How type of parturition and health status influence hormonal and metabolic profiles in newborn foals

Thyroid hormones, insulin growth factor I (IGF-I) and non-esterified fatty acids (NEFA) represent important hormonal and metabolic factors associated with perinatal growth and maturation. Their action could be influenced by the type of parturition and the health status of the foal and therefore the aim of this work is to evaluate their plasma concentrations in newborn foals during the first 2 wks of life. Three groups of subjects were enrolled: 15 healthy foals born by spontaneous parturition, 24 healthy foals born by induced parturition and 26 pathologic foals. From each of the healthy foals, blood was collected at 10, 20 and 30 minutes, 3 and 12 hours from birth, daily from Day 1 to Day 7, and at Day 10 and 14 of life. In pathologic foals samples were collected twice a day from the day of admission at the hospital until the day of discharge or death. Thyroid hormones (T3 and T4) and IGF-I were analyzed by radioimmunoassay and NEFA by enzymatic-colorimetric methods. In all the three groups a declining trend of T3 and T4 plasma concentrations was detectable, with lower levels in the pathologic group compared to healthy foals. Spontaneous foals showed higher levels of T3 at 7 d compared to induced foals, while T4 levels were higher in spontaneous vs. induced foals before 6 h of life, at three and seven days. IGF-I showed increasing plasma concentrations in all three considered groups. No differences were found between healthy and pathologic foals. NEFA in spontaneous and induced healthy foals showed a declining trend with higher levels during the first hours of life. Pathologic foals presented higher levels compared to spontaneous foals only at 24 h and 10 d. These data suggest that the type of foaling could influence the reference ranges for thyroid hormones. Moreover, pathologic foals showed some hormonal and metabolic differences related to their health status. Above all changes of thyroid hormones levels, early in postnatal life, could be a cause, and not only a consequence, of the diseased condition of these foals.     

Gross placental morphology and foal serum biochemistry as predictors of foal health

The aim of this study was to verify if changes in blood glucose, creatinine, urea, and fibrinogen concentrations evaluated at birth reflect gross placenta abnormalities, and are useful to identify foals that suffered from placental dysfunction. A total of 92 mares were included in the present study: 68 delivered healthy foals and they were included in group 1; 24 delivered sick foals and they were included in group 2. In group 2, foals' clinical diagnoses included perinatal asphyxia syndrome (PAS; n = 20) and prematurity and/or dysmaturity (n = 4). The proportion of sick foals was greater when placental abnormalities were observed (χ² [1, n = 89] = 5.00; P = 0.025). Serum creatinine concentration at birth was higher in sick than in healthy foals (P = 0.003), and blood glucose concentrations at birth was smaller in sick than in healthy foals (P = 0.007). No difference was found in blood chemistry results between survivors and nonsurvivors of group 2. Serum creatinine concentration was higher in foals born from grossly abnormal than in foals born from grossly normal placenta (P = 0.029), and it was higher in foals affected by PAS (311.17 μmol/L) than in healthy foals (238.24 μmol/L) (P = 0.004). In a clinical setting, serum creatinine and blood glucose concentrations should be evaluated at birth, particularly in foals born from grossly abnormal placenta. The association of clinical and laboratory data could be particularly important to promptly identify and treat foals with a higher risk to develop PAS.     

