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PubMed2006

[Study on mtDNA D-loop of Chinese main indigenous sheep breeds using PCR-RFLP].

The polymorphism of mtDNA D-loop of 83 individuals from 9 Chinese indigenous sheep breeds and 2 imported sheep breeds were studied with 5 endonucleases, Hinf I, Msp I, Sau3A I, Xsp I and Taq I, using PCR-RFLP. The results indicated that there existed two basic haplotypes in the region of mtDNA D-loop. It could be inferred that Chinese indigenous sheep breeds originated from two maternal ancestors. The averaged polymorphic degree (Pi value=0.0421%) of mtDNA D-loop showed that the genetic diversity of mtDNA of Chinese indigenous sheep breeds was very poor.

Animals↗

PubMed2000

Profitabilities of some mating systems for dairy herds in New Zealand.

The aim of this study was to evaluate the profitability of dairy herds under three mating systems involving the Holstein-Friesian, Jersey, and Ayrshire breeds. Mating systems were straight breeding and rotational cross-breeding using two or three breeds. A deterministic model was developed to simulate the nutritional, biological, and economic performance of dairy herds under New Zealand conditions. Expected performances per cow were obtained using estimates of breed group and heterosis effects, age effects, and age distribution in the herd. Requirements for dry matter in feed were estimated per cow for maintenance, lactation, pregnancy, and growth of the replacements. Stocking rate was calculated by assuming 12,000 kg of dry matter utilized annually per hectare. Productivity per hectare was calculated as performance per cow multiplied by stocking rate. Profitability was the difference between income (sale of milk and salvage value of animals) and costs (related to the number of cows in the herd and the land area farmed). Under current market values for milk and meat, all of the rotational crossbred herds showed superior profitability to the straightbred herds (Holstein-Friesian x Jersey, NZ$505/ha; Holstein-Friesian x Jersey x Ayrshire NZ$493/ha; Jersey x Ayrshire, NZ$466/ha; Holstein-Friesian x Ayrshire, NZ$430/ha; Jersey, NZ$430/ha; Holstein-Friesian, NZ$398/ha; and Ayrshire, NZ$338/ha). Changes in the value for fat relative to protein affected profitability more significantly in herds using the Jersey breed, and changes in the value for meat affected profitabiity more significantly in herds using the Holstein-Friesian and Ayrshire breeds. Results suggested that, under New Zealand conditions, the use of rotational crossbreeding systems could increase profitability of dairy herds under the conceivable market conditions.

Animals↗

PubMed1985

Ontogeny of thermoregulation and energy metabolism in pygoscelid penguin chicks.

The ontogeny of thermoregulation and energy metabolism of chinstrap (Pygoscelis antarctica) and gentoo (P. papua) penguins was studied on King George Island, South Shetland Island, Antarctica. The major findings of this study are: Chinstrap and gentoo penguin chicks hatched completely poikilothermic, due to their poor heat-production ability at low ambient temperatures. They were able to maintain high body temperatures and metabolic rates only by being brooded by adults. Newly hatched chinstrap penguin chicks had, at a specified ambient temperature, significantly higher metabolic rates than newly hatched gentoos. Moreover, chinstrap chicks maintained a significantly higher body temperature. It is suggested that this is a non-acclimatory metabolic adaptation of chinstrap penguin chicks to the lower mean temperatures of their breeding areas. On the 15th day after hatching, chinstrap chicks were completely, and gentoo chicks almost completely, homeothermic. In spite of their high thermogenic capacity from about day 10, chicks were not at that time capable of controlling heat dissipation, and were still dependent on their parents. In older downy chicks and fledglings, heat loss at low temperatures, expressed as heat conductance (CA), was similar to that found for the adults of other penguin species. Just before moulting the CA of chicks was lower than after moulting. Moulting alone did not cause a clear increase in CA. Towards the end of their stay on land the CA of pre-fledged gentoos decreased by 31%. This decrease was not connected with the development of feathers or growth in the chicks' weight. The combination of the low CA and high SMR of chicks gave very low lower critical temperatures, near -15 degrees C. The wide thermoneutral zones of the chicks covered the whole range of air temperature variations in the breeding colonies of both species studied on King George Island. The CA values of homeothermic chinstrap chicks were not lower than those of gentoos, despite the more southern breeding range of the former species. The older chicks of both species are well protected against cold. Any further increase in insulation in chinstrap chicks would be of no adaptative importance.

