Changes in skin temperature and behaviors of preweaning Holstein calves in a hot environment monitored by a multimodal tail-attached device.

This study aimed to determine the applicability of a tail-attached device in monitoring animal-based indicators (ABI) associated with changes in environmental conditions in calves through investigating the relationship between sensor-derived ABI and the temperature-humidity index (THI). Furthermore, to identify effective ABI indicative of heat stress status, sensor-derived ABI of calves under differing heat stress levels based on rectal temperature (RT) were compared. The tail-attached device, which is capable of measuring skin temperature (ST), activity intensity, and roll angle along the longitudinal axis of the tail at 3-min intervals, was attached to 99 preweaning female Holstein calves for an average of 4 wk (26.4 ± 6.8 d). After selecting data from mild to hot days (daily average THI of ≥55), physiological (daily maximum tail ST) and behavioral (daily average activity intensity, daily total lying time, and daily total body position change) ABI were computed, and their relationship with the daily average THI was determined using piecewise regression analysis. Additionally, during the hot season, RT of 20 randomly selected tested calves were measured thrice a week (every 2.4 ± 0.5 d), and a comparison was conducted between the ABI of calves with normal RT (<39.5°C) and those with high RT (≥39.5°C), utilizing data from days characterized by potential heat stress (daily average THI of ≥75). During the study, ambient temperature (°C) and relative humidity (%) were recorded every 10 min using an automatic digital data logger, from which the daily average THI was calculated. Piecewise regression analysis identified THI breakpoints of 73.6 for tail ST, 79.1 for average activity intensity, 72.3 for lying time, and 79.1 for position change. All the tested ABI tended to increase as THI increased, and this trend was pronounced in tail ST, activity intensity, and position change after the breakpoint. These 3 ABI were higher in calves with high RT compared with those with normal RT, whereas lying time shared similar values between the RT groups. Overall, these findings suggest that the tail-attached device can simultaneously monitor both physiological and behavioral ABI in calves, and among the ABI, tail ST, activity intensity, and position change are the effective ABI indicative of heat stress status.

Effect of exogenous oestrogen treatment frequency on induction of artificial lactation in pseudopregnant sows.

In this study, we examined whether the frequency of exogenous oestrogen treatment affects the induction of artificial lactation and milk production. Furthermore, we analysed changes in milk components obtained from artificially lactating sows. Pseudopregnant induced by treatment with 30 mg of estradiol dipropionate (EDP) on Day 10 (Day 0 = the last day of estrus) were divided into three groups: those administered 5 mg of EDP once on Day 39 (n = 5), twice on Days 32 and 39 (n = 5) and three times on Days 25, 32 and 39 (n = 6). All animals were treated with prostaglandin F2α (PGF2α) on Day 46 for induced lactation. Artificial lactation was induced in 66.7%-80.0% of sows, and the EDP treatment frequency before PGF2α administration had no significant effect on either the induction rate of artificial lactation or the milk yield during the experimental period. The milk composition (levels of crude protein, crude fat, crude ash, lactose and immunoglobulin) did not differ among the groups. In conclusion, the number of EDP treatments prior to PGF2α administration had no effect on either the efficiency of artificial lactation induction or milk production.

Effect of pseudopregnancy duration in nonpregnant sows on induced lactation.

This study was conducted to examine the effects of different pseudopregnancy periods in nonpregnant sows on artificial lactation induction efficiency and milk composition. Sixteen pseudopregnant sows (n = 4 per group) were treated with 5 mg of estradiol dipropionate at 28 (Group D38), 35 (Group D45), 42 (Group D52), and 49 (Group D59) days after the end of estrus, followed by prostaglandin F2α as 0.175-mg cloprostenol twice at 12 h intervals 10 days later. The overall success rate of lactation induction was 81.3%. The lactation rates were significantly higher in Groups D38, D45, and D59 (100.0%) than in Group D52 (25.0%). The milk immunoglobulin (Ig) G concentration was significantly higher in Group D38 than in Group D59. However, IgA levels and milk compositions (protein, ash, and lactose) did not differ among the groups. Lactation induction was successful between 38 and 59 days of pseudopregnancy. Apart from IgG, pseudopregnancy length did not affect milk components from 38 to 59 days of pseudopregnancy.

