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31.
In this study of the pregnant uterus of the ewe and the pygmy goat, the simultaneous use of real-time ultrasound scanning and electromyography is introduced. In unanaesthetized animals it was possible to visualize the uterine wall, the placentomes, parts of the fetal skeleton, the fetal kidneys, different parts of the fetal stomach and several structures of the fetal heart and vascular system. From these features the intra-abdominal position of the fetus could be determined. It was observed that Episodes of Myometrial Electrical Activity (EMEA's), as registered by chronically implanted uterine surface electrodes, coincided with passive displacements of the fetus in the direction of the maternal pelvis. These passive displacements could clearly be discerned from active fetal body movements. In both species the number of active fetal movements was significantly reduced during and/or shortly after an EMEA. In one of the pygmy goats, in which three different types of movement were discerned, this reduction of fetal movements could be studied in more detail.It is concluded that real-time ultrasound scanning of the fetus in small ruminants might contribute to studies of the complex maternal-fetal interactions that exist during late gestation.  相似文献   
32.
OBJECTIVE: To determine whether the addition of chromic oxide (Cr(2)O(3)) to creep feed could be used as a visual marker in feces for selection of creep feed-eating suckling pigs. ANIMALS: 20 suckling pigs. PROCEDURES: Via syringe, 5 pigs (2 to 3 days old on day 0; 1 pig/treatment) from each of 4 litters received oral administrations of 10, 20, 30, or 40 g of creep feed containing 10 g of Cr(2)O(3)*kg(1) on each of 2 consecutive days (days 20 and 21) or 30 g of creep feed containing 10 g of Cr(2)O(3)*kg(1) on day 20 and 30 g of Cr(2)O(3)-free creep feed on day 21. On days 21 through 24, 6 fecal samples were collected from each pig at regular intervals between 8:00 AM and 6:00 PM. Green-colored feces were considered indicative of creep feed consumption (eaters). Data analyses were based on single and multiple fecal samples. RESULTS: On day 22, evaluation of 1 fecal sample/pig and multiple fecal samples per pig resulted in identification of as many as 40% and only 15% of the feed-treated pigs wrongly as noneaters, respectively. Repeated sampling over multiple days would identify 99% of eaters accurately. Pigs erroneously identified as noneaters were those administered either low amounts of Cr(2)O(3)-supplemented creep feed for 2 days or Cr(2)O(3)-supplemented creep feed on only 1 day. CONCLUSIONS AND CLINICAL RELEVANCE: Data suggest that addition of Cr(2)O(3) to creep feed enables selection of individual creep feed-eating suckling pigs via examination of feces, provided that repeated fecal samples are evaluated.  相似文献   
33.
The objectives of the current study were to determine how intermittent suckling (IS) affects nursing behavior, litter activity, and general behavioral patterns during lactation, and whether IS during an extended lactation period results in behavioral patterns associated with piglet distress. Intermittent suckling was applied either with 6-h separation intervals (IS6) or with 12-h separation intervals (IS12) and was compared with the conventional treatment (CT). In the CT (n = 17 litters), sows were continuously present until weaning (d 21, d 0 = farrowing). In both IS6 and IS12, sows were separated from their litter for 12 h/d, beginning at d 14 and lasting until weaning (d 43 +/- 1 d). In IS6, litters (n = 14) and sows were separated from 0800 to 1400 and from 2000 to 0200; in IS12 litters (n = 14) and sows were separated between 0800 and 2000. In IS litters, the activity pattern over the 24-h cycle was markedly changed by IS; litter activity was lower (P < 0.001) during sow absence and greater (P < 0.001) during sow presence compared with the unweaned CT litters. Moreover, both total nursing frequency (P < 0.001) and the percentage (P < 0.002) of successful nursings were reduced by IS. Although total nursing frequency was greater in IS6 compared with IS12 (on d 21 and 28), no differences in the frequency of successful nursings existed between IS6 and IS12 from d 14 onward. Eating behavior was increased shortly after the onset of IS (d 17) in both IS6 (P = 0.059) and IS12 (P < 0.001) compared with the unweaned CT litters. The IS12 litters showed more eating behavior compared with IS6 and their exploratory behavior increased in time (P < 0.001), whereas IS6 showed more nursing behavior. Aggressive or manipulative behavior of both IS treatments was similar compared with the unweaned CT, and remained relatively unaltered with time in IS12 and IS6. Weaning in the CT resulted in more manipulative (P < 0.001) and aggressive (P = 0.004) behavior compared with pre-weaning values. Intermittent suckling may contribute to adaptation to the postweaning state by stimulating eating behavior, without causing obvious behavioral distress.  相似文献   
34.
