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PubMed1995

Comparison of bronchoalveolar lavage findings and measurements of gas exchange during exercise in horses with poor racing performance.

Twenty-four Thoroughbred and twelve Standardbred racehorses aged between 2 and 6 years, presented for reported poor racing performance, underwent clinical exercise testing. During the last 10 s of exercise at each speed throughout an incremental speed exercise test on a treadmill inclined at a 10% slope, samples of arterial blood and expired gases were collected. Maximum oxygen uptake and the partial pressures of oxygen and carbon dioxide in arterial blood were determined. These values were compared between the two breeds of horses and also with reference to cytological findings of bronchoalveolar lavage samples, including neutrophil, erythrocyte and haemosiderophage percentage and the total nucleated cell concentration. The results revealed an inverse relationship (Spearman R = -0.45, p < 0.05) between the total nucleated cell count in bronchoalveolar lavage samples and arterial oxygen partial pressure during exercise at 11 m.s(-1). This result suggests that subclinical pulmonary disease may be a more important cause of poor racing performance than previously thought. Also of note was a positive correlation (Spearman R = 0.50, p < 0.05) between maximum oxygen uptake and the percentage of erythrocytes.

Journal Article↗

PubMedDate not supplied

A review of canine inherited bleeding disorders: biochemical and molecular strategies for disease characterization and carrier detection.

Many different inherited bleeding disorders have been identified in dogs, defined on the basis of quantitative, functional, or structural defects in specific hemostatic proteins or pathways. Most of these disorders are caused by single-gene defects and biochemical assays provide an accurate measure of disease phenotype. Phenotypic disease classifications, however, are often genetically heterogeneous. Protein-based carrier detection assays are fast, inexpensive, and do not require specific identification of causative mutations. The limitations of these tests arise from variable "overlap" regions between carrier and clear dogs, influencing positive and negative predictive values of carrier detection tests within breed populations. Molecular diagnostic techniques enhance the accuracy of carrier detection, providing their clinical application takes into account the molecular heterogeneity underlying naturally occurring hemostatic defects in dogs.

Animals↗

PubMed2006

An amylase gene polymorphism is associated with growth differences in the Pacific cupped oyster Crassostrea gigas.

This study investigated the non-neutrality of genetic polymorphism in two alpha-amylase genes (AMYA and AMYB) in the oyster Crassostrea gigas. Bi-parental oyster families, bred to be polymorphic for markers in these genes, were monitored for growth and survival for 1 year under standard culture conditions in two French production sites. Within-family genotype frequencies indicated that the two amylase genes were closely linked (c. 1.7 cM). Within two of three families, significant differences in growth were observed between genotypes at one of the two production sites, suggesting that this polymorphism is not neutral and might be under selection because of its role in digestive function. Estimated daily yields were different between amylase genotypes, indicating the potential value of amylase markers in selective breeding programmes to improve oyster growth.

Animals↗

PubMedDate not supplied

Long-term follow-up of partial limb amputation in 13 horses.

Thirteen cases of partial limb amputation in horses were reviewed. Nine horses (69%) survived 18 to 111 months (mean, 41 months). Four unsuccessfully treated horses were euthanatized within 21 days of surgery. The horses' ages at amputation were 4 to 13 years (mean, 7.3 years). There was no predilection for the left or right limb nor for fore or hind limb involvement. Osteomyelitis in six horses (46%) was the most common cause for amputation. Severe, open, comminuted fractures of the third metacarpal bone that were impossible to stabilize by any currently available technique in four horses (31%) were the second most common cause for amputation. One gelding was salvaged because of his sentimental value, two horses were used as breeding stallions, and six were broodmares. One stallion lived 30 months, completed two breeding seasons, and started a third. The other stallion began breeding, but became sterile. Three of the mares have produced five foals. One mare died while in foal. One mare aborted near-term twin fetuses and died of uterine hemorrhage. One mare aborted twice before the femoral head ligament on the contralateral limb ruptured, and she was euthanatized.

Amputation, Surgical↗

PubMed1999

Improved phytonutrient content through plant genetic improvement.

