Seasonal changes in blood serum protein fractions and in activity of AspAT and AlAT in Arabian brood mares and their foals

In 34 pure breed Arabian horses divided into four groups (Gr. I--10 pregnant mares, Gr. II--7 barren mares, Gr. III--10 foals born in 1981, Gr. IV--7 foals born in 1982) seasonal changes in total blood serum protein, its electrophoretic fractions and the activity of AspAT and AlAT were studied. Seasonal cyclicity was found in all groups in the amount of total serum proteins, and alpha 2- and beta 1-globulin fractions. Cyclicity was found in the level of albumin and activity of AspAT in three groups, not Gr. II, and in gamma-globulin, not Gr. IV. beta 2-globulin and AlAT cyclicity was found in two groups and alpha 1-globulin cyclicity was found only in Gr. II. Out of nine indices studied, cyclicity was found in eight of them in pregnant mares, Gr. I; in seven in older foals, Gr. III; in six in the young foals, Gr. IV; and in five in barren mares, Gr. II.     

Seasonal changes in the white blood cell system, lyzozyme activity and cortisol level in Arabian brood mares and their foals

In 34 pure-breed Arabian horses divided into four groups (Gr. I, ten pregnant mares; Gr. II, seven barren mares; Gr. III, ten foals born in 1981; Gr. IV, seven foals born in 1982) seasonal changes in the white blood cell system, cortisol level and lyzozyme activity were studied. Seasonal periodicity was found in all groups for the number of lymphocytes, segmented neutrophils and eosinophils and cortisol level. Leukocyte periodicity was found in three groups, but not in the barren mares. In lyzozyme activity there was periodicity in three groups but not in the youngest foals. In the stab neutrophils, basophils and monocytes no cycle was observed. The behaviour of the indices studied showed the influence of age of the horses (mature vs young) and the physiological state of the mares (pregnancy or barrenness).     

Influence of pregnancy on diurnal and seasonal changes in glucose level and activity of FDPA, AlAT and AspAT in mares.

1. The diurnal changes in the glucose level and in activity of FDPA, A1AT and AspAT in four pregnant standard-bred mares were studied. 2. As a control four barren mares, were kept and examined in the same conditions. 3. Blood samples were taken every 4 hr for one day, each month, throughout pregnancy, or one year. 4. A diurnal rhythm in activity of A1AT and AspAT in barren mares was found. The pregnancy masked diurnal rhythm in activities of both transaminases. 5. No diurnal rhythm in glucose level and FDPA activity in both groups of mares was observed. 6. Seasonal cyclicity was found in all indices studied, in both groups of mares. 7. The pregnancy did not abolish cyclicity in parameters studied but modified their behaviour--causing a shift of acrophases (glucose, FDPA, AspAT) and lowering the amplitudes (FDPA, A1AT, AspAT).     

Seasonal changes in the red blood cell system in the European bison, Bison bonasus L

1. In 195 European bisons divided into four groups (Group 1, 0-3 year-old males; Group 2, 0-3 year-old females; Group 3, mature bulls, over 3 years old; Group 4, mature cows, over 3 years old) seasonal changes in red blood cell number and diameter, haemoglobin level, haematocrit value, index F, MCH, MCHC and MCV were studied. 2. Seasonal cyclicity was found only in red blood cell diameters in all groups. 3. In young males the cyclicity was found in MCHC and in MCV only. 4. In young females the cyclicity was found in Hb and Hct values, in MCH and in MCV. 5. In mature bulls cyclicity was found only in RBC diameter and in MCV. 6. In mature cows the cyclicity was found in index F, MCH and in MCHC values. 7. Seven out of 14 acrophases of cyclic indices occurred just before autumnal equinox and three before vernal equinox.     

Influence of pregnancy on diurnal and seasonal changes in cortisol, T3 and T4 levels in the mare blood serum.

1. The diurnal changes in the level of total protein, cortisol, T3 and T4 were studied in four barren and four pregnant standard-bred mares, kept and examined under the same conditions. 2. Blood samples were taken every 4 hr. for one day each month, throughout one year. 3. In barren mares, a diurnal rhythm in cortisol level (acrophase at 0530 hr in summer and at 0830 hr in winter) and in T3 level (acrophase at 1330 hr in summer and at 1800 hr in winter) was found. 4. In pregnant mares, a diurnal rhythm in cortisol level only till 5th month of pregnancy was observed. 5. A diurnal rhythm in T3 level was found throughout the pregnancy, with acrophase always at 1400 hr. 6. No diurnal rhythm in the total protein content and in the T4 level was observed. 7. In both groups of mares the seasonal cyclicity in T3 and T4 levels were found. A seasonal cyclicity in cortisol level was found only in pregnant mares. 8. Pregnancy abolished seasonal cyclicity in total protein and showed it in cortisol level. 9. Pregnancy in mares modifies diurnal rhythms as well as seasonal cycles in secretion and metabolism of the hormones studied.     

