Detection of Mycoplasma hyopneumoniae viability using a PCR-based assay.

Mycoplasma hyopneumoniae detection in clinical specimens is accomplished by PCR targeting bacterial DNA. However, the high stability of DNA and the lack of relationship between bacterial viability and DNA detection by PCR can lead to diagnostic interpretation issues. Bacterial messenger RNA is rapidly degraded after cell death, and consequently, assays targeting mRNA detection can be used for the exclusive detection of viable bacterial cells. Therefore, this study aimed at developing a PCR-based assay for the detection of M. hyopneumoniae mRNA and at validating its applicability to differentiate viable from inert bacteria. Development of the RNA-based PCR encompassed studies to determine its analytical sensitivity, specificity, and repeatability, as well as its diagnostic accuracy. Comparisons between DNA and mRNA detection for the same target gene were performed to evaluate the ability of the RNA-based PCR to detect exclusively viable M. hyopneumoniae after bacterial inactivation using various methods. The RNA-based PCR was also compared to the DNA-based PCR as a tool to monitor the growth of M. hyopneumoniae in vitro. Under the conditions of this study, the developed RNA-based PCR assay detected only viable or very recently inactivated M. hyopneumoniae, while the DNA-based PCR consistently detected cells irrespective of their viability status. Changes in growth activity over time were only observable via RNA-based PCR. This viability PCR assay could be directly applied to evaluate the clearance of M. hyopneumoniae or to determine the viability of the bacterium at late stages of eradication programs.

Evaluation of Improvest effects on production parameters of gilts from two different genetic sire lines.

The objective was to evaluate the effects of Improvest on the performance and carcass characteristics of gilts from two different genetic sire lines and the performance of Improvest gilts with castrated male pigs. It was hypothesized that performance parameters observed for Improvest gilts would be similar to barrows, thus narrowing the performance gaps between traditionally managed gilts and barrows. Pigs were from Large White/Landrace dams and either Duroc-Pietrain (DP) or Duroc (D) sires. Females within each genetic sire line were randomized by weight to receive the first dose of Improvest (IMP) on day 25 of the study or to serve as a nontreated control (DP IMP gilt (n = 6 pens; 19 pigs/pen), D IMP gilt (n = 6 pens; 19 pigs/pen), DP CON gilt (n = 6 pens; 19 pigs/pen), D CON gilt (n = 6 pens; 19 pigs/pen). The second dose of Improvest was administered 6 wk later (i.e., day 67). Barrows did not receive Improvest (DP barrow [n = 10 pens; 19 to 20 pigs/pen], D barrow [n = 10 pens; 19 to 20 pigs/pen]). Average daily gain (ADG), average daily feed intake (ADFI), and gain-to-feed ratio (G:F) were measured at 21 d intervals throughout the duration of the study. The targeted weight for pigs to be marketed was 133 ±â€…2.5 kg. Carcass characteristics and loin quality parameters were evaluated on a subset of pigs (n = 283). Improvest-treated gilts of both genetic lines had increased (P ≤ 0.05) ADG and ADFI compared to untreated gilts during the post-second dose intervals with values exceeding that of barrows from day 84 to marketing. Overall, DP IMP gilts had increased (P ≤ 0.05) G:F post-second dose compared to DP CON gilts and DP barrows, yet all other treatments were similar. As pigs were marketed at a similar weight, there was no difference in the final weight, however, DP IMP gilts and DP barrows reached market weight sooner (P ≤ 0.05) than DP CON gilts (109.9 and 111.8 vs. 114.3 ±â€…0.8 d). Backfat and loin weight were greater (P < 0.01) in IMP gilts versus CON gilts, while IMP gilts and barrows had similar values within each respective genetic sire line. There were no differences between treatments (P ≥ 0.08) for pH and instrumental color of the loins. When the pass rate of loins (Japanese color score ≥ 3.0 and marbling ≥ 2.0) was evaluated, IMP gilts were at intermediate values between CON gilts and barrows for each respective genetic sire line. Overall, Improvest within a genetic line improved gilt carcass measurements so that they were more similar to barrows.

Timing of maternal nutrient restriction during mid- to late-gestation influences net umbilical uptake of glucose and amino acids in adolescent sheep.