Aging↗

PubMed1984

[Analysis of factors affecting the electric conductivity of cow's milk--breed, locale, season].

The problem was studied in a set of 678 mammary glands of 212 cows - crossbreds between the Holstein-Friesian breed with the Slovak Spotted cattle, crossbreds of the Black-Pied Lowland and Bohemian Spotted breed, and three-way crossbreds of the Black-Pied Lowland, Swedish White and Bohemian Spotted cattle. The confrontation of the confidence intervals of milk conductivity (MC) in healthy mammary glands at alpha = 0.05 showed that in the crossbreds of the Black-Pied Lowland cattle the MC was statistically significantly higher than in the breed types of the Holstein-Friesian cattle. The MC values decrease when there is a larger proportion of the blood of beef-and-dairy cattle (Slovak Spotted and Bohemian Spotted breeds). The locality where the stock was kept was found to act as an important factor underlying MC only in cases when both the geographical conditions and breed proportions were different. In a set homogenized with respect to the breeds, statistically significant differences in MC were demonstrated between the spring and summer season, spring and autumn, summer and autumn, and autumn and winter season.

Animals↗

PubMed1999

Interindividual differences in the pattern of melatonin secretion of the Wistar rat.

In vivo trans-pineal microdialysis was performed in male Wistar rats maintained under a 12 hr light:12 hr dark (LD 12:12) cycle. Collected dialysates were assayed by radioimmunoassay for melatonin concentrations. A non-linear regression was fitted through the obtained datapoints to determine the time points at which a 50% increase (IT50) and decrease (DT50) of the nocturnal melatonin peak were reached. In a first experiment, the nocturnal melatonin profiles of four animals were determined throughout 5 consecutive days. In a second experiment, we analysed the melatonin profiles during the night in rats originating from three different breeding colonies (Dépré Harlan, and Iffa-Cŕedo). A low intraindividual variability was found on the phase markers IT50 and DT50, as on peak duration of melatonin rhythms estimated over 5 subsequent days in the same animal. In contrast, animals showed a large interindividual variability in their profile phase markers and the values were dependent on the origin of the breeding colony. Each rat colony was characterized by early or late IT50 and DT50 as long or short peak length. It is concluded from experiment 1 that the melatonin rhythm is a very stable circadian marker. Nevertheless, great caution must be taken in the choice of animal groups while studying circadian rhythms due to the large interindividual variability observed in experiment 2. Therefore, as the technique allows the use of the animal as its own control, the present study demonstrated that the use of the microdialysis technique is of interest in studies on the circadian system.

Animals↗

PubMed1981

Productivity of purebred and crossbred finnsheep. II. Lamb weights and production indices of ewes.

Birth and weaning weights were studied for purebred Finnsheep, Suffolk, Targhee and Minnesota 100; F1 Finnsheep crosses; F2: and standard breed and Finnsheep backcrosses. Finnsheep lambs were the smallest of all lambs at birth, but ranked second among purebreds in 70-day weaning weight (Suffolks, 21.0 kg vs Finnsheep, 17.6 kg). Ewe body weight, grease fleece production and total adjusted weight of weaned lamb were compared among purebreds and crossbreds. The Finnsheep was the smallest pure breed, yielded the lightest fleeces, but produced the heaviest total weight of weaned lamb. The F1 ewes were all heavier and produced more wool than the midparent mean of their respective breeds. They also produced markedly more weaned lamb than did the parental standard breeds. Body weight, wool and lamb production were all lower in the F2 than in the F1 groups. Ewe index was calculated as the total adjusted (male, 70-day equivalent) weight of weaned lamb plus three times the grease fleece weight. The ranking of purebreds was Finnsheep, Targhee, Suffolk and Minnesota 100. Average ewe index values for F1 ewes were greater than those for respective parental and standard breeds. F2 and standard breed backcross ewes had lower index values than did F1 or Finnsheep backcross ewes. Ewe index per unit of ewe body weight was also evaluated. Finnsheep ranked highest, followed by the 3/4 Finnsheep. The Targhee was the best of the standard breeds for this index.