Uterine epithelial Gp130 orchestrates hormone response and epithelial remodeling for successful embryo attachment in mice.

Leukemia inhibitory factor (LIF) receptor, an interleukin 6 cytokine family signal transducer (Il6st, also known as Gp130) that is expressed in the uterine epithelium and stroma, has been recognized to play an essential role in embryo implantation. However, the molecular mechanism underlying Gp130-mediated LIF signaling in the uterine epithelium during embryo implantation has not been elucidated. In this study, we generated mice with uterine epithelium specific deletion of Gp130 (Gp130 ecKO). Gp130 ecKO females were infertile due to the failure of embryo attachment and decidualization. Histomorphological observation revealed that the endometrial shape and embryo position from Gp130 ecKO were comparable to those of the control, and uterine epithelial cell proliferation, whose attenuation is essential for embryo implantation, was controlled in Gp130 ecKO. Comprehensive gene expression analysis using RNA-seq indicates that epithelial Gp130 regulates the expression of estrogen- and progesterone-responsive genes in conjunction with immune response during embryo implantation. We also found that an epithelial remodeling factor, snail family transcriptional repressor 1 (Snai1), was markedly reduced in the pre-implantation uterus from Gp130 ecKO. These results suggest that not only the suppression of uterine epithelial cell proliferation, but also Gp130-mediated epithelial remodeling is required for successful implantation in mice.

Effect of Porcine Colostral Exosomes on T Cells in the Peripheral Blood of Suckling Piglets.

Growing evidence indicates that porcine colostral exosomes may contribute to the healthy development of piglets. Here, we evaluated in vitro the effect of porcine milk-derived exosomes, in particular colostral exosomes, on T cells in the peripheral blood of suckling piglets. A total of seven sows and thirteen suckling piglets were used. Peripheral blood mononuclear cells (PBMCs) from suckling piglets were cultured with or without milk-derived exosomes (control). Using flow cytometry, the proportion of each T cell subset in cultured PBMCs was analyzed three days post-incubation. PBMCs cultured with porcine colostral exosomes had a higher proportion of CD3+CD4-CD8+ T cells (cytotoxic T cells; Tc) than the control. However, exosomes induced no increase in the Tc cell population in PBMC whose endocytosis was inhibited. We further measured the concentrations of cytokines in the culture supernatant. Exosome-treated PBMCs had a higher cytokine IL-2 concentration than the control. The present study demonstrated that porcine colostral exosomes could increase the Tc cell proportion in the peripheral blood of suckling piglets, with the underlying mechanism believed to be the stimulation of IL-2 production in PBMCs via endocytosis. Moreover, our results suggested that porcine colostral exosomes were involved in the development of cellular immunity in suckling piglets.

Macroglossia in a pig diagnosed as Becker muscular dystrophy due to dystrophin pseudoexon insertion derived from intron 26.

We report a case of Becker muscular dystrophy in a 6-month-old, mixed-breed, castrated male pig detected with macroglossia at a meat inspection center. The pig presented a severely enlarged tongue extending outside its mouth. The tongue was firm and pale with discolored muscles. Histologically, there was severe fibrosis, fatty replacement, and myofiber necrosis, degeneration, and regeneration. Immunofluorescence showed focal and severely weak labeling for dystrophin at the sarcolemma of myocytes in the tongue. Analysis of dystrophin mRNA showed a 62 base pair insertion between exons 26 and 27. The insertion was derived from intron 26. Based on these findings, we diagnosed the case as Becker muscular dystrophy-the first known muscular dystrophy case induced by pseudoexon insertion in animals.

Induction of short-term pseudopregnancy in gilts by the administration of estradiol benzoate or estradiol dipropionate to achieve ovulatory synchronization for embryo collection.

