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PubMed2005

[QTLs mapping and genetic analysis of tiller angle in rice (Oryza sativa L.)].

Tiller angle is one of the most important morphological characters that has a significant effect on the formation of rice high-yield population. The tiller angles were measured in a japonica/indica RIL population with 71 lines and a genome-wide chromosome segment substitution line (CSSL) population with 65 lines at two experimental sites. A transgressive segregation was observed in both populations. QTL analysis of tiller angle was conducted based on the saturated RFLP marker linkage map and the CSSL graphical genetype. Five main-effect QTLs and three pairs of epstatic loci were detected in the RIL population. A main QTL, qTA-9, located on chromosome 9 at XNpb108 - C506, was identified at both experiment sites. The positive allele TA-9(I) on qTA-9 was contributed by indica rice IR24 with 28.6% average contribution to variance. Meanwhile, an analysis of CSSL graphical genetypes also showed that there was a positive allele on the IR24 chromosome substitution segment delimited by RFLP marker C609 and C506 with approximate 15 cM interval, which proved the existence of qTA-9. The TA-9(I) could increase tiller angle by about 15 degrees in japonica Asominori background under the two environments. The measurement of the F1 from the cross between background parent and CSSL AIS68 with TA-9(I) and the analysis of F2 population indicated that the TA-9(I) was an incomplete dominant gene. Genetype x environment interaction(G xE) was not widely present except a pair of epistatic loci with 5.32% contribution to variance of tiller angles and a relatively small additive effect. The combining action of the additive effect of the genes from both parents and the two-loci epistasis-effect may be responsible for the transgressive segregation of tiller angle in rice population. The value and approach of application of TA-9(I) in hybrid rice breeding program were discussed.

Chromosome Mapping↗
PubMedDate not supplied

Circannual prolactin rhythm in intact dogs housed outdoors.

Prolactin (PRL) and progesterone (P4) values were collected from eight intact (4 female, 4 male) mixed-breed dogs housed outdoors for a two-year span. A circannual component was significant for PRL for each dog (P less than 0.01) and the rhythm was validated for the population (P less than 0.004). Females had two estrus periods a year demonstrated by a P4 frequency of 23.5 +/- 0.47 wk. A 6-month component was statistically significant for P4 for three dogs and of borderline statistical significance for the fourth dog. Circannual acrophases yielded a statistically significant population rhythm (P = 0.012), whereas the 6-month component was of borderline statistical significance (P = 0.056). No time-macroscopic relationship between PRL cycles and P4 cycles was seen. These findings are consistent with similar PRL rhythms in non-domestic canids and emphasize the importance of considering seasonal effects when interpreting PRL data.

Animals↗
PubMed1987

[Acid-base equilibrium in calves with enteritis].

Studied were the indices of the acid-alkaline balance and the lactate level in a total of 19 Black-and-white calves manifesting clinical forms of enteritis as well as in 10 clinically normal calves that belonged to the same breed. In most of the calves affected with enteritis the blood pH values proved essentially lower than those found in normal calves. Differences were established between the normal and the diseased animals with regard to ABE, HCO-3, and pCO2, the ABE values with some of the animals with enteritis reaching -9.2 mmol/l, and the HCO-3 values--up to 16.5 mmol/l. Enteritis animals also showed higher pCO2 values than normal ones. The differences observed in the acid-alkaline balance pointed to the presence of metabolic respiratory acidosis in calves with clinical enteritis.

Acid-Base Equilibrium↗
PubMed1981

Determination of plasma fibrinogen concentration in the horse.

The microhematocrit heat-precipitation methods of Millar et al (1971) and Schalm et al (1975) were compared with the reference clottable protein method of Ratnoff and Menzie (1951) in the measurement of plasma fibrinogen concentration in horses. The millar et al method was more precise and accurate and showed better positive correlation with the reference method than did the Schalm et al method. There was no significant difference in the plasma fibrinogen concentration between healthy Thoroughbreds and healthy horses of other breeds. Horses with bacterial pneumonia and abscesses had significantly greater plasma fibrinogen values than did those with colic, fractures, and nonsuppurative wounds. The Millar et al method was recommended as a simple, relatively accurate procedure for the determination of plasma fibrinogen that might be used as an additional diagnostic and prognostic indicator in the laboratory investigation of diseases in the horse.

Animals↗
PubMed1995

Comparison of maternal blood and fetal liver selenium concentrations in cattle in California.