Animals↗

PubMed1977

Physiological and endrocine parameters in beef cattle: breed, sex and year differences.

Plasma corticoids, potassium and sodium, thyroid activity and hemoglobin and hematocrit values were determined at slaughter over a period of four years in 1612 animals representing the following sire groups: Short-horn, Charolais, Simmental, Limousin, Red Angus, Beefmaster, Brown Swiss, Chianina and Jersey. Differences among years and among breeds of sire were significant for all the parameters studied. Hematocrit values were the highest in females and the lowest for entire males, while hemoglobin levels were the lowest in females and the highest for bulls. Plasma corticoid levels were lower for entire males as compared to steers and heifers. Plasma sodium and potassium levels were the highest for females and the lowest entire males. The values reported in this study for several blood components, based on a large number of animals, could serve as clinical guides and as a basis for further research.

Animals↗

PubMed2004

Additive genetic relationships between heifer pregnancy and scrotal circumference in Nellore cattle.

To estimate heritability (h2) for yearling heifer pregnancy and to estimate the genetic correlation between heifer pregnancy and scrotal circumference, 18,145 records of Nellore heifers exposed to breeding at an age of approximately 14 mo and 25,466 records of contemporary young bulls were analyzed. Heifer pregnancy was considered as a categorical trait, with the value 1 (success) assigned to heifers that were pregnant after rectal palpation approximately 60 d after the end of a 90-d breeding season and the value 0 (failure) otherwise. A single-trait animal model for heifer pregnancy and a two-trait animal model including heifer pregnancy and scrotal circumference were used. Contemporary groups were defined in two ways: including (CG2) or not including (CG1) weaning management of the heifer. Heritability estimates obtained by Method R in single-trait analyses were 0.68 +/- 0.09 and 0.61 +/- 0.10 using CG1 and CG2 definitions, respectively. Heritability estimates for two-trait analyses were 0.69 +/- 0.09 (CG1) and 0.63 +/- 0.08 (CG2) for heifer pregnancy and 0.57 +/- 0.03 (both CG) for scrotal circumference. The genetic correlation estimates between the two traits were 0.20 +/- 0.12 (CG1) and 0.20 +/- 0.13 (CG2). Based on the results of this study, EPD for heifer pregnancy can be used to select bulls for the production of precocious daughters and will be more effective than selecting on scrotal circumference EPD in Nellore cattle. However, scrotal circumference can be incorporated in a two-trait analysis to increase the accuracy of prediction for heifer pregnancy EPD for young bulls. Using contemporary group without heifer weaning management gave higher h2 and, for two-trait analysis, converged more quickly.

Animals↗

PubMed2006

Genetic diversity within and between European pig breeds using microsatellite markers.

An important prerequisite for a conservation programme is a comprehensive description of genetic diversity. The aim of this study was to use anonymous genetic markers to assess the between- and the within-population components of genetic diversity for European pig breeds at the scale of the whole continent using microsatellites. Fifty-eight European pig breeds and lines were analysed including local breeds, national varieties of international breeds and commercial lines. A sample of the Chinese Meishan breed was also included. Eleven additional breeds from a previous project were added for some analyses. Approximately 50 individuals per breed were genotyped for a maximum of 50 microsatellite loci. Substantial within-breed variability was observed, with the average expected heterozygosity and observed number of alleles per locus being 0.56 [range 0.43-0.68] and 4.5 respectively. Genotypic frequencies departed from Hardy-Weinberg expectations (P < 0.01) in 15 European populations, with an excess of homozygotes in 12 of them. The European breeds were on average genetically very distinct, with a Wright F(ST) index value of 0.21. The Neighbour-Joining tree drawn from the Reynolds distances among the breeds showed that the national varieties of major breeds and the commercial lines were mostly clustered around their breeds of reference (Duroc, Hampshire, Landrace, Large White and Piétrain). In contrast, local breeds, with the exception of the Iberian breeds, exhibited a star-like topology. The results are discussed in the light of various forces, which may have driven the recent evolution of European pig breeds. This study has consequences for the interpretation of biodiversity results and will be of importance for future conservation programmes.

