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PubMed2006

Evaluation of genetic diversity in Chinese indigenous chicken breeds using microsatellite markers.

China is rich in chicken genetic resources, and many indigenous breeds can be found throughout the country. Due to poor productive ability, some of them are threatened by the commercial varieties from domestic and foreign breeding companies. In a large-scale investigation into the current status of Chinese poultry genetic resources, 78 indigenous chicken breeds were surveyed and their blood samples collected. The genomes of these chickens were screened using microsatellite analysis. A total of 2740 individuals were genotyped for 27 microsatellite markers on 13 chromosomes. The number of alleles of the 27 markers ranged from 6 to 51 per locus with a mean of 18.74. Heterozygosity (H) values of the 78 chicken breeds were all more than 0.5. The average H value (0.622) and polymorphism information content (PIC, 0.573) of these breeds suggested that the Chinese indigenous chickens possessed more genetic diversity than that reported in many other countries. The fixation coefficients of subpopulations within the total population (F(ST)) for the 27 loci varied from 0.065 (LEI0166) to 0.209 (MCW0078), with a mean of 0.106. For all detected microsatellite loci, only one (LEI0194) deviated from Hardy-Weinberg equilibrium (HWE) across all the populations. As genetic drift or non-random mating can occur in small populations, breeds kept on conservation farms such a Langshan chicken generally had lower H values, while those kept on large populations within conservation regions possessed higher polymorphisms. The high genetic diversity in Chinese indigenous breeds is in agreement with great phenotypic variation of these breeds. Using Nei's genetic distance and the Neighbor-Joining method, the indigenous Chinese chickens were classified into six categories that were generally consistent with their geographic distributions. The molecular information of genetic diversity will play an important role in conservation, supervision, and utilization of the chicken resources.

Animals↗

PubMed1991

Evaluation of feed conversion in steers from a diallel of Simmental, Limousin, Polled Hereford, and Brahman beef cattle.

A total of 269 steers produced in a four-breed diallel mating design of Simmental, Limousin, Polled Hereford, and Brahman breeds were evaluated for the unadjusted and maintenance-adjusted total feed intake to total weight gain ratio. Time on feed ranged from 184 to 251 d. Covariate adjustments were made separately for age- and 12th rib fat-constant end points. Purebred, general combining ability, and maternal effects and heterosis were estimated. Effects of year, breed of dam, slaughter group, and days on feed accounted for most of the variation in feed conversion. Significantly higher unadjusted cumulative feed/gain ratios were found for steers from Brahman sires and for those from Simmental, Limousin, and Brahman dams. Adjustment to either fat- or age-constant values did not rerank breed groups, but a small reduction in the differences between these groups was detected for fat-constant efficiency. For maintenance-adjusted feed intake, progeny of Simmental and Limousin dams were less efficient than those of Polled Hereford and Brahman dams. Negative values for general combining ability, maternal effects, and heterosis would indicate less feed required per unit of weight gain. General combining ability for Polled Hereford crosses was negative and significant for cumulative feed/gain ratios, but no difference among dam breeds was found for the maintenance-adjusted ratio. Maternal effects for Limousin dams were positive and significant for all maintenance-adjusted ratios. Heterosis estimates for specific breed crosses were generally negative and ranged from -.87 to .22.

Animals↗

PubMed2001

Use of breed-specific ranges for the vertebral heart scale as an aid to the radiographic diagnosis of cardiac disease in dogs.

The vertebral heart scale was measured on right lateral recumbent thoracic radiographs of 320 dogs of six popular breeds, including for each breed at least 20 dogs with no clinical signs of cardiovascular or respiratory disease and at least 19 dogs with cardiac or respiratory disease. There were significant differences between the mean values of the scale for the different breeds; the normal boxer dogs had a significantly higher mean value than the normal dogs of all the other breeds, and the labrador retrievers had a significantly higher mean value than all the other breeds except the boxer and the cavalier King Charles spaniel. For all the breeds except the boxer, there was a trend for dogs with cardiac disease (but not respiratory disease) to have higher mean values on the scale than normal dogs of the same breed; however, at the optimal value of the scale for distinguishing between dogs of each breed with and without cardiac disease, the sensitivity and specificity were relatively low, in the range 58 to 83 per cent. The scale was most accurate for the diagnosis of cardiac disease in the Yorkshire terrier and the cavalier King Charles spaniel, breeds affected by predominantly dilative forms of cardiac disease. In contrast, it was very inaccurate in the boxer, a breed that has a higher incidence of cardiac diseases associated with concentric hypertrophy.

