Evolution over the last 40 years of the assisted reproduction technologies in cattle - the Brazilian perspective I - timed artificial insemination.

The reproductive efficiency of the herd is correlated with higher productivity in livestock. Reproduction biotechniques, such as ovulation synchronization protocols, are important to optimize production and accelerate genetic profit in beef and dairy herds. The objective of this review is to describe the evolution over the last 40 years of the artificial insemination (AI) and the timed-AI (TAI) protocols in cattle from a Brazilian perspective.

Effects of supplementation of grazing Nellore cows with β-carotene and vitamins A + D3 + E + biotin on follicle diameter, oestrus, establishment of pregnancy, and foetal morphometry.

The objectives of this experiment were to evaluate the effects of supplementation of Nellore (Bos indicus) cows with β-carotene + vitamins A + D3 + E + biotin on body condition score (BCS), oestrus, pregnancy, and foetal morphometry. Lactating cows (n = 497) from two herds were balanced for BCS and calving period [early calving (EC); late calving (LC)] and were assigned randomly to: Control (n = 251)-supplementation with a mineral supplement; and SUP (n = 246)-supplementation with the mineral supplement fed to control + β-carotene (150 mg/day) + vitamin A (40,000 IU/day) + vitamin D3 (5000 IU/day) + vitamin E (300 mg/day) + biotin (20 mg/day). Cows were supplemented from Days -30 to 30 (Day 0 = timed artificial insemination; TAI).

Accuracy of early pregnancy diagnosis and determining pregnancy loss using different biomarkers and machine learning applications in dairy cattle.

This study aimed to compare the accuracy of IFN-τ stimulated gene abundance (ISGs) in peripheral blood mononuclear cells (PBMCs), CL blood perfusion by Doppler ultrasound (Doppler-US), plasma concentration of P4 on Day 21 and pregnancy-associated glycoproteins (PAGs) test on Day 25 after timed-artificial insemination (TAI) for early pregnancy diagnosis in dairy cows and heifers. Holstein cows (n = 140) and heifers (n = 32) were subjected to a hormonal synchronization protocol and TAI on Day 0. On Day 21 post-TAI, blood samples were collected for PBMC isolation and plasma concentration of P4.

Metabolic imprinting in beef calves supplemented with creep feeding on performance, reproductive efficiency and metabolome profile.

This experiment evaluated the influence of creep feeding supplementation on productive and reproductive performance and on serum metabolome profile in Nelore (Bos indicus) heifers. Female calves were assigned to treatments: Creep (n = 190), with ad libitum access to a nutritional supplement from 70 to 220 days after birth, or Control (n = 140), without supplementation. After weaning (Day 220), both groups followed the same pasture and nutritional management.

Pleomorphic adenoma gene1 in reproduction and implication for embryonic survival in cattle: a review.

The pleomorphic adenoma gene1 (PLAG1) encodes a DNA-binding, C2H2 zinc-finger protein which acts as a transcription factor that regulates the expression of diverse genes across different organs and tissues; hence, the name pleomorphic. Rearrangements of the PLAG1 gene, and/or overexpression, are associated with benign tumors and cancers in a variety of tissues. This is best described for pleomorphic adenoma of the salivary glands in humans.

The effectiveness of low-dose of eCG in timed AI Nelore (Bos indicus) heifers.

This study evaluated the efficacy of the administration of different doses of equine chorionic gonadotropin (eCG; 0 IU, 200 IU, or 300 IU) at the time of the progesterone device removal in 2-year-old Nelore (Bos indicus) heifers synchronized for fixed-timed artificial insemination (FTAI). On day 0 (D0), a total of 398 heifers received 2 mg of oestradiol benzoate i.m.

Supplementation with long-acting injectable progesterone 3 days after TAI impaired luteal function in buffaloes.

Three 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).

Applying assisted reproductive technology and reproductive management to reduce CO-equivalent emission in dairy and beef cattle: a review.

Methane emission from beef and dairy cattle combined contributes around 4.5-5.0% of total anthropogenic global methane.

Use of new recombinant proteins for ovarian stimulation in ruminants.