Previous research demonstrated that maternal nutrient restriction during mid- to late-gestation influenced net umbilical uptakes of glucose and amino acids in sheep. However, it is unclear how the timing and duration of nutrient restriction during mid- to late-gestation influences net uterine, uteroplacental, and fetal flux of glucose and amino acids. On day 50 of gestation, 41 adolescent ewe lambs carrying singletons were randomly assigned to one of six dietary treatments: 1) 100% of nutrient requirements from days 50 to 90 of gestation (CON; n = 7); 2) 60% of nutrient requirements (RES; n = 7) from days 50 to 90 of gestation; 3) 100% of nutrient requirements from days 50 to 130 of gestation (CON-CON; n = 6); 4) 100% of nutrient requirements from days 50 to 90 of gestation and 60% of nutrient requirements from days 90 to 130 of gestation (CON-RES; n = 7); 5) 60% of nutrient requirements from days 50 to 90 of gestation and 100% of nutrient requirements from days 90 to 130 of gestation (RES-CON; n = 7); or 6) 60% of nutrient requirements from days 50 to 130 of gestation (RES-RES; n = 7). On day 90 (n = 14) and day 130 (n = 27), intraoperative procedures were performed to evaluate uteroplacental blood flows, collect blood samples, and then ewes were euthanized. Net uterine, uteroplacental, and umbilical fluxes of glucose and amino acids were calculated by multiplying blood flow by the arterial-venous concentration difference. Data from days 90 and 130 were analyzed separately using ANOVA in SAS. Maternal nutrient restriction during mid-gestation increased (P = 0.04) net umbilical glucose uptake but, maternal nutrient restriction during late-gestation decreased (P = 0.02) net umbilical glucose uptake. Net umbilical essential amino acid uptake decreased (P = 0.03) with nutrient restriction during mid-gestation; however, net umbilical uptakes of Phe (P = 0.02), Thr (P = 0.05), Met (P = 0.09), and His (P = 0.08) increased or tended to increase after nutrient restriction during late-gestation. These data demonstrate that net umbilical glucose and amino acid uptakes were influenced by the timing of nutrient restriction during mid- to late-gestation. Elevated net umbilical glucose uptake after mid-gestational nutrient restriction was sustained throughout late-gestation, independent of late-gestational feeding level. Long-term adaptations in umbilical glucose uptake may have implications for prenatal and postnatal growth and development of the offspring.

Maternal undernutrition during gestation can lead to decreased fetal growth, decreased uteroplacental blood flow, and changes in nutrient supply to the fetus. However, it is unclear how the timing (mid-gestation vs. late-gestation) and duration (40 d vs. 80 d) of nutrient restriction influence nutrient supply to the fetus during mid- to late-gestation. Pregnant ewe lambs fed a pelleted diet to meet 100% of nutritional requirements or 60% of nutritional requirements during mid-gestation alone (days 50 to 90) or during mid- and late-gestation (days 50 to 130). At the end of mid-gestation and late-gestation, the net nutrient supply between the maternal, placental, and fetal compartments was measured. The results indicated that the timing of nutrient restriction influenced the net nutrient supply to the fetus but, the duration of nutrient restriction did not. Nutrient restriction during mid-gestation increased glucose to the fetus but nutrient restriction during late-gestation decreased glucose to the fetus. The opposite response occurred for fetal essential amino acid supply where nutrient restriction during mid-gestation decreased essential amino acid supply to the fetus but increased for several essential amino acids during late-gestational nutrient restriction. The timing of maternal undernutrition during mid- to late-gestation can affect the amount of nutrients delivered to the fetus and thus, could potentially impact postnatal growth and development.

The effect of timing of Improvest administration on growth performance and carcass characteristics in gilts.

Improvest (IMP; Zoetis Inc., Parsippany, NJ) has been approved by the U.S. Food and Drug Administration for use in gilts. Improvest is administered twice: the first dose should be administered no earlier than 9 wk of age and the second dose (D2) at least 4 wk after the first dose. The aim of this study was to determine how the timing of IMP before harvest affects growth performance and carcass characteristics in gilts. A total of 1,632 gilts were allocated to four groups (12 pens/treatment; 34 gilts/pen): 1) a control group did not receive IMP; 2) T-early gilts received IMP on day 7 (day 0 = 10 wk postweaning), and D2 on day 40 (i.e., 35 d prior to first removal for harvest); 3) T-medium gilts received IMP on day 21 and D2 on day 56 (i.e., 19 d prior to first removal for harvest); 4) T-late gilts received IMP on day 35 and D2 on day 70 (i.e., 5 d before first removal for harvest). Pigs were selected for harvest by visual observation on days 75, 89, 103, and 117: 1) the heaviest 7 gilts/pen for each treatment on day 75; 2) the heaviest 10 gilts/pen of each treatment at day 89; 3) the heaviest 10 gilts/pen of each treatment on day 103; and 4) the remaining 7 gilts/pen on day 117. Weights and feed disappearance were recorded every 2 wk and during harvest dates to calculate average daily gain (ADG), average daily feed intake (ADFI), and feed efficiency (Gain:Feed; G:F). Generalized linear mixed models of SAS were used to analyze all variables. The increase in ADFI over Control gilts was observed 15 d post D2 and continued through 77 d post D2, with advantages in ADG occurring between 15 and 35 d post D2. Control and IMP treated gilts had similar G:F 15 to 33 d post D2. The overall ADG and ADFI from day 0 to market, final live weights, and hot carcass weights were significantly greater (P ≤ 0.05) in IMP gilts compared to Control. When G:F based on live weight was averaged across all groups (i.e., from day 0 to market), T-early had the lowest (P ≤ 0.05) G:F compared to Control, T-medium, and T-late gilts, which did not differ. Carcasses from IMP gilts had increased (P < 0.01) backfat, but similar (P = 0.5) Longissimus muscle depth, compared to Control. Within a cohort of similar aged gilts finishing during the summer, this study indicates that the trajectory of growth is enhanced within a similar window post D2 of IMP. Gilts treated with IMP had heavier carcasses with increased backfat and similar Longissimus muscle depth.

