for progesterone and estradiol concentrations.

Effects of melatonin treatment on follicular development and oocyte quality in Chios ewes - short communication.

Follicular development and oocyte quality were assessed by laparoscopic observation and in vitro fertilisation, respectively, in melatonin-treated (Group M) and control (Group C) anoestrous Chios ewes (n = 10 in each group). Fourteen days after melatonin insertion, all ewes had laparoscopic evaluation of the follicular population followed by oocyte pick-up (OPU); on day 22 intravaginal progestagen sponges were inserted for 14 days. Two days after sponge removal the follicular population was re-evaluated and a second follicular aspiration was performed.