Currently, gonadotropin products (follicle stimulating hormone, FSH, and luteinizing hormone, LH) used in animal reproduction are produced by extraction and purification from abattoir-derived pituitary glands. This method, relying on animal-derived materials, carries the potential risk of hormone contamination and pathogen transmission. Additionally, chorionic gonadotropins are extracted from the blood of pregnant mares (equine chorionic gonadotropin; eCG) or the urine of pregnant women (human chorionic gonadotropin; hCG).

Review: Development, adoption, and impact of assisted reproduction in domestic buffaloes.

The domestic buffalo (Bubalus bubalis), also known as water buffalo, comprises two sub-species the River buffalo (B. bubalis ssp. bubalis; 50 chromosomes) and the Swamp buffalo (ssp.

Plasma metabolomics reveals major changes in carbohydrate, lipid, and protein metabolism of abruptly weaned beef calves.

H NMR-based metabolomics was used to study the effect of abrupt weaning on the blood metabolome of beef calves. Twenty Angus calves (258 ± 5 kg BW; 5 to 6 months old) were randomly assigned to a non-weaned (NW) group that remained grazing with their dam or a weaned (W) group that underwent abrupt separation from their dam to a separate paddock on d 0 of the study. Body weight, behaviour, and blood samples for cortisol and metabolomics were measured at d 0, 1, 2, 7, and 14 of the study.

Evaluation of clinical and subclinical endometritis impacts on the reproductive performance and milk production of dairy cows in Brazilian herds.

Clinical endometritis (CE) and subclinical endometritis (SE) are two of the main uterine diseases in dairy cows during the puerperium period that can directly affect milk production and fertility in dairy herds. The first objective of this study was to investigate the effects of the CE and SE on the subsequent reproductive performance and milk production of dairy cows in Brazilian herds, and the second objective was to evaluate the reproductive performance and milk production of dairy cows according to the positive or negative isolation of bacteria in the uterine environment. A total of 279 lactating Holstein dairy cows (28-33 days in milk) from six commercial farms were studied.

In vitro effects of cinnamon, oregano, and thyme essential oils against Escherichia coli and Trueperella pyogenes isolated from dairy cows with clinical endometritis.

Clinical endometritis causes serious economic losses in dairy farms, mainly due to its negative health impact on fertility and milk production, as well as the additional costs of medicines used to treat the affected animals. The therapy for uterine diseases is principally performed with antibiotic treatment; however, its indiscriminate use in dairy herds can favor the increase in the resistance of pathogenic bacteria, leading to treatment failures. In this regard, the use of unconventional treatment may be a good option to reduce the use of antimicrobials in milk production.

Use of injectable progesterone at the beginning of the TAI protocol is not necessary in super-early resynchronization started 14 days after artificial insemination in Bos indicus beef heifers.

In a protocol for the resynchronization of ovulation starting 14 days (D14) after timed artificial insemination, the effects of short-action injectable progesterone (P4i) administration and the length of treatment with an intravaginal progesterone (P4) device on follicular dynamics, the conception rate (P/AI) and the percentage of false positives were evaluated in 1065 Nelore heifers previously timed-inseminated. On D14, P4 devices were inserted, and heifers allocated, based on a 2 × 2 factorial design, to receive (P4i) or not 50 mg of P4i (NoP4i), and to remove the P4 device after 6 (6Day) or 8 days (8Day). At the time of P4 device removal (D20 and D22), non-pregnancy diagnosis was performed using vascularization of the corpus luteum (VCL) evaluated.

Temporal evaluation of follicular dynamics and endocrine patterns of Holstein (Bos taurus), Gir (Bos indicus), and Murrah (Bubalus bubalis) heifers kept under the same nutritional, management and environmental conditions.

The objective of the study was to simultaneously compare ovarian follicular dynamics and endocrine parameters of taurine (Holstein; n = 14), zebuine (Gir; n = 5), and bubaline (Murrah; n = 15) heifers kept under the same environmental, nutritional and management conditions. Heifers were synchronized with two PGF treatments 14 days apart. Ovaries of cyclic heifers were scanned daily during two consecutive ovulations and blood samples were collected every 24 h from each animal.

The use of herbal treatments as alternatives to control uterine diseases in dairy cows.