Maternal metabolizable protein restriction during gestation affects the vascular function of maternal and fetal placental arteries in sheep.

We hypothesized isocaloric diets low in protein would decrease the sensitivity of caruncular (CAR) and cotyledonary (COT) arteries compared to placental arteries from ewes receiving adequate metabolizable protein (MP) requirements. Pregnant ewes were fed one of three isocaloric dietary treatments that provided 60% (MP60), 80% (MP80), or 100% (MP100) of the MP requirements. Diets were fed from day 100-130 of gestation. In vitro dose response curves to bradykinin (BK), sodium nitroprusside (SNP), potassium chloride (KCl), and phenylephrine (PE) in CAR and COT arteries were performed. As MP decreased, the sensitivity to a low dose of KCl increased (P = 0.05) in the COT arteries. There was an overall treatment effect in the CAR and COT arteries for the BK dose response curve, where CAR arteries of MP80 ewes were more sensitive (P = 0.05) to BK compared with MP60 and MP100 ewes, and COT arteries of MP60 and MP80 ewes were more sensitive (P = 0.01) to BK compared with MP100 ewes. There were no treatment effects (P ≥ 0.09) on the SNP or PE dose response curves in CAR or COT arteries. The mechanism of the BK induced vasodilation needs to be elucidated. Moreover, MP restriction appears to alter placental vascular function, which could help explain the differences in nutrient flux previously reported.

Mid- to late-gestational maternal nutrient restriction followed by realimentation alters development and lipid composition of liver and skeletal muscles in ovine fetuses.

Maternal nutrient restriction during gestation adversely affects offspring growth and development of liver and skeletal muscle tissues. Realimentation following nutrient restriction may alleviate these negative impacts on development but may alter metabolism and tissue composition. Forty-eight ewes, pregnant with singletons, were fed to meet 100% National Research Council (NRC) recommendations starting at the beginning of gestation. On day 50 of gestation, seven ewes were euthanized (BASE), and fetal liver, skeletal muscles, and blood samples were collected. The remaining animals were fed either 100% of NRC recommendations (CON) or 60% NRC recommendations (RES), a subset were euthanized at day 90 of gestation (n = 7/treatment), and fetal samples were collected. Remaining ewes were maintained on the current diet (CON-CON, n = 6; RES-RES, n = 7) or switched to the alternate diet (CON-RES, RES-CON; n = 7/treatment). On day 130 of gestation, the remaining ewes were euthanized, and fetal samples were collected. At day 130 of gestation, maternal nutrient restriction during late-gestation (RES-RES and CON-RES) decreased fetal liver weight (P < 0.01) and cross-sectional area in triceps brachii (P = 0.01; TB), longissimus dorsi (P = 0.02; LM), and semitendinosus (P = 0.05; STN) muscles. Maternal nutrient restriction during mid-gestation increased hepatocyte vacuole size at day 130 of gestation. Late-gestational maternal nutrient restriction increased mRNA expression of insulin-like growth factor (IGF) binding protein-1 (P < 0.01), glycogen synthase 2 (P = 0.01; GYS2), and pyruvate dehydrogenase kinase 1 (P < 0.01; PDHK1) in the liver and IGF receptor 1 (P = 0.05) in the LM. Lipid concentration in the LM was decreased by late-gestational nutrient restriction (P = 0.01) and increased by mid-gestational nutrient restriction in STN (P = 0.03) and TB (P < 0.01). Principal component analysis of lipidomics data demonstrated clustering of principal components by day of gestation and elastic net regression identified 50, 44, and 29 lipids that classified the treatments in the fetal liver, LM, and blood, respectively. In conclusion, restricting maternal nutrition impacts fetal liver and muscle morphology, gene expression, and lipid metabolism, whereas realimentation attenuated some of these effects. Therefore, realimentation may be a viable strategy to reduce the impacts of nutrient restriction, but can lead to alterations in lipid metabolism in sheep.

Water intake of pigs consuming tiamulin during the nursery phase.

