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Macroevolutionary changes such as variation in habitat use or diet are often associated with convergent, adaptive changes in morphology. However, it is still unclear how small-scale morphological variation at the population level can drive shifts in ecology such as observed at a macroevolutionary scale. Here, we address this question by investigating how variation in cranial form and feeding mechanics relate to rapid changes in diet in an insular lizard (Podarcis siculus) after experimental introduction into a new environment. We first quantified differences in the skull shape and jaw muscle architecture between the source and introduced population using three-dimensional geometric morphometrics and dissections. Next, we tested the impact of the observed variation in morphology on the mechanical performance of the masticatory system using computer-based biomechanical simulation techniques. Our results show that small differences in shape, combined with variation in muscle architecture, can result in significant differences in performance allowing access to novel trophic resources. The confrontation of these data with the already described macroevolutionary relationships between cranial form and function in these insular lizards provides insights into how selection can, over relatively short time scales, drive major changes in ecology through its impact on mechanical performance. [ABSTRACT FROM AUTHOR]

We present evidence of optical Tamm states to surface plasmon polariton (SPP) coupling. We experimentally demonstrate that for a Bragg stack with a thin metal layer on the surface, hybrid Tamm-SPP modes may be excited when a grating on the air-metal interface is introduced. Out-coupling via the grating to free space propagation is shown to enhance the transmission as well as the directionality and polarization selection for the transmitted beam. We suggest that this system will be useful on those devices, where a metallic electrical contact as well as beaming and polarization control is needed. [ABSTRACT FROM AUTHOR]

Daily separation of sows and piglets during lactation, intermittent suckling (IS), improves feed intake and postweaning adaptation in piglets. The aim of the current study was to determine how, in pig- lets that have been subjected to IS, age at weaning and the duration of the preceding IS period contribute to postweaning adaptation through effects on feed in- take, growth, and gut characteristics. All piglets had ad libitum access to creep feed from d 7. Litters were subjected to conventional weaning (CW) or to 1 of 3 IS regimens. In CW, litters (n = 29) had continuous access to the sow until weaning (d 26, d 0 = farrowing). During IS, litters had access to the sow between 1600 and 0600 h. Litters in the IS treatments were subjected to IS 1) from d 19 onward and weaned at d 26 (IS19- 7D, n = 33), 2) from d 19 onward and weaned at d 33 (IS19-14D, n = 28), or 3) from d 26 onward and weaned at d 33 (IS26-7D, n = 33). The IS19-7D regimen resulted in a relative growth check within the first 2 d after weaning similar to CW litters (72 ± 13 and 90 ± 7%, respectively), but in a greater piglet growth (P = 0.0 14) and feed intake (P = 0.001) between d 2 and 7 postweaning. Moreover, IS19-7D was not associated with a (further) reduction in villus height as observed at d 2 postweaning in CW litters. In IS piglets weaned after an extended lactation (d 33), a markedly smaller weaning-associated relative growth check was observed shortly postweaning (11 ± 18 and 32 ± 19% for IS19-14D and IS26-7D litters, respectively). In these litters, feed intake and growth within the first 2 d after weaning were slightly greater when piglets were subjected to IS for 2 wk (IS19-14D) rather than for 1 wk (IS26-7D; P = 0.032 and P = 0.037 for feed intake and growth, respectively). Irrespective of duration of IS, weaning at d 33 with IS was not associated with a reduction in villus height. Irrespective of treatment, plasma citrulline concentrations were reduced at d 2 and 8 postweaning compared with the values at weaning (P ≤ 0.01). No correlation was observed between postweaning plasma citrulline concentrations and postweaning small intestinal villus height. This study indicates that 1 wk of IS before weaning at d 26 of lactation improves feed intake and growth between d 2 and 7 postweaning and does not result in a reduction of villus height as observed in CW piglets, although it did not prevent a profound growth check shortly after weaning. However, combining 1 wk of IS with an extended lactation improved postweaning adaptation markedly in terms of growth, feed intake, and gut characteristics. Increasing the du- ration of IS from 1 to 2 wk slightly improved growth and feed intake shortly after weaning, but the contribution to postweaning adaptation seemed to be relatively small compared with extending lactation. [ABSTRACT FROM AUTHOR]