During the twentieth century, plant breeding and genetics improved the nutritive value of horticultural and agronomic crops, particularly of macronutrients and fiber. Current research focuses more on micronutrients. Successful development of phytonutrient-enriched crop plants will be bolstered by interdisciplinary collaborative research, analytical and biotechnology advances, and public education. Although the melding of plant and nutrition research holds great promise, the genetic enhancement of crop plants for improved phytonutrient content will be challenging. This paper reviews the knowledge base on which genetic enhancement may be based, identifies gaps in scientific knowledge and technical capacities, and suggests a role for the federal government in research.

Agriculture↗

PubMed1985

Equine leucocyte antigens in sarcoid-affected horses.

The distribution of equine leucocyte antigens (ELA) in horses affected by equine sarcoid tumours was determined and compared with unaffected controls. ELA-haplotype W3,B1 occurred more frequently in affected riding horses of Irish, Swiss and French background. The combined data for the three breeds resulted in a chi 2 value of 20.35 (P less than 0.0005 after correction). Simultaneously, ELA-specificity W11 was more frequently found in horses of Irish background, while W5 was found in Swiss and French horses with sarcoids. The combined data for haplotype W3,B1 and/or W5 specificity demonstrated, in the genetically closely-related Swiss and French horses, a highly significant difference in the occurrence of these haplotypes between affected horses and healthy controls (chi 2 = 28.69, P less than 0.00001 after correction). Thus, the results strongly suggest that the predisposition of horses to sarcoid is associated with or linked to the major histocompatibility complex.

Animals↗

PubMed1993

Calcium sensitivity of skinned ferret EDL, soleus, and cremaster fibers.

The properties of the contractile system at different times of the year in the ferret extensor digitorum longus (EDL), soleus and cremaster muscles were examined by using chemically skinned (Triton X-100) preparations. The results show clear differences in calcium sensitivity between these skeletal muscles. The apparent calcium threshold for activation was lower in soleus than in EDL, while calcium concentrations ([Ca2+]) required to obtain the half-maximal tension, expressed as pCa50 (-log[Ca2+]), was lower in EDL than in soleus muscle. In fact, pCa50 obtained in fast and slow fibers by fitting the experimental data points by a modified Hill equation was 5.92 +/- 0.02 (n = 9) and 6.09 +/- 0.03 (n = 11) respectively. So EDL appears to be a typical fast-twitch muscle and soleus a typical slow-twitch muscle. Adult ferret cremaster muscle was composed of two types of fibers during the quiescent period similar to EDL and soleus, and only one type that was intermediate between EDL and soleus in the breeding period, as assessed by pCa50 values. These annual modifications in calcium activation of adult ferret cremaster muscle could be related to changes in the function of these muscles and may be correlated with seasonal variations of sexual activity.

Animals↗

PubMed1994

Energy and protein requirements for molt in the king penguin Aptenodytes patagonicus.

Adult king penguins annually fast ashore for 1 mo for molting. By the end of molt, they have lost 44% of their prefasting body mass. About 18% of new feather synthesis occurs at sea, thus reducing both nutrient requirement and fasting duration. Plumage synthesis continues during the first 3 wk of fasting. Loss of old feathers occurs between day 12 and day 21 of the molt, and it is associated with a peak in daily body mass loss. The dry mass of epidermal structure synthesized during molt is 395 g. Body composition analysis indicates that fat oxidation accounts for 85% of total energy expenditure. The proportion for protein is 15%, a value twofold higher than during the breeding (nonmolting) fast. The mean energy expenditure is also 21% higher during the molting fast (3.04 W/kg). Compared with other birds, the energetic cost of feather synthesis is the lowest in king penguins (85 kJ/g) and consequently the energetic efficiency is the highest (25%). Changes in tissue composition during molt show that integument is the main lipid source (72% of the lipid loss) and thus the main source of energy (61% of the total energy expenditure). The integument and the pectoral muscles play a major role in molting protein metabolism, providing 20 and 57%, respectively, of the total protein needs for feather synthesis and/or energy expenditure. This result emphasizes the role of integument as a protein source, because the large premolting muscle hypertrophy is not sufficient to account for the totality of the protein cost of molt.