Thyroid hormone concentrations in foals affected by perinatal asphyxia syndrome

The hypothalamus-pituitary-thyroid axis has specific functions, mostly related to metabolic activities, cell differentiation, and development. To the authors’ knowledge, there are no studies about thyroid hormone (TH) concentrations in foals affected by perinatal asphyxia syndrome (PAS). Hence, the aims of the study are (1) to evaluate plasma TH concentrations (T₃ and T₄) in healthy foals during the first 7 days of life; (2) to evaluate plasma TH concentration (T₃ and T₄) in critically ill foals affected by PAS during the first 7 days of hospitalization; and (3) to compare TH concentrations between surviving and nonsurviving critically ill foals. Forty-five Standardbred foals were enrolled in this prospective observational study: 21 healthy foals (group 1) and 24 foals affected by PAS (group 2). Jugular blood samples were collected within 10 minutes from birth/admission and every 24 hours for 7 days (t0–t7). TH concentrations were analyzed by RIA. In both groups, T₃ concentration was significantly lower at t4, t5, t6, and t7 compared with t1 (P < 0.05), and T₄ concentration was significantly higher at birth than at all other time points (P < 0.01). No differences were found in TH concentrations at admission between surviving (n = 20) and nonsurviving (n = 4) foals. Statistical comparison between healthy and PAS foals divided into age groups showed significantly lower TH concentrations at t0 in PAS foals <12 hours old at admission (P < 0.01). In conclusion, PAS may cause lower T₃ and T₄ concentrations in affected foals than in age-matched healthy foals, as reported for other systemic illnesses, such as sepsis and prematurity. TH concentrations showed no prognostic value, which maybe due to the small number of nonsurviving foals in this study. Further studies are needed to find out if thyroid replacement therapy could be useful in the treatment of critically ill foals affected by PAS.     

15-Ketodihydro-PGF2α and cortisol plasma concentrations in newborn foals after spontaneous or oxytocin-induced parturition

Hormonal changes during early neonatal life play a major role in the physiological processes underlying the maturation of several organs. Since prostaglandins and cortisol are associated with fetal organ system maturation, the aim of this study was to evaluate 15-ketodihydro-PGF_2α (PGM) and cortisol plasma concentrations during the first 21 days after birth in foals born by either spontaneous (24 foals) or low-dose oxytocin (OT)-induced parturition performed after at least 320 gestational days (25 foals) since induction is often considered to be a cause of prematurity. After spontaneous birth, the PGM concentration was significantly (P < 0.05) higher at 20 and 30 min compared to samples taken several hours or days later, while induced foals showed significantly (P < 0.05) higher concentrations at 10, 20, and 30 min. Regarding differences between the two groups, the plasma concentration of PGM was significantly higher 10 (P < 0.01), 20 (P < 0.05), and 30 (P < 0.05) min and 3 h (P < 0.05) after birth in induced foals compared to foals born by spontaneous parturition. It is difficult to determine whether the higher initial PGM concentrations in induced foals is related to higher uterine or fetal PGM release induced by exogenous OT stimulation. Cortisol plasma levels in both groups were higher at birth (P < 0.05) compared to the later sampling times. No differences were observed between the two groups indicating that the induction protocol used does not seem to result in premature foals.     

Enhanced or Reduced Fetal Growth Induced by Embryo Transfer into Smaller or Larger Breeds Alters Post-Natal Growth and Metabolism in Pre-Weaning Horses

In equids, placentation is diffuse and nutrient supply to the fetus is determined by uterine size. This correlates with maternal size and affects intra-uterine development and subsequent post-natal growth, as well as insulin sensitivity in the newborn. Long-term effects remain to be described. In this study, fetal growth was enhanced or restricted through ET using pony (P), saddlebred (S) and draft (D) horses. Control P-P (n = 21) and S-S (n = 28) pregnancies were obtained by AI. Enhanced and restricted pregnancies were obtained by transferring P or S embryos into D mares (P-D, n = 6 and S-D, n = 8) or S embryos into P mares (S-P, n = 6), respectively. Control and experimental foals were raised by their dams and recipient mothers, respectively. Weight gain, growth hormones and glucose homeostasis were investigated in the foals from birth to weaning. Fetal growth was enhanced in P-D and these foals remained consistently heavier, with reduced T₃ concentrations until weaning compared to P-P. P-D had lower fasting glucose from days 30 to 200 and higher insulin secretion than P-P after IVGTT on day 3. Euglycemic clamps in the immediate post-weaning period revealed no difference in insulin sensitivity between P-D and P-P. Fetal growth was restricted in S-P and these foals remained consistently lighter until weaning compared to S-D, with elevated T₃ concentrations in the newborn compared to S-S. S-P exhibited higher fasting glycemia than S-S and S-D from days 30 to 200. They had higher maximum increment in plasma glucose than S-D after IVGTT on day 3 and clamps on day 200 demonstrated higher insulin sensitivity compared to S-D. Neither the restricted nor the enhanced fetal environment affected IGF-1 concentrations. Thus, enhanced and restricted fetal and post-natal environments had combined effects that persisted until weaning. They induced different adaptive responses in post-natal glucose metabolism: an early insulin-resistance was induced in enhanced P-D, while S-P developed increased insulin sensitivity.     

