J Anim Sci
December 2024
Changes in maternal nutrition during the periconceptional period can influence postnatal growth in cattle. This study aimed to identify the impact of supplementing beef cows with rumen-protected methionine (RP-Met) during the periconceptional period on their female progeny. In exp 1, plasma methionine (Met) levels were analyzed in samples from 10 Angus crossbred, non-lactating beef cows.
View Article and Find Full Text PDFThis study aimed to evaluate embryo yield in Holstein heifers superovulated with a single injection of recombinant, long-acting human follicle-stimulating hormone (rFSH) vs. multiple injections of pituitary-derived follicle-stimulating hormone (FSH). In experiment 1, heifers were assigned randomly to one of four experimental groups: Control (280 mg of pituitary-derived FSH; six injections of 40 mg and two injections of 20 mg, each ~12 h apart, n = 16); rFSH1 (50 µg of FSH analog protein, n = 16); rFSH2 (75 µg of FSH analog protein, n = 16); or rFSH3 (100 µg of FSH analog protein, n = 16).
View Article and Find Full Text PDFCholine is a vital micronutrient. In this study, we aimed to confirm, and expand on previous findings, how choline impacts embryos from the first 7 days of development to affect postnatal phenotype. Bos indicus embryos were cultured in a choline-free medium (termed vehicle) or medium supplemented with 1.
View Article and Find Full Text PDFThree experiments were conducted to evaluate the effects of long-acting injectable progesterone (iP4) in buffalo cows. In Experiment 1, ovariectomized buffaloes received 300 mg (iP300) or 600 mg (iP600) of iP4, and serum P4 concentrations were evaluated. In experiment 2, three groups were compared: control or administration of 300 mg of iP4 3 (iP4-D3) or 6 days (iP4-D6) after timed artificial insemination (TAI).
View Article and Find Full Text PDFEndometrial inflammation is associated with reduced pregnancy per artificial insemination (AI) and increased pregnancy loss in cows. It was hypothesized that induced endometritis alters histotroph composition and induces inflammatory signatures on conceptus that compromise development. In Experiment 1, lactating cows were assigned to control (CON; n = 23) or to an intrauterine infusion of Escherichia coli and Trueperella pyogenes (ENDO; n = 34) to induce endometritis.
View Article and Find Full Text PDFIn Brief: The concentration of progesterone through the estrous cycle modulates uterine function to affect the luminal metabolome. This paper reports that the dynamic changes in the bovine uterine luminal metabolome during diestrus are independent of the concentration of progesterone in the previous cycle.
Abstract: In cattle, the concentration of sex steroids modulates uterine function, which is reflected in the composition of the luminal metabolome.
In Brief: Elevated temperatures disturbed sperm physiology. Bovine sperm cells exposed to heat shock led to diminished mitochondrial activity, fertilizing ability, increased oxidative stress and caspase activity concomitant with a delay in embryonic developmental kinetics and modulation of sperm-borne microRNAsmiRNAs.
Abstract: Sperm function is susceptible to adverse environmental conditions.
This study aimed to assess the semen ubiquitin levels of stallions with good (GF) and poor semen freezability (PF) and to evaluate the relationship between sperm ubiquitination and sperm morphological defects. Five ejaculates from eight adult stallions (n = 40) were collected and cryopreserved. Then, the ubiquitin level in equine sperm cells was assessed by immunohistochemistry with epifluorescence microscopy, and sperm morphology was assessed by differential interference contrast microscopy.
View Article and Find Full Text PDFInformation on molecular mechanisms through which sex-steroids regulate oviductal function to support early embryo development is lacking. Here, we hypothesized that the periovulatory endocrine milieu affects the miRNA processing machinery and miRNA expression in bovine oviductal tissues. Growth of the preovulatory follicle was controlled to obtain cows that ovulated a small follicle (SF) and subsequently bore a small corpus luteum (CL; SF-SCL) or a large follicle (LF) and large CL (LF-LCL).
View Article and Find Full Text PDFThe objective of this study was to create a stochastic, agent-based simulation model of a synthetic population of beef cattle, and then use it to compare the technical performance of different reproductive strategies. The model was parameterized using data from a real beef cattle herd and from the peer-reviewed scientific literature to represent a Nelore cattle herd in the state of São Paulo, Brazil. Ten scenarios were evaluated: natural mating (NM) only (ONM); one timed artificial insemination (TAI) plus NM (1TAI + NM); two TAI plus NM, with 24, 32, and 40 days between inseminations (2TAI/24 + NM, 2TAI/32 + NM, and 2TAI/40 + NM, respectively); three TAI without NM, with 24, 32, and 40 days between TAI (3TAI/24, 3TAI/32, and 3TAI/40, respectively); and three TAI plus NM, with 24 and 32 days (3TAI/24 + NM and 3TAI/32 + NM, respectively).