Animals↗

PubMed2006

Seasonal changes in plasma calcium and inorganic phosphate levels in relation to parathyroid structure of the grey quail, Coturnix coturnix coturnix Linnaeus.

Plasma Ca concentration (annual mean) in males Coturnix cotumix coturnix was 10.27 +/- 0.14 mg/100 ml while it was slightly higher (11.85 +/- 0.15 mg/100 ml) among females. Plasma Pi levels (annual mean) in males and females were 5.62 +/- 0.12 mg/100 ml and 6.52 +/- 0.20 mg/100 ml, respectively. While the males did not exhibit marked fluctuation in plasma Ca and Pi levels either in winter or summer, the females did record significant elevation in the levels of both these electrolytes during breeding season. The peak values of plasma Ca (17.66 +/- 0.38 mg/100 ml) and Pi (8.64 +/- 0.22 mg/100 ml) in females were observed during June. Parathyroid gland of the grey quail exhibited hyperactivity (hypertrophy and hyperplasia) during breeding season, however, the activity was more conspicuous among females than in males. The maximum increase in cell and nuclear diameters were observed in females during May-July. The follicles were also filled with AF- and PAS-positive materials during these months. The glands depicted signs of hypoactivity and degeneration during peak winter season (November-December) as evident by decrease in cell and nuclear diameters as well as vacuolation in the chief cells.

Animals↗

PubMed1992

The value of electrophoretic fingerprinting and karyotyping in wine yeast breeding programmes.

Electrophoretic banding patterns of total soluble cell proteins, DNA restriction fragments and chromosomal DNA were used to characterise ten strains of Saccharomyces cerevisiae used for commercial production of wine. These fingerprinting procedures provided unique profiles for all the different yeast strains and can therefore be used to identify and control industrial strains. Furthermore, the protein profiles, restriction fragments banding patterns and electrophoretic karyotyping by contour clamped homogeneous electric field electrophoresis (CHEF), were valuable to differentiate hybrid and parental strains in yeast breeding programmes. Hybrid strains, with desirable oenological properties, were obtained by mass spore-cell mating between a heterothallic killer yeast and two homothallic sensitive strains and all were shown to have unique DNA fingerprints and electrophoretic karyotypes.

DNA Fingerprinting↗

PubMed2002

Comparative assessment of the erythrocyte osmotic fragility and of haematological and plasma biochemical values in the Nigerian white Fulani and N'dama breeds of cattle.

The blood profiles of the Nigerian White Fulani and N'dama breeds of cattle were compared. The White Fulani cattle had a significantly higher haemoglobin concentration (p < 0.001), mean corpuscular haemoglobin (p < 0.05), plasma sodium (p < 0.02), total protein (p < 0.01), albumin (p < 0.01) and globulin (p < 0.02), but lower neutrophil counts (p < 0.01) and osmotic fragility of erythrocytes than the N'dama cattle. The plasma potassium, calcium, bicarbonate, inorganic phosphate, albumin/globulin ratio, urea, creatinine, packed cell volume and mean corpuscular volume, and the erythrocyte, leukocyte, lymphocyte, eosinophil and monocyte counts were similar in the two breeds.

Animals↗

PubMed2003

Use of mid-parent values and progeny tests to increase the efficiency of potato breeding for combined processing quality and disease and pest resistance.

A potato breeding strategy is presented which avoids the common but ineffective practice of intense early-generation visual selection between seedlings in a glasshouse and spaced plants at a seed site. Once pair crosses have been made, progeny tests are used to discard whole progenies before starting conventional within-progeny selection at the unreplicated small-plot stage. Clones are also visually selected from the best progenies for use as parents in the next cycle of crosses whilst they are multiplied to provide enough tubers for assessment of their yield and quality. Mid-parent values, as well as progeny tests, are then used to select between the resultant crosses. Material from other breeding programmes can be included in the parental assessments and used in the next cycle of crosses if superior. Finally, in seeking new cultivars, the number of clones on which to practise selection is increased by sowing more true seed of the best progenies, but without selection until the small-plot stage. Traits considered are resistance to late blight [ Phytophthora infestans (Mont.) de Bary] and to the white potato cyst nematode [ Globodera pallida (Stone)], fry colour and tuber yield and appearance, as visually assessed by breeders. The theoretical superiority of the strategy for seeking new cultivars lies in being able to practise between-cross selection for a number of economically important traits within 1 or 2 years of making crosses, something that is not possible on individuals as seedlings in the glasshouse or spaced plants at the seed site. This also means that full-sib family selection can be operated on a 3-year cycle, an improvement on current practice of clonal selection on what is often at least a nine-year cycle. New cultivars can be sought with more confidence from the best progenies in each cycle, and modern methods of rapid multiplication used to reduce the number of clonal generations required to find the best clones.