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.     

Responses of intestinal morphology and function in offspring to heat stress in primiparous sows during late gestation

Late gestation is a key period for intestinal development. Maternal heat exposure may induce intestinal dysfunction of offspring. To investigate the responses of intestinal morphology and function of offspring to the maternal heat stress (HS), twelve first-parity Landrace × Large White sows were assigned to thermoneutral (TN) (18-22 °C; n = 6) or HS (28-32 °C; n = 6) treatment groups at 85 d of gestation until natural farrowing. Twenty-four newborn piglets (two piglets at medium body weight from each litter) were randomly selected and divided into in utero thermoneutral (IUTN, n = 12) and heat-stressed (IUHS, n = 12) groups according to the sow’s treatment. Blood and intestinal samples were harvested to evaluate stress hormone levels, intestinal morphology, integrity and barrier function in the newborn piglets. Our results showed that maternal HS piglets exhibited increased serum adrenocorticotropic hormone (ACTH) concentration compared with that observed in the IUTN group. IUHS piglets showed lower lactase activities in the jejunum and ileum, whereas no significant differences were found between the two groups in the length of intestine, villus length or crypt depth. Serum diamine oxidase (DAO) activity was increased in IUHS piglets. IUHS piglets also exhibited decreased ZO-1, ZO-2 and MUC2 mRNA expression in the jejunum, while the protein levels were not affected. Additionally, IUHS piglets had a lower apoptotic percentage and FAS mRNA expression in the jejunum than those in the IUTN group. Taken together, these results demonstrate that high ambient temperature during late gestation of primiparous sows causes stress response in neonatal piglets, compromising intestinal permeability and mucosal barrier function, which may be partly mediated by inducing intestinal apoptosis.     

Effects of Administration of Live or Inactivated Virulent Rhodococccus equi and Age on the Fecal Microbiome of Neonatal Foals

Background

Rhodococcus equi is an important pathogen of foals. Enteral administration of live, virulent R. equi during early life has been documented to protect against subsequent intrabronchial challenge with R. equi, indicating that enteral mucosal immunization may be protective. Evidence exists that mucosal immune responses develop against both live and inactivated micro-organisms. The extent to which live or inactivated R. equi might alter the intestinal microbiome of foals is unknown. This is an important question because the intestinal microbiome of neonates of other species is known to change over time and to influence host development. To our knowledge, changes in the intestinal microbiome of foals during early life have not been reported. Thus, the purpose of this study was to determine whether age (during the first month of life) or administration of either live virulent R. equi (at a dose reported to protect foals against subsequent intrabronchial challenge, viz., 1×10¹⁰ colony forming units [CFU]) or inactivated virulent R. equi (at higher doses, viz., 2×10¹⁰ and 1×10¹¹ [CFU]) altered the fecal microbiome of foals.

Methodology/Principal Findings

Fecal swab samples from 42 healthy foals after vaccination with low-dose inactivated R. equi (n = 9), high-dose inactivated R. equi (n = 10), live R. equi (n = 6), control with cholera toxin B (CTB, n = 9), and control without CTB (n = 8) were evaluated by 454-pyrosequencing of the 16S rRNA gene and by qPCR. No impact of treatment was observed among vaccinated foals; however, marked and significant differences in microbial communities and diversity were observed between foals at 30 days of age relative to 2 days of age.