Uterine diseases are a common gynecological issue that affects dairy cows during the postpartum period. The treatment of uterine diseases is mainly managed through antimicrobials; however, the problem of antibiotic residues, increased antimicrobial resistance of pathogens, and the abuse of antibiotics causes serious problems in the dairy chain around the world, which can affect the efficiency of conventional medicines. In these regards, alternative treatment strategies are needed to reduce the use of antibiotics in dairy production.

Impact of oocyte donor age and breed on embryo production in cattle, and relationship of dairy and beef embryo recipients on pregnancy and the subsequent performance of offspring: A review.

Genomic selection combined with in vitro embryo production (IVEP) with oocytes from heifer calves provides a powerful technology platform to reduce generation interval and significantly increase the rate of genetic gain in cattle. The ability to obtain oocytes with developmental competence from calves has been recognised for more than 60years. There is renewed interest in the potential of this reproductive technology as the beef and dairy industries seek to identify and multiply animals that satisfy consumer demand for efficient utilisation of natural resources, with minimal environmental impact and high product quality.

Assessment of the main pathogens associated with clinical and subclinical endometritis in cows by culture and MALDI-TOF mass spectrometry identification.

Clinical endometritis (CE) and subclinical endometritis (SCE) are diseases that affect dairy cows during the puerperium, causing negative effects on the animals' milk production and fertility. The objective of this study was to assess the main bacteria related to cases of CE and SCE from uterine samples of dairy cows in Brazilian herds. Selective and differential media were used for isolation of aerobic and anaerobic bacteria and further MALDI-TOF mass spectrometry (MS) identification.

Sperm function and oxidative status: Effect on fertility in Bos taurus and Bos indicus bulls when semen is used for fixed-time artificial insemination.

Semen quality is one of the criteria used for the selection of bulls with relatively greater fertility. In addition, bull fertility depends on the integrity and function of all sperm structures. The aim of this study, therefore, was to determine associations when there was conducting of conventional and functional techniques for the evaluation of sperm samples from bulls with known fertility history as determined when semen from these bulls was used for fixed-time artificial insemination programs.

Clinical endometritis with Trueperella pyogenes reduces reproductive performance and milk production in dairy cows.

The aim of this study was to identify the impact of Trueperella pyogenes in cows with clinical endometritis (CE) on reproductive performance and milk production in affected cows. In total, 230 lactating Holstein dairy cows from six commercial dairy herds were sampled once between 28 and 33 days post-partum. Cows included in the present study did not receive antibiotic or anti-inflammatory treatments prior to the experimental period.

Lack of effect of melatonin on ovarian function and response to estrous synchronization and fixed-time AI during the nonbreeding season in lactating dairy buffalo (Bubalus bubalis).

The present study was conducted to examine whether pretreatment with melatonin would enhance ovarian follicular functions and increase response to estrous synchronization and fixed-time AI (TAI) during the nonbreeding season in lactating dairy buffalo. In Experiment 1, buffalo cows without a detectable corpus luteum (CL) were assigned on Day -20 (D-20) to three groups: control (n = 12); melatonin (n = 13); progesterone (P) (n = 15). Cows in the melatonin group were implanted with melatonin on D-20.

Estradiol Priming Potentiates the Kisspeptin-Induced Release of LH in Ovariectomized Cows.

The present study examined whether priming with estradiol benzoate (EB) for 12 h increased both the peak and duration of LH release in response to kisspeptin (KISS1, KP) in cows. In a Latin square design, ovariectomized Nelore cows ( = 8) received: Control, i.m.

Effects of eCG and FSH in timed artificial insemination treatment regimens on estrous expression and pregnancy rates in primiparous and multiparous Bos indicus cows.

Effects were evaluated in Bos indicus cows of eCG and FSH on follicular growth, estrous expression, and pregnancy per artificial insemination (P/AI) as a result of fixed-time artificial insemination (TAI). In Experiment 1, extent of timing-of-ovulation synchronization among cows was evaluated after imposing an estrogen/progesterone-based treatment regimen. At progesterone device removal (D8), cows were administered: eCG, or FSH or served as untreated Controls.