Effect of peripartum dexamethasone treatment on farrowing outcomes and newborn piglet traits in multiparous sows.

This study assessed the effects of dexamethasone treatment on farrowing performance and piglet traits in the first 5 days of life in multiparous sows, a high-risk group for stillbirths and prolonged farrowing. In this study, 185 multiparous sows (parity 4.25 ± 0.14) were selected on the day of farrowing and divided into three treatments: CON - control, without dexamethasone treatment; DexaPF - treatment with dexamethasone (20 mg im per female) at the time of copious colostrum secretion (pre-farrowing); and DexaFO - treatment with dexamethasone (20 mg im per female) when the first piglet was born (farrowing onset). All sows and their litters were monitored for farrowing duration, obstetric interventions, colostrum yield and intake, newborn piglet traits, and piglet performance until 5 d of age. A subsample of 106 females (∼35 per treatment) had their blood glucose concentration checked hourly shortly after the first piglet was born until the end of farrowing. Additionally, blood samples from 42 litters were collected for immunocrit evaluation. The results showed no differences regarding farrowing duration (CON = 258.02 ± 13.81 min; DexaPF = 251.29 ± 13.60 min; DexaFO = 294.92 ± 13.89 min; P = 0.06) and obstetric intervention rates among treatments (CON = 36.58 ± 6.78 %; DexaPF = 42.16 ± 6.89 %; DexaFO = 48.05 ± 7.08 %; P = 0.45). The blood glucose concentration during farrowing was higher in DexaPF (94.56 ± 1.57 mg/dL; P < 0.001) than in CON (73.50 ± 1.72 mg/dL) and DexaFO (87.94 ± 1.80 mg/dL). No differences were observed regarding total piglets born and born alive, stillborn, newborn piglet vitality, colostrum intake, immunocrit, colostrum yield, and glycemia and rectal temperature at 24 h of age (P ≥ 0.13). Regarding meconium staining, higher percentages of piglets born without meconium staining were observed in DexaFO (54.77 ± 5.21 %; P = 0.02) compared with CON (48.58 ± 5.26 %), and no difference was observed for the DexaPF group (53.23 ± 5.21 %). In addition, a higher unbroken umbilical cord rate was observed in DexaFO (92.41 ± 1.31 %; P < 0.01) than the CON or DexaPF (86.91 ± 1.97 % and 89.31 ± 1.67 %, respectively). However, the treatments did not affect piglet performance (weight gain and survival) until 5 d of age (P ≥ 0.15). In summary, dexamethasone treatment in periparturient multiparous sows did not improve farrowing performance and key production parameters, such as the piglet weight gain and survival up to 5 d of age.

Relationship between dexamethasone treatment around parturition of primiparous sows and farrowing performance and newborn piglet traits.

This study evaluated the relationship between the steroidal anti-inflammatory action of dexamethasone treatment in primiparous sows and farrowing and piglet performance in the first 5 d of life. For this purpose, 234 gilts were selected on the day of farrowing and distributed among three treatments: CON - control, without dexamethasone treatment; DexaPF - treatment with dexamethasone (20 mg im) per female at the moment of copious colostrum secretion (pre-farrowing); and DexaFO - treatment with dexamethasone (20 mg im), per female when the first piglet was born (farrowing onset). All females and their litters were evaluated regarding farrowing duration, obstetric interventions, colostrum yield and intake, newborn piglet traits, and piglet performance until 5 d of age. A subsample of 79 females (∼26 per treatment) had their blood glucose concentration evaluated hourly shortly after the first piglet was born until the end of farrowing. Additionally, blood samples from 11 litters per treatment were collected for immunocrit evaluation. As a result, faster farrowing was observed in the DexaPF treatment (188.14 min; P = 0.002) compared with CON (229.99 min) and DexaFO (221.79 min). Additionally, lower obstetric intervention rates were observed in sows treated with dexamethasone (DexaPF = 7.69%; DexaFO = 5.13%) compared with CON (19.23%; P = 0.02). The sow's blood glucose concentration during farrowing was higher in DexaPF (90.55 mg/dL) than in CON (73.15 mg/dL) and DexaFO (80.06 mg/dL) treatments (P < 0.01). Besides the effect on farrowing duration, no differences among treatments were observed regarding piglets born alive and stillbirths, newborn piglet vitality, colostrum consumption, immunocrit, and colostrum yield (P ≥ 0.17). Regarding piglet traits, higher percentages of piglets born without meconium staining and lower percentages of piglets with meconium scores 2 and 3 were observed in the groups treated with dexamethasone (DexaPF and DexaFO; P < 0.01) compared with CON. However, piglet weight gain and survival rate until 5 d of age were not affected by the treatment (P ≥ 0.61). In summary, dexamethasone treatment before farrowing onset, in primiparous sows, had the potential to reduce the farrowing duration and the necessity of obstetric intervention, but it did not affect the main productive parameters such as the occurrence of stillbirths, piglet weight gain, and survival rates until 5 d of age.