Breeding↗

PubMed2000

Trade-off between mating opportunities and parental care: brood desertion by female Kentish plovers.

Why do some parents care for their young whereas others divorce from their mate and abandon their offspring? This decision is governed by the trade-off between the value of the current breeding event and future breeding prospects. In the precocial Kentish plover Charadrius alexandrinus females frequently, but not always, abandon their broods to be cared for by their mate, and seek new breeding partners within the same season. We have shown previously that females' remating opportunities decline with date in the season, so brood desertion should be particularly favourable for early breeding females. However, the benefits are tempered by the fact that single-parent families have lower survival expectancies than those where the female remains to help the male care for the young. We therefore tested the prediction that increasing the value of the current brood (by brood-size manipulation) should increase the duration of female care early in the season, but that in late breeders, with reduced remating opportunities, desertion and thus the duration of female care should be independent of current brood size. These predictions were fulfilled, indicating that seasonally modulated trade-offs between current brood value and remating opportunities can be important in the desertion decisions of species with flexible patterns of parental care.

Animals↗

PubMed1994

Macrothrombocytosis in cavalier King Charles spaniels.

Low platelet counts (< 150 x 10(9)/litre) have been measured by autoanalyser in cavalier King Charles spaniels with a wide range of diseases. However, the direct examination of blood smears revealed adequate numbers of platelets but many abnormally large platelets and it was not clear whether the large platelets were the result of disease or a breed abnormality. The numbers and diameters of the platelets in a group of clinically normal King Charles spaniels and a group of other breeds were measured by autoanalyser and manually. The automated platelet counts were lower in the King Charles spaniels than in the other breeds (P < 0.01), but the manual counts were similar. The platelet diameter was greater in the cavalier King Charles spaniels (median values 2.5 to 3.75 microns, P < 0.001) than the other breeds (median values 1.25 to 2.5 microns) and had a bimodal distribution with peaks at 1.25 to 2.5 microns and 3.75 to 5 microns. No clinical evidence of platelet dysfunction was detected. These findings indicate that cavalier King Charles spaniels may have large platelets which could lead to the erroneous diagnosis of thrombocytopenia by automated haematological analysis.

Animals↗

PubMed1991

Variation in hormonal feedback and reproductive performance in adult rams of different genotypes.

Adult Moroccan rams of two different genotypes were compared on the basis of seasonality, fertility and sensitivity to gonadal feedback on the pituitary and hypothalamus. One breed with less seasonal breeding and high fertility, D'Man and one with less fertility and marked seasonal variation in breeding behaviour, Bnihsen. Four animals in each genotype were hemicastrated and 9 mo later castrated, to examine the effect of hormonal control on the hypothalamo-hypophyseal feedback system. Nine months after hemicastration the D'Man breed showed higher gonadotrophine values (LH, FSH). The remaining testicule in turn produced more estradiol-17beta but less testosterone in these rams. The testosterone production was increased in the Bnihsen rams following castration. After castration the FSH values increased rapidly in all animals with higher values for the D'Man rams. LH-release was faster in the hemicastrated rams than in controls. This is the first report on differences for hormonal feedback-systems in adult rams from different genotypes. The hormonal feedback-system is less sensitive for adult rams from breeds with higher fertility and nonseasonaly. In addition to that it was found that a difference seems to exist in the regulation for the release of FSH and LH.

Journal Article↗

PubMed1998

Serotonin transporter on rat platelets: levels of mRNA underlie inherited differences in uptake kinetics.

By the breeding selection for the extreme values of platelet serotonin transporter activity, two sublines of Wistar-derived rats, with constitutionally high or low platelet serotonin uptake (PSU), were previously developed. In order to study the genetic background of these inherited differences, comparative Northern blot analysis of the platelet serotonin transporter messenger RNA levels of the animals from the two sublines was performed. If the values of animals from the high-PSU subline are taken as 100%, animals from the low-PSU subline demonstrated lower values of both platelet serotonin uptake and transporter mRNA levels (amounting to 62 and 76% respectively). Correlation between platelet serotonin uptake and the respective levels of messenger RNA for the serotonin transporter (r = 0.829, P < 0.01, N = 8) points to the same direction, indicating that the process of breeding selection for the extreme values of transporter kinetics has influenced transcription mechanisms of the serotonin transporter gene.