Mass medication to manage population health can be achieved by providing therapeutics in the drinking water. Young nursery pigs are highly sensitive to the flavor and smell of water. Medications that reduce water palatability often lead to an interruption in water and feed intake. With the availability of several generic water-soluble antimicrobials for pigs, questions have arisen about their palatability compared with the original product. In this study, we compared the intake of water containing tiamulin hydrogen fumarate from two different manufacturers with the intake of unmedicated water. The hypothesis was that the intake of tiamulin-containing water would be similar to unmedicated water. Water intake was monitored upon entry into the nursery and just prior to leaving the nursery. Also, average daily gain (ADG) and feed efficiency (FE) were determined. A total of 300 pigs were individually weighed (4.2-10.9 kg; avg = 6.8 kg) for randomization to pen (n = 30 pens). The experiment had two time points: 1) early nursery (periods 1-3) and 2) late nursery (period 4). Pens were randomly assigned to a sequence (period 1-3) in a crossover experimental design containing three 10-d periods, with 5 d for the resetting of baseline where unmedicated water was provided followed by 5 d on tiamulin source addition [i.e., TriamuloxTM (Zoetis, Parsippany, NJ); Denagard (Elanco Animal Health, Greenfield, IN)] or unmedicated water. After period 3 was concluded, all pens were given unmedicated water (via nipple waterers) and the number of pigs per pen was reduced to six pigs to maintain adequate space per pig. Ten days prior to pigs leaving the nursery, a fourth period was performed. After a 5-d water baseline was achieved, pens were treated with either unmedicated water or Triamulox- or Denagard-containing water. Pigs had ad libitum access to water and feed. During the testing periods, daily water intake was measured by a cup water system in each pen. Feed intake was measured every 5 d. There was no effect of treatment on initial body weights or weights at the beginning or end of each period (P ≥ 0.51). Therefore, there was no effect of treatment on ADG (P ≥ 0.23). Water intake (P ≥ 0.16) and FE (P ≥ 0.35) were not affected by treatment. Water consumption was similar among all treatments in each of the four periods. There appears to be no aversion to water intake when tiamulin hydrogen fumarate is added to the drinking water.

Effects of administering exogenous bovine somatotropin to beef heifers during the first trimester on conceptus development as well as steroid- and eicosanoid-metabolizing enzymes.

The aim of this study was to evaluate the effect of bovine somatotropin (bST) on fetal and placental development during the first third of gestation in beef heifers. Angus heifers (n = 97) were randomly assigned to either receive a 500-mg injection of bST (BST) biweekly on days 0, 15, 29, 43, and 57 of gestation or not receive bST (CTL) throughout the experiment. Body weight (BW) was assessed on days -9, -3, 0, 15, 22, 29, 43, 50, 57, 64, and 77, while blood samples were collected on days 0, 22, 50, and 64. Pregnancy status was determined via transrectal ultrasonography on days 29 and 64. A subset of pregnant heifers (BST, n = 7; CTL, n = 5) were harvested on day 84, and complete gravid reproductive tracts and liver tissue were collected for analysis. Cytochrome P450 1A (CYP1A), 2C (CYP2C), 3A (CYP3A), and uridine 5'-diphospho-glucuronosyltransferase (UGT) activities were determined. Mean change in BW and average daily gain of heifers between fixed-time artificial insemination (day 0) and day 77 did not differ between treatments (P ≥ 0.05). Mean concentrations of insulin-like growth factor 1 (IGF-1) were greater (P < 0.001) in BST (347 ± 27.7 ng/mL) compared with CTL (135 ± 32.8 ng/mL) heifers. Mean placental weight, fetal membrane weight, uterine weight, and ovarian and corpus luteum (CL) weights, as well as fetal morphometric data, did not differ (P ≥ 0.05) between treatments. However, BST heifers had greater (P = 0.03) quantities of combined fetal fluid compared with CTL (521.6 ± 22.9 vs. 429.6 ± 27.14 g, respectively). Tendencies were observed for BST heifers to have reproductive tracts with fewer placentomes (P = 0.08) and fetuses with greater umbilical diameters (P = 0.09) compared with CTL. The activity of CYP1A did not differ (P ≥ 0.05) within the maternal and fetal liver, caruncle, cotyledon, or CL tissue samples between treatments. Furthermore, CYP3A activity was only observed in maternal liver samples and was not different between treatments (P ≥ 0.05). Interestingly, CYP2C activity was greater (P = 0.01) in the liver of BST vs. CTL heifers, and UGT activity was greater (P = 0.02) in the CL from BST heifers compared with CTL. In conclusion, the administration of bST during the first third of gestation increased plasma concentrations of IGF-1, which resulted in an increase in fetal fluid, decrease in placentome number, and greater umbilical diameter, but failed to alter fetal development.

