Relationship between piglets' survivability and farrowing kinetics in hyper-prolific sows.

BACKGROUND: Prolonged farrowing and more piglets born with low birth weight are undesirable consequences of genetic selection for increased litter size. The objective of the present observational study was to evaluate the relationship between piglets' survivability and farrowing kinetics in hyperprolific sows. A total of 58 sows of different parities and 1190 piglets were included. The entire farrowing process was monitored and the following parameters were recorded: inter-piglet birth interval, birth order, total born, live born, dead born, and mummified piglets, obstetric intervention, weight at birth and 24h, colostrum yield and intake. RESULTS: The sows included in this study had on average 20.6 ± 0.6 total piglets born, of which 16.4 ± 0.6 were live born, 3.3 ± 0.4 were stillborn and 0.9 ± 0.2 were mummified piglets. The average farrowing duration and average birth interval were 411.3 ± 31.6 and 20.6 ± 1.7 min, respectively. Farrowing duration was positively associated (p < 0.05) with parity, number of stillborn and mummified piglets. Piglet mortality 24h after birth was negatively affected (p < 0.01) by birth weight and positively affected (p < 0.01) by cumulative birth interval. The last tercile of piglets born (birth order ≥ 17) had the highest (p < 0.01) inter-piglet birth interval (IPBI) (43.4 ± 4.17 min) compared to piglets born in the first (birth order between 2 and 7) (26.5 ± 3.8 min) and second (birth order between 8 and 16) terciles (21.9 ± 3.8 min). Cumulative birth interval, birth weight, occurrence of stillborn piglets and manual intervention were positively associated (p < 0.05) with IPBI. Piglet birth weight was also positively associated (p < 0.01) to individual colostrum intake. Piglets ingesting more colostrum had lower (p < 0.01) mortality from 24h after birth until weaning. Sow's parity and cumulative birth interval were positively associated with the presence of stillborn piglets (p = 0.02 and p < 0.01, respectively). CONCLUSION: Reducing farrowing duration may be crucial to decrease stillbirth rate and neonatal mortality in hyperprolific sows. Moreover, special care must be provided to the lighter piglets within a litter to increase their colostrum intake and minimize piglet's mortality throughout lactation.

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.

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.

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.

Acute exposure to hyperosmotic conditions reduces sperm activation by urine in the yellowtail tetra Astyanax altiparanae, a freshwater teleost fish / Exposição aguda a condições hipereosmoticas reduz ativação do sêmen por urina em lambari do-rabo-amarelo (Astyanax altiparanae), um teleósteo de água doce

In freshwater fish with external fertilization, sperm sampling can be contaminated with urine, which triggers motility and gives rise to decreased fertilization success. The maintenance of freshwater fish in hyperosmotic conditions may reduce urine production and improve sperm quality. Thus, the aim of this work was to verify if acute exposure to various NaCl concentrations improves sperm quality in the yellowtail tetra Astyanax altiparanae. Spermiation was induced using a single dose of carp pituitary gland (5 mg kg-1) and the males were maintained at various NaCl concentrations: NaCl 0.00% (control), NaCl 0.45% (hypoosmotic), NaCl 0.9% (isosmotic) and NaCl 1.0% (hyperosmotic) for 6 h at 26 °C. Sperm was collected and verified for activation by urine and motility traits. At 0.00%, 0.45%, and 0.90%, the sperm was motile just after sampling, indicating activation by urine. Surprisingly, at hyperosmotic conditions, no activation was observed. Other sperm and motility parameters did not show any statistical differences, including sperm viability (P = 0.7083), concentration (P = 0.9030), total motility (P = 0.6149), VCL (curvilinear velocity; P = 0.1216), VAP (average path velocity; P = 0.1231) and VSL (straight-line velocity; P = 0.1340). Our results indicate that acute maintenance at hyperosmotic conditions eliminates sperm activation by urine and maintains sperm quality. Such a new procedure is interesting for both basic and applied sciences, including reproductive practice in fish.(AU)

Em peixes de água doce com fertilização externa, a amostragem de espermatozoides pode ser contaminada pela urina, o que desencadeia motilidade e gera menor sucesso na fertilização. A manutenção de peixes de água doce em condições hiperosmóticas pode reduzir a produção de urina e melhorar a qualidade do esperma. Assim, o presente trabalho foi delineado para verificar se a exposição aguda a várias concentrações de NaCl melhora a qualidade do esperma no tetra-amarelo Astyanax altiparanae. A espermiação foi induzida usando uma dose única de hipófise da carpa (5 mg kg-1) e os machos foram mantidos em várias concentrações de NaCl: NaCl 0,00% (controle), NaCl 0,45% (hipoosmótico), NaCl 0,9% (isosmótico) e NaCl 1,0% (hiperosmótico) por seis horas a 26 °C. O esperma foi colhido e verificado quanto à ativação por urina e traços de motilidade. Em 0,00%, 0,45%, 0,90% os espermatozóides eram móveis logo após a amostragem, indicando ativação pela urina. Surpreendentemente, em condições hiperosmóticas, nenhuma ativação foi observada. Outros parâmetros espermáticos e de motilidade não mostraram diferenças estatísticas, incluindo viabilidade espermática (P = 0,7083), concentração (P = 0,9030), motilidade total (P = 0,6149), VCL (Velocidade Curvilinear; P = 0,1216), VMD (Velocidade Média de Deslocamento; P = 0,1230) e VLR (Velocidade em linha Reta; P = 0,1340). Nossos resultados indicam que a manutenção aguda em condições hiperosmóticas elimina a ativação do esperma pela urina e mantém a qualidade do esperma. Esse novo procedimento é interessante para as ciências básicas e aplicadas, incluindo a prática reprodutiva em peixes.(AU)