Influence of pregnancy and lactation on diurnal and seasonal changes in lactic acid and pyruvic acid levels and in values of pH, pCO2 and pO2 in the mare blood.

1. The diurnal changes in the levels of lactic (LA) and pyruvic (PA) acids and in values of pH, pO2 and pCO2 were studied in the blood of barren and later on in pregnant and lactating mares, throughout three subsequent years. 2. Blood samples were taken every 4 hr, for one day, each month, throughout 3 years. 3. The mares were kept and fed in the same conditions, lighting was natural. 4. In barren mares, diurnal rhythm in LA, PA, pO2 and pCO2 was found. 5. The pregnancy as well as lactation masked diurnal rhythms in parameters studied, except the LA level during lactation but then the acrophase was shifted by 3-4 hr. 6. Seasonal cyclicity was found in the values of LA, PA and pCO2 in barren mares. The pregnancy abolished cyclicity in LA level and modified the behaviour of PA and pCO2 values causing a shift of acrophases and lowering the amplitudes of the indices. 7. In the pO2 tensions no seasonal cycles were observed. 8. In the values of pH neither diurnal rhythms nor seasonal cycles throughout study years were observed.     

Diurnal changes in the haemoglobin level, red blood cell number and mean corpuscular haemoglobin in foals during the first 13 weeks of life and in their lactating mothers

1. In six foals and their mothers (of Standard breed) diurnal changes in the haemoglobin level, red blood cell number and mean corpuscular haemoglobin during the first 13 weeks of foal life were studied. 2. Studies begun when a foal reached 7 days of age and were repeated every two weeks till 13 weeks of foal life. Blood was taken every 6 hr in foals and every 4 hr in mares. 3. No diurnal rhythmicity in parameters studied either in foals or in mares was found. 4. Decrease of haemoglobin level in lactating mares (14.0-12.5 g/100 ml) without changes in red blood cell number were observed. Mean corpuscular haemoglobin changed distinctly from one study day to another. 5. In foals were stated: significantly higher haemoglobin level and erythrocyte number and lower mean corpuscular haemoglobin than in mares.     

Acceleration and Timing of Fertile Ovulation in Cyclic Mares with a Deslorelin Implant

In a blinded trial, the effectiveness and safety of 2.2 mg of the GnRH analog deslorelin acetate, administered in a short–term implant (STI) to normally cycling mares in estrus with a dominant ovarian follicle of 30 mm in diameter or larger, were evaluated, using a placebo implant as a negative control. A total of 39 mares received treatments at admittance with pre–randomized implants containing either 2.2 mg or 0 mg deslorelin. Mares were teased daily and examined rectally with ultrasound at 24 h intervals to determine time to Ovulation and duration of estrus. The number of breedings and the pregnancy rate at 18 (±3) and 38 (±3) days were recorded, as were systemic side effects and local reactions at the implantation sites. Pregnancies resulting from breedings during the treatment estrus and/or from breedings during the next estrus were followed and the early and late pregnancy loss rate, the number of pregnancies going to term and of live–born foals was recorded. Mean follicle diameter at treatment was not significantly different between the deslorelin and placebo treatment group with 41.6 mm and 40.8 mm, respectively. Treatment with deslorelin STI reduced the time interval to Ovulation significantly from 69.5±25.48 h to 42.7±12.35 h (p<0.001). The percentage of mares having ovulated within 48 h rose from 26.3% to 95.0%, respectively, for placebo and deslorelin STI (p<0.001). As a consequence, the duration of estrus in days and the percent of animals requiring more than 1 breeding were significantly reduced in deslorelin treated animals from 5.4 days to 4.6 days, and from 55.6% to 5.0%, respectively (p=0.009 and =0.001). The percent of mares pregnant from breedings at the treatment estrus (65.0% versus 44.4%) or the next estrus (83.3% versus 92.3%) was satisfactory and similar for deslorelin and placebo treated mares (p>0.005), and in 70.0% and 66.7% of these once or twice bred mares did pregnancies go to term and live foals were born. kw|Keywords|k]GnRH     

Concentrations of altrenogest in plasma of mares and foals and in allantoic and amniotic fluid at parturition