Alleles↗

PubMed1998

Haematological changes in N'Dama and Gobra Zebu bulls during Trypanosoma congolense infection maintained under a controlled feeding regimen.

Haematological changes were monitored in Gobra-Zebu and N'Dama bulls following infection with Trypanosoma congolense. The cattle were offered a diet which provided levels of protein and energy above maintenance requirement and a pair feeding regimen was used in order to eliminate the confounding anorexic effects of trypanosomosis on the traits studied. Packed red cell volume (PCV), red blood cells (RBC) and haemoglobin (Hb) were monitored weekly. Mean corpuscular haemoglobin (MCH), mean corpuscular haemoglobin concentration (MCHC), and mean corpuscular volume (MCV) were derived by computation. Significant breed differences (P < 0.001) were observed in the baseline data collected with N'Dama bulls having higher (P < 0.001) values for RBC and Hb. PCV levels were similar in both breeds pre-infection. Post-infection, there was a significant (P < 0.001) infection effect on the RBC, Hb and PCV in both breeds. The pathogenic effects were more severe in the Gobra-Zebu bulls where three out of ten bulls compared with only one out of eight infected N'Dama bulls attained the low PCV threshold, treated and withdrawn from the study along with their pair mates. Throughout the infection in N'Dama cattle and during the first 6 weeks of infection in the Gobra-Zebu bulls, the infection presented a normochromic normocytic anaemia. However, in the chronic phase, the Gobra-Zebu bulls became macrocytic. The infection reduced total dry matter intake in both breeds although this persisted longer in the Gobra-Zebus. However, their pair-fed controls showed no haematological changes indicating that the anorexia was not compounding the effects of the infection. The severity and type anaemia in N'Dama correlates with their innate ability to resist the effects of trypanosome infection compared to the Gobra-Zebu bulls.

Anemia↗

PubMedDate not supplied

Genetic diversity in Spanish donkey breeds using microsatellite DNA markers.

Genetic diversity at 13 equine microsatellite loci was compared in five endangered Spanish donkey breeds: Andaluza, Catalana, Mallorquina, Encartaciones and Zamorano-Leonesa. All of the equine microsatellites used in this study were amplified and were polymorphic in the domestic donkey breeds with the exception of HMS1, which was monomorphic, and ASB2, which failed to amplify. Allele number, frequency distributions and mean heterozygosities were very similar among the Spanish donkey breeds. The unbiased expected heterozygosity (H(E)) over all the populations varied between 0.637 and 0.684 in this study. The low G(ST) value showed that only 3.6% of the diversity was between breeds (P<0.01). Significant deviations from Hardy-Weinberg equilibrium were shown for a number of locus-population combinations, except HMS5 that showed agreement in all analysed populations. The cumulative exclusion probability (PE) was 0.999 in each breed, suggesting that the loci would be suitable for donkey parentage testing. The constructed dendrogram from the D(A) distance matrix showed little differentiation between Spanish breeds, but great differentiation between them and the Moroccan ass and also with the horse, used as an outgroup. These results confirm the potential use of equine microsatellite loci as a tool for genetic studies in domestic donkey populations, which could also be useful for conservation plans.

Alleles↗

PubMed2000

Parental investment strategies in two species of nuthatch vary with stage-specific predation risk and reproductive effort.