Fetal expression of genes related to metabolic function is impacted by supplementation of ground beef and sucrose during gestation in a swine model.

To determine the effects of maternal supplementation on the mRNA abundance of genes associated with metabolic function in fetal muscle and liver, pregnant sows (Landrace × Yorkshire; initial body weight (BW) 221.58 ± 33.26 kg; n = 21) fed a complete gestation diet (corn-soybean meal based diet, CSM) were randomly assigned to 1 of 4 isocaloric supplementation treatments: control (CON, 378 g/d CSM, n = 5), sucrose (SUGAR, 255 g/d crystalized sugar, n = 5), cooked ground beef (BEEF, 330 g/d n = 6), or BEEF + SUGAR (B+S, 165 g/d cooked ground beef and 129 g/d crystalized sugar, n = 5), from days 40 to 110 of gestation. Sows were euthanized on day 111 of gestation. Two male and 2 female fetuses of median BW were selected from each litter, and samples of the longissimus dorsi muscle and liver were collected. Relative transcript level was quantified via qPCR with HPRT1 as the reference gene for both muscle and liver samples. The following genes were selected and analyzed in the muscle: IGF1R, IGF2, IGF2R, GYS-1, IRS-1, INSR, SREBP-1C, and LEPR; while the following were analyzed in the liver: IGF2, IGF2R, FBFase, G6PC, PC, PCK1, FGF21, and LIPC. No effect of fetal sex by maternal treatment interaction was observed in mRNA abundance of any of the genes evaluated (P > 0.11). In muscle, the maternal nutritional treatment influenced (P = 0.02) IGF2 mRNA abundance, with B+S and SUGAR fetuses having lower abundance than CON, which was not different from BEEF. Additionally, SREBP-1 mRNA abundance was greater (P < 0.01) for B+S compared with CON, BEEF, or SUGAR fetuses; and females tended (P = 0.06) to have an increased abundance of SREBP-1 than males. In fetal liver, IGF2R mRNA abundance was greater (P = 0.01) for CON and BEEF than SUGAR and B+S; while FBPase mRNA abundance was greater (P = 0.03) for B+S compared with the other groups. In addition, maternal nutritional tended (P = 0.06) to influence LIPC mRNA abundance, with increased abundance in CON compared with SUGAR and B+S. These data indicate limited changes in transcript abundance due to substitution of supplemental sugar by ground beef during mid to late gestation. However, the differential expression of FBPase and SREBP-1c in response to the simultaneous supplementation of sucrose and ground beef warrants further investigations, since these genes may play important roles in determining the offspring susceptibility to metabolic diseases.

Prediction of the Secretome and the Surfaceome: A Strategy to Decipher the Crosstalk between Adipose Tissue and Muscle during Fetal Growth.

Crosstalk between adipose and muscular tissues is hypothesized to regulate the number of muscular and adipose cells during fetal growth, with post-natal consequences on lean and fat masses. Such crosstalk largely remains, however, to be described. We hypothesized that a characterization of the proteomes of adipose and muscular tissues from bovine fetuses may enhance the understanding of the crosstalk between these tissues through the prediction of their secretomes and surfaceomes. Proteomic experiments have identified 751 and 514 proteins in fetal adipose tissue and muscle. These are mainly involved in the regulation of cell proliferation or differentiation, but also in pathways such as apoptosis, Wnt signalling, or cytokine-mediated signalling. Of the identified proteins, 51 adipokines, 11 myokines, and 37 adipomyokines were predicted, together with 26 adipose and 13 muscular cell surface proteins. Analysis of protein-protein interactions suggested 13 links between secreted and cell surface proteins that may contribute to the adipose-muscular crosstalk. Of these, an interaction between the adipokine plasminogen and the muscular cell surface alpha-enolase may regulate the fetal myogenesis. The in silico secretome and surfaceome analyzed herein exemplify a powerful strategy to enhance the elucidation of the crosstalk between cell types or tissues.

Hemodynamics of the umbilical artery and conceptus-related measurements in singleton and twin pregnancies in ewes.

In sheep, adequate physiological maternal adaptations to twin fetuses are key for their prenatal development. We hypothesized that there is a relationship between maternal circulating steroid hormone concentration, hematocrit, and patterns of conceptus growth and umbilical artery hemodynamics in twin vs singleton pregnancies. Ewes carrying singletons (n = 6) or twins (n = 7) were selected. Hematocrit, progesterone (P4) and estradiol-17ß (E2) concentrations were analyzed. Blood flow of the umbilical artery (UBF) was assessed through Doppler ultrasonography. Ewes carrying twins had a decreased (p = 0.03) hematocrit. There was a tendency (p = 0.08) for ewes carrying twins to have increased P4 from day 20 to 40. From day 50 to 70, P4 tended to be increased (p = 0.07) and E2 was increased (p = 0.01) in ewes carrying twins. From day 90 to 120, ewes carrying twins had greater (p ≤ 0.04) P4. Ewes carrying twins had increased (p < 0.01) P4 and tended to have (p = 0.06) increased E2. From day 60 until 110, placentomes from twins were larger (p ≤ 0.05). On day 50, UBF was greater (p = 0.04; 27.38 vs. 20.95 ± 1.99 ml/min) in twins. It has been suggested that physiological adaptations during early pregnancy can significantly impact fetal development in multiple offspring carrying ewes. Our findings suggest that increased umbilical artery blood flow early in gestation, associated with increased maternal concentrations of P4 and E2, and decreased hematocrit (related to plasma volume) could contribute to those adaptations.

