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At least 829 records · Page 46Linked to original sources
PubMed2005

Efficiency of rubidium marking in Aedes albopictus (Diptera: Culicidae): preliminary evaluation on persistence of egg labeling, survival, and fecundity of marked female.

Rubidium chloride (RbCl) has been used for the study of vector biology and behavior, although the efficacy of marking, egg production, and survivorship of marked females have been poorly studied. Four concentrations of RbCl were tested, among which 0.025 M was the best for marking Aedes albopictus: more than 80% of egg batches of females fed once with blood containing RbCl were marked; Rb-marked egg batches, interspersed with non marked ones were recovered until 61 days after a blood meal containing RbCl followed by non marked meals; RbCl was essentially detected in the abdomen of marked females, whose egg production and survivorship did not differ from non marked ones, at least in the three weeks following the Rb-marked blood meal.

Aedes↗
PubMed2006

Age-dependent fecundity and fertility life tables of the predator Brontocoris tabidus (Heteroptera: Pentatomidae) under field conditions.

Reproductive potential, longevity, life expectancy, and fertility life tables of Brontocoris tabidus (Signoret) (Heteroptera: Pentatomidae), a predator of lepidopteran defoliators in eucalyptus (Eucalyptus spp.) plantations, were studied in the field. After a 50-d preoviposition period (emergence of adults to the deposition of the first egg mass), ovipositional activity of B. tabidus continued until females died at 160 d. Females laid an average of 4.2 eggs per day and 601.1 eggs in a lifetime. Gross and net reproductive rates were 216.7 and 75.8 females, respectively. Generation time was 146.1 d, the period for doubling the population was 23.4 d, intrinsic rate was 0.03, and finite population increase was 1.03. Number of females per generation increased at 33.4 times. Results from our field studies indicate that B. tabidus has greater potential reproduction, oviposition period, and longevity than was expected from previous laboratory experiments. This suggests that B. tabidus has potential as a biological control agent to limit economically damaging pests in eucalyptus plantations.

Aging↗
PubMed1992

Expression of the genes for alpha inhibin, beta A inhibin and follistatin in the ovaries of Booroola ewes which were homozygotes or non-carriers of the fecundity gene FecB.

Ovine cDNA probes for the alpha and beta A inhibin subunits and for follistatin were used to investigate the mRNA species for these hormones in ovaries obtained during the luteal phase of the oestrous cycle, from Booroola ewes which were homozygous carriers (BB) or non-carriers (++) of the FecB gene. BB ewes had significantly higher concentrations of peripheral FSH and LH immunoreactivity than ++ ewes, but the peripheral inhibin immunoreactivity and ovarian inhibin and progesterone secretion rates were not significantly different between genotypes. No gene-specific differences in the number or size of mRNA transcripts detected by Northern blotting were noted for any of these genes. A single alpha inhibin mRNA species at 1.5 kb was observed in the follicle RNA from ++ and BB ovaries. Low amounts of alpha inhibin hybridization were discerned occasionally in ++ and BB stroma and also in BB, but not in ++, corpora lutea. The beta A inhibin gene was expressed only in the follicles from both ++ and BB ovaries. At least three beta A inhibin transcripts were observed; one at 7.5 kb and at least two between 1.4 and 5.0 kb. The follistatin cDNA probe detected two major transcripts at 2.7 and 1.5 kb and a minor band at 0.5 kb in both follicle and corpora lutea RNA. Densitometry of the Northern blots revealed no significant gene-specific differences in the levels of alpha inhibin and follistatin gene mRNA transcripts.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1982

Oxytocin concentrations in peripheral blood during the oestrous cycle and after ovariectomy in two breeds of sheep with low and high fecundity.

Oxytocin was measured radioimmunologically during the oestrous cycle in six ewes of each of two local Moroccan breeds of sheep. Concentrations in both breeds approached the lower limit of the assay (3 pg/ml) from 2 days before oestrus, throughout heat and ovulation until day 2 of the cycle. Oxytocin concentrations then increased in both breeds, the resulting highest levels on days 5-7 were, on average, between 30 and 60 pg/ml in the D'man sheep and 13-31 pg/ml in the Timhadite breed. Oxytocin levels then decreased to about 7 pg/ml in the D'man and about 4-5 pg/ml in the Timhadite breed on days 14-15. After ovariectomy oxytocin concentrations remained at about the limit of detection for a further 19-20 days in both breeds.