Life-history theory predicts that differences in reproductive effort and residual reproductive value among species should result in differences in the level of risk that parents are willing to tolerate to themselves versus their offspring. Specifically, highly fecund and shorter-lived species are expected to place greater value in current offspring than themselves, whereas less fecund and longer-lived species are expected to place greater value in their own survival and future breeding opportunities. Here, we test the prediction that parental investment decisions are correlated with life histories by comparing risk-taking behaviour in two species of nuthatch that differ in reproductive effort: the white-breasted nuthatch, Sitta carolinensis (more fecund, lower survival) and the red-breasted nuthatch, S. canadensis (less fecund, higher survival). We experimentally manipulated stage-specific predation risk by presenting models of an adult predator (hawk) and an egg predator (wren) and measured the willingness of males to feed incubating females on the nest. We found that both species of nuthatch responded to predators by increasing the length of time between visits and aborting more visits to the nest. However, as predicted by their life histories, S. carolinensis displayed a significantly stronger response to the egg predator, whereas S. canadensis responded more strongly to the adult predator. Thus, species can differ in their willingness to tolerate risk to themselves and their young, and such differences appear to be related to differences in investment in current reproduction and the probability of future survival. Copyright 2000 The Association for the Study of Animal Behaviour.

Journal Article↗

PubMed2006

Assessing the importance of genotype x environment interaction for root traits in rice using a mapping population. I: a soil-filled box screen.

Altering root system architecture is considered a method of improving crop water and soil nutrient capture. The analysis of quantitative trait loci (QTLs) for root traits has revealed inconsistency in the same population evaluated in different environments. It must be clarified if this is due to genotype x environment interaction or considerations of statistics if the value of QTLs for marker-assisted breeding is to be estimated. A modified split-plot design was used where a main plot corresponded to a separate experiment. The main plot factor had four treatments (environments), which were completely randomized among eight trials, so that each treatment was replicated twice. The sub-plot factor consisted of 168 recombinant inbreed lines of the Bala x Azucena rice mapping population, randomly allocated to the seven soil-filled boxes. The aim of the trial was to quantify QTL x environment interaction. The treatments were chosen to alter partitioning to roots; consisting of a control treatment (high-soil nitrogen, high light and high-water content) and further treatments where light, soil nitrogen or soil water was reduced singly. After 4 weeks growth, maximum root length (MRL), maximum root thickness, root mass below 50 cm, total plant dry mass (%), root mass and shoot length were measured. The treatments affected plant growth as predicted; low nitrogen and drought increased relative root partitioning, low-light decreased it. The parental varieties Bala and Azucena differed significantly for all traits. Broad-sense heritability of most traits was high (57-86%). Variation due to treatment was the most important influence on the variance, while genotype was next. Genotype x environment interaction was detected for all traits except MRL, although the proportion of variation due to this interaction was generally small. It is concluded that genotype x environment interaction is present but less important than genotypic variation. A companion paper presents QTL x environment analysis of data.

Chromosome Mapping↗

PubMed1991

Evaluation of total serum bile acid concentrations for the diagnosis of hepatobiliary disease in cattle.

Serum bile acid concentrations were measured in 41 clinically healthy cattle of different breeds. There was no diurnal variation in values and age and sex had no effect. There was no significant difference between serum and plasma bile acid concentrations in clinically healthy cattle. Serum bile acids were stable on storage at -20 degrees C. The total serum bile acid concentrations, together with other tests of hepatic disease, were evaluated in cattle with various types of hepatobiliary disease (hepatic lipidosis, hepatic abscessation, leptospirosis, biliary calculi, fascioliasis), respiratory, cardiovascular and infectious diseases, and in various other conditions not affecting the liver. Total serum bile acids were the most specific and sensitive indicators of a wide variety of hepatic diseases and were significantly correlated with the degree of clinical illness.

Animals↗

PubMed1985

Effects of estrous cycle and season on ultrasonic uterine anatomy in mares.

