QTL affecting conformation traits in Angora goats

A genomic screen for quantitative trait loci (QTL) affecting conformation traits was performed by genotyping 288 Angora goats offspring from 8 half-sub families with 76 microsatellite markers. The following traits were recorded: weaning weight (WW, Kg); stature (S, cm); chest depth (CD, cm); shoulder width (SW, cm); rump length (RL, cm); rump width (RW, cm); head length (HL, cm); head width (HW, cm); shin circumference (SC, cm); chest circumference (CC, cm) and body length (BL, cm). Data were analyzed using the QTL Express program. A total of 5 QTL were detected in five chromosomes with chromosome wide significance level. For the 11 analysed traits the results were: evidence of two possible QTL for HL were found in chromosomes 1 and 4, a putative QTL for trait CD was found in chromosome 2, evidence for BL was found in chromosome 8 and a possible QTL was found for trait CC in chromosome 9. The results reported here show the existence of chromosomal regions in Angora goats involved in conformation traits and represent the first in depth search in some specific-genome sections in order to identify and characterize the genetic variability involved in these traits.     

QTL affecting fleece traits in Angora goats

With the aim to detect chromosome segment (quantitative traits loci, QTL) affecting fleece traits in Angora goats, a genome scan using 76 microsatellite markers spanning 1261 cM on 21 chromosomes was conducted. Eight paternal half-sib families were used, which included a total of 288 kids from a dispersed nucleus herd.Mid-side mohair samples were taken from kids at 4 months of age and eight phenotypic fleece traits were measured.We found putatives QTL for coefficient of variation of average fiber diameter (CVAFD) in chromosome 1 and 13, for kemp fiber (KEMP) in chromosome 5 and for discontinuous medullated fibers (DISC) and staple length (SL) in chromosome 2.These results demonstrate the segregation of quantitative traits involved in mohair production. Further studies will concentrate on these regions to characterize the variation of these QTL.     

Superovulation treatments and embryo transfer in Angora goats

A high incidence of early luteal regression after PMSG superovulation was associated with low recovery of embryos from reproductive tracts of Angora goats flushed later than Day 5 after onset of oestrus. Embryos were successfully recovered (mean 7.9/female) by flushing on Days 2-5. Mean ovulation rate after an FSH regimen (16.1 +/- 0.8) was significantly higher than that after a single injection of PMSG (10.8 +/- 1.2). Fertilization rate and survival of embryos following transfer to naturally synchronized recipient feral goats did not differ between the two gonadotrophin regimens: the mean number of kids born to 47 donors treated with FSH (7.5 +/- 0.6) was significantly greater than that to 28 donors treated with PMSG (4.8 +/- 0.6). Irrespective of hormonal treatment, the numbers of embryos recovered and of kids born were correlated with ovulation rate (r = 0.82, P less than 0.001 for both). Embryo survival was influenced by ovulation rate in recipients, with 52%, 63% and 75% of transferred embryos being carried to term by recipients with 1,2 and 3 CL, respectively (P less than 0.01). More embryos survived (65%) when 2 embryos were transferred to each recipient than when 1 (51%) or 3 (48%) were transferred. In recipients receiving 2 embryos, survival was significantly improved by transfer of both embryos to the same oviduct (70%) than when one was transferred to each oviduct (62%). The percentage survival of embryos was optimal when oestrus of recipients was synchronized within +/- 1 day of oestrus in donors.     

QTL for mohair traits in South African Angora goats

The aim of this study was to identify QTL associated with mohair production and quality traits in South African Angora goats. Limited research has been performed on QTL influencing the economically important mohair traits of Angora goats. Twelve half-sib Angora goat families with an average of 58 offspring per sire were genotyped for 88 microsatellites covering 22 autosomes. Phenotypic data was collected at second and third shearing for males and females respectively. A linkage analysis was performed under the half-sib model using the least squared regression approach of GridQTL. Three putative QTL were detected for fleece weight on CHI 2, 5 and 24, which corresponds with the locations of keratin and keratin-associated proteins. This study detected two putative QTL associated with mohair fibre diameter (on CHI 4 and 24, respectively), which is the most important price-determining trait. Four QTL were detected on CHI 8, 13, 18 and 20 which influence both comfort factor and spinning fineness. The variance explained by the QTL ranged between 6.9% for fibre diameter and 33.6% for standard deviation along the length of the staple. These results reveal segregation of QTL influencing mohair production and quality, and contribute to the understanding of the genetic variation of mohair traits.     

Inheritance of beta-mannosidosis in goats

Plasma levels of beta-mannosidase activity were measured in the phenotypically normal members of a family of goats in which 12 cases of beta-mannosidosis have been reported. Normal or carrier genotypes were assigned on the basis of these results, and mating tables drawn up. Similar data were collected on a number of other small families unrelated to the one with beta-mannosidosis. The results indicate that the plasma beta-mannosidase level is a reasonably good indicator of carrier status and confirm that the disease beta-mannosidosis is inherited in a recessive manner and is not X-linked.     