Adult↗

PubMed1991

Role of the thyroid gland in seasonal reproduction: thyroidectomy blocks seasonal suppression of reproductive neuroendocrine activity in ewes.

Seasonal reproductive transitions in ewes are generated endogenously and are synchronized by annual changes in photoperiod. Previous evidence indicates that thyroidectomy prevents the transition to anestrus in ewes maintained in a fixed day length, suggesting that the thyroid is needed for endogenously generated reproductive arrest. Here we tested the hypothesis that the thyroid is required for endogenous seasonal suppression of the neuroendocrine mechanism that regulates pulsatile LH secretion. Ewes were thyroidectomized (n = 6) in summer, 6 weeks before the onset of the breeding season, or they remained thyroid intact (n = 6). They were housed in a simulated natural photoperiod until the winter solstice; thereafter, they remained on that photoperiod (10 h of light, 14 h of darkness). To monitor pulsatile LH secretion, the ewes were ovariectomized and implanted with estradiol, and LH was measured in both frequent (every 6 min for 4 h) and infrequent (twice weekly) blood samples. In this model, high LH indicates low response to estradiol negative feedback and reproductive induction; low LH signifies high response to estradiol negative feedback and reproductive arrest. LH levels (samples twice weekly) rose some 50-fold in both groups concurrently at the start of the breeding season in September. Frequent sampling in midbreeding season (autumn) revealed that both thyroidectomized and thyroid-intact ewes exhibited frequent LH pulses, with no group difference, in either the presence or absence of the estradiol implant. A marked group difference, however, emerged at the end of the breeding season. LH fell to basal values in thyroid-intact ewes (onset of low values Feb 3 +/- 8 days), whereas levels remained elevated in thyroidectomized ewes through the end of the study (April 26). At this time, thyroidectomized ewes had more frequent LH pulses than thyroid-intact ewes both in the presence and absence of estradiol. The circadian pattern of melatonin secretion and the seasonal change in PRL were found to be unaffected by thyroidectomy. These observations support the hypothesis that the thyroid is necessary for endogenous suppression of neuroendocrine mechanisms that generate LH pulses, a suppression crucial for the transition to anestrus.

Animals↗

PubMed1981

Relationship between antler development and plasma androgen concentrations in adult roe deer (Capreolus capreolus).

Four male deer (4-5 years old), living in normal park conditions, were captured every 2 weeks in the year to study annual variations in androgen levels and the relationship between testicular activity and the antler cycle. Data were also obtained from 77 wild adult males (greater than 3 years old) caught in the forest. Plasma androgen concentrations rose briefly in April and markedly in August; the high values in August corresponded with the breeding period. From the time of casting to maximum growth was about 60 days; mineralization of the antlers then lasted for 45 days only. The mineralization phase of antler growth corresponded to the reactivation of testicular function in late January (0.43 +/- 0.16 to 1.99 +/- 0.42 ng androgen/ml, N = 4).

Androgens↗

PubMed1984

Seasonal changes in spermatogenesis in the blue fox (Alopex lagopus), quantified by DNA flow cytometry and measurement of soluble Mn2+ -dependent adenylate cyclase activity.

The testes of the blue fox (Alopex lagopus) showed marked seasonal variations in size. Testicular weight and volume increased rapidly during January and February to reach maximal values by the beginning of the breeding season (approximately 15 March). During May and June the weights and volumes of the testes declined gradually to the quiescent state which lasted from July until October. Quantitation by DNA flow cytometry of the seasonal changes in the relative numbers of haploid (1C), diploid (2C) and tetraploid (4C) cell numbers in the testis showed that the increase in testis size from December to February was associated with a rapid expansion of the haploid cell compartment as spermatogenesis resumed. In addition, an increase in number of more mature cell types within the haploid cell population was observed over a 2-month period before the breeding season. The decline in testicular size from the middle of April until October was associated with a reduction in both the absolute and relative sizes of the haploid and tetraploid cell populations and a concomitant increase in the relative numbers of diploid cells. Measurements of the activity of the soluble Mn2+ -dependent adenylate cyclase revealed seasonal variations that closely paralleled those of the haploid cell population, indicating that, as in other species, the enzyme may be associated with maturing germ cells.