Conclusions

The results suggest age-related changes in the fecal microbial population of healthy foals do occur, however, mucosal vaccination does not result in major changes of the fecal microbiome in foals.     

Vitamin D Metabolites and Their Association with Calcium,Phosphorus, and PTH Concentrations,Severity of Illness,and Mortality in Hospitalized Equine Neonates

Background

Hypocalcemia is a frequent abnormality that has been associated with disease severity and outcome in hospitalized foals. However, the pathogenesis of equine neonatal hypocalcemia is poorly understood. Hypovitaminosis D in critically ill people has been linked to hypocalcemia and mortality; however, information on vitamin D metabolites and their association with clinical findings and outcome in critically ill foals is lacking. The goal of this study was to determine the prevalence of vitamin D deficiency (hypovitaminosis D) and its association with serum calcium, phosphorus, and parathyroid hormone (PTH) concentrations, disease severity, and mortality in hospitalized newborn foals.

Methods and Results

One hundred newborn foals ≤72 hours old divided into hospitalized (n = 83; 59 septic, 24 sick non-septic [SNS]) and healthy (n = 17) groups were included. Blood samples were collected on admission to measure serum 25-hydroxyvitamin D₃ [25(OH)D₃], 1,25-dihydroxyvitamin D₃ [1,25(OH) ₂D₃], and PTH concentrations. Data were analyzed by nonparametric methods and univariate logistic regression. The prevalence of hypovitaminosis D [defined as 25(OH)D₃ <9.51 ng/mL] was 63% for hospitalized, 64% for septic, and 63% for SNS foals. Serum 25(OH)D₃ and 1,25(OH) ₂D₃ concentrations were significantly lower in septic and SNS compared to healthy foals (P<0.0001; P = 0.037). Septic foals had significantly lower calcium and higher phosphorus and PTH concentrations than healthy and SNS foals (P<0.05). In hospitalized and septic foals, low 1,25(OH)₂D₃ concentrations were associated with increased PTH but not with calcium or phosphorus concentrations. Septic foals with 25(OH)D₃ <9.51 ng/mL and 1,25(OH) ₂D₃ <7.09 pmol/L were more likely to die (OR=3.62; 95% CI = 1.1-12.40; OR = 5.41; 95% CI = 1.19-24.52, respectively).

Conclusions

Low 25(OH)D₃ and 1,25(OH)₂D₃ concentrations are associated with disease severity and mortality in hospitalized foals. Vitamin D deficiency may contribute to a pro-inflammatory state in equine perinatal diseases. Hypocalcemia and hyperphosphatemia together with decreased 1,25(OH)₂D₃ but increased PTH concentrations in septic foals indicates that PTH resistance may be associated with the development of these abnormalities.     

Phimosis in male dromedary camels: Clinical findings and changes in the hemogram,nitric oxide metabolites,and testosterone concentrations

The objectives of this study were to elucidate the clinical findings in male dromedary camels with phimosis (PHI, n = 43) and to investigate the association of this syndrome with the hemogram, nitric oxide metabolites (NOMs), and testosterone concentrations. History and signalment were obtained, and a breeding soundness examination was performed. The penis was exteriorized after administration of a pudendal nerve block. Abnormal masses obtained from the prepuce and penis were prepared for histopathology. Blood samples for hemogram assessment were taken from the diseased animals and from 10 healthy control males. Total nitrates/nitrites were determined in sera using the Griess assay. Testosterone was estimated in sera using ELISA. Phimosis associated with detectable pathologic lesions, mainly including ulcerative posthitis and lacerated glans penis, was present in 34 (79.1%) of the 43 cases (PHI-P), whereas the remaining nine (20.9%) of the 43 cases had no noticeable lesions (PHI-N). The PHI-P group showed higher leukocyte counts (P = 0.001), especially neutrophils (P = 0.0001), and greater NOM concentrations (P = 0.002) than the PHI-N and control groups. However, testosterone concentrations did not differ among groups. In conclusion, PHI in the male dromedary camels was mainly associated with ulcerative posthitis and laceration of the glans penis. The presence of pathologic lesions in cases with PHI was associated with leukocytosis, neutrophilia, and high NOM concentrations.     