Treatment with the progestin altrenogest is widely used in pregnant mares. The fact that foals born from healthy mares treated with altrenogest until term suffered from neonatal problems raises the question of direct effects of altrenogest on vital functions in the neonate. We have therefore investigated altrenogest concentrations in maternal and neonatal blood plasma and in fetal fluids. Pregnant mares were treated with altrenogest orally once daily (0,088 mg/kg bodyweight, n = 7) or left untreated (n = 8) from 280 d of gestation until foaling. Altrenogest concentration was determined in plasma of the mares, their foals and in amniotic and allantoic fluid. The concentration of altrenogest in plasma from treated mares (2.6 ± 1.0 ng/mL) was significantly lower than in plasma from their foals immediately after birth (5.6 ± 1.9 ng/mL; p < 0.05), but was significantly higher than in their fetal fluids (amniotic fluid: 0.4 ± 0.1 ng/mL; p < 0.05; allantoic fluid: 3.0 ± 1.5 ng/mL). Altrenogest was undetectable in maternal and fetal plasma and fetal fluids of control pregnancies at all times. Altrenogest concentration in plasma of foals from treated mares was strongly correlated to the altrenogest concentration in plasma of their dams (r = 0.938, p < 0.001) and in amniotic (r = 0.886, p < 0.001) and allantoic fluid (r = 0.562, p < 0.05). A significant decrease in altrenogest concentration between the time periods 0-15 min, 30-120 min, and 180-360 min after parturition was seen in the plasma from foals born to altrenogest-treated mares. In conclusion, our data demonstrate that altrenogest reaches the equine fetus at high concentrations.     

Absence of effects from immunocontraception on seasonal birth patterns and foal survival among barrier island wild horses

Despite a large body of safety data, concern exists that porcine zonae pellucidae (PZP) immunocontraception--used to manage wild horse populations--may cause out-of-season births with resulting foal mortality. Our study at Assateague, Maryland indicated the effects of immunocontraception on season of birth and foal survival between 1990 and 2002 on wild horses from Assateague Island. Among 91 mares never treated, 69 (75.8%) of foals were born in April, May, and June (in season). Among 77 treated mares, 50 (64.9%) were born in season. Of 29 mares foaling within 1 year after treatment (contraceptive failures), 20 (68.9%) were born in season. Of 48 mares treated for greater than 2 years then withdrawn from treatment, 30 (62.5%) of 48 foals were born in season. There were no significant differences (p <.05) between either treatment group or untreated mares. Survival did not differ significantly among foals born in or out of season or among foals born to treated or untreated mares. Data indicate a lack of effect of PZP contraception on season of birth or foal survival on barrier island habitats.     

Maternal care and foal social relationships in a herd of Sorraia horses: Influence of maternal rank and experience

The influence of maternal rank and experience on patterns of maternal care and social relationships of foals were investigated in a managed herd of Sorraia horses, Equus caballus. Social interactions and spatial relationships of 13 foals (seven females and six males) born to seven mares were examined from birth to 10 months of life, within the three major periods of foal development. Conflict over suckling between dam and foal was not generally affected by rank and experience, but higher-ranking mothers allowed more suckling during late lactation than lower-ranking mothers. Foals of higher-ranking mares spent more time in proximity to the mother during socialization. Maternal rank and experience did not significantly affect maternal protectiveness, foal independence from the mother or the development of affiliative relationships between foals and group members. Foals of higher-ranking mares received lower frequencies of aggression from other horses only in the first month of life. Dominance relationships among foals depended mainly on aggressiveness and were not associated with maternal rank. The large variability in maternal behaviour, the absence of a significant association between maternal rank and body condition at parturition and the stable social environment within this herd may partly account for the reported results.     

A mare mule--dam or foster mother?

A female, horse-like foal was apparently born to a mare mule from mating to a Shetland stallion. The presence of three pregnant Shetland mares in the same pasture, however, raised some questions about parentage, even though all three mares apparently gave birth to single foals within 6 weeks after the birth of the propositus. The transferrin system indicated that the foal was not born to the mare mule but was the offspring of one of the Shetland mares. Apparently one Shetland mare gave birth to twins 3 to 6 weeks apart, and the mare mule came into lactation spontaneously and adopted the first twin. The offspring was determined to be a horse by appearance, karyotype, blood type, and voice.     