Contents The aims of this study were (i) to describe the changes in the volume of large ovarian follicles (diameter >3 cm) during the 48 h egg laying cycle in farmed ostriches, and (ii) to quantify factors affecting the volume of the largest measured follicle and the plasma concentrations of progesterone (P4) and estradiol-17β (E2β). In eight egg-producing birds, which all ovulated during the study period, transcutaneous ultrasound scanning and blood sampling was performed at 3 h intervals. The average volume of the total number of visualized large follicles ( Vtotal), the largest measured follicle ( VF1), the second largest follicle ( VF2) and of all follicles smaller than F2 ( VF3–Fn) were each higher before than after oviposition. Vtotal, VF2 and VF3–Fn nearly doubled in the 24-h period before oviposition, while VF1 remained at an equal, rather high level until oviposition. Immediately after oviposition Vtotal, as well as the volume of the other follicle categories, decreased within 6 h, i.e. around the moment of ovulation. By performing statistical analysis on the basis of linear mixed-effects modelling, we quantified that: (i) VF1 was 13.2% higher before than after oviposition and increased with 6.5% when LH increased with 1 ng/ml; (ii) P4 levels were 93.2% higher before than after oviposition and increased with 43.1% for every 3 h closer to oviposition; when LH and E2β levels and VF1 increased with 1 ng/ml, 10 pg/ml and 10 ml, respectively, P4 increased with 116.6%, 50% and 6.1%; and (iii) E2β levels were 35.6% higher before than after oviposition, increased with 2.7% for every 3 h closer to oviposition and increased with 14.6% when LH increased with 1 ng/ml. It is concluded that during the egg-laying cycle in ostriches: (i) follicular mass, as estimated by the volume of visualized follicles larger than 3 cm, increases before and decreases after ovulation, and (ii) follicular dynamics and its accompanying endocrine plasma hormone profiles during the egg-laying cycle in ostriches follow a pattern similar to that in chickens. [ABSTRACT FROM AUTHOR]

Contents The bovine cervix contains a large amount of smooth muscle cells distributed over an outer muscular layer and within a stromal layer. The stromal layer exhibits no electromyographic (EMG) activity at parturition. This leads to the question whether the stromal smooth muscle cells of the bovine cervix are prepared to contract with parturition, or whether they have another function. To this end, cervical biopsies were repeatedly taken from 10 pregnant cows at day-185 and -275 of gestation, at spontaneous, uncomplicated calving and at 30 days after calving. The smooth muscle bundles of the stroma were immunohistochemically analysed (n = 5) with regard to their integrity and cellular density, and the degree of staining for connexin-43, smooth muscle actin α (SMA), desmin and vimentin. Additionally, the mRNA expression for connexin-43, SMA, desmin and vimentin was determined with RT-PCR (n = 5). The smooth muscle tissue was arranged in bundles, also at parturition. However, the cellular density of these bundles and the SMA mRNA expression were decreased at parturition. Additionally, the SMA staining and connexin-43 expression and staining remained constant during pregnancy and at parturition. This might indicate that stromal smooth muscle cells are not prepared to contract with parturition, in contrast to the myometrial smooth muscle cells. The smooth muscle cells, stained for SMA, also expressed vimentin, and the proportion of co-expression was increased at day-275 of pregnancy. This suggests that the stromal smooth muscle cells predominantly have a secretory function in cows. [ABSTRACT FROM AUTHOR]