Animals↗

PubMed1976

Familial renal disease in Norwegian Elkhound dogs: physiologic and biochemical examinations.

Renal disease was detected in 21 of 56 progeny from a specific line of inbred Norwegian Elkhound (NE) dogs. Results of hematologic and clinical chemistry examinations revealed that minor differences existed between affected and nonaffected NE dogs. Of 21 NE dogs with renal disease, 3 had persistent glucosuria without hyperglycemia. The 21 affected dogs had impaired ability to concentrate urine. According to renal function tests, glomerular filtration rate of normal NE dogs was less than that of normal mixed breed dogs. Although a few affected NE dogs excreted large amounts of amino acids in urine, statistically significant differences did not exist between normal and affected NE dogs with regard to alpha-amino acid nitrogen content of their plasma or urine. By paper chromatographic separation techniques, free amino acids of plasma, urine, and extracts of liver and kidney were not qualitatively different for mixed breed dogs, normal NE, and NE with renal disease. Statistically significant differences were not detected between serum calcium concentrations of normal and affected NE dogs. In NE dogs with renal disease, there was significant hypercalciuria, but a few normal dogs excreted more than did some dogs with disease. Blood pressure values of normal mixed breed dogs and affected NE dogs were similar. It was concluded that hematologic and blood chemical abnormalities, derangement of amino acid or calcium metabolism, and hypertension were not associated with renal disease in these NE dogs.

Animals↗

PubMed1980

[Indirect methods of determining the amount of cellular elements in bulk cow's milk].

Comparative studies have been carried out to establish the practical value of three indirect methods--Whiteside, Bernburg, and the antiformin one--intended for the rapid determination of the somatic cell count in pooled cow milk. A total of 556 samples of milk from various sources have been studied. The data obtained with the use of the direct method of Prescott and Breed served as control values of the cell elements in milk. A conclusion has been made that the test after Whiteside is the most appropriate one for the rapid determination of the cell count in pooled cow milk: it gives positive results in 100 per cent of the investigated samples having a count of more than 500000 cells. The use of this method is suggested in the case of detecting farms where mastitis is a problem.

Animals↗

PubMedDate not supplied

Breed and seasonal variation of plasminogen activator activity and plasminogen activator inhibition in spermatozoa and seminal plasma of the ram in correlation with testosterone in the blood.

Plasminogen activator activity (PAA) and plasminogen activator inhibition (PAI), against t-PA (t-PAI) or u-PA (u-PAI), in spermatozoa and seminal plasma as well as testosterone in the blood of Friesland, Chios, and Karagouniki rams all showed a seasonal variation with the highest values during the corresponding breeding season of the ewes (Autumn-Winter). The seasonal variation of PAA and PAI in spermatozoa or seminal plasma as well as blood testosterone was different among the three breeds studied. Increased spermatozoal PAA was observed in November and May in Friesland rams, in October and November in Chios rams, and in October in Karagouniki rams. Spermatozoal t-PAI was increased in December and June in Friesland rams, in November and December in Chios rams, and in November in Karagouniki rams. Spermatozoal u-PAI was increased in December in Friesland rams, in October and December in Chios rams, and in November and December in Karagouniki rams. Plasminogen activator activity and PAI in seminal plasma also showed similar seasonal variations. Plasminogen activator activity and PAI in spermatozoa and seminal plasma showed a positive correlation with blood testosterone. The results of the present study support our previous findings on the possible role of spermatozoal PAA and PAI in the fertilizing ability of spermatozoa.

Animals↗

PubMed1990

Effect of ovariectomy at two periods of the year on LH and FSH basal concentrations and pituitary response to LHRH in the brown hare (Lepus europaeus).

In the brown hare, fertile mating takes place from the beginning of December to September. Seasonal variations of basal concentrations of LH and FSH, and pituitary response to a monthly i.v. injection of LHRH were studied in intact control females and in females ovariectomized during the seasonal anoestrus (OVX1) or during the breeding season (OVX2). In intact females, both basal and LHRH-stimulated LH levels showed an annual variation, with minimal values during anoestrus. During the breeding season, the LH response to LHRH exhibited a biphasic pattern. In contrast, there was no clear seasonal variation in basal and LHRH-stimulated FSH concentrations. After ovariectomy during anoestrus, basal LH remained low for 2 months and began to increase in December. After ovariectomy during the breeding season, LH basal concentrations increased within a few days after the operation. Thereafter, LH values remained high in both groups of females until September, and decreased significantly as in intact females. The pattern of LH release after LHRH remained monophasic in the two groups of ovariectomized females. In OVX1 females, the LH response increased as early as October, was maximum from December to April and decreased progressively until October. IN OVX2 females, the LH response decreased regularly after ovariectomy to a minimum in October. In the 2 groups of ovariectomized females, basal FSH concentrations and pituitary response to LHRH rose rapidly after ovariectomy and did not vary significantly thereafter. These results showed a direct central effect of season on the regulation of basal concentrations of LH, modulated by a negative feed-back of ovarian secretions during the breeding season. In intact hares, the enhanced LH response after LHRH during the breeding season was related to an acute positive effect of ovarian secretions. The regulation of FSH was less dependent on season and remained under a negative control of the ovary throughout the year.