OBJECTIVE: To design a treatment that increases plasma corticosteroid concentrations to mimic prenatal stress in pregnant sows. ANIMALS: 24 pregnant sows. PROCEDURE: Sows were assigned to 1 of 4 treatment groups; treatment consisted of twice-daily oral administration of a placebo or 20, 60, or 180 mg of hydrocortisone acetate (HCA)/sow from 7 to 11 weeks of gestation. Blood and saliva samples for determination of cortisol concentrations were obtained hourly on treatment days 3 and 25 and twice weekly for the remainder of the treatment period. The WBC, neutrophil, and lymphocyte counts and concentrations of interleukin (IL)-2 and IL-4 were determined on 4 days during treatment. Litter characteristics were recorded. RESULTS: Plasma and salivary cortisol concentrations were significantly increased in sows that received 60 or 180 mg of HCA (0.30 to 0.37 mg/kg and 0.95 to 1.15 mg/kg, respectively), compared with control sows. Except for the second day of treatment, the number of WBCs and the IL-2:IL-4 ratio did not differ among treatment groups. The neutrophil-to-lymphocyte ratio was significantly higher in sows that received 180 mg of HCA. Gestation duration was significantly shorter in sows that received 180 mg of HCA. CONCLUSIONS AND CLINICAL RELEVANCE: Oral administration of 60 mg of HCA is suitable to increase plasma and salivary cortisol concentrations in pregnant sows in a controlled manner to concentrations comparable to concentrations detected after psychologic stressors. This model seems to be suitable to study the effects of increased maternal corticosteroid concentrations on young pig behavior, physiologic variables, and development.  相似文献   
35.
During lactation, daily separation of sow and piglets, intermittent suckling (IS), can induce lactational oestrus and ovulation. This study examined effects of IS on subsequent early embryo survival and development. Multiparous Topigs40 sows were separated from their piglets for either 12 consecutive hours per day (IS12, n = 13) or two times for 6 h per day (IS6, n = 10) from day 14 of lactation onwards until 23 days after ovulation. Control sows (C, n = 17) were weaned at day 21 of lactation. Oestrus was shown in all treatments within 5 days after the start of treatment. Sows were inseminated each day of oestrus and slaughtered at D23 after ovulation. Intermittent suckling did not significantly affect pregnancy rates of sows (75% IS12 vs 78% IS6 vs 94% C; p > 0.10). Embryo survival was not significantly affected by IS (IS12: 57%; IS6: 51%; p > 0.10) although it seemed to be lower than in C sows (70%). Some parameters of embryo, placental and uterine development were affected by IS, especially in the IS6 group. IS6 embryos had shorter placentas (17.5 +/- 1.2 cm; p < 0.05) than C (20.3 +/- 1.4 cm) and IS12 sows (20.9 +/- 0.7 cm) were smaller and less developed than C sows (p < 0.05). In conclusion, embryo survival does not seem significantly affected by IS, although numerical differences were great. Embryo development, however, was negatively affected in IS6 sows possibly due to a combination of high milk production, stress and lactational effects on uterine development.  相似文献   
36.
Prenatal stress is known to affect several offspring characteristics, but its effects depend among other factors on the period of gestation in which it is applied. In the present study, oral administration of hydrocortisone-acetate (HCA) was used to elevate cortisol concentrations in pregnant sows to levels also observed after psychological stress. HCA was administered during three different periods of gestation (115 days in pigs): period 1: 21-50 (P1, n = 10), period 2: 51-80 (P2, n = 10) and period 3: 81-110 (P3, n = 10) days after insemination. Control sows (n = 11) received vehicle from 21-110 days after insemination. When P1-, P2- and P3-sows did not receive HCA, they also received vehicle. During gestation, weekly saliva samples were taken from the sows to determine salivary cortisol concentrations. Treatment effects on sow, litter and piglet characteristics were determined. In addition, two female piglets per litter were subjected to an ACTH-challenge test at 6 weeks of age to determine the adrenocortical response to ACTH. Pigs were slaughtered at 6 months of age and slaughter weight, back fat thickness and percentage of lean meat were analysed. During the period of treatment with HCA, salivary cortisol concentrations were increased in P1-, P2- and P3-sows compared to control sows (P < 0.01). The total number of piglets born per litter did not differ among treatment groups (P > 0.30), but pooled HCA-litters had a higher percentage of live born piglets (P < 0.05) and fewer mummies than control litters (P < 0.05). Gestation length did not differ among treatment groups (P = 0.21), but did affect treatment effects on birth weight. Overall, HCA-piglets weighed less at birth, and remained lighter until weaning (P < 0.05). The salivary cortisol concentrations after i.m. injection of ACTH (2.5 IU/kg) were lower in P1- and P3-piglets compared to control piglets. At slaughter, HCA-treatment indirectly decreased lean meat percentage and increased back fat thickness. In conclusion, elevated peripheral cortisol concentrations in pregnant sows affect both litter characteristics and piglet physiology, the latter depending on the period of gestation during which concentrations were elevated. Underlying mechanisms require further investigation.  相似文献   
37.