The objective of the current study was to investigate whether plasma citrulline or intestinal fatty acid-binding protein (I-FABP) concentrations might be used as longitudinal markers for small intestinal function in piglets after weaning. Plasma citrulline and I-FABP concentrations were measured longitudinally in weaned and unweaned piglets, and related to intestinal absorption values (i.e., plasma mannitol and D-xylOSe concentrations in a sugar absorption test). Within each litter (n = 10), 2 piglets with a close-to-litter-average BW were selected. At 20.8 ± 0.4 d of age, the selected piglets per litter were either weaned conventionally (CW) or remained with the sow (UNW). One day before, and 0.5, 2, 4, and 7 d after weaning of the CW piglets, the selected piglets of both groups were subjected to a sugar absorption test. After a 2-h fast, piglets were administered an oral dose of 2 mL/kg of sugar solution, containing 50 mg/kg of mannitol and 100 mg/kg of D-xylose. One hour after administration, a blood sample was collected from a jugular vein for determination of plasma I-FABP, citrulline, mannitol, and D-xylose concentrations. Plasma I-FABP concentration showed great variation within treatments, and no difference was observed in plasma I-FABP concentrations between the CW and TJNW treatments (P = 0.63). The absorption of D-xylose was not different between treatments (P = 0.83). Mannitol absorption, however, was less in the weaned CW piglets compared with the UNW piglets (P = 0.003), with the nadir on d 4 postweaning. Weaning also reduced plasma citrulline concentrations in the CW treatment compared with the UNW treatment (P < 0.001). On d 4 and 7 postweaning, plasma citrulline concentrations of CW piglets were less (P < 0.001 and P = 0.0013) than preweaning values. Furthermore, in the CW treatment, plasma citrulline concentrations correlated with plasma mannitol concentrations at d 4 postweaning (r = 0.89, P = 0.008) and overall (r = 0.76, P = 0.001). Based on these results, plasma citrulline concentration seems to be a possible marker for monitoring intestinal function in pigs after weaning. [ABSTRACT FROM AUTHOR]

Xanthine oxidoreductase (XOR) is a key enzyme in the evolvement of reperfusion injury resulting from birth asphyxia, a common cause of decreased viability and perinatal mortality in newborn piglets under farm conditions. At present no standard pharmacological intervention strategy is available to reduce these adverse effects of birth asphyxia. In the present study we aimed to evaluate placental transfer of allopurinol, an inhibitor of XOR. For this purpose, fetal catheterization of the jugular vein was conducted in five late pregnant sows (one fetus per sow). At 24–48 h after surgery, sows received allopurinol (15 mg/kg body weight; i.v.) and pharmacokinetics of allopurinol and its active metabolite oxypurinol were measured in both late pregnant sows and fetuses. Maternal and fetal blood samples were collected during and after allopurinol administration. Maternal Cmax values averaged 41.90 μg/mL (allopurinol) and 3.68 μg/mL (oxypurinol). Allopurinol crossed the placental barrier as shown by the average fetal Cmax values of 5.05 μg/mL at 1.47 h after allopurinol administration to the sow. In only one fetus low plasma oxypurinol concentrations were found. Incubations of subcellular hepatic fractions of sows and 24-h-old piglets confirmed that allopurinol could be metabolized into oxypurinol. In conclusion, we demonstrated that allopurinol can cross the placental barrier, a prerequisite for further studies evaluating the use of allopurinol as a neuroprotective agent to reduce the adverse effects following birth asphyxia in neonatal piglets. [ABSTRACT FROM AUTHOR]

Contents Compared with other parts of the reproductive cycle, the parturition process of domestic animals has received relatively little attention from researchers during the last two decades. Yet, interventions during parturition, either by the owner or the veterinarian, are frequently judged necessary and perinatal losses in most of the domestic species are (still) rather high. The present paper focuses on the birth process in three domestic species, the dog, pig and cow, mainly because most of the experimental and research work of the authors themselves was dealing with these three species. Against the background of specific clinical problems, breeding circumstances and economic performance, selected topics and questions are addressed to identify areas for future research. These are, among others, related to the mechanisms that trigger the birth process (are the foetuses involved in the dog and sow?), the role of hormones and cytokines during ripening of the cervix (activation and/or de-activation of specific matrix metallo-proteinases and their local inhibitors), the functional significance of fetal body movements to prepare the foetus for expulsion, and the exact time course of events involved in the transportation of an individual foetus from its intrauterine location, via the pelvic canal, to the outside world. Research on some of these topics, such as the ripening of the cervix in cows, might also contribute to resolve clinical problems in human obstetrics. [ABSTRACT FROM AUTHOR]