Animals↗
PubMed1992

Classical and mixed-model analysis of an index selection experiment for fecundity in Drosophila melanogaster.

A comparison of three family indices to increase number of pupas from 3-d lay in Drosophila melanogaster is reported. The three indices were Id, based exclusively on dam's information; Ihd, based additionally on dam's full-sibs' and half-sibs' information; and Ihs, which also included the sire's full-sibs' and half-sibs' records. Three lines, D, HD, and HS, were selected, each according to one of the three indices: Id, Ihd, or Ihs. Each line consisted of 10 sires and 60 dams. Each dam contributed one male offspring and three female offspring. Seven generations of selection were performed in a two-replicate experiment. The expected advance of Ihs and Ihd over Id in the seventh generation was .38 and .15 phenotypic standard deviations, respectively. The experiment was analyzed in terms of both classical ordinary least squares (OLS) and mixed-model methodology (MMM). The phenotypic trends in the first replicate were 4.06 +/- 1.74, 1.42 +/- 1.76, and .26 +/- 1.94 pupas per generation for Lines D, HD, and HS, respectively, and in the second replicate 8.52 +/- 2.40, 6.16 +/- 3.21, and 4.21 +/- 2.60, respectively. The genetic trends in the first replicate were 2.18 +/- .61, 1.08 +/- .67, and .24 +/- .68 pupas per generation and, in the second replicate, 2.51 +/- .60, .16 +/- .61, and .05 +/- .64 for Lines D, HD, and HS, respectively. Despite theoretical expectations, the Id index was consistently better than the more complex indices. Several explanations for these results are possible: 1) smaller than expected selection differential, 2) inbreeding depression, and 3) incorrect heritability used to construct the indices.(ABSTRACT TRUNCATED AT 250 WORDS)

Analysis of Variance↗
PubMed1994

Effect of delayed breeding on the endocrinology and fecundity of sows.

The effect of serving sows at first or second estrus after weaning was determined using 114 Camborough sows (Parities 1 to 8). Eighty sows were paired according to weaning-to-estrus interval and parity. One sow of each pair was bred at first and the other at second estrus after weaning. A further 27 sows were catheterized on d 3 after weaning or d 20 of the first estrous cycle and bred at first or second estrus, respectively. Blood samples were taken every 30 min from 0800 to 1330 on the day after catheterization, every 6 h from catheterization until 1 d after standing estrus, and every 12 h for a further 3 d. Of the 80 sows, litter size increased (P < .002) by breeding Parity 1 and 2 sows at second rather than at first estrus (10.4 vs 12.8 total pigs born). These increases in litter size were achieved in the absence of any significant changes in sow weight or backfat during lactation and between weaning and breeding, and predicted changes in fat and protein during lactation. Similar but nonsignificant results (P = .15) were observed for the 27 catheterized sows. Plasma progesterone concentrations measured 50 h after the preovulatory LH surge were higher in Parity 1 and 2 sows bred at second rather than at first estrus (5.4 +/- .7 vs 3.7 +/- .3 ng/mL, P < .04). Sows of Parity 1 and 2 bred at first rather than at second estrus had higher plasma IGF-I (P < .05) and glycerol (P < .001) concentrations and tended to have lower preprandial insulin concentrations (P = .09).(ABSTRACT TRUNCATED AT 250 WORDS)

Animal Nutritional Physiological Phenomena↗
PubMed1980

Fraternity size and swine reproduction. I. Effect on fecundity of gilts.

Data from three generations of a selection experiment with Yorkshire swine were analyzed. Fraternity size was defined as the number of sibs at 2 weeks of age. In one line, potential replacements were reared in fraternity sizes initially set at six, while in the other two lines fraternity size was not altered. Over the period of study, gilts reared in small fratermites (mean = 5.77) averaged 11.30 pigs born, whereas gilts reared in an unaltered fraternity size (mean = 10.06) averaged 10.19 pigs born. Both of these lines had experienced two generations of selection for increased litter size. A randomly selected control line in which fraternity size (mean = 7.80) was not altered averaged 10.77 pigs born. Gilts reared in small fraternities were heavier at 21 days, but there were no significant body weight differences between lines at breeding or farrowing.

Animals↗
PubMed1981

Synchronization of estrus in gilts with allyl trenbolone: fecundity after natural service and insemination with frozen semen.