Cerebrospinal nematodiasis caused by Parelaphostrongylus tenuis in Angora goats in Texas.

A natural infection of meningeal worm (Parelaphostrongylus tenuis) accounted for the death of 11 of 17 (65%) Angora goats in a study in South Texas during 1975. Clinical signs, gross pathology and histopathology in Angoras were similar to other abnormal hosts.     

Inheritance of seed color in Capsicum

The mode of seed color inheritance in Capsicum was studied via an interspecific hybridization between C. pubescens Ruiz and Pav. (black seed color) and C. eximium Hunz. (yellow seed color). Black seed color was dominant over yellow seed color. The F(2) segregation pattern showed continuous variation. The generation means analysis indicated the presence of a significant effect of additive [d], dominance [h], and additive x additive [i] interaction for seed color inheritance. The estimate for a minimum number of effective factors (genes) involved in seed color inheritance was approximately 3.     

Inheritance of flower color in chickpea

Flower color is a useful morphological marker in chickpea (Cicer arietinum L.). Inheritance of this trait was studied using two white-flowered chickpea genotypes, P 9623 and RS 11, and one blue-flowered genotype, T 39-1. The genetic constitutions of the white flower colors of P 9623 and RS 11 were different, for in an earlier study their F1 produced pink flowers. The two F1s of the crosses P 9623 x T 39-1 and RS 11 x T 39-1 also produced pink flowers. Each of the two F2 populations segregated in 9 pink:3 blue:4 white-flowered plants. These results can be explained by a three-gene model. These three independently segregating genes are probably the same as C, B, and P reported in the literature earlier. Allelic tests could not be undertaken, as the genetic stocks used in the earlier studies are not available. The genetic constitutions of the three parents and their F1s are proposed. These accessions should be useful for conducting allelic tests for determining flower color loci in chickpea and for comparative studies with field pea. The seeds of these genetic stocks are maintained at the Genetic Resources and Enhancement Program at ICRISAT and are available for research purposes on request.     

Inheritance of β-mannosidosis in goats

Summary. Plasma levels of β-mannosidase activity were measured in the phenotypically normal members of a family of goats in which 12 cases of β-mannosidosis have been reported. Normal or carrier genotypes were assigned on the basis of these results, and mating tables drawn up. Similar data were collected on a number of other small families unrelated to the one with β-mannosidosis. The results indicate that the plasma β-mannosidase level is a reasonably good indicator of carrier status and confirm that the disease β-mannosidosis is inherited in a recessive manner and is not X-linked.     

Genetic parameters for physical and quality traits of mohair in South African Angora goats

The continuous evaluation and genetic improvement of fleece traits in Angora goats are of major importance to the Angora goat industry. The objective of this study was to estimate variance components and genetic parameters for both physical and quality traits of mohair in South African Angora goats. The data used for this study were collected on between 898 and 6211 kids (depending on the trait measured) born between 2000 and 2006 in 11 different Angora goat studs. Variance components and genetic parameters were estimated with the ASREML programme for fleece weight, fibre diameter, coefficient of variation of fibre diameter, standard deviation of fibre diameter, comfort factor, spinning/effective fineness and standard deviation of fibre diameter along the length of the staple. Most of these traits (excluding fleece weight) are measured using OFDA technology exclusively, and this study was the first attempt to calculate genetic parameters for these traits in South Africa. A model including the direct additive genetic effects only, were the most appropriate for estimation of all parameters. Heritability estimates were 0.24 ± 0.03 for fleece weight, 0.45 ± 0.03 for fibre diameter, 0.37 ± 0.10 for coefficient of variation of fibre diameter, 0.32 ± 0.11 for standard deviation of fibre diameter, 0.63 ± 0.10 for comfort factor, 0.61 ± 0.10 for spinning/effective fineness and 0.14 ± 0.08 for standard deviation of fibre diameter along the length of the staple. Results from this study can now be applied for the estimation of breeding values for fleece production of South African Angora goats and in incorporation into selection programs.     

Inheritance of the red color in tilapias

The inheritance of the red color was studied in two different varieties of tilapia which are both considered as hybrids of Oreochromis mossambicus. Crosses between red tilapia from the Philippines (PRT) and Sarotherodon galilaeus, or Oreochromis aureus gave a 1:1 ratio of red: normal and crosses between F₁ black fish gave only black offspring. On the other hand crosses between the F₁ red fish gave a 3:1 ratio of red:black and crosses between F₁ red and black offspring gave a 1:1 ratio. These results lead to the conclusion that red color is dominant over the normal black color and controlled by a single autosomal gene (R). A unique phenotype named albino with black eyes was observed among offspring of PRT and a presumed model of inheritance of this trait is proposed. Genetic analysis of a second variety of red tilapia (derived from an unknown origin) showed the following results: crosses between parents and between their F₁ offspring consistently gave 100% red fish and crosses between this red tilapia and Oreochromis aureus gave 100% black offspring. The crosses between red and black F₁ of these last two crosses gave a 1:1 ratio and crosses carried out between the black F₁ offspring gave a 1:3 ratio of red:black. It may be concluded from these results that the black color is dominant in this strain and that this color is controlled by a single autosomal gene (B). The presumed mode of action of the dominant gene (R) as well as of the recessive gene (b) are discussed.     