Nuclear and membrane progesterone receptors expression in placenta from early to late pregnancy in sheep: Effects of restricted nutrition and realimentation.

Nutrient restriction and/or realimentation may affect several placental functions, such as expression of selected regulatory factors, blood flow and other processes in sheep and other species. To determine the effects of the plane of nutrition, nulliparous white face ewes (6-8 months) carrying singletons on day 50 of gestation were randomly assigned to two dietary treatments receiving 100% of National Research Council recommendations (control; C) or 60% of C (restricted; R). Two groups remained on C or R diets from day 50 until day 130. From day 90-130 another group of C fed ewes was switched to the R diet, and another group of R fed ewes was switched to the C diet. This resulted in 7 groups (n = 5-6 ewes/group): C (day 50, 90 and 130), R (day 90 and 130), CR (day 130) and RC (day 130). At these time points, placental tissues were collected for the evaluation of progesterone receptor (PGR) protein expression (whole tissue), and mRNA expression in maternal (caruncular, CAR) and fetal (cotyledon, COT) (separated tissues). Data were statistically analyzed using analysis of variance (SAS 9.4). Protein for PGRAB and PGRB isoforms was detected using immunohistochemistry in all placental tissues, but the pattern of expression differed depending on pregnancy stage and placental compartment (e.g., CAR vs COT). PGRAB protein expression, quantified using image analysis, was greater (P < 0.04) on day 50 than 90 or 130, and was not affected by plane of nutrition. In CAR and COT, PGRAB mRNA expression was greater (P < 0.05) on day 50 than 90 or 130. PGRB mRNA expression was greater (P < 0.03) in CAR on day 50 than 90 and 130, and was greatest (P < 0.02) in COT on day 50, less on day 130, and least on day 90. For the membrane progesterone receptors, PAQR7 (membrane PGR alpha) mRNA expression was greater (P < 0.05) on days 50 and 90 than 130 in CAR, and greater (P < 0.01) on days 50 than 90 and 130 in COT; PAQR8 (membrane PGR beta) was similar throughout pregnancy in CAR and COT, and PAQR5 (membrane PGR gamma) was greatest (P < 0.0001) on day 130 in COT, but similar throughout pregnancy in CAR. Plane of nutrition affected (P < 0.05) mRNA expression for all genes in CAR and COT throughout pregnancy. These data indicate that expression of PGR in ovine placenta is dependent on stage of pregnancy and plane of nutrition in sheep. The mechanisms of how diet and stage of pregnancy influences placental PGR expression and function remains to be elucidated.

Effects of Nutrient Restriction During Midgestation to Late Gestation on Maternal and Fetal Postruminal Carbohydrase Activities in Sheep.

To examine the effects of nutrient restriction during midgestation to late gestation on maternal and fetal digestive enzyme activities, 41 singleton ewes (48.3 ±â€…0.6 kg of BW) were randomly assigned to dietary treatments: 100% (control; CON; n = 20) or 60% of nutrient requirements (restricted; RES; n = 21) from day 50 until day 90 (midgestation). At day 90, 14 ewes (CON, n = 7; RES, n = 7) were euthanized. The remaining ewes were subjected to treatments of nutrient restriction or remained on a control diet from day 90 until day 130 (late gestation): CON-CON (n = 6), CON-RES (n = 7), RES-CON (n = 7), and RES-RES (n = 7) and were euthanized on day 130. The fetal and maternal pancreas and small intestines were weighed, subsampled, and assayed for digestive enzyme activity. One unit (U) of enzyme activity is equal to 1 µmol of product produced per minute for amylase, glucoamylase, lactase, and trypsin and 0.5 µmol of product produced per minute for maltase and isomaltase. Nutrient restriction during midgestation and late gestation decreased (P < 0.05) maternal pancreatic and small intestinal mass but did not affect fetal pancreatic or small intestinal mass. Maternal nutrient restriction during late gestation decreased (P = 0.03) fetal pancreatic trypsin content (U/pancreas) and tended to decrease (P < 0.08) fetal pancreatic trypsin concentration (U/g), specific activity (U/g protein), and content relative to BW (U/kg of BW). Nutrient restriction of gestating ewes decreased the total content of α-amylase (P = 0.04) and tended to decrease total content of trypsin (P = 0.06) and protein (P = 0.06) in the maternal pancreas on day 90. Nutrient restriction during midgestation on day 90 and during late gestation on day 130 decreased (P = 0.04) maternal pancreatic α-amylase-specific activity. Sucrase activity was undetected in the fetal and maternal small intestine. Nutrient restriction during late gestation increased (P = 0.01) maternal small intestinal maltase and lactase concentration and tended to increase (P = 0.06) isomaltase concentration. Realimentation during late gestation after nutrient restriction during midgestation increased lactase concentration (P = 0.04) and specific activity (P = 0.05) in the fetal small intestine. Fetal small intestinal maltase, isomaltase, and glucoamylase did not respond to maternal nutrient restriction. These data indicate that some maternal and fetal digestive enzyme activities may change in response to maternal nutrient restriction.