Blood analysis in newborn donkeys: hematology,biochemistry, and blood gases analysis

The knowledge of reference ranges for hematologic, biochemical, and blood gas parameters in the different species and the influence of breed and age on them is a fundamental tool for the clinician. For this reason, the aim of this study was to evaluate the age-related changes of hematologic and biochemical parameters in Martina Franca donkey foals during the first 3 weeks of life and of blood gases during the first 24 hours of age. Fifteen healthy donkey foals were enrolled; blood samples were collected from each foal at 10 minutes after birth, 1 hour after the first and second suckles, 12 and 24 hours after birth, daily from Day 2 to 7, and at Days 10, 14, and 21 of life. Erythrocytes, leukocytes, and platelets counts were assessed; also metabolic (alanine aminotransferase, aspartate aminotransferase, gamma glutamyl transferase, creatinphospokinase, lactate dehydrogenase, alkaline phosphatase, glucose, blood urea nitrogen, creatinine, total proteins, albumins, cholesterol, and total bilirubin) and electrolytic parameters (Ca, P, Mg, Na, K, and Cl) were evaluated. Finally, blood gases and metabolic parameters (pH, pCO₂, pO₂, sO₂, TCO₂, HCO₃, lactate, and base excess) on venous blood were assessed with a portable analyzer. A statistical analysis to evaluate the influence of age and sex was performed. Several differences were found between sampling times, demonstrating that age influences these parameters. Moreover differences were found compared with data reported in literature for donkey foals of another species, horse foals, and adult donkeys. Although a great interindividual variation for some parameters exists, this study demonstrated that interval references should be addressed not only to different species, but also to specific breeds and to the neonatal period.     

Urinary and plasma proteomics to discover biomarkers for diagnosing between diabetic nephropathy and minimal change nephrotic syndrome or membranous nephropathy

The choice of treatment for primary nephrotic syndrome depends on the pathologic type of the disorder. Renal biopsy is necessary for a definitive diagnosis, but it is burdensome for the patients, and can be avoided if tests could be performed using urine or plasma. In this study, we analyzed 100 urinary proteins, 141 plasma proteins, and 57 urine/plasma ratios in cases of diabetic nephropathy (DN; n = 11), minimal change nephrotic syndrome (MCNS; n = 14), and membranous nephropathy (MN; n = 23). We found that the combination of urinary retinol-binding protein 4 and SH3 domain-binding glutamic acid-rich-like protein 3 could distinguish between MCNS and DN, with an area under the curve (AUC) of 0.9740. On the other hand, a selectivity index (SI) based on serotransferrin and immunoglobulin G, which is often used in clinical practice, distinguished them with an AUC of 0.9091. Similarly, the combination of urinary afamin and complement C3 urine/plasma ratio could distinguish between MN and DN with an AUC of 0.9842, while SI distinguished them with an AUC of 0.8538. Evidently, the candidates identified in this study were superior to the SI method. Thus, the aim was to test these biomarkers for accurate diagnosis and to greatly reduce the burden on patients.     