Selenium concentration was measured in paired maternal blood samples and fetal liver specimens collected at a San Joaquin County, Calif, slaughterhouse (beef = 19, dairy = 54) and from bovine aborted fetuses submitted to the California Veterinary Diagnostic Laboratory System (CVDLS; beef = 20, dairy = 20). Of the slaughterhouse samples and specimens, dairy maternal blood selenium concentration was significantly (P < 0.001) higher (mean +/- SD; 0.22 +/- 0.056 microgram/ml) than that for beef breeds (0.137 +/- 0.082 microgram/ml). The CVDLS mean maternal blood selenium concentration for the dairy-breed samples (0.192 +/- 0.028 microgram/ml) was similar to that for the slaughterhouse dairy-breed samples, but was greater than that for the slaughterhouse beef-breed samples. Slaughterhouse mean fetal liver selenium content also was higher (P < 0.001) for the dairy breeds (0.777 +/- 0.408 microgram/g), compared with the beef breeds (0.443 +/- 0.038 microgram/g). Mean fetal liver selenium content for slaughterhouse specimens was higher (P < 0.002) than that for the CVDLS specimens (beef, 0.244 +/- 0.149 microgram/g; dairy, 0.390 +/- 0.165 microgram/g). At the CVDLS, dairy fetal liver content was greater (P < 0.001) than that for beef breeds. Mean ratio of fetal liver selenium content to maternal blood selenium concentration was 3.53 +/- 1.89 for dairy breeds at the slaughterhouse (liver-to-blood correlation [r] = 0.38), and was 2.11 +/- 1.00 for dairy breeds at the CVDLS (r = 0.31) and 3.43 +/- 1.50 for beef breeds (r = 0.58). Both slaughterhouse breed ratios were significantly (P < 0.002) greater than the CVDLS dairy-breed ratio. On the basis of these results, breed and source location should be taken into account when interpreting selenium values. Fetal liver selenium content should only be used as a screening test and combined with whole blood selenium concentration from clinically normal herdmates to evaluate herd selenium status.

Abattoirs↗
PubMed2003

A neuroendocrine model for prolactin as the key mediator of seasonal breeding in birds under long- and short-day photoperiods.

Seasonal breeding is associated with sequential increases in plasma luteinizing hormone (LH) and prolactin in the short-day breeding emu, and in long-day breeding birds that terminate breeding by the development of reproductive photorefractoriness. A model of the avian neuroendocrine photoperiodic reproductive response is proposed, incorporating a role for prolactin, to account for neuroendocrine mechanisms controlling both long- and short-day breeding. The breeding season terminates after circulating concentrations of prolactin increase above a critical threshold to depress gonadotropin releasing hormone (GnRH) neuronal and gonadotrope (LH) activity. Subsequently, photorefractoriness develops for prolactin secretion and for LH secretion, independently of high plasma prolactin. The breeding season in the emu is advanced compared with long-day breeders, because after photorefractiness for both LH and prolactin secretion is dissipated, plasma concentrations of both hormones increase to maximum values while days are still short.

Animals↗
PubMed1998

[Continuous serologic study and sanitation inspection of Sarcoptes scabiei var. suis infection: preliminary results].

Pig mange was investigated serologically with ELISA using Chekit Sarcoptest. The test consists of a homogenized antigen of Sarcoptes scabiei var. vulpes. A total of 356 sows sera samples were collected from 16 mange free breeding units and 19 units with clinical manifestation of mange infestation. The specificity of the test was 99.34% and the mean sensitivity value was 62%. This test will allow in the future not only the rapid and certain diagnosis of pig mange but also the screening of the pig breeding units after eradication of the disease.

Animals↗
PubMed2001

Intestinal permeability testing using lactulose and rhamnose: a comparison between clinically normal cats and dogs and between dogs of different breeds.

In the experiment reported here, the lactulose/rhamnose urinary excretion test was used to compare intestinal permeability between four breeds of healthy adult dogs and a group of healthy adult cats. A significant difference in permeability was found between dogs and cats (P <0.001) and between different breeds of dogs (P <0.005). The range of urinary lactulose/rhamnose ratios in the dogs in this study (0.07-0.61) was wider than previously reported (0.03-0.12). The mean value for dogs was 0.19. The range in cats was 0.41-1.25 and the mean 0.52. The results of this study suggest that breed or some other factor such as environment, diet or sexual status as well as species should be taken into account when assessing intestinal permeability using the lactulose/rhamnose urinary excretion test.

Animals↗
PubMed2003

Polymorphism of E. coli F18 receptor gene in different pig breeds.

The genetic variation of E. coli F18 receptor(ECF18R) loci in 867 pigs including Large Yorkshire, Landrace, Duroc, Ningxiang pig, Shaziling pig and Daweizi pig was detected by PCR-RFLP with Hin6 I. The results showed as follows: The three exotic breeds including Large Yorkshire, Landrace and Duroc were proved to be polymorphic at the Hin6 I-RFLP site. The average susceptibility genotype frequency of AG and GG in the exotic breeds was 0.94, G allelic frequency was 0.76. The C-->A mutation frequency at M307 site was very low in exotic breeds. The resistance genotype frequency of AA was 0.06. But the three native breeds including Ningxiang pig, Shaziling pig and Daweizi pig presented only GG genotype and no variation at the Hin6 I-RFLP site. The chi 2 value of ECF18R genotype distribution at the Hin6I-RFLP site in different pigs indicated that ECF18R genotype distribution of every exotic pig breed had significant or highly significant differences with three native pig breeds'. The ECF18R genotype distribution of three native pig breeds was the same completely. The others had no difference except that Landrace ECF18R genotype distribution had significant differences with Duroc's in the exotic breeds of pig.