A study was conducted to investigate whether ovulation in gilts could be synchronized for embryo collection by the administration of estradiol benzoate (EB) or estradiol dipropionate (EDP) to induce pseudopregnancy, followed by the treatment with prostaglandin F2α (PGF2α ) on 10 days after. Ten gilts each received a total of 20 mg of EB or EDP on Day 10 or EB on Day 10 and 14 to induce pseudopregnancy (Day 0 = onset of estrus). Donors received PGF2α 10 or 15 days (as a control) after the first administration of estrogens and subsequently eCG and hCG, and were then inseminated artificially. The embryos were collected 7 days after the administration of hCG, and assessed for embryo yield and their developmental stages. All protocols resulted in good embryo yield (9.8-13.2 embryos in average), and the embryos showed average ability to develop to the expanded blastocyst stage (3.29-4.03 as developmental scores) without any significant differences among the protocols. These results suggest that the administration of PGF2α 10 days after the treatment of gilts with EB or EDP would allow synchronization of ovulation and embryo collection, as well as shortening the period from estrus detection to embryo collection, thus improving embryo collection efficiency.

Artificial lactation by exogenous hormone treatment in non-pregnant sows.

This study aimed to determine if lactation can be induced by exogenous hormonal treatment in non-pregnant sows. In experiment 1, pseudopregnant animals were divided into four groups and given: 1) 5 mg of estradiol dipropionate (EDP) 5 days before (n = 4), 2) 5 mg of EDP 10 days before (n = 3), 3) 10 mg of EDP 5 days before (n = 3) or 4) 10 mg of EDP 10 days (n = 3) before PGF2α treatment. Artificial lactation was induced in seven pseudopregnant sows (53.8%) by exogenous hormonal treatment. There was no significant effect of either an increased EDP dosage or interval from the EDP treatment to PGF2α treatment on the induction rate of artificial lactation. In experiment 2, milk samples were collected from artificial lactating and natural lactating sows (n = 6). IgG and IgA levels in the milk collected from both groups were significantly associated with time during the experimental period. Milk IgG levels 24 h after PGF2α treatment in artificial lactating sows were higher than those in the colostrum of lactating sows. In experiment 3, hormonal profiles in pseudopregnant sows with (n = 3) or without (n = 3) EDP treatment were determined. There was a significant difference in estradiol-17ß levels on days 8, 7 and 5 before PGF2α treatment between groups. Progesterone and prolactin concentrations did not differ between groups. The present study revealed for the first time that lactation could be induced by exogenous hormonal treatment in non-pregnant sows and that the milk collected from these sows contained high immunoglobulin levels.

Pharmacokinetics in plasma and alveolar regions of healthy calves subcutaneously administered a single dose of enrofloxacin.

This study aimed to analyze the pharmacokinetics of enrofloxacin (ERFX) and its metabolite ciprofloxacin (CPFX) in plasma, as well as their migration to, and retention in, the epithelial lining fluid (ELF) and alveolar cells within the bronchoalveolar fluid (BALF). Four healthy calves were subcutaneously administered a single dose of ERFX (5 mg/kg). ERFX and CPFX dynamics post-administration were analyzed via a non-compartment model, including the absorption phase. The Cmax of plasma ERFX was 1.6 ± 0.4 µg/ml at 2.3 ± 0.5 hr post-administration and gradually decreased to 0.14 ± 0.03 µg/ml at 24 hr following administration. The mean residence time between 0 and 24 hr (MRT0-24) in plasma was 6.9 ± 1.0 hr. ERFX concentrations in ELF and alveolar cells peaked at 3.0 ± 2.0 hr and 4.0 ± 2.3 hr following administration, respectively, and gradually decreased to 0.9 ± 0.8 µg/ml and 0.8 ± 0.5 µg/ml thereafter. The plasma half-life (t1/2) of ERFX was 6.5 ± 0.7 hr, while that in ELF and alveolar cells was 6.5 ± 3.6 and 7.4 ± 4.3 hr, respectively. The Cmax and the area under the concentration-time curve for 0-24 hr for ERFX were significantly higher in alveolar cells than in plasma (P<0.05). These results suggest that ERFX is distributed at high concentrations in ELF and is retained at high concentrations in alveolar cells after 24 hr in the BALF region; hence, ERFX may be an effective therapeutic agent against pneumonia.

Day of prostaglandin F2α administration after natural ovulation affects the interval to ovulation, the type of ovulated follicle, and the failure to induce ovulation in cows.