The effects of different PMSG doses on estrus behavior and pregnancy rate in Angora goats

Artificial insemination protocols depend on efficient behavioral estrus detection and insemination time in Angora goat. Therefore, we aim to determine the accuracy of an estrus scoring system in Angora goats with different PMSG doses during the breeding season. Does (n: 260) were randomly divided into three groups: group-1 (n: 93), group-2 (n: 85) and group-3 (n: 82). All animals received an intravaginal sponge on day 0 for 11 days, and on the day of sponge insertion 150 μg prostaglandin F2Α was administered. Pregnant mare’s serum gonadotropin was injected 300, 400 and 500 IU intramuscularly 24 h before sponge removal to groups 1, 2 and 3, respectively. Estrus signs were detected with a teaser buck, 24 h after sponge removal according to a visual scoring system. Artificial insemination was performed with 0.25 ml fresh diluted semen at 43 to 45 h after sponge removal. Differences were observed within PMSG groups in terms of standing, tail wagging, courtship behavior, vaginal discharge and vaginal hyperemia (P<0.001). Nevertheless, the most accurate indicators of estrus that result in pregnancy were tail wagging and courtship behavior followed by standing estrus (P<0.05). According to the results obtained, 300 IU PMSG dose is sufficient, both to inseminate at a fixed time (43 to 45 h after sponge removal) and to record the estrus behavior by teaser male 24 h after sponge removal. Higher PMSG doses (400 to 500 IU) altered the timing of ovulation; specifically, 500 IU dose shortened the duration of estrus behaviors. In conclusion, even though the different doses of PMSG displayed similar effects on estrus synchronization and pregnancy rates, we concluded that tail wagging, courtship behavior and standing heat are the most reliable estrus signs for artificial insemination in Angora goat.     

Inheritance of color and horns in blue-gray cattle

Ohne Zusammenfassung     

Red cell enzymes--V. Enzyme activities in the red blood cells of Saanen and Angora goats.

1. Activities of several enzymes associated with glucose metabolism were measured in the red blood cells of Saanen and Angora breed of goat. 2. No significant breed differences were observed in any enzyme activity.     

The relationship between permanent incisor wear and mohair production and attributes in grazing adult Angora goats

We aimed to quantify if and to what extent permanent incisor wear affected mohair production in adult Angora castrate goats. The goats were grazed on annual temperate pastures for 6 years. During their sixth year mohair was harvested every 6 months and liveweight measured. Incisors were inspected at age 6 years and the amount and pattern of wear quantified. Restricted maximum likelihood (REML) base models were developed to account for background sources of variation. Once a base model had been selected for each fleece attribute, an extra term for the linear effect of the first and other permanent incisor wear were added to the model. During the year mean liveweight, greasy mohair production, clean mohair production and mean fibre diameter were (S.D.): 55.6 (5.85) kg, 4.97 (1.00) kg, 4.16 (0.87) kg, 34.8 (4.02) μm. Mean wear on permanent first incisors was 9% (range 0–30%). There was little wear on other permanent incisors. Greasy fleece weight, clean fleece weight, staple length and fleece entanglement were reduced significantly with increased wear of first permanent incisors. There were no significant effects of incisor wear detected for nine other fleece attributes or liveweight. The results indicate that 30% wear of the permanent first incisors reduced greasy fleece production by 20% and reduced clean fleece production by 30%. Given the magnitude of the effects detected it is clear that relatively small amounts of wear of permanent incisors in adult Angora goats reduce production of mohair and consequently will reduce financial returns from mohair sales. The clear implication is that managers of mohair producing enterprises should assess the incisors of adult Angora goats and use this information in determining which animals to cull from their flocks.     

Inheritance of the harlequin color in Great Dane dogs

The harlequin color pattern of Great Dane dogs differs from merle in that the background is white instead of blue. Harlequin by harlequin matings produced 60 black, 77 harlequin, 42 merle, and 35 homozygous merle pups. Harlequin by black matings produced 44 black, 26 harlequin, 25 merle, and one white (homozygous merle?) pups. All harlequins produced some merles. These data best fit the hypothesis that harlequin is a modification of merle (Mm) caused by an autosomal dominant mutation that is lethal to homozygotes, and to about half of heterozygotes when combined with the MM genotype. The symbol H is proposed for this mutation.