The uptake of glycerol, alpha-aminoisobutyric acid and 2-deoxy-D-glucose by spermatozoa of a line of chickens selected for fertility of frozen-thawed semen and a control line.

The uptake of glycerol, alpha-aminoisobutyric acid and 2-deoxy-D-glucose by fowl spermatozoa was each measured in two trials using seventh generation males of a line selected for duration of fertility of frozen-thawed semen and those of a randomly selected control line. The selected line had significantly (P< 0.01) higher fertility of frozen-thawed and fresh semen than the control line. The association between glycerol level in spermatozoa before freezing and the fertility of frozen-thawed semen was examined. Significantly greater amounts (CPM/10(9) cells) of glycerol, alpha-aminoisobutyric acid and 2-deoxy-D-glucose were taken up by the spermatozoa of the selected line than those of the control line at 15, 30 and 60 min of incubation. Rank correlations between the fertility of frozen-thawed semen and glycerol levels were generally positive but low in magnitudes.

The effect of selection for fertility of frozen-thawed semen on spermatozoa oxygen uptake, motility and concentration, and ejaculate volume in the chicken.

The response to 3 generations of selection for duration of fertility of frozen-thawed semen on fertility and hatchability of fresh and frozen-thawed semen, spermatozoa oxygen uptake, motility and concentration, and ejaculate volume was measured in a broiler line of chickens. The selected line, as compared to the control, had significantly higher levels for all fertility traits of frozen-thawed semen but not hatchabilities. For fresh semen, the lines differed only for duration of fertility. The only difference in semen quality traits was in oxygen uptake by spermatozoa of frozen-thawed semen. The differences between lines for the other parameters were not significant but were in a direction that supported the hypothesis that selection had resulted in improved reproductive capacity. All estimates of fertility within an ejaculate were positively correlated (P<0.01). Correlations between corresponding fertility estimates of fresh and frozen-thawed semen were positive, low and generally non-significant. The proportion of variation as determined by stepwise regression, in fertility estimates accounted for by the measurements of oxygen uptake and motility of fresh and frozen-thawed spermatozoa, ejaculate volume and spermatozoa concentration ranged from 12 to 19 percent.

Eight generations of selection for duration of fertility of frozen-thawed semen in the chicken.

The response to eight generations of selection for duration of fertility of frozen-thawed chicken semen, the correlated responses of other fertility parameters of frozen-thawed semen and the fertility of fresh semen, and the heritabilities of frozen-thawed and fresh semen were studied. The selected and control lines were derived from a base meat-type control male population developed at Peel's Poultry Farm Ltd., Port Perry, Ontario. Selection has improved duration of fertility of frozen-thawed semen significantly (P less than .01) with the mean increasing from 1 day in Generation 1 to 5 days in Generation 8 and an average improvement per generation of .29 day since Generation 3. There were significant (P less than .01) correlated increases in percent fertility for 2 to 8 days postinsemination and percent fertility for the duration of fertility of frozen-thawed semen as well as the fertility of fresh semen. Percent hatchability of fertile eggs of frozen-thawed semen did not change. In Generation 8, means and standard errors of fertility parameters of frozen-thawed semen in the selected and control lines, respectively, were: 38.54 +/- 1.39 and 25.58 +/- 1.77 for percent fertility for 2 to 8 days postinsemination, 47.73 +/- 3.54 and 32.02 +/- 2.17 for percent fertility for the duration of fertility, and 78.21 +/- 1.56 and 79.27 +/- 2.53 for percent hatchability of fertile eggs. For fertility of fresh semen, means and standard errors were: 12.69 +/- .20 and 11.54 +/- .42 for duration of fertility, 82.91 +/- 1.45 and 75.71 +/- 2.83 for percent fertility for 2 to 8 days postinsemination, and 71.89 +/- 1.25 and 69.22 +/- 2.06 for percent fertility for the duration of fertility. The means of the heritability estimates of the fertility of frozen-thawed and fresh semen, respectively, ranged from .01 to .31 and -.01 to .21. The realized heritability of duration of fertility of frozen-thawed semen, based on five generations, was .17 +/- .05. The phenotypic correlations of duration of fertility of frozen-thawed semen with percent fertility for 2 to 8 days postinsemination and percent fertility for the duration of fertility of frozen-thawed semen were high and positive and correlations between fertility of frozen-thawed and fresh semen were low but positive.

Fertility of frozen chicken semen after intravaginal and intrauterine inseminations using various concentrations and equilibration times of dimethylsulfoxide and a range of freezing and thawing rates.

The use of dimethyl sulfoxide (DMSO) as a cryoprotective agent for freezing chicken semen was examined with respect to intravaginal (I.V.) and intrauterine(I.U.) inseminations. Semen diluted in DMSO was subjected to various freeze rates, equilibration times and thawing rates. Various concentrations of DMSO were examined as was the effect of diluting DMSO with phosphate buffer and Lake's solution. There was no significant (p greater than 0.05) effect of rate of freeze (ranging from 1.3 degrees C to 7.2 degrees C. per min) on fertility. However, rapid thawing in an ice bath resulted in a longer (p less than 0.05) duration of fertility than thawing at 1 degree C. per min., but had no effect on percent fertility during duration or percent hens fertile. Equilibration time and concentration of DMSO had no significant (p greater than 0.05) effects on fertility. There was no interaction between insemination route and Lake's solution vs. phosphate buffer with respect to duration of fertility. It was concluded that intrauterine (I.U.) insemination resulted in superior fertility to intravaginal (I.V.) inseminations with semen frozen in DMSO.