Late gestation supplementation of corn dried distiller's grains plus solubles to beef cows fed a low-quality forage: III. effects on mammary gland blood flow, colostrum and milk production, and calf body weights.

Objectives were to investigate the effects of supplementation with corn dried distiller's grains plus solubles (DDGS) to late gestating beef cows on arterial blood flow to the mammary glands during late gestation and early lactation; colostrum and milk production; dystocia and immunity; and calf BW. Cows were fed a control (CON; n = 15; 5.1% CP; 36.2% ADF) diet consisting of 90% corn stover and 10% corn silage on a dry basis offered ad libitum or CON diet with supplementation of DDGS (0.30% of BW; SUP n = 12). Mammary gland blood flow was assessed on day 245 of gestation. At parturition, maternal and calving parameters were assessed; colostrum and jugular blood was sampled; and dams were weighed. Mammary gland blood flow and milk production was measured on day 44 of lactation. Calves were weighed fortnightly for 8 wk and at weaning. Colostrum production tended to be greater in SUP dams than in CON dams (837 vs. 614 ± 95 g, P = 0.10). Calves of SUP dams were heavier at birth and 24 h (0 h, 43.2 vs. 39.8 ± 1.0 kg, P = 0.02; 24 h, 44.0 vs. 40.4 ± 1.1 kg, P = 0.02). At birth and 24 h, blood pCO2 was greater in calves born to SUP dams (6.82 vs. 6.00 ± 0.41 kPa, P = 0.04). Serum IgG did not differ (P = 0.21) at 24 h. Ipsilateral mammary gland blood flow of SUP cows was greater than CON cows (2.76 vs. 1.76 ± 0.30 L/min; P = 0.03); however, when summed with contralateral, total blood flow was similar (P = 0.33). Hemodynamic measures on day 44 of lactation were similar (P ≥ 0.32). Milk production tended to be increased (13.5 vs. 10.2 ± 1.2 kg/d, P = 0.07) in SUP vs. CON cows. Despite similar BW through 56 d, calves from SUP cows were heavier (P = 0.04) at weaning (309.7 vs. 292.0 ± 6.0 kg). In conclusion, we accept our hypothesis that DDGS supplementation during gestation influenced mammary blood flow, milk production and calf weights. These findings implicate maternal nutrition's leverage on both nutrient and passive immunity delivery to the calf early in life as well as potential advantages on long-term performance.

Ovine placental steroid synthesis and metabolism in late gestation.

Steroid synthesis is required for pregnancy maintenance and for parturition, but comparatively little is known about the major metabolic routes that influence circulating concentrations. Dietary intake changes progesterone and estradiol concentrations in pregnant ewes but whether this reflects placental synthesis is unknown. Progesterone metabolism by 5alpha-reduction is a major metabolic route in other species and can influence the onset of parturition. Therefore, studies were conducted to (1) determine placental enzyme activity, progesterone, and estradiol measured by immunoassay in late gestation ewes on low-, moderate-, and high-nutritional planes, (2) to assess the significance of 5alpha-reduction of progesterone in determining progesterone concentrations in late gestation ewes (gestation day 145) given finasteride to inhibit 5alpha-reductase metabolism. In the second experiment, steroid profiles were examined comprehensively in blood and tissues by liquid chromatography tandem mass spectrometry for the first time in this species. Dietary intake altered progesterone and estradiol serum concentrations but without correlated changes in placental 3beta-hydroxysteroid dehydrogenase, 17alpha-hydroxylase/17,20-lyase cytochrome P450 or aromatase activity. 5alpha-reduced pregnane metabolites were identified in ewes at 145 days of gestation, but concentrations were lower than those of progesterone. Finasteride inhibited 5alpha-reduced progesterone metabolism but did not impact serum progesterone concentrations in these ewes. We conclude that (1) diet-induced changes in serum progesterone and estradiol concentrations are not likely a result of altered placental synthesis of sex steroid but most likely by their metabolism, and (2) metabolism by 5α-reduction is not a major determinant of systemic progesterone concentrations in late gestation ewes.