Contents 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. [ABSTRACT FROM AUTHOR]

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 ISG 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 ISG 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 preweaning values. Intermittent suckling may contribute to adaptation to the postweaning state by stimulating eating behavior, without causing obvious behavioral distress. [ABSTRACT FROM AUTHOR]

An experiment was conducted to determine if the improved creep feed intake observed during intermittent suckling (IS) is important for postweaning performance. Therefore, creep feed intake of litters was assessed, and within litters, eaters and noneaters were distinguished using chromic oxide as an indigestible marker. Batches of sows were suckled intermittently (IS, 7 batches; n = 31) or continuously (control, 7 batches; n = 31). In the IS group, litters were separated from the sow for a period of 12 h/d (0930 to 2130), beginning 11 d before weaning. Litters were weaned at 4 wk of age. Litters had free access to creep feed from 1 wk of age onward. Five days after weaning, the piglets were moved as a litter to weanling pens. At 8 wk of age, 2 barrows and 2 gilts were randomly chosen from each litter and moved to a finishing facility. Feed intake was improved by IS during the last 11 d of lactation (IS, 284 ± 27 vs. control, 83 ± 28 g/piglet; P < 0.001) and after weaning during the first (IS, 201 ± 24 vs. control, 157 ± 25 g·piglet-1·d-1 P < 0.05) and second (IS, 667 ± 33 vs. control, 570 ± 35 g·piglet-1·d-1; P <0.05) wk. Thereafter, no differences were found to slaughter. Weaning BW was lower in IS litters (IS, 7.1 ± 0.01 vs. control, 8.1 ± 0.01 kg/piglet; P < 0.05), but 7 d after weaning BW was similar (IS, 8.5 ± 0.2 vs. control, 8.7 ± 0.2 kg/piglet; P = 0.18), and no differences were found to slaughter. The percentage of eaters within a litter was not increased by IS during lactation (IS, 23 ± 4.5% vs. control, 19 ± 4.1%; P = 0.15). Weaning BW did not differ between eaters and noneaters (eater, 7.7 ± 0.1 vs. noneater, 7.5 ± 0.08 kg/piglet; P = 0.63). From 1 until 4 wk after weaning, piglets that were eaters during lactation had heavier BW than noneaters (eater, 20.3 ± 0.3 kg vs. noneater, 18.2 ± 0.2 kg; P < 0.05). The influence of eating creep feed during lactation on BW and ADG and the influence of suckling treatment never showed an interaction. We conclude that IS increases ADFI during lactation on a litter level and improves ADG in the first week and ADFI in the first and second weeks after weaning. No long-term effects on ADFI or ADG were observed throughout the finishing period. In the current experiment, in which creep feed intake was low, the percentage of eaters within a litter was not increased, suggesting that creep feed intake of piglets that were already eating was stimulated by IS. Further, piglets that were eaters during lactation had heavier BW up to 4 wk after weaning. [ABSTRACT FROM AUTHOR]