This paper presents quantitative results of canine pregnancy diagnoses performed by abdominal palpation and/or linear-array real-time echography. Each animal was first palpated by an experienced clinician and then another investigator performed ultrasound scanning using a 3 MHz transducer. In other dogs echography was undertaken only when the result of abdominal palpation was negative or doubtful or when the owner requested ultrasound scanning. Using all tests performed between days 20 and 49 of pregnancy (day 0 = day of first mating or insemination), the results of abdominal palpation (n = 116) versus real-time scanning (n = 135) were: sensitivity: 89.0% v 92.9%; specificity: 93% v 96.0%; positive predictive value: 95.6% v 97.5%; negative predictive value: 83.3% v 88.9%. Results of ultrasound tests performed in 97 other dogs were: sensitivity: 92.4%; specificity: 97.7%; positive predictive value: 98.0% and negative predictive value: 91.4%. Almost identical figures were found when only the tests performed between days 25 and 35 of pregnancy were included. It was concluded that real-time ultrasound scanning is an accurate method for discriminating between pregnant and non-pregnant bitches; sensitivity and specificity of the abdominal palpation technique executed by an experienced clinician approach that of ultrasound scanning; small litter size and lack of knowledge of conception date are the main sources of false negative diagnoses.  相似文献   
38.
Summary

The acid‐base status of 58 calves (all in normal anterior presentation) was determined from venous blood samples before the onset of traction and immediately after vaginal delivery.

Calves were assigned to one of three groups according to their blood pH value: group 1 ‐ normal, pH >7.2; group 2 ‐ acidotic, pH 7.2 to 7.0; group 3 ‐ severely acidotic, pH < 7.0. Before the onset of traction (i.e. during the 30 minutes following the appearance and rupture of the membranes), 43 calves (74.1%) had normal acid‐base values, 14 (24.1%) had slight acidosis, and only 1 (1.7%) had severe acidosis. At birth the three groups of calves showed the following distribution: 23 (39.7%) were normal, 29 (50%) had slight acidosis, and 6 (10.3%) had severe acidosis.

Seven calves (12. 1%) died during birth or within 48 hours after birth; 2 were normal shortly before birth, 4 were acidotic shortly before birth, and 1 was severely acidotic even before the onset of traction. Traction was significantly longer for cows that delivered severely acidotic calves compared to cows in the other two groups.  相似文献   
39.
Pregnancy diagnosis was carried out in sheep by means of transabdominal linear-array real-time ultrasound scanning. Animals were restrained standing, and the transducer was placed on the hairless area of the ventral abdominal wall just in front of the udder. Of a total of 818 tests, 724 were performed between days 29 and 89 of pregnancy, 598 animals subsequently lambed and 126 were non-lambing animals. Only 8 of these tests were wrong: 3 false positive and 5 false negative diagnoses. Sensitivity, specificity, positive- and negative predictive values for these tests were 99.2%, 97.6%, 99.5%, and 96% respectively. There was evidence to indicate that the three false positive tests were caused by foetal mortality or unobserved abortions that took place after testing. Only 2 of the 5 false negative tests were carried out after day 39 of gestation. Counting of foetal numbers (1, 2 or 3) was performed in only some animals (n = 210) between days 45 and 77 of gestation. Three groups of animals (A: 89 ewes; B: 27 PMSG-treated ewes; C: 94 ewes) were analyzed separately. Overall accuracy of all predictions was 83.1%, 37.0% and 78.7% for the 3 groups respectively. Animals in group B produced only 3 or more lambs. Sensitivity of the countings of singles, twins and triplets or more were 90.4%, 90.4% and 50% respectively for the animals from group A and 91.9%, 86% and 21.4% for the animals from group C.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   
40.
Inoculation with Actinomyces pyogenes and administration of prostaglandin (PG)F(2alpha) were used to induce late embryonic mortality (LEM) in heifers (n=8) on Days 30-38 of pregnancy in order to compare the profile for bovine pregnancy associated glycoprotein 1 (PAG1), progesterone and 15-keto-13,14-dihydro-PGF(2alpha) (PGFM). Two pregnant heifers were used as controls. Inoculation into the uterine body caused LEM, as established by ultrasonography in each heifer within 24h of treatment. When the inoculum was injected into the first part of the cervix, LEM occurred in one of two heifers (Heifer A) between 48 and 72 h after treatment. Similarly, PGF(2alpha) treatment caused LEM in three of four heifers. In six of eight heifers, PAG1 started to decrease steadily when it was accompanied by the subsequent death of the embryo. Inoculation through the cervix caused luteolysis in three of four heifers within 6-10 days after induction. After induction of LEM, PGFM concentrations showed a two to 3.8 fold increase in three of four heifers during the following six days, and from that time changed within normal ranges. The results of this study indicate that a PAG1 assay may provide an alternative method to ultrasonography for determining LEM in the cow.  相似文献   
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