Supplying the ethanol demand for 2030 in Brazil as a land-based climate change mitigation alternative: Implications on greenhouse gases emissions.

Transitioning from a fossil-based to a bio-based economy is crucial to climate action and achieving neutrality in greenhouse gas (GHG) emissions. Biofuel production is an essential land-based GHG mitigation alternative. However, it raises concerns about biodiversity conservation, competition with food production, and net GHG emissions associated with direct land-use change (dLUC).

Plasma Estradiol Profile After Administration of Different Types of Estradiol Esters in Acyclic Mares.

Although the use of different estradiol esters has been extensively studied in hormonal protocols in cows, such information is lacking in mares. The present study aimed to assess the effects of treatment with the same doses and administration frequency of estradiol cypionate, estradiol benzoate and 17β estradiol on plasma estradiol (E2) concentrations of acyclic mares and correlate the E2 profile to the endometrial edema score. Sixteen treatments were performed in 14 mares randomly divided into three groups: EB (n = 5), EC (n = 5), and 17β (n = 6), receiving 10 mg on day 0 (D0), 6 mg on D1, and 4 mg on D2 of estradiol benzoate, estradiol cypionate, and estradiol 17β, respectively.

Peri-estrus ovarian, uterine, and hormonal variables determine the uterine luminal fluid metabolome in beef heifers.

In cattle, uterine luminal fluid (ULF) is the main source of molecules that support embryo development and survival during the peri-implantation period. Our overarching hypothesis is that peri-estrus changes in uterine function, including ULF accumulation and absorption, are uneven among individuals, and affect ULF composition and fertility. Our objectives were (1) to characterize temporal and spatial changes in ULF volume, endometrial and luteal blood perfusion, endometrial and luteal size, and circulating progesterone concentrations during the peri-estrus period in beef heifers and (2) to associate such changes with the metabolite composition in the ULF, 4 days after estrus (d 0).

Use of pregnancy-associated plasma protein-A during oocyte in vitro maturation increases IGF-1 and affects the transcriptional profile of cumulus cells and embryos from Nelore cows.

Insulin-like growth factor 1 (IGF-1) activity is established by the regulation of IGF binding protein activity, which blocks IGF-1 functions, whereas pregnancy-associated plasma protein-A (PAPP-A) improves IGF-1 bioavailability and facilitates binding to IGF receptors. To further extend our understanding of the effect of exogenous PAPP-A on bovine embryo production, we added this protein during in vitro maturation of cumulus-oocyte complexes (COCs); moreover, we assessed its effects on IGF-1 quantity in the maturation medium, embryonic yield and postwarming survival, blastocyst quality, and transcript abundance. Bovine COCs were matured in a serum-free medium, either with PAPP-A supplementation (100 ng/ml) or without (control).

Supplementation with sunflower seed increases circulating cholesterol concentrations and potentially impacts on the pregnancy rates in Bos indicus beef cattle.

We aimed to evaluate the effect of supplementation with sunflower seed on blood concentrations of progesterone and cholesterol and on the pregnancy rate in beef cattle subjected to timed artificial insemination (TAI) and timed embryo transfer (TET). In experiment 1, cows were received 22-day supplements containing (sunflower, n = 66) sunflower seed or not (control, n = 67) immediately after a progesterone/estradiol-based TAI protocol (Day 0). The cholesterol concentration on Day 21 and the pregnancy rate were greater (P < 0.

Plasma steroid dynamics in late- and near-term naturally and artificially conceived bovine pregnancies as elucidated by multihormone high-resolution LC-MS/MS.

The plasma levels of corticosteroids and sex steroids during pregnancy are key indicators of mammalian placental function and the onset of parturition. Steroid hormones are believed to be disturbed in pregnancies produced using assisted reproductive technologies (ARTs) due to placental dysfunction and the frequently observed lack of parturition signals. To elucidate the plasma steroid dynamics, a liquid chromatography-tandem mass spectrometry method was developed and used to determine the levels of corticosteroids (corticosterone, 11-deoxycortisol, and cortisol) and their direct precursors (progesterone and 17α-OH-progesterone) as well as sex steroids (androstenedione, estrone, estrone sulfate, testosterone, and 17β-estradiol) in bovine plasma.

Changes in luteinizing hormone secretion after estradiol treatment in prepubertal Nelore heifers.

Changes in luteinizing hormone (LH) secretion after 17β-estradiol (E(2)) injection were evaluated during sexual maturation in 10 prepubertal Nelore heifers. Heifers were divided into 2 groups: intact (I) and ovariectomized (OVX). 17β-estradiol (2 μg/kg) was administered to both groups at 10, 13, and 17 mo of age.

Ovariectomy by left flank approach in prepubertal Nelore (Bos indicus) heifers.

The main objective of this study was to evaluate a recumbent left flank approach to bilateral ovariectomy in prepubertal heifers and to develop an optimal surgical technique for this procedure. Both ovaries were removed from 6 Nelore heifers by left flank approach without any complications, except in 1 heifer, which was believed to have had only 1 ovary based on ultrasound and exploration during surgery, but was later found to have a remaining functional ovary. Ovariectomy via left flank approach in recumbent prepubertal heifers is feasible and technically easy.

Follicular dynamics and plasma FSH and progesterone concentrations during follicular deviation in the first post-ovulatory wave in Nelore (Bos indicus) heifers.

The objective of the present study was to characterize ovarian follicular dynamics and hormone concentrations during follicular deviation in the first wave after ovulation in Nelore (Bos indicus) heifers. Ultrasonographic exams were performed and blood samples were collected every 12h from the day of estrus until 120-144 h after ovulation in seven females. Deviation was defined as the point at which the growth rate of the dominant follicle became greater than the growth rate of the largest subordinate follicle.