Effects of mode and carbohydrate on the granulocyte and monocyte response to intensive, prolonged exercise

The influence of exercise mode and 6%carbohydrate (C) vs. placebo (P) beverage ingestion on granulocyte andmonocyte phagocytosis and oxidative burst activity (GMPOB) afterprolonged and intensive exertion was measured in 10 triathletes. Thetriathletes acted as their own controls and ran or cycled for 2.5 h at~75% maximal O₂ uptake,ingesting C or P (4 total sessions, random order, with beveragesadministered in double-blind fashion). During the 2.5-h exercise bouts,C or P (4 ml/kg) was ingested every 15 min. Five blood samples werecollected (15 min before exercise, immediately after exercise, and 1.5, 3, and 6 h after exercise). The pattern of change over time for GMPOBwas significantly different between C and P conditions(P  0.05), with postexercise valueslower during the C trials. Little difference was measured betweenrunning and cycling modes. C relative to P ingestion (but not exercise mode) was associated with higher plasma levels of glucose and insulin,lower plasma levels of cortisol and growth hormone, and lower bloodneutrophil and monocyte cell counts. These data indicate that C vs. Pingestion is associated with higher plasma glucose levels, anattenuated cortisol response, and lower GMPOB.

     

Umbilical blood flow and the effects of premature severance in the neonatal horse

Thirteen randomly assigned Quarter Horse foals were used in a study to determine the presence of umbilical blood flow immediately post partum and to determine if premature severance of the umbilical cord would alter significantly the hematology of the horse neonate. Packed cell volume (PCV), mean corpuscular volume (MCV), mean corpuscular hemoglobin concentration (MCHC), hemoglobin concentration (Hgb), red blood cell count (RBC), plasma protein (PP), and heart and respiratory rates were determined every 30 min for the first 6 h of life for both control and treated foals. Control foals had their umbilical cords measured for the presence of umbilical blood flow. Treated foals had their umbilical cords separated after birth and any free flow of blood collected and a volume measure determined. The umbilicus was separated within 10 sec post partum.No blood flow was detected in the control group of foals within 2 min post partum. The blood obtained from the separated umbilicus of the treatment group measured less than 125 cc. PCV, MCV, MCHC, Hgb, RBC, and PP were not significantly different between the two groups (P > 0.05). Except for MCHC and PP, all parameters studied decreased over the first 6 h of life. Heart rate and respiration rates did not significantly differ from each other (P > 0.05) and decreased over the first 6 h of life.     

The Effects of Feeding Clinoptilolite on Hematology,Performance, and Health of Newborn Lambs

The effects of feeding clinoptilolite on hematology, performance, and health of newborn Balouchi lambs were evaluated in this experiment. In a completely randomized design, 30 newborn lambs were allocated to three groups and fed by basal diet (C0; without clinoptilolite) and C1 and C2 (the basal diet plus 1.5% and 3% clinoptilolite, respectively, for 6 weeks (3 weeks before and 3 weeks after weaning)). Blood samples were taken from all lambs, at the time when the animals were allocated to the experimental diet and at the end of each week of experiment, and analyzed for hematology, plasma fibrinogen, and total protein. Performance and health of all lambs were measured. Fecal consistency score and diarrhea severity were evaluated. There was no difference between lambs in case of hematological parameters. Lambs fecal consistency score and severity of diarrhea were lowest (P < 0.05) for lambs on C1 and C2 and highest for lambs on C0. Dry matter intake and feed conservation ratio were similar between the groups of lambs fed by different diets, but daily gain of lambs differed significantly (P < 0.05) and was higher in C2. It was concluded that addition of 3% clinoptilolite to starter diet of newborn lamb can reduce incidence and severity of diarrhea, although its effect on hematology and performance was negligible.     

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.     

Effect of age,size and digestive tract development on weaning effectiveness in crucian carp,Carassius carassius (Linnaeus, 1758)