Reproductive performance of gilts and weaned sows grouped at different days after insemination.

The objective of the study was to compare the reproductive performances of gilts and weaned sows grouped at different days after insemination. The study was conducted on a sow farm in the Midwest of Paraná State, Brazil, using animals from the Camborough genetic line (PIC®, Patos de Minas, Brazil, Landrace × Large White crossbred). The groups of comparison have considered the distribution of gilts (n = 407) and sows (parity 1 to 5; n = 843) according to the day of group housing in collective pens in relation to the day of last insemination (AI). Thus, gilts were distributed in four groups of comparison: group housing on days 1, 2, 3, or 4 after the last AI (AI). Sows were distributed in three groups of comparison: group housing on the day after the last AI (0), at day 1 or 2 after the last AI. Farrowing rate (FR), the total number of piglets born (TB), and return to estrus (RE) were recorded. In a subsample (254 gilts and 622 sows), the presence and the score of skin lesions (0, no lesions; 1, low; 2, moderate; or 3, high) were evaluated 24 and 48 h after mixing. Statistical analysis was performed using the SAS® 9.4 software using the GLIMMIX procedure. Comparisons of means were performed using the Tukey-Kramer test and frequencies by logistic regression. Group housing gilts on different days after insemination did not affect FR, TB, and RE (P ≥ 0.79). However, sows mixed 2 days after AI had a reduction in TB compared to those mixed on day 1 (P = 0.05), without differences from sows mixed on the day of the last AI. All the females had low (score 1; 60.5%) or moderate (score 2; 39.5%) skin lesions. For both female categories, the presence of low or moderate lesion scores did not affect ER, FR, and TB (P ≥ 0.25). Fights within 48 h were not severe enough to compromise reproductive performance (P ≥ 0.25). In conclusion, group housing gestating sows 2 days after breeding compromised litter size; however, mixing gilts on days 1 to 4 after breeding did not impair reproductive performance.

Follicular dynamic and reproductive performance of gilts submitted to estrous cycle synchronization using two different progestogen sources.

This study evaluated reproductive indicators of gilts treated with altrenogest or an intravaginal device (IVD) containing medroxyprogesterone acetate (MPA) for estrous cycle synchronization, starting the protocol on different days of the estrous cycle or replacing the IVD in the middle of treatment. In Experiment 1, 126 gilts were assigned, according to the day of treatment onset (Day 5 or 10 of the estrous cycle), to the following treatments: Control-5 (no hormone); Control-10 (no hormone); IVD-5 (IVD with MPA); IVD-10 (IVD with MPA); ALT-5 (altrenogest); or ALT-10 (altrenogest). The first day of the previous estrus was considered as Day 0 of the estrous cycle, and progestogen groups were treated for 14 d. In Experiment 2, 63 gilts were assigned to Control, ALT, or IVD groups. Progestogen treatment started on Day 10 of the estrous cycle, and the IVD was replaced after 7 d of treatment. In both experiments, no gilts expressed estrus during progestogen administration. In Experiment 1, the interval hormonal withdrawal-to-estrus (IHE) tended to be shorter when treatment started on Day 10 than on Day 5 (3.6 vs. 4.1 d, respectively; P = 0.09). The percentage of gilts expressing estrus after hormone withdrawal was lower for IVD-gilts (76.3%) compared to ALT (100%) and Control-gilts (92.9%; P ≤ 0.07). The percentage of persistent follicles (PFOL) was greater in IVD-10 (60.0%) and ALT-10 (33.3%) than CONT-10 (0.0%; P ≤ 0.06). The adjusted farrowing rate (AFR) was lower in IVD (65.5%) and ALT (80.5%) compared with CONT (97.4%; P ≤ 0.08). In Experiment 2, the IHE was longer for ALT than IVD (4.9 vs. 3.9 d, respectively; P < 0.01). No difference among groups was observed in the percentage of gilts expressing estrus (overall 86.4%), but the occurrence of PFOL was higher in IVD (61.5%) compared to ALT (5.3%), and Control groups (10.5%; P < 0.01). The AFR was lower in IVD (53.8%) than in ALT (88.2%) and Control (94.7%; P ≤ 0.05). The total number of piglets born was not affected by hormonal treatments in either experiment. Estrous expression was delayed in gilts treated with altrenogest or IVD-MPA. However, the reproductive performance of IVD-gilts was compromised, which was not circumvented by IVD replacement in the middle of treatment. Therefore, further studies are necessary to understand MPA pharmacodynamics and investigate alternative devices for a steady release of progestogens in gilts.