View Article and Find Full Text PDFIn cattle, conceptus development after elongation relies on well-characterized, paracrine interactions with the hosting maternal reproductive tract. However, it was unrecognized previously that the pre-hatching, pre-implantation bovine embryo also engages in biochemical signalling with the maternal uterus. Our recent work showed that the embryo modified the endometrial transcriptome in vivo.
View Article and Find Full Text PDFBackground: A major, unresolved issue is how the uterine microenvironment determines pregnancy success in cattle. Before implantation, conceptus development depends on the uterine secretome (i.e.
View Article and Find Full Text PDFAdaptation is a relevant characteristic to be understood in livestock animals in order to maintain and raise productivity. In Brazil, the Nellore beef cattle are widely disseminated and well-adapted breed that present good thermoregulatory characteristics for tropical environment conditions. Conversely, the physiological and cellular mechanisms required for thermoregulation and thermotolerance in this breed are still limited.
View Article and Find Full Text PDFThe extracellular matrix (ECM) is a group of molecules that offer structural and biochemical support to cells and interact with them to regulate their function. Also, growth factors (GFs) stored in the ECM can be locally released during ECM remodeling. Here, we hypothesize that the balance between ECM components and remodelers is regulated according to the ovarian steroid milieu to which the oviduct is exposed during the periovulatory period.
View Article and Find Full Text PDFIn cattle, the oviduct is a tubular organ that connects the ovary and the uterus. The oviduct lumen stages a dynamic set of cellular and molecular interactions to fulfill the noble role of generating a new individual. Specific anatomical niches along the oviduct lumen provide the appropriate microenvironment for final sperm capacitation, oocyte capture and fertilization, and early embryo development and transport.
View Article and Find Full Text PDFBackground: This study evaluated the impact of hormonal modulation at the onset of proestrus on ovarian response and uterine gene expression of beef cows.
Methods: A total of 172 anestrous beef cows were assigned to one of four groups according to the treatment with estradiol cypionate (ECP) and/or equine chorionic gonadotropin (eCG) [CON ( = 43), ECP (n = 43), eCG ( = 44) and ECP + eCG ( = 42)].
Results: ECP-treated cows (ECP and ECP + eCG groups) presented greater occurrence of estrus (44.
In cattle, the oviduct plays a fundamental role in the reproductive process. Oviductal functions are controlled by the ovarian sex steroids: estradiol and progesterone. Here, we tested the hypothesis that the exposure to contrasting sex steroid milieus differentially impacts the oviductal transcriptional profile.
View Article and Find Full Text PDFIn cattle, molecular control of oviduct receptivity to the embryo is poorly understood. Here, we used a bovine model for receptivity based on size of the pre-ovulatory follicle to compare oviductal global and candidate gene transcript abundance on day 4 of the estrous cycle. Growth of the pre-ovulatory follicle (POF) of Nelore (Bos indicus) cows was manipulated to produce two groups: large POF large corpus luteum (CL) group (LF-LCL; greater receptivity) and small POF-small CL group (SF-SCL).
View Article and Find Full Text PDFThe uterus plays a central role among the reproductive tissues in the context of early embryo-maternal communication and a successful pregnancy depends on a complex series of endometrial molecular and cellular events. The factors responsible for the initial interaction between maternal and embryonic tissues, leading to the establishment of pregnancy, remain poorly understood. In this context, Illumina's next-generation sequencing technology has been used to discover the uterine transcriptome signature that is favourable for ongoing pregnancy.
View Article and Find Full Text PDFPregnancy success is critical to the profitability of cattle operations. However, the molecular events driving the uterine tissue towards embryo receptivity are poorly understood. This study aimed to characterize the uterine transcriptome profiles of pregnant (P) versus non-pregnant (NP) cows during early pregnancy and attempted to define a potential set of marker genes that can be valuable for predicting pregnancy outcome.
View Article and Find Full Text PDFThe timing and magnitude of exposure to preovulatory estradiol followed by post-ovulatory progesterone (periovulatory endocrine milieu) in cattle modulate endometrial gene expression, histotroph composition, and conceptus development, but the mechanisms underlying this regulation remain unknown. Using an experimental model based on the modulation of follicle growth, this work aimed to evaluate if the polyamine metabolic pathway is regulated by the periovulatory endocrine milieu. Nelore cows were manipulated to ovulate small (n = 15) or large (n = 15) follicles, then the profiles of polyamines and their synthetic enzymes were compared between groups.
View Article and Find Full Text PDFIn this freemartin case report the authors present the clinical and morphological findings of a freemartin ewe with an abnormal position of two lymph nodes. Freemartins, infertile females from mixed-sex twin pregnancies, are chimeras, having two cell populations: one of their own (XX DNA) and one from their male twin (XY DNA). Freemartins can have varying degrees of phenotypic masculinization, including, in some cases, having active male gonads and exhibiting male behaviors such as heat detection and aggressiveness.
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