The study aim was to determine the optimum age, wet body weight (WBW) and total length (TL) of the crucian carp, Carassius carassius (L.), to ensure the effectiveness of weaning directly without a gradual transfer from live food to a compound feed. Moreover, the state of development of the digestive tract was analyzed histologically based on the height of enterocytes. Experimental rearing was conducted between days 5 and 45 post hatch (DPH). Initial WBW of fish was 2.2 ± 0.6 (n = 30) mg and TL 6.1 ± 0.1 (n = 30) mm. Rearing was carried out at 27 ± 0.5°C, with fish divided into six groups: one control (C) fed with Artemia sp. nauplii, and five groups initially fed with Artemia sp. but later replaced by a compound feed. Weaning with the compound diet started at 15, 20, 25, 30 and 35 DPH in groups labeled F15, F20, F25, F30, F35, respectively. Larvae were fed three times per day (08.00 h, 13.00 h, 18.00 h) in equal portions (4% of larvae biomass per day, converted to the dry matter of the feed). Daily biomass growth was adopted as 15%. Each group was triplicated (n = 50 individuals per replicate). Highest values of TL 42.1 ± 0.7 (n = 30) mm and WBW 905.3 ± 50.3 (n = 30) mg were recorded in the control group at 45 DPH; lowest survival rate of 45 DPH was in group F15 (90.7 ± 1.2%, n = 30). The highest value of the enterocyte epithelial length was observed in individuals within groups F30, 34.8 ± 1.2 μm (n = 30) and F35, 35.4 ± 3.6 μm (n = 30), respectively, 30 and 35 DPH; highest percentage of deformations on the final day of the experiment was in group F15 (100 ± 0.0%, n = 30). The results indicate that an effective direct transfer from live food to prepared diets (with no gradual transfer) cannot be performed with crucian carp larvae before 30 DPH at 27°C, when the fish have reached TL = 31.1 ± 0.4 mm (n = 30) and WBW = 436.9 ± 13.7 mg (n = 30).     

Bioactivity of ovulation inducing factor (or nerve growth factor) in bovine seminal plasma and its effects on ovarian function in cattle

To understand the role of ovulation-inducing factor (or nerve growth factor) (OIF [NGF]) in bovine seminal plasma, we (1) used an in vivo llama bioassay to test the hypothesis that bovine seminal plasma induces ovulation and CL development in llamas similar to that of llama seminal plasma when the dose of seminal plasma is adjusted to ovulation-inducing factor content (experiment 1) and (2) determined the effect of bovine seminal plasma on the interval to ovulation and luteal development in heifers (experiment 2). Within species, seminal plasma was pooled (n = 160 bulls, n = 4 llamas), and the volume of seminal plasma used for treatment was adjusted to a total dose of 250 μg of ovulation-inducing factor. In experiment 1, mature female llamas were assigned randomly to four groups and treated intramuscularly with either 10 mL of PBS (negative control, n = 5), 50-μg GnRH (positive control, n = 5), 6-mL of llama seminal plasma (n = 6), or 12 mL of bull seminal plasma (n = 6). Ovulation and CL development were monitored by transrectal ultrasonography. In experiment 2, beef heifers were given a luteolytic dose of prostaglandin followed by 25-mg porcine LH (pLH) 12 hours later to induce ovulation. Heifers were assigned randomly to three groups and given 12 mL bovine seminal plasma intramuscularly 12 hours after pLH treatment (n = 10), within 4 hours after ovulation (n = 9), or no treatment (control, n = 10). Ovulation was monitored by ultrasonography every 4 hours, and the CL development was monitored daily until the next ovulation. In experiment 1, ovulation was detected in 0/5, 4/5, 4/6, 4/6 llamas in the PBS, GnRH, llama seminal plasma, and bovine seminal plasma groups, respectively (P < 0.05). Luteal development was not different among groups. In experiment 2, the interval to ovulation was more synchronous (range: 4 vs. 22 hours; P < 0.0001) in heifers treated with seminal plasma before ovulation compared with the other groups. Luteal development was not different among groups; however, plasma progesterone concentrations tended to be greater in the postovulation treatment group compared with other groups. In summary, results confirmed the presence of bioactive ovulation-inducing factor in bull seminal plasma and supported the hypothesis that bovine and llama seminal plasma have similar ovulatory effects, using a llama bioassay. Treatment with bovine seminal plasma resulted in greater synchrony of ovulation in heifers pretreated with pLH. Plasma progesterone concentration tended to be higher in heifers given bovine seminal plasma within 4 hours after ovulation, suggesting that bovine ovulation-inducing factor is luteotrophic.     