Age of the Jeju pony (Equus caballus) at first reproduction: potential costs for foals and mothers that first reproduce early in life

In a related paper, we showed that mares that reproduced early in life tended to have higher fecundity because of a decrease in the duration of inter-birth intervals relative to mares that reproduced later in life. However, we know that young mares are subordinate to older mares. Hence, costs associated with low dominance rank might offset the benefits of earlier reproduction. We compared harassment of foals of female Jeju ponies that first reproduced at three years of age with that of foals of females that first reproduced at five years of age. As a consequence of their positions in the linear dominance hierarchy, foals born to and guarded by young mares were harassed more frequently than foals whose mothers were older when they first reproduced. A mare that reproduced early in life guarded her offspring more closely and intervened between her foal and neighboring mares more frequently than those mares which first reproduced when older. This need to guard their foals and the harm that might ensue from frequent harassment might counter-balance selection towards earlier reproduction in mares.     

Variation in the susceptibility of sockeye salmon Oncorhynchus nerka to infectious haemopoietic necrosis virus

Haemoglobin concentrations, haematocrit values, red blood cell counts, red blood cell diameter, erythrocyte sedimentation rate and plasma haemoglobin concentration were measured on the air-breathing mud eel Amphipnous cuchia .     

Histomorphometric parameters and fractal complexity of the equine placenta from healthy and sick foals

Computer-based digital image analysis of tissue samples shows promise both to reduce the subjectivity of traditional manual tissue assessments and potentially to shorten the time required to analyze each sample. The present study used digital image analysis to investigate the histomorphometric parameters and fractal complexity of the equine placenta from healthy and sick foals. We hypothesized that the placentas of sick foals could have a different growth pattern and complexity that could be objectively estimated by their fractal dimension (FD). Fourteen placentas from 30 mares were selected in the 2013 breeding season and divided into two groups: seven mares with normal pregnancy, eutocic delivery, and healthy foals (group 1) and seven mares with normal or high-risk pregnancy, eutocic delivery and sick foals (group 2). Four mares in group 2 were classified as having a high-risk pregnancy on the basis of anamnesis and/or ultrasound findings. Clinical diagnosis of group 2 foals included perinatal asphyxia syndrome (n = 4), prematurity/dysmaturity (n = 2), and both diagnoses (n = 1). Seven out of fourteen placentas showed diffuse gross abnormalities. Grossly abnormal placentas were observed in one out of seven (14.28%) animals in group 1 and in six out of seven (85.72%) animals in group 2. Digital image analysis proved to be reliable and efficient in segmentation, calculation, outline extraction of villi as also resulted in sampled test images. The placentas of group 1 foals displayed a uniform and homogeneous villi development, as revealed by geometric parameters and FD. These results can be interpreted as a harmonic growth pattern of microcotyledons throughout the placenta in healthy foals. By contrast, the placentas of group 2 foals showed a nonuniform growth pattern and complexity with more villi and more developed villi in pregnant horn (PH) and nonpregnant horn (NPH) compared with body (B) and higher FD in NPH than in the other areas. This finding can be interpreted as a compensatory growth with increased complexity. Our results show that morphometric analysis, particularly FD measurement, can be proposed as an ancillary histological tool for equine placenta evaluation. Chorionic villi tend to have greater branching and complexity in sick than in healthy foals, particularly in the NPH. This could represent an attempt to increase the exchange area between fetal and maternal compartments of the equine placenta, and merits further investigation.     

Some aspects of haematology of a common Indian field rat, Rattus rattus arborious (Linn.) in relation to sex and size.

In the present investigation the studies on erythrocyte and leucocyte counts, haemoglobin concentration, haematocrit values, blood biochemistry of protein, glucose and cholesterol, erythrocyte sedimentation rate, pH value, diameter of erythrocyte and clotting time were made in different sex and size (weight group) of an Indian field rat, Rattus rattus arborious. The number of erythrocyte, haemoglobin concentration, haematocrit values were found to be higher in females than the males, while the number of leucocyte was lower in females in comparison to males. In the biochemical estimation the value of protein in females was high while that of the glucose and cholesterol were lower than that of the males. All the above values showed an increasing tendency with the increase in body weight. pH value, diameter of erythrocyte and clotting time were found to be almost constant in rats of different weight groups and different sex.     