The synthetic progestogen, allyl trenbolone, was fed daily to 60 gilts at 15 mg/gilt for 18 days. Sixty-eight gilts that came into estrus the same week as treated gilts served as controls. Gilts were checked for estrus twice daily and were artificially inseminated with frozen semen or bred by natural service. All but two treated gilts returned to estrus between 4 and 7 days after withdrawal of allyl trenbolone (mean = 5.6; SD = .82). The farrowing rate among gilts inseminated with frozen semen was significantly lower than that among gilts bred by natural service (52.5 vs 89.6%). The farrowing rate among synchronized gilts was similar to that among untreated gilts (70.7 vs 73.5%). Average total and live litter sizes at birth and litter size at weaning were significantly smaller for untreated gilts inseminated with frozen semen than for synchronized gilts inseminated with frozen semen or those of untreated gilts bred by natural service. Average litter size for synchronized gilts bred by natural service was not significantly larger than that for synchronized gilts inseminated with frozen semen or that of untreated gilts bred by natural service.

Animals↗
PubMed1982

Use of boar spermatozoa for artificial insemination. III. Fecundity of boar spermatozoa stored in Beltsville liquid and Kiev extenders for three days at 18 C.

A field trial was conducted on several hundred farms in The Netherlands to compare the fertilizing capacity of boar spermatozoa stored for 1, 2, or 3 d at 18 C in either Kiev or Beltsville liquid extender (BL-1). Two storage volumes (25 and 100 ml) were used. Twelve Dutch Landrace boars, all in routine commercial artificial insemination service, provided the semen in twice-a-week collections. Over an 8-wk period in March and April, 1979, 2,849 sows and gilts were inseminated. Farrowing rates were higher (P less than .0001) with Kiev extender than with BL-1 extender (69.3 vs 60.5%) when semen was used over a 3 d period. The volume at which the semen was extended and stored had no effect on any parameter. Farrowing rate declined significantly when semen stored at 18 C for more than 2 d was used (74.5% vs 64.7% with semen stored for 1 and 3 in Kiev extender; 65.9% vs 52.7% with semen stored for 1 and 3 d in BL-1 extender). The farrowing rate, total number of pigs/litter and live pigs/litter were significantly higher for sows than for gilts inseminated with similar extended semen. On the basis of the results of this trial, Kiev extender appears to be more suitable as a diluent for liquid semen than does BL-1. AI with semen extended and stored for 3 d at 18 C can be expected to result in a lower farrowing rate than AI with semen stored for 1 or 2 d.

Animals↗
PubMed1994

Reduced longevity and fecundity in Leishmania-infected sand flies.

Phlebotomus papatasi and P. langeroni were infected with Leishmania major and L. infantum by membrane feeding. Each sand fly ingested approximately 200 parasites per blood meal. Higher mortality in both sand fly species was seen with mixed infections than with a single parasite species. There was no significant difference between infections with either L. major or L. infantum in their natural vectors or experimental hosts. Infection significantly depressed the mean number of eggs laid per female.

Animals↗
PubMed2006

[Evaluation of the calcium ionophore induced acrosome reaction: a more realistic approach to the fecundant capacity of the spermatozoid].

OBJECTIVES: The aim of this investigation was to evaluate the acrosome reaction by fluorescence microscopy and the flow citometry in a group of men with unknown fertility. METHODS: Each individual gave a semen sample for the analysis of the calcium ionophore-induced acrosome reaction after the capacitation process, using lectin Pisum sativum aglutinina (fluorescence microscopy) and antibody anti-CD46 (flow citometry). RESULTS: Five of out six individuals increased the number of the sperm with calcium ionophore-induced acrosome reaction versus the percentage of spontaneous acrosome reaction, using fluorescence microscopy (7.4 +/- 2.4 vs 22.5 +/- 10.1) and flow citometry (8.5 +/- 2.8 vs 25.4 +/- 6.0). On the other hand, the other individual the values of the acrosomal reaction with calcium ionophore A23187 were similar to those of the spontaneous reaction. CONCLUSIONS: Both techniques are useful to evaluate the in vitro capacity of the spermatozoa to undergo acrosomal reaction, after the capacitation, without fusion between the sperm and the egg, but the flow citometry is more objective and allow the detection of a higher cell numbers of cells. On the other hand, although the individual that did not respond to the stimulus with calcium ionophore has unknown fertility, the obtained results allow to propose that the evaluation of the acrosomal reaction could be a useful tool in the study of the men who consult for infertility.

Acrosome Reaction↗