Effect of maternal diet on placental development, uteroplacental blood flow, and offspring development in beef cattle.

Considerable effort has been made to understand how nutrition influences livestock health and productivity during the postnatal period. Moreover, while efforts have been made to understand how nutrition impacts many different aspects of female reproduction, there is a growing body of literature that focuses on how maternal nutrition impacts the developing fetus. Providing adequate nutrition during pregnancy is important for maternal health and well- being, as well as conceptus development. Proper establishment of the placenta is important for fetal survival. However, placental adaptations to inadequate maternal nutrition, or other stressors, are imperative for fetal growth to be optimal. By understanding how the maternal environment impacts uterine and umbilical blood flows and other uteroplacental hemodynamic parameters, we can better implement supplementation strategies to protect the developing offspring. This review focuses on how maternal nutrition affects conceptus growth in sheep and beef cattle and offspring performance after birth.

A Preliminary Evaluation of Ovine Bladder Mucosal Damage Associated With 2 Different Indwelling Urinary Catheters.

OBJECTIVE: To determine whether a new catheter design with a low-profile, open-ended rounded rather than pointed Foley catheter tip can reduce mucosal damage to the bladder of ewes. METHODS AND MATERIALS: Six ewes were randomly assigned to 1 of 2 indwelling urinary catheters-a 16 Fr Foley catheter or a 16 Fr open-tip CystoSure catheter. After 96 hours, all the animals were sacrificed and their bladder and urethra harvested for analysis. RESULTS: Image analysis of the bladder surfaces demonstrated a significant decrease in the percentage of bladder area covered by ulceration and inflammation in sheep with CystoSure catheters compared with Foley catheters (P < .002) as well as a trend toward less edema (P = .17). Macro-morphologic evaluations were confirmed with immunohistochemical markers of cell proliferation and inflammation. CONCLUSION: In this pilot study, we were able to demonstrate that a new catheter design with an open-ended rounded rather than pointed tip and a reduced balloon base-to-tip profile may reduce mucosal damage to the bladder of ewes. Based on the findings from this trial, we believe this new catheter design with its low-profile, rounded tip may reduce bladder mucosal injury, which is a risk factor for catheter-associated urinary tract infections.

Impacts of Maternal Nutrition on Vascularity of Nutrient Transferring Tissues during Gestation and Lactation.

As the demand for food increases with exponential growth in the world population, it is imperative that we understand how to make livestock production as efficient as possible in the face of decreasing available natural resources. Moreover, it is important that livestock are able to meet their metabolic demands and supply adequate nutrition to developing offspring both during pregnancy and lactation. Specific nutrient supplementation programs that are designed to offset deficiencies, enhance efficiency, and improve nutrient supply during pregnancy can alter tissue vascular responses, fetal growth, and postnatal offspring outcomes. This review outlines how vascularity in nutrient transferring tissues, namely the maternal gastrointestinal tract, the utero-placental tissue, and the mammary gland, respond to differing nutritional planes and other specific nutrient supplementation regimes.

Effect of melatonin or maternal nutrient restriction on vascularity and cell proliferation in the ovine placenta.

Previously we reported increased umbilical artery blood flow in ewes supplemented with melatonin from mid- to late-pregnancy, while maternal nutrient restriction decreased uterine artery blood flow. To further unravel these responses, this study was designed to assess placental cell proliferation and vascularity following supplementation with melatonin or maternal nutrient restriction. For the first experiment, 31 primiparous ewes were supplemented with 5mg of melatonin per day (MEL) or no melatonin (CON) and allocated to receive 100% (adequate fed; ADQ) or 60% (restricted; RES) of their nutrient requirements from day 50 to 130 of gestation. To examine melatonin receptor dependent effects, a second experiment was designed utilizing 14 primiparous ewes infused with vehicle, melatonin, or luzindole (melatonin receptor 1 and 2 antagonist) from day 62 to 90 of gestation. For experiment 1, caruncle concentrations of RNA were increased in MEL-RES compared to CON-RES. Caruncle capillary area density and average capillary cross-sectional area were decreased in MEL-RES compared to CON-RES. Cotyledon vascularity was not different across dietary treatments. For experiment 2, placental cellular proliferation and vascularity were not affected by infusion treatment. In summary, melatonin interacted with nutrient restriction to alter caruncle vascularity and RNA concentrations during late pregnancy. Although melatonin receptor antagonism alters feto-placental blood flow, these receptor dependent responses were not observed in placental vascularity. Moreover, placental vascularity measures do not fully explain the alterations in uteroplacental blood flow.