The morphological changes in ultrasound images of the uterus at various times of the year were characterized in nonbred mares, using a linear-array scanner. The uterus was recorded as having an ultrasonic morphology characteristic of diestrus (uterine score 1, endometrial folds not visible), estrus (score 3, distinct endometrial folds), or an intermediate stage (score 2). In Experiment I, uterine scores for the first ovulatory period of the year were compared to scores for the second period in 23 pony mares. More mares (P<0.05) showed endometrial folding prior to the second ovulation of the year (14 23 ) than prior to the first (5 23 ). Mean uterine scores were higher (P<0.05) on Day -10 (ovulation = Day 0) and tended to be higher (P<0.1) on Days -14, -13, and -11 of the first ovulatory period than on the corresponding days of the second period. Uterine scores for the first ovulatory period were lower (P<0.05) on Days -5, -4, -3, -2, -1, and 0 and tended to be lower (P<0.01) on Day -6. In addition, the pattern of change in uterine scores paralleled the pattern of change in the intensity of estrous behavior. In Experiment II, in 20 horse mares, the curve for uterine scores during interovulatory intervals in May-June, but not in September-October, was bimodal due to a small rise (P<0.05) and subsequent return to baseline between Days +3 and +6. The mean uterine scores for both May-June and September-October began to increase on Day -7 or -8, reached maximum on Day -3, declined between Days -2 and 0, continued to decline after Day 0, and reached a value characteristic of diestrus by Day +2. Results indicated that the ultrasonic characteristics of the uterus may provide an instant indicator of estrogen exposure and may have practical value in judging the optimal time to breed.

Journal Article↗

PubMed2026

Comparative metabolomic and transcriptomic profiling of flavonoid diversity and antioxidant capacity in three Isatis species.

Flavonoids are key bioactive compounds in plants with significant health benefits. This study employs an integrated multi-omics approach to investigate flavonoid diversity and antioxidant capacity across three Isatis species: I. oblongata, I. tinctoria, and I. indigotica. Metabolomic profiling identified 200 flavonoids, with glycosides being the most abundant class. I. tinctoria exhibited the highest total flavonoid content and antioxidant activity, strongly correlated with the accumulation of 53 core differential flavonoid metabolites, most of which were glycosylated derivatives. Transcriptomic analysis revealed coordinated upregulation of phenylpropanoid pathway genes and specific UDP-glycosyltransferases (UGTs) in I. tinctoria, providing a genetic basis for its enhanced glycoside production. The study establishes a clear genotype-metabolite-phenotype linkage, highlighting glycosylation as a key mechanism underlying flavonoid-driven antioxidant superiority in Isatis. Although the current evidence is primarily correlative, the consistent and strong associations across independent transcriptomic, metabolomic, and antioxidant datasets provide a robust foundation for this conclusion. These findings offer new insights into the metabolic evolution and regulatory networks of flavonoids, with implications for breeding and metabolic engineering of high-value medicinal plants.

Flavonoids↗

PubMedDate not supplied

Early modelling for assessing health and economic outcomes of drug therapy.

Models for assessing health and economic outcomes of new drugs have an increasing role in the early phases of drug development. Their input into go/no go and priority setting decisions can reveal that further development of a drug is unattractive from an economic viewpoint, or that developing a certain indication is more attractive than another. They may also influence the later choice of indication, positioning, comparators, length of follow-up, and other elements in the further development of drugs. Their specific nature, characterized by limited budget, timelines and data availability should not necessarily lead to compromises in design and conduct. It is argued that high quality early models form the breeding ground for later solid evidence on value for money, and are consequently both worthwhile to the pharmaceutical industry and to health care decision-makers and payers.

Journal Article↗

PubMed1976

Seasonal changes in the plasma retinol-binding holoprotein concentration of sheep.

1. Seasonal variations in plasma retinol-binding holoprotein concentration have been found in two groups of entire ewes and in a control group of wethers (castrated rams). 2. In each group retinol-binding holoprotein level was minimal in summer and increased to peak values in September just before the autumn breeding season.

Animals↗