Estrus Synchronization of Replacement Gilts Using Estradiol Cipionate and PGF2α and Its Effects on Reproductive Outcomes.

In this study, we evaluated the effectiveness of using estrogen-induced prolonged luteal function followed by prostaglandin F2 alpha (PGF2α) treatment to synchronize estrus in gilts. On day12 of the estrus cycle (D0 = first day of standing estrus), 52 gilts were assigned at random to two experimental groups: non-treated gilts (CON, n = 22), serving as controls, and prolonged luteal function group (CYP, n = 30), receiving a single treatment with 10 mg of estradiol cypionate intramuscularly Starting on day 12, blood samples were collected for estradiol and progesterone assays. Estrus detection started on day 17. Gilts from the CON group were inseminated at the onset of natural estrus. On day 28 CYP gilts were treated with PGF2α to induce luteolysis and inseminated at the onset of estrus. Gilts were slaughtered 5 d after the last insemination. A single treatment with estradiol cypionate prolonged luteal function in 90% of treated gilts. The duration of the estrous cycle was longer (p < 0.0001) for CYP gilts compared to CON gilts. CYP gilts showed synchronized estrus 3.96 ± 0.19 d after induction of luteolysis. The conception rate was similar (p = 0.10) for CON and CYP gilts. No difference was observed in the embryo recovery rate (p = 0.18) and total number of embryos per female (p = 0.06). The percentage of unfertilized oocytes, fragmented embryos and viable embryos was similar among females from CON and CYP groups (p > 0.05). The treatment of gilts with a single application of 10 mg of estradiol cypionate on day 12 of the estrous cycle was effective in prolonging luteal function and treatment with PGF2α resulted in synchronized estrus. Additionally, the synchronization protocol had no deleterious effect on fertility and embryonic development.

Impact of cryopreservation protocols (one- and two-step) on boar semen quality at 5 °C and post-thawing.

The two-step protocol (2 S) is currently used for boar semen cryopreservation. In this method, the cryoprotectant penetrant agents (CPAs) are added at 5 °C to reduce the toxicity of CPAs. An alternative is the one-step protocol (1 S), which is easier, cheaper, and reduces the necessity of equipment, but could increase the toxicity of CPAs. Currently, there are no studies that compared both protocols for boar semen cryopreservation. This experiment aimed to study the effect of cryopreservation protocol (1 S vs 2 S) on boar spermatozoa. In the one-step protocol, after centrifugation, the spermatozoa pellet was resuspended at 17 °C in the extender containing CPAs to achieve a concentration of 1 × 109 spermatozoa/mL and then submitted to cryopreservation. For the two-step protocol, the sperm pellet was resuspended in fraction A at 17 °C to achieve a concentration of 1.5 × 109 spermatozoa/ mL, and then allowed to cool to 5º C before fraction B with CPA was added to the sample to achieve a final concentration of 1 × 109 spermatozoa/mL and followed by freezing. The cryopreservation protocol did not impact total motility at 5 °C (1 S: 78.5 % vs 2 S: 79 %, p > 0.05). After thawing, the two-step protocol improved (p < 0.05) total (1 S: 18.2 % vs 2 S: 29.5 %) and progressive motility (1 S: 9 % vs 2 S: 15%). Further, the 2 S protocol increased (p < 0.05) the percentage of rapid spermatozoa (1 S: 8.7 % vs 2 S: 14.6 %) and spermatozoa with intact plasma and acrosomal membrane (IAIP) (1 S: 40.5 % vs 2 S: 61.5 %), and increased (p < 0.05) live sperm cells with high mitochondrial potential (MHIP) (1 S: 42.9 % vs 2 S: 60 %). The boar semen cryopreservation method (TRT) did not (p > 0.05) alter membrane lipid disorder, lipid peroxidation, and superoxide anion. Thus, the best method for boar semen cryopreservation is the two-step protocol.

Altrenogest Supplementation during Early Pregnancy Improves Reproductive Outcome in Pigs.

Progesterone plays an important role in initial conceptus development and in a successful pregnancy, but results related to progesterone or its analogues (altrenogest) supplementation in early pregnancy of pigs are conflicting. The present study evaluated the effects of altrenogest supplementation in sows during days 6 and 12 of pregnancy on reproductive performance. On day 6 of pregnancy, 301 females were allocated at random to one of the following treatments: CON (Control: non-supplemented females, n = 163) or ALT (females daily supplemented with 20 mg of altrenogest, orally, from day 6 to 12 of pregnancy, n = 138). Ovulation was considered as occurred at 48 h after the first estrus detection to standardize the first day of pregnancy. The supplementation increased the number of total piglets born (ALT: 17.3 ± 0.4; CON: 16.6 ± 0.4), piglets born alive (ALT: 15.6 ± 0.4; CON: 14.8 ± 0.3), and placenta weight (ALT: 4.2 ± 0.1; CON: 3.8 ± 0.1) and decreased the stillbirth rate (ALT: 5.9 ± 0.6; CON: 7.6 ± 0.6) and the number of piglets born weighing less than 800 g (ALT: 6.6 ± 0.6; CON: 8.0 ± 0.6), without impairment on farrowing rate. These results demonstrated that altrenogest supplementation on swine females between days 6 and 12 of pregnancy may be used to improve reproductive performance.