Endogenous transplacental transmission of Neospora hughesi in naturally infected horses

Over a 2-yr study period, we investigated possible endogenous transplacental transmission of Neospora hughesi in 74 mare and foal pairs following the diagnosis of neuronal neosporosis in a weanling foal. Presuckle and postsuckle serum of each foal, serum and colostrum of each periparturient mare, and serum of each mare and foal pair, collected at 3-mo intervals thereafter, were tested for N. hughesi using an indirect fluorescent antibody test (IFAT). Furthermore, whole blood and colostrum samples and placentae were tested for the presence of N. hughesi by real-time PCR. The mares' seroprevalence at foaling based on IFAT (titer ≥ 160) was 52 and 6% in 2006 and 2007, respectively. Colostral antibodies against N. hughesi were detected in 96 and 11% of the mares in the 2-yr study. With the exception of 3 foals, all remaining foals were born seronegative to N. hughesi. Passive transfer of colostral antibodies to N. hughesi was documented in 15 foals. Three foals born from 2 different mares had presuckle antibodies at a titer ranging from 2,560 to 20,480. All 3 foals were born healthy. Two foals were born to the same dam that also gave birth to the weanling diagnosed with neuronal neosporosis in 2005. The third foal was born to a second mare with no previous foaling history at the farm. Seroconversion was documented in 10 foals and 9 mares over the 2-yr study. All blood and colostrum samples tested PCR negative for N. hughesi. Only 1 placenta collected in 2007 from the mare with the 2 congenitally infected foals tested PCR positive for N. hughesi. In conclusion, N. hughesi persisted in this population via endogenous transplacental infection.     

The role of the fetal gonads and placenta in steroid production, maintenance of pregnancy and parturition in the mare.

The effects of fetal gonadectomy on steroid production and the maintenance of pregnancy in the mare were studied. Removal of the fetal gonads resulted in an immediate fall in maternal plasma concentrations of conjugated and unconjugated oestrogens whereas progestagen levels remained unchanged. Hormone profiles in mares carrying sham-operated fetuses remained similar to those in unoperated control mares. Plasma levels of 13,14-dihydro-15-oxo-PGF-2 alpha (PGFM) were much lower, and uterine contractions weaker, during labour in mares carrying gonadectomized foals than in control mares. Pregnancy was maintained until parturition at term in the mares carrying gonadectomized fetuses. However, 3 of the 4 gonadectomized foals were dysmature and died during or soon after birth. The biosynthetic pathways involved in the production of oestrogens by the feto-placental unit and the possible role of oestrogens in fetal development in the pregnant mare are discussed.     

Body weight of mares and foals, estrous cycles and plasma glucose concentration in lactating and non-lactating Lipizzaner mares

This study summarizes weight development, plasma glucose concentrations and reproductive parameters in lactating (n = 46) and non-lactating Lipizzaner mares (n = 11) throughout the breeding season. It was the aim of the study to analyse if an energy deficit with possible effects on reproductive functions occurs at any time during the first 4 months of gestation. Mean gestation length was 334.3 +/- 7.3 days. Gestation of foals born in May/June was shorter (P < 0.01) than for foals born in March/April. Out of the 46 lactating mares, 44 ovulated between Days 8 and 18 postpartum and two mares ovulated on days 30 and 145, respectively. Pregnant mares were significantly (P < 0.001) heavier (600.1 +/- 5.3 kg) than non-pregnant mares (521.8 +/- 10.0 kg) at the beginning of the study. Birth resulted in weight reduction of 64.8 +/- 2.4 kg. During the first 2 weeks postpartum mares lost on average 3.0 +/- 1.8 kg and in the following 2 weeks gained 3.6 +/- 1.4 kg of weight. Thereafter, weight increased slightly but continuously (P < 0.01). At no time after foaling, weight differed significantly between groups. Weight of the foals three days after birth varied between 29 and 67 kg (53.7 +/- 1.1 kg). Average daily weight gain of foals was relatively constant throughout the study period (1.15 +/- 0.17 kg). Although lactation at no time was associated with a major weight loss, it had clear effects on energy metabolism as shown by constantly lower plasma glucose concentrations in lactating mares. Glucose concentrations decreased after foaling and were significantly lower in lactating mares from Weeks 3 to 16 after foaling than at corresponding times in non-lactating mares (P < 0.01). However, glucose concentrations were still within the physiological range. Mares seem to be able to compensate energy losses during lactation mainly by increasing feed intake and not by mobilisation of body fat.     

二龄鲢和鳙血液的比较研究

以１１５尾二龄链和９１尾二龄鳙为材料,测定了血液中红细胞数,白细胞数、血红蛋白值、红细胞脆性植、比积及比重,红细胞沉降率,白细胞分数计数值及各型血细胞大小等正常值。结果显示：红细胞和白细胞值,比积值及淋巴细胞所占百分比值均是鲢高于鳙,而红细胞沉降率和中性粒细胞却是鳙高于链,在鲢上,其血液指标植也存在雌雄差异,上述血液指标值也存在周年变化。