The factors that affect the interval to ovulation, the type of ovulated dominant follicle (DF), and the cause of anovulation after prostaglandin (PG) treatment were investigated. Nine cows were assigned to six groups (54 cows in total) but the group size was later fixed at eight cows (48 in total). They received 25 mg tromethamine dinoprost as dinoprost on Day 6 (Group D6), Day 7 (Group D7), Day 8 (Group D8), Day 9 (Group D9), Day 10 (Group D10), or Day 11 (Group D11) after natural ovulation (Day 0). If the DF did not ovulate, then the cow was assigned to Group NO. In Group D6, the 1st DF ovulated in all cows 4 days after PG treatment, whereas in Groups D9, D10, and D11, the 2nd DF ovulated in all cows 4 to 7 days after PG treatment. In 10 cows, the DF did not ovulate, and late anovulation was significantly higher in Group D6 cows than in Group D11 cows. The progesterone (P4) levels decreased to less than 1 ng/ml in all groups on the day after PG treatment. The estradiol-17ß (E2) levels began to increase after PG treatment and peaked at 2 days before ovulation in the cows that ovulated. In anovulated cows, E2 tended to be higher and there was no clear E2 peak in some cows. These results indicated that the number of days to ovulation, the type of ovulated DF, and anovulation were affected by factors that were associated with the DF when it was producing E2.

Embryo collection from pigs post-pseudopregnancy induced by estradiol dipropionate.

We aimed to define whether embryo collection carried out after pseudopregnancy was of similar outcome and quality as after artificial abortion. To induce pseudopregnancy, 30 gilts or sows were given 20 mg intramuscular estradiol dipropionate (EDP) 10-11 days after the onset of estrus. Ten additional pigs were inseminated artificially at natural estrus as a control group. Prostaglandin F2α (PGF2α ) was administered twice with a 24 hr interval beginning 15, 20, or 25 days after EDP-treatment (n = 10 per group) or between 23 and 39 days after artificial insemination in control pigs. Following this, all pigs were given 1,000 IU equine chorionic gonadotropin and 500 IU human chorionic gonadotropin (hCG) and then inseminated. Embryos were recovered 6 or 7 days after hCG treatment and outcome was recorded. There was no significant difference in the number of normal embryos collected from the pigs with PGF2α initiated at different time points or from the control group. Embryonic developmental stages 7 days after hCG treatment also did not differ among groups. These results indicate that the use of EDP to induce pseudopregnancy, followed by PGF2α administration to synchronize estrus for subsequent embryo harvest, is a suitable alternative to the artificial abortion method.

The In Vivo and In Vitro Toxicokinetics of Citreoviridin Extracted from Penicillium citreonigrum.

Citreoviridin (CTVD), a mycotoxin called yellow rice toxin, is reported to be related to acute cardiac beriberi; however, its toxicokinetics remain unclear. The present study elucidated the toxicokinetics through in vivo experiments in swine and predicted the human toxicokinetics by comparing the findings to those from in vitro experiments. In vivo experiments revealed the high bioavailability of CTVD (116.4%) in swine. An intestinal permeability study using Caco-2 cells to estimate the toxicokinetics in humans showed that CTVD has a high permeability coefficient. When CTVD was incubated with hepatic S9 fraction from swine and humans, hydroxylation and methylation, desaturation, and dihydroxylation derivatives were produced as the predominant metabolites. The levels of these products produced using human S9 were higher than those obtained swine S9, while CTVD glucuronide was produced slowly in human S9 in comparison to swine S9. Furthermore, the elimination of CTVD by human S9 was significantly more rapid in comparison to that by swine S9. These results suggest that CTVD is easily absorbed in swine and that it remains in the body where it is slowly metabolized. In contrast, the absorption of CTVD in humans would be the same as that in swine, although its elimination would be faster.

Development of a Model of Porcine Epidemic Diarrhea in Microminipigs.

Porcine epidemic diarrhea virus (PEDV) induces an often fatal gastrointestinal disease in piglets. In this study, we performed a PEDV infection experiment with the Microminipig, the smallest of experimental minipigs, as a novel small animal model. We orally inoculated a neonatal Microminipig with an intestinal homogenate of a PEDV-infected pig and housed it in a small cage originally designed for rats in an animal biosafety level 2 facility. The infected Microminipig showed the typical signs of porcine epidemic diarrhea (PED), such as watery diarrhea, loss of appetite and weight loss. We also recognized a high amount of excreted PEDV in its rectal swabs and villus atrophy of the small intestine. These results suggest that the Microminipig is a good small animal model for PED, which may contribute to a better understanding of the pathogenesis of PEDV.