Alleles↗
PubMed1981

Hormonal and follicular relationships in ewes of high and low ovulation rates.

Total follicular populations and peripheral plasma concentrations of LH, FSH, prolactin, oestradiol-17 beta and progesterone during the preceding cycle were studied in two breeds of sheep (Romanov and Ile-de-France) which differed widely in their ovulation rates (3.2 and 1.5 respectively). No LH parameters could be correlated with the follicular details measured. The second peak of FSH occurring 20-30 h after the preovulatory surge of LH was significantly larger in the Romanov ewes and the area under this peak was correlated (P less than 0.01) with the number of antral follicles present in the ovary 17 days later. This suggests that formation of the antrum during the follicular growth phase is under the control of FSH. The discharge of prolactin preceding the LH peak, although not significantly different between breeds, was correlated with several of the follicular classes measured, including the number of preantral follicles. The peak value of oestradiol-17 beta measured before the LH peak was significantly higher (P less than 0.05) in the Romanov ewes and was correlated with the number of the largest follicles present. There was no significant difference between breeds in the concentration of oestradiol at the onset of oestrus. The progesterone concentration during the luteal phase was highly correlated with the number of preovulatory follicles.

Animals↗
PubMed1991

The National Sheep Improvement Program: a review.

A nationally organized sheep improvement program for sheep producers in the United States was implemented in 1987 under the name of the National Sheep Improvement Program (NSIP). This program completed a 3-yr Phase I project on February 16, 1990, that involved the definition of a uniform set of performance guidelines, development of an NSIP records processing center with associated performance recording materials and computer software, and the enrollment of both purebred and commercial flocks. Organizers of the NSIP have defined 12 traits of economic importance to the U.S. sheep industry for genetic evaluation: number of lambs born, total ewe productivity, six growth traits, and four wool traits. Genetic evaluations are currently being conducted on a within-flock basis and will move to an across-flock, within-breed basis when sufficient genetic ties between flocks are established. The genetic evaluations use BLUP procedures and provide genetic merit values in the form of expected progeny differences for every animal in a flock.

Animals↗
PubMed2000

Reproductive Effort and Reproductive Values in Periodic Environments.

Life-history theory concerns the optimal spread of reproduction over an organism's life span. In variable environments, there may be extrinsic differences between breeding periods within an organism's life, affecting both offspring and parent and giving rise to intergenerational trade-offs. Such trade-offs are often discussed in terms of reproductive value for parent and offspring. Here, we consider parental life-history optimization in response to varying offspring values of a population regulated by territoriality, where the quality of the environment varies periodically. Periods are interpreted as either within-year (seasonality) or between-years variation (cyclicity). The evolutionarily stable strategy in a general model with two-phased periodicity in the environment can generate either higher or lower effort in the more favorable of the two phases; hence knowing survival prospects of offspring does not suffice for predicting reproductive effort-the future of all descendants and the parent must be tracked. We also apply our method to data on the Ural owl Strix uralensis, a species preying on cyclically fluctuating voles. The observed dynamics are best predicted by assuming delayed reproductive costs and Type II functional response. Accounting for varying offspring values can lead to cases where both reproductive effort and recruitment of offspring are higher in the phase when voles are not maximally abundant, a pattern supported by our data.

Ural owl↗
PubMed1991

Profiles of some clinical chemical parameters in growing dwarf and landrace kids.

Plasma creatinine, urea, bilirubin, glucose, cholesterol, calcium, magnesium, sodium, potassium, inorganic phosphorus and total serum proteins were analyzed in kids of Dwarf and Danish Landrace breeds from birth to 12 months of age. The purpose was to determine the reference ranges, age profiles and the influence of other factors. Comparisons between parametric (mean +/- standard deviation) and the corresponding nonparametric (5th and 95th percentile, median) values were calculated for each parameter, the results of which indicated no apparent differences. The levels were very much dependent on age. Creatinine, urea and total serum protein levels increased gradually with age. Glucose and cholesterol levels were high at birth and then decreased with age. The electrolyte concentrations were maintained within narrow limits. Significant differences were observed between kids of different ages (within the breeds), breeds (within similar age) and herds (within the same age and breed). Differences between female and male Landrace kids of the same ages were observed in plasma urea, creatinine, glucose and total serum proteins. It is concluded that age has a major influence on the clinical chemical reference values in young goats, followed by herd and breed, but the influence of sex was small and is negligible in most parameters.