Causes of Sow Mortality and Risks to Post-Mortem Findings in a Brazilian Intensive Swine Production System.

The present study was conducted to investigate the risk factors for post-mortem findings and causes of sow mortality. A post-mortem examination and microbiological investigation were conducted on 123 sows from a breeding herd with 15,000 dams. The mortality of spontaneous death in sows occurred mostly in the peripartum period (53%; p < 0.05). The spontaneous deaths were associated with heart failures, hemorrhagic and perforating gastric ulcers, and liver torsion, while in the euthanized sows, the post-mortem findings were associated with locomotor disorders. A higher body condition score (BCS ≥ 3.5) increased (p < 0.05) heart failure on the post-mortem examination. The excessive use of manual obstetric interventions increased sow deaths resulting from cervix/uterus ruptures and increased the odds of death (p < 0.05) due to metritis. Sow mortality had a multifactorial etiology. Infections were polymicrobial. The main microbial agents identified from a septic lesion in locomotor, genitourinary, and respiratory systems were Trueperella pyogenes, Escherichia coli, and Actinobacillus pleuropneumoniae, respectively. In conclusion, sow mortality involved multiple risk factors and several bacterial agents. These results indicate that better management practices can reduce sow mortality in swine production and increase sow welfare.

Altrenogest during early pregnancy modulates uterine glandular epithelium and endometrial growth factor expression at the time implantation in pigs.

This study evaluated the effects of supplying altrenogest from day 6-12 of pregnancy on the endometrial glandular epithelium, corpora lutea (CL) morphology, and endometrial and CL gene expression. A total of 12 crossbred females (Landrace × Large White) were used. The females were assigned to 4 treatments according to a random design with a 2 × 2 factorial arrangement, with two categories (sow or gilt) and two treatments (non-treated and treated with altrenogest). On day 6 of pregnancy, animals were allocated to one of the following groups: non-treated (NT, n = 6; 3 sows and 3 gilts), and (T, n = 6; 3 sows and 3 gilts) treated daily with 20 mg of altrenogest, from day 6-12 of pregnancy. All animals were euthanized on day 13 of pregnancy. All CLs were individually weighed, and their volume were determined. The endometrial glandular density (GD), mean glandular area (MGA), and vascular density (VD) were determined by histomorphometric and immunohistochemical analyses. Endometrium samples were collected and analyzed by qRT-PCR to evaluate the abundance of transcripts for VEGF and IGF-I. Females in the T group had higher MGA (P < 0.05) compared to the NT group. There was no effect of treatment on GD or VD for both experimental groups. Sows in the T group had augmented expression of IGF-I (P < 0.05). Progestagen had no detrimental effect on CL morphology. In conclusion, altrenogest improves the uterine environment during the peri-implantation period in pigs without compromising corpora lutea development.

Vagococcus sp. a porcine pathogen: molecular and phenotypic characterization of strains isolated from diseased pigs in Brazil.

INTRODUCTION: Vagococcus spp. is known for its importance as a systemic and zoonotic bacterial pathogen even though it is not often reported in pigs. This is related to the pathogen misidentification due to the lack of usage of more discriminatory diagnostic techniques. Here we present the first report of Vagococcus lutrae in swine and the characterization of Vagococcus fluvialis and Vagococcus lutrae isolated from diseased animals. METHODOLOGY: Between 2012 and 2017, 11 strains with morphological characteristics similar to Streptococcus spp. were isolated from pigs presenting different clinical signs. Bacterial identification was performed by matrix assisted laser desorption ionization time of flight (MALDI-TOF) mass spectrometry and confirmed by 16S rRNA sequencing and biochemical profile. Strains were further genotyped by single-enzyme amplified fragment length polymorphism (SE-AFLP). Broth microdilution was used to determine the minimal inhibitory concentration of the antimicrobials of veterinary interest. RESULTS: Ten strains were identified as V. fluvialis and one was identified as V. lutrae. The SE-AFLP analysis enabled the species differentiation with specific clustering of all V. fluvialis separately from the V. lutrae strain. Most strains presented growth in the maximum antibiotic concentration values tested for eight of the 10 analyzed antimicrobial classes. CONCLUSIONS: The observed resistance pattern can represent a problem for veterinary and producers in the treatment of diseases associated Vagococcus spp. in swine production. Vagococcus species may also be a risk for pig industry workers. The data described here will be of great value in further understanding the behavior of this pathogen in animal production.