The objective of this study was to determine whether intermittent suckling (IS) combined with an extended lactation can reduce postweaning growth check in pigs. Three weaning regimens [conventional weaning (CW), IS with 6-h separation intervals (IS6), and IS with 12-h separation intervals (IS12)] were compared. In CW (n = 17 litters), litters had continuous access to the sow until weaning (d 21, d 0 = farrowing). In IS6 and IS12, litters were separated from the sow for 12 h/d, beginning at d 14 and lasting until weaning (d 41 to 45). Litters were with the sow from 1400 to 2000 and from 0200 to 0800 (IS6, n = 14) or between 2000 and 0800 (IS12, n = 14). Litter size was standardized within 2 d after farrowing by crossfostering, resulting in an average litter size of 10.9 ± 1.8 piglets. Piglets had ad libitum access to creep feed from d 7 onward. One week after the onset of IS (d 20), creep feed intake was increased in litters from both IS groups compared with CW litters (P < 0.05). Both IS groups consumed considerable amounts of creep feed before weaning (d 41 to 45). Total feed intake before weaning was greater (P = 0.004) in IS12 (3,808 ± 469 g/piglet) than in IS6 (2,717 ± 404 g/piglet). In comparison, CW litters consumed 18 ± 9 g/piglet before weaning (d 21). Irrespective of weaning regimen, total feed intake of litters before weaning was highly correlated with postweaning feed intake (P < 0.001). Furthermore, in all treatment groups, total preweaning feed intake was correlated with postweaning growth (P < 0.10). Irrespective of treatment, piglets suckling anterior teats grew faster than piglets suckling middle or posterior teats during the first 2 wk of lactation. Body weights at the end of the experiment (d 55) were similar among weaning regimens. Onset of IS induced a growth check in both IS groups (34% for IS12 and 22% for IS6). Only a mild growth check was observed after weaning of IS litters (14% for both IS groups). However, a serious growth check (98%) was observed after weaning of CW litters. Results of the current study indicate that IS stimulated feed intake during lactation, providing a more gradual transition to weaning. Because the IS6 regimen did not prevent the growth check after the onset of IS and is rather laborious, we suggest that IS12 might be preferable for a practical implementation of IS. [ABSTRACT FROM AUTHOR]

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Summary Transvaginal ultrasound-guided follicle aspiration was performed repeatedly in 5 Dutch Warmblood mares during a time span of 3 months (mid-June-mid-September 1992). During 24 aspiration sessions (4-7/mare), 200 follicles were aspirated and 34 oocytes retrieved, giving oocyte recovery rates of 12.3% and 24.4% when using single channel needles or double barrel needles respectively. There was no significant effect of cycle stage on oocyte recovery rates. Follicle aspiration performed without any hormonal pretreatment gave significantly higher oocyte recovery rates of 26.9%, compared with 8.2 and 15.3% for pretreatments with prostaglandin F [ABSTRACT FROM AUTHOR]

With electromyography and strain gauges the uterine motility of the sow during the oestrous cycle and early pregnancy was studied. Special attention was paid to characterization of myometrial activity at the time of intrauterine migration of blastocysts. From recordings of 4 animals (3 became pregnant) 3 types of electrical spiking activity (each could be correlated with an elevation of the strain gauge tension) were discerned. Two of them appeared regularly and were suitable for analysis: 'High Voltage Slow Acticity' (with relative high amplitude and low frequency of spikes) and 'Low Voltage Fast Activity' (with relative low aplitude and high frequency of spikes). The sexual status markedly influenced myometrial activity: during prooestrus and oestrus only one type of electrical activity was present whereas the myoelectrical complex (an episode of this activity and the subsequent interval of inactivity) was shorter than 10 min. During dioestrus the myoelectrical complex was longer than 10 min and 'High Voltage Slow Activity' (solely on the cervix and bifurcation) and 'Low Voltage Fast Activity' occurred simultaneously in episodes which mainly appeared to originate on the bifurcation. The characteristics of uterine activity during pregnancy were similar to those of a cyclic sow until day 12. It was only on day 12 that gestation appeared from an increased frequency of myoelectrical complexes. It is concluded that 'Low Voltage Fast Activity' as it was found on the uterine horn at days 8-9 might be involved in the process of intra-uterine migration of blastocysts. In cyclic and in pregnant animals the patterns of 'Low Voltage Fast Activity' were similar. Therefore, the occurrence of 'Low Voltage Fast Activity' is independent of the actual presence of blastocysts. It seems to be exhibited in dependence on the ovarian hormones. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

An abstract of the conference paper "First embryonic movements are executed rhythmically," by J. I. de Vries and colleagues, is presented.