Animals↗
PubMed2024

Genome-wide scan for selection signatures in Mexican Sardo Negro Zebu cattle.

The Sardo Negro cattle (SN) is the only zebu cattle breed developed in Mexico. Since its development, the selection could have led to an increase in the homozygosity level in some regions of the genome and made differentiation with other cattle populations. We aimed to identify and characterize selection signatures in SN using medium-density SNP data using four approaches: 1) Runs of homozygosity (ROH) 2) Nucleotide Diversity 3) Tajima's D and 4) the Wright's fixation index (FST). A sample of 555 SN animals genotyped for 65k SNPs was used to obtain ROH segments considered regions under selection. The FST values were estimated by comparing the sample of genotyped SN animals with samples of genotyped animals from the Gir, Brahman, and Ongole breeds. Only one region mapped to 35.78-42.51 Mb on BTA6 was considered a selection signature by the ROH method. This selection signature overlapped with the lowest diversity, negative values of Tajima's D and a diversification region between SN and the other Zebu breeds by FST. We found several candidate genes (LCORL, NCAPG, and SLIT2) related to growth and other economically important productive traits in this common region. Using the FST method, different regions, such as regions on BTA8 (8:93.4-93.9 Mb), BTA11 (11:99.2-99.7), and BTA14 (14: 26.1-26.8) related to growth and milk traits also were defined as candidate selection signatures. The selective signals identified in this study reflected the direction of the selection pressure that primarily involves the increase of live weight traits in the Sardo Negro cattle breeding program.

Animals↗
PubMed1991

Concentrations of progestagens and oestrogens in the faeces of pregnant Lipizzan, trotter and thoroughbred mares.

Faecal samples were collected at weekly intervals from pregnant Lipizzan mares during Weeks 7-16 following mating and from Lipizzan, Trotter and Thoroughbred mares during the last 3 months of gestation. After parturition, samples were taken daily from the Thoroughbred mares for another 6 days. Non-pregnant mares served as controls. The concentrations of unconjugated oestrogens (Eg), 20 alpha-OH-progestagens (20 alpha-G) and 20 beta-OH-progestagens (20 beta-G) were measured by enzyme immunoassay. In the faeces of Lipizzan mares, immunoreactive progestagens were significantly (P less than 0.01) elevated above the levels in non-pregnant mares by Week 11, and Eg by Week 13 of pregnancy onwards. During the last 3 months of gestation, concentrations of Eg were significantly higher in Trotter mares than in Lipizzan and Thoroughbred mares. Concentrations of 20 alpha-G and 20 beta-G increased to maximal values in the last month of gestation. There was no significant difference among the 3 breeds with respect to 20 alpha-G but, during the 10 weeks before parturition, concentrations of 20 beta-G in the Lipizzan mares were significantly lower (P less than 0.05) than those in the Thoroughbred mares. They were also significantly lower than those of the Trotter mares during the last 4 weeks of gestation. After parturition, the concentrations of Eg and progestagens had declined to baseline values by Days 3 and 4 respectively. From these results we conclude that high concentrations of progestagens with 20 alpha- and 20 beta-hydroxyl groups are present in the faeces of pregnant mares, especially during the last month of gestation.

Animals↗
PubMed1985

Preliminary studies on the performance and productivity indices of N'Dama and west African shorthorn cattle in Ghana.

The performance of N'Dama and West African Shorthorn cattle in the humid forest zone of Ghana was evaluated using records (1969-1979) on these breeds kept at the UST livestock farm. The mean age at first calving for N'Dama was 32.07 months. Calving intervals of 501.92 and 462.83 days were obtained for N'Dama and West African Shorthorn cattle respectively. The secondary sex ratio for N'Dama calves was not significantly different from the expected theoretical value of 50%; that of the West African Shorthorn was, however, significantly different from the expected theoretical value mainly due to the small size of the population. Average birth weight for the two breeds was not significantly affected by breed, season of birth, weight and age of dam. Sex significantly affected the birth weight of the N'Dama calves. Pre-weaning and post-weaning growth rates of N'Dama male calves were significantly greater than the pre-weaning and post-weaning growth rates of females. For the West African Shorthorn sex did not significantly (P greater than 0.05) affect these traits. Calf mortalities for the two breeds were 10.53% for N'Dama and 21.05% for the West African Shorthorn. Calving percentage was not affected by breed. The productivity indices per cow per year were 72.7 kg for N'Dama and 32.1 kg for the West African Shorthorn. The productivity indices per 100 kg cow maintained per year were 36.8 kg for N'Dama and 16.6 kg for the West African Shorthorn.

Animals↗