Animals↗

PubMed2002

Progress in breeding for trace minerals in staple crops.

Staples are not considered an important source of minerals in the diet. However, because of high staple consumption, any increase in mineral concentration might well have a significant effect on human nutrition and health. The nutritional quality of staple crops (rice, cassava, wheat, maize and beans) can be improved by breeding. Studies have shown the potential to exploit the genetic variation in seed concentration of iron and other minerals without the general negative effect on yield of adding new traits. The relationship between yield and mineral concentration may be positive, particularly in mineral-deficient soil. Initial evaluations have shown that some crop varieties have high Fe, Zn and carotene in their edible portions. The next step for conventional breeding will be to study the genetics of trace mineral inheritance to determine the best selection technique. Initial investigations of the genetics for high iron in rice have indicated a complex mode of inheritance, demonstrating additive and dominant gene and environmental effects. Breeding strategies have been developed based on these genetic findings. The use of biotechnological tools, such as molecular marker-assisted selection, will significantly increase the pace and prospects of success for breeding to improve the nutritional value of staple food crops.

Agriculture↗

PubMed1984

Seasonal reproduction in the mongoose, Herpestes auropunctatus. IV. Organ weight and hormone changes in the female.

The mongoose, Herpestes auropunctatus, shows a well-defined breeding season in Hawaii. In this study, females were live-trapped throughout the year and sacrificed within 48 hr to obtain information about reproductive organ weights and gonadotropin levels. Pregnant females were found from February through September and lactating females from March through October. Body weight did not change significantly throughout the year, but anterior pituitary, adrenal, ovarian, and uterine weights were significantly reduced during the nonbreeding season. LH and FSH levels were extremely variable among individuals and, although mean values were higher during the breeding than during the non-breeding season, no significant differences could be demonstrated. After castration, there was not a clearcut rise in either LH or FSH, regardless of the season of the year, when animals were followed for up to l5 days. This contrasts with the male mongoose, where FSH rose significantly by 4 days after castration in either the breeding or nonbreeding season, while LH rose more slowly in the nonbreeding season but by l0 days after castration was significantly elevated and comparable to values in males castrated in the breeding season. We conclude that the female mongoose population shows less synchrony in changes in gonadotropin levels than the males, in spite of the well-defined breeding season.

Animals↗

PubMed1990

Hormonal abnormalities in Pomeranians with normal coat and in Pomeranians with growth hormone-responsive dermatosis.

Clinical status, skin biopsy specimens, and endocrine function were evaluated in normal-coated Pomeranians (n = 12) and Pomeranians affected with growth hormone (GH)-responsive dermatosis (n = 7), then were compared with values in mixed-breed dog controls (n = 19). All Pomeranians were clinically normal; however, the Pomeranians with GH-responsive dermatosis had bilateral alopecia and hyperpigmentation of the trunk, caudal portion of the thighs, and ventral neck region. Skin biopsy specimens from the affected Pomeranians had decreased-to-normal epidermal thickness and follicular atrophy, compared with normal-coated Pomeranians. Numerous elastin fibers were observed in the skin biopsy specimens of unaffected and affected Pomeranians. Both groups of Pomeranians had normal results of thyrotropin-releasing hormone (TRH) and thyrotropin (TSH) response, adrenocorticotropin (ACTH) stimulation, and dexamethasone suppression testing. There was no significant increase in serum GH concentration in either group of Pomeranians after xylazine or human GH-releasing factor (GHRF) administration, whereas control dogs had significant (P less than or equal to 0.05) increase in serum GH concentration after administration of either agent. Baseline plasma ACTH concentration in unaffected and affected Pomeranians was increased above the normal range (40 to 90 pg/ml). Post-ACTH administration serum progesterone, 17-hydroxyprogesterone, and androgen (dehydroepiandrosterone sulfate or androstenedione) concentrations were consistently high in unaffected and affected Pomeranians, compared with values in control dogs.(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenocorticotropic Hormone↗