Adenylyl Cyclases↗

PubMed1990

Progesterone and oestrogen concentrations in plasma of Barbary sheep (aoudad, Ammotragus lervia) compared with those of domestic sheep and goats during pregnancy.

Steroid hormone concentrations have been measured in the peripheral plasma of 3 Barbary sheep over 3 breeding seasons. During pregnancy mean progesterone values rose initially and after a small decline between Days 30 and 50, increased again and remained between 17 and 28 nmol/l until the last 2 days of pregnancy. Oestradiol-17 beta reached a peak of about 300 pmol/l during mid-pregnancy, increasing to over 400 pmol/l in the last 5 days of pregnancy. Oestrone sulphate began to increase in concentration from about Day 40 of pregnancy and reached a peak of about 19 nmol/l by Day 120. Following a slight decrease from Day 130, there was a further rise in values just before parturition. Values for these steroids in the Barbary sheep studied were between those expected for domestic sheep and goats.

Animals↗

PubMed2002

Effect of diflubenzuron on immature stages of Haematobia irritans (L.) (Diptera: Muscidae) in Uberlândia, State of Minas Gerais, Brazil.

Horn fly immatures were raised in media containing different concentrations of diflubenzuron in order to verify their susceptibility to this insect growth regulator (IGR). The 50% and 95% lethal concentrations of diflubenzuron for the population (LC50, LC95) were determined as well as the effect of this IGR on the different immature horn fly stages. The tests were performed using the progeny of adults collected in the field. The immatures were maintained in a growth chamber at 25.0 +/- 0.5oC and 12-12 h photoperiod. IGR concentrations of 300 ppb, 100 ppb and 50 ppb were lethal for 100% of the sample. Pupae malformation occurred in the breeding media containing different diflubenzuron concentrations. Values for LC50, LC95 (+/- 95% fiducial limits) and the slope of the regression line were respectively, 25.521 +/- 1.981 ppb, 34.650 +/- 2.001 ppb and 12.720 +/- 1.096. The third larval instar was more sensitive to the sub-lethal concentration of the product than the first and second ones were. The results indicate that this IGR can be an important tool for controlling horn fly populations as well as for managing horn fly resistance to conventional insecticides against Haematobia irritans in Uberlândia, State of Minas Gerais.

Animals↗

PubMed1994

Predicting net energy and protein requirements for growth of implanted and nonimplanted heifers and steers and nonimplanted bulls varying in body size.

Energy and protein retained in 50, 38, and 54 nonimplanted Holstein and Angus heifers, steers, and bulls, respectively, 17 pens (237 cattle) of beef breed implanted heifers, and 65 pens (535 cattle) of beef breed implanted steers were compared to values predicted by the 1984 National Research Council (NRC), Cornell Net Carbohydrate and Protein System (CNCPS), and the model of Oltjen et al. (OLTJEN). The NRC accounted for 83, 85, 86, 88, and 88% of the variation in retained energy (RE) with biases of -8, +13, -6, +6, and -12% for nonimplanted heifers, implanted heifers, nonimplanted steers, implanted steers, and bulls, respectively. The CNCPS accounted for 93, 98, 92, 95, and 91% of the variation in RE with biases of +2, +10, -6, +1, and -13% for nonimplanted heifers, implanted heifers, nonimplanted steers, implanted steers, and bulls, respectively. OLTJEN accounted for 78, 76, 48, 93, and 96% of the variation with biases of -3, -2, +9, -8, and -1% for nonimplanted heifers, implanted heifers, nonimplanted steers, implanted steers, and bulls, respectively. For retained protein (RP), the NRC accounted for 57, 68, 70, 86, and 84% of the variation with biases of -12, -7, +16, -8, and -10% for nonimplanted heifers, implanted heifers, nonimplanted steers, implanted steers, and bulls, respectively. The CNCPS accounted for 69, 77, 84, 94, and 84% of the variation in RP with biases of -7, -11, 0, -3, and -9% for nonimplanted heifers, implanted heifers, nonimplanted steers, implanted steers, and bulls, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1983

Estimating the impact of management decisions on the occurrence of puberty in beef heifers.