Effects of Dietary and Lighting Conditions on Diurnal Locomotor Activity and Body Temperature in Microminipigs.

The effects of dietary and lighting conditions on diurnal rhythm of locomotor activity (LA) and body temperature (BT) using four adult male microminipigs were investigated. Different feeding times, diet and lighting conditions were applied sequentially for 3 weeks in each phase as follows: Phase I: Morning mealtime, normal diet, 12-h lights on; phase II: mealtime changed to afternoon; phase III: diet changed to high-fat diet; phase IV: lighting changed to 20-h on; and phase V: phase I repeated. LA was measured by an actigraph which was worn on the body of each pig. A BT recording module (Thermochron Type-SL) was implanted in the neck subcutaneously. Phase II increased BT compared with phase I. Phase III increased LA and BT compared with phase II. Phase IV increased LA compared with phase III. LA in phase V was higher compared with phase I. These results can be extrapolated to other diurnal animals such as humans. This study provides an example of the effects of diet and lighting on biological activities in microminipigs under low-invasive procedures measuring LA and BT, leading to low variations in these measures.

Corpus luteum Regression Induced by Prostaglandin F2α in Microminipigs During the Normal Estrous Cycle.

Induction of corpus luteum regression and subsequent estrus using prostaglandin F2α (PGF2α) in microminipigs was investigated. Microminipigs with normal estrous cycle were treated with PGF2α as 0.75 mg (0.75 PG group, n=3) or 1.5 mg (1.5 PG group, n=4) dinoprost injected into the vulva at 24-h intervals at 10 days after the onset of estrus (D0), D1 and D2. Three microminipigs were not treated (control group). The estrous interval in the 1.5 PG group was significantly shortened compared to the control and 0.75 PG groups. Plasma progesterone levels started to decline and reached the base line in the 1.5 PG group significantly faster than in the control group. In conclusion, we demonstrate that multiple PGF2α treatments can induce corpus luteum regression and estrous synchronization in female microminipigs.

Transrectal guidance of the ovaries reduces operative time during bovine laparoscopic ovariectomy.

The main objective of this study was to evaluate the effects of transrectal guidance of the ovaries by an assistant on operative time during bovine laparoscopic ovariectomy. Twenty four clinically healthy Holstein dairy cows were divided randomly into two groups. In the transrectal guidance group, an assistant grasped the ovaries via the transrectal route and pulled them to a position where they could be visualized with a camera. On the other hand, the control group was operated without guidance. The time required to remove both ovaries in the guidance group was shorter than that in the control group (P<0.01). We concluded that laparoscopic ovariectomy with transrectal guidance of the ovaries can substantially shorten operative time, thereby greatly contributing to animal welfare and to reducing the burden on the operator.

The effect of porcine epidemic diarrhea (PED) on ovarian function and reproductive performance after weaning in Berkshire sows.

The purpose of this study was to investigate the ovarian condition at weaning and subsequent reproductive performance of Berkshire sows following an outbreak of PED. This study was conducted on a farrow-to-finish farm that experienced a PED outbreak beginning on January 6, 2014. Blood samples were collected at weaning from 19 to 20 sows every month from July 2013 until July 2014 to investigate the ovarian condition. The mean progesterone concentration was numerically higher during January 2014 than the other months, but this difference was not significant. The mean estradiol-17ß concentration was higher during January 2014 than during July and October 2013 (P < 0.05). In addition, reproductive performance was compared during January, February, and March before (2013) and after (2014) the PED outbreak. Sows that farrowed in January had higher preweaning mortality in 2014 than in 2013 (P < 0.05), but sows that farrowed in February and March had similar preweaning mortality in 2013 and 2014 (P > 0.10). Sows that farrowed between January and March 2014 had 15% lower farrowing rate than those that farrowed during the same months in 2013 (P < 0.05). In conclusion, our results demonstrate poorer reproductive performance of Berkshire sows after a PED outbreak compared with before the outbreak.