Supplementation of l-tryptophan (an aromatic amino acid) in tris citric acid extender enhances post-thaw progressive motility,plasmalemma, mitochondrial membrane potential,acrosome, and DNA integrities,and in vivo fertility rate of buffalo (Bubalus bubalis) bull spermatozoa

The aromatic amino acid l-tryptophan is an essential and versatile molecule, acts by transferring an electron to free radicals and protects the plasma membrane from injuries. The aim of the present study was to investigate the effects of l-tryptophan in extender on semen quality parameters, in vitro longevity and in vivo fertility rate of buffalo spermatozoa during cryopreservation. Two ejaculates were collected from each bull (n = 2 ejaculates and n = 4 bulls) with artificial vagina at 42 °C followed by initial evaluation for volume, motility, concentrations and were diluted in five extenders (C = lacking l-tryptophan, D1 = 25 μ M l-tryptophan, D2 = 50 μ M l-tryptophan, D3 = 75 μ M l-tryptophan, and D4 = 100 μ M l-tryptophan) respectively, and cryopreserved. The experiment was repeated four times (n = 4 replicates). At post-dilution, sperm plasma membrane integrity (PMI, %), supravital plasma membrane integrity (SVPMI, %), hypo-resistivity (HR, %) and acrosome integrity (ACR-I, %) were significantly higher (P < 0.05) in extender supplemented with D4 than control. At post-thawing, progressive motility (PM, %), PMI, SVPMI, HR, ACR-I, and DNA-I of buffalo bull spermatozoa were significantly higher in D4 than control. Sperm in vitro longevity (%) assessed in terms of PM, SVPMI, and ACR-1 were significantly higher in D4 than control. Sperm mitochondrial membrane potential (%) was higher in treated groups than the control. The in vivo fertility rate was significantly higher in D4 than control (60.17% vs. 44.17%, P < 0.05). It is concluded that the supplementation of l-tryptophan in tris citric acid extender improves semen quality parameters, in vitro longevity and in vivo fertility rate of buffalo spermatozoa during freezing and thawing process.     

Effects of bovine colostrum, foal serum immunoglobulin concentration and intravenous plasma transfusion on chemiluminescence response of foal neutrophils

Summary. The effects of bovine colostrum, absorption of equine colostral immunoglobulins and age on phagocytic and serum opsonizing activity of nine clinically healthy foals were examined. Cells and serum were collected prior to suckling and at 7, 14 and 28 days of age. Seven foals had serum IgG concentrations >600mg/dl whereas two foals had <350mg of IgG/dl. Phagocytic and serum opsonic activity of eight clinically ill foals with <400mg of IgG/dl of serum were also examined before and after plasma transfusion. Phagocytic and serum opsonizing activities were evaluated by an assay for chemiluminescence (CL) after addition of opsonized streptococci. Results showed that bovine colostrum stimulated CL of foal neutrophils. Preliminary characterization of opsonins in bovine colostrum by ammonium sulphate fractionating and heat inactivation indicated that opsonins generating CL were mainly associated with immunoglobulin G. Chemiluminescence generated by foal neutrophils varied with age with foal neutrophils collected at day 14 producing more CL than adult neutrophils ( P <0.05). Foal serum opsonizing activity was similar to adult opsonizing activity if serum IgG concentrations were >600mg/dl but it was less if IgG concentration was <350mg/dl ( P <0.05). Chemiluminescence generated by foal and adult neutrophils was higher when post-transfusion foal serum was used as the source of opsonin than when pre-transfusion foal serum was used ( P <0.05). When adult serum was the opsonin, chemiluminescence of foal neutrophils collected before and after plasma transfusion did not differ. The increase in CL following plasma transfusion was probably due to an increase in serum opsonizing activity.