Age and weight at puberty in beef heifers were hypothesized to be jointly dependent random variables with the joint distribution conditional upon values of exogenous variables such as breed, date of birth and postweaning rate of gain. A statistical model was specified that tested the joint dependency hypothesis and measured the impact of variation in the explanatory variables on puberty. Model parameters were estimated by two-stage least-squares procedures from data on 556 beef heifers: 190 raised at the Northern Agricultural Research Center (NARC), Havre, Montana and 366 raised at the Livestock and Range Research Station (LARRS), Miles City, Montana. Results did not support the hypothesis that age and weight at puberty were jointly dependent; weight at puberty did depend upon age at puberty, but age at puberty did not depend upon weight at puberty when postweaning level of nutrition was known. Thus, the appropriate probability distribution was a conditional univariate probability distribution on age. Results were consistent with past research in that breed and breed-cross differences existed, and heifers heavier at weaning and fed higher levels of postweaning nutrition reached puberty at an earlier age and heavier weight.

Age Factors↗

PubMed2005

[Spectrometric determination of trace elements in 'Jinguang' prunus mume var. bungo of different growth periods].

A study was carried out on the content of trace elements such as Ca, Fe, Zn, Mn and Cu of prunus mume var. bungo in different growth periods by WFX-110 atomic absorption spectrometry. The results indicated that the linear relationships of different elements within the limits of working curves are good and the range of the recovery is 98% -105%, hence showing that the results are satisfactory. The total content of these five trace elements increases as the fruit grows, but the concentration is related to the growth of fruit and fruit core, which provides us with valuable data. The contents of the trace elements essential to human body are relatively high, which shows that this fruit breed has a relatively high nutritive value.

Calcium↗

PubMed2005

Analysis of normal electrocardiograms of Jamunapari goats.

In the present study, the normal electrocardiographic (ECG) values in the adult male Jamunapari breed of the goats were described. The mean heart rate in the goats was 127 +/- 3.46 per minute and ranged 107 and 168. The amplitudes and duration of various waveforms of ECG for six standard limb leads (I, II, III, aVL, aVR and aVF) were estimated. The overall P, QRS and T amplitudes (millivolts) were 0.065 +/- 0.01, 0.47 +/- 0.06 and 0.20 +/- 0.014 respectively. The duration (seconds) of these wave forms were 0.042 +/- 0.005, 0.033 +/- 0.002 and 0.10 +/- 0.014, respectively. The P-R interval and R-R intervals ranged between 0.06- 0.14 and 0.40-0.58 respectively. The average Q-T interval was 0.24 +/- 0.01 second, indicating the time for which the caprine ventricle remained depolarized. The corrected QT interval was also calculated which was found to vary from 0.24 to 0.57. The mean frontal plane vectors for the wave forms P, QRS and T wave forms were +49.99 +/- 6.02, +37.34 +/- 4.05 and +52.26 +/- 6.79 degrees respectively.

Animals↗

PubMedDate not supplied

[Population-genetic study of the polymorphism of structural genes and ISSR-PCR markers in some cattle breeds].

The comparative analysis of genetic structures of five cattle breeds has been carried out using polymorphism of two different types of molecular-genetic markers--20 structural genes and 128 DNA loci (the DNA fragments flanked by inverted microsatellite loci repetitions--ISSR-PCR method). In spite of availability of breed-specific singularities of genotype distribution detected by the both methods the level of mean heterozygosity of structural genes was similar in all the investigated breeds. A part of polymorphic loci and the average value of the polymorphic information contents (PIC) of ISSR-PCR markers has appeared much higher in commercial breeds with high effective number in comparison with Ukrainian autochthonous breeds. The population-genetic processes detected by different methods are discussed.

Animals↗