Birth of Cloned Microminipigs Derived from Somatic Cell Nuclear Transfer Embryos That Have Been Transiently Treated with Valproic Acid.

In our previous study, we found that treatment of miniature pig somatic cell nuclear transfer (SCNT) embryos with 4 mM valproic acid (VPA), a histone deacetylase inhibitor, for 48 hours after activation enhanced blastocyst formation rate and octamer-binding transcription factor-3/4 (Oct-3/4) gene expression at the late blastocyst stage; however, the production of viable cloned pups failed, when those VPA-treated SCNT embryos were transferred to recipients. This failure suggests that the present VPA treatment is suboptimal. In the present study, we explored the optimal conditions for VPA to have beneficial effects on the development of SCNT embryos. When miniature pig SCNT embryos were treated with 8 mM VPA for 24 hours after activation, both the rates of blastocyst formation and blastocysts expressing the Oct-3/4 gene were significantly (p < 0.05) improved. A similar increase in blastocyst formation was also observed when microminipig-derived cells were used as SCNT donors. Five cloned piglets were obtained after the transfer of 152 microminipig SCNT embryos that had been treated with 8 mM VPA for 24 hours. The results indicated that a short duration of treatment with VPA improves the development of both miniature pig and microminipig SCNT embryos, possibly via an enhanced reprogramming mechanism.

Estrus synchronization in microminipig using estradiol dipropionate and prostaglandin F2α.

The induction of pseudopregnancy by the exogenous administration of estradiol dipropionate (EDP) was investigated in cyclic Microminipigs (MMpigs) and the effects of exogenous administration of prostaglandin (PG) F2α on estrus exhibition were assessed in pseudopregnant MMpigs. In experiment 1, ovariectomized MMpigs were given a single intramuscular injection of 0.5, 1.5, or 2.5 mg of EDP. The estradiol-17ß level at each of these doses was significantly higher 1 to 3 days after EDP administration than on the day of the injection. In experiment 2, animals were given 1.5 mg of EDP once at 9 to 12 days after the end of estrus (D0) and then no (1.5 mg × 1 group), one (D0 and D4; 1.5 mg × 2 group), or two (D0, D4 and D7; 1.5 mg × 3 group) additional treatments. The pseudopregnancy rate was significantly higher in the 1.5 mg × 3 than in the 1.5 mg × 1 group. In experiment 3, PGF2α was administered twice between 26 and 28 days after EDP treatment to five pseudopregnant gilts with a 24-h interval between the two injections. Estrus after PGF2α treatment and LH surge were observed in 100% and 80% pseudopregnant MMpigs, respectively. The interval from the day of the first PGF2α treatment to the onset of estrus was 6.5 ± 0.2 days. These results indicate that multiple EDP treatments are required for induction of pseudopregnancy in MMpigs and estrus exhibition can be controlled in MMpigs by treatment with EDP and PGF2α.

Microminipigs as a new experimental animal model for toxicological studies: comparative pharmacokinetics of perfluoroalkyl acids.

In this study, we evaluated the efficacy of a novel minipig strain, the Microminipig (MMPig), as an animal model for studying the pharmacokinetics of a mixture of 10 perfluoroalkyl acids (PFAAs). After a single oral dose was given, we found that the blood depuration of PFAAs (blood t1/2), which we calculated using first-order elimination curves, ranged from 1.6 to 86.6 days. Among the five body compartments analyzed, the liver was the greatest site of accumulation of perfluorooctanesulfonate and longer chain perfluorinated carboxylates such as perfluorodecanoic acid, perfluoroundecanoic acid and perfluorododecanoic acid. We observed an increasing accumulation trend of perfluorinated carboxylates in the organs associated with the fluorinated carbon chain length. The perfluorononanoic acid burden was the highest among the treated compounds 21 days after a single exposure, as 29% of the given perfluorononanoic acid dose was accumulated in the tissues. The persistence of PFAAs in edible pig tissues even after 21 days post-exposure raises concerns about the safety of swine products. This was the first study to use MMPigs to elucidate the pharmacokinetics of a group of environmental pollutants. We found that MMPigs could be excellent experimental animals for toxicological studies due to their easy handling, cost efficacy for target compounds and ease of waste treatment.