A note on the lack of difference in fertility between old and young hens when inseminated with frozen semen.

Semen was frozen (in glycerol) from 24 males (9 months of age) of a commercial broiler line and was inseminated intravaginally into old (19 months of age) and young (7 months of age) commercial Leghorn females. Duration of fertility, percent fertility during duration and percent hens fertile were measured. The means for old and young hens respectively, were: duration of fertility (1.4 +/- 0.4 and 1.6 +/- 0.5 days), percent fertility (19.1 +/- 5.1 and 15.9 +/- 5.1) and percent hens fertile (29.2 +/- 7.7 and 25.3 +/- 7.2). The "t" test revealed no significant (P greater than 0.05) differences between old and young females in fertility.

The activity of some peptide hydrolase enzymes in fresh and stored poultry semen from full sib groups of males and their relationship to fertility.

The seminal plasma and sperm of fresh and stored poultry semen were analyzed for the presence of eight peptide hydrolase enzymes. Five enzymes: carboxypeptidase A, carboxypeptidase B, chymotrypsin, glycylglycylglycine hydrolase and pepsin were not present in either plasma or sperm. An aminopeptidase-like and a cathepsin-like activity were found in seminal plasma and sperm while a trypsin-like activity was found in sperm only. There was a significant difference between full sib groups with respect to aminopeptidase-like activity in fresh and stored plasma, while storage for 24 hours resulted in a significant increase in trypsin-like activity of sperm. The aminopeptidase-like activity of fresh sperm was positively correlated with duration and percent fertility of fresh semen, while neither cathepsin-like activity nor trypsin-like activity were correlated with fertility of fresh or stored semen except for a positive correlation between the cathepsin-like activity of fresh plasma and percent fertility of fresh semen.

Comparison of two procedures for freezing semen from cocks of high and low fertility with frozen semen.

Semen samples from groups of males chosen for high or low freezability of semen were frozen by two different methods, one using glycerol as the cryoprotectant and the other using DMSO. Fertilizing capacity was highest from semen collected from males of the high group and frozen in the presence of DMSO. Neither semen source nor method of freezing had any influence on the hatch of fertile eggs.

Effect of four lighting regimes on broiler performance, leg abnormalities and plasma corticoid levels.

The effect of four lighting regimes: (1) continuous light (5 to 10 lux); (2) an intermittent system of 1 hr. of light (5 to 10 lux) and 3 hr. of darkness; (3) an intermittent system of 1 hr. of light (5 to 10 lux) and 3 hr. of darkness interrupted by 13 hr. of regular light (5 to 10 lux); (4) as with (3) but with low intensity light (less than 1 lux) during the 13 hr. period while the intermittent system continued, was studied in 2400 broilers of two commercial crosses over two trials. Lighting regime had a significant effect of body weight in trial 2 with birds on treatments 3 and 4 being lighter than those on treatments 1 and 2 which did not differ. Lighting regime had no significant effect on feed to gain ratio, percent crooked toes or mortality to 8 weeks. Birds grown on continuous light had significantly more leg abnormalities than those grown on any of the intermittent regimes. In trial 1 birds grown on continuous light had significantly higher plasma corticoid levels than those grown on any of the intermittent regimes. The same trend existed in trial 2, except that birds on treatment 3 had the highest plasma corticoid level.

A new dwarf isolate in the chicken: a possible new allele at the dw locus.

A dwarf isolate has been found in the chicken which is due to an allele other than dw at the dw locus. The distribution of offspring from males heterozygous for dwB and the allele responsible for the dwarf isolate was inconclusive with respect to whether they were the same allele or not. However, the results of this mating in conjunction with the appearance of the pure line dwarf isolate birds led the authors to tentatively conclude that the dwarf isolate was not due to dwB but rather to a new allele at the dw locus designated dwM.

Effect of selection for fertility of frozen-thawed semen in chickens on the fertility of fresh and stored semen.

Studies were conducted using 68 males from the seventh generation of a line of meat-type breeder chickens selected for increased duration of fertility of frozen-thawed semen and 69 males of the randomly selected control line. These chickens were used to determine the presence or absence of differences between the selected and control lines with respect to fertility and spermatozoal motility when the semen was subjected to the following preinsemination treatments: 1) frozen in a diluent containing 13.6% glycerol; 2) frozen in a diluent containing 1.7% glycerol; 3) fresh undiluted; 4) fresh diluted; 5) diluted and stored for 24 hr; and 6) diluted and stored for 48 hr. Semen from each male was inseminated into 4 to 6 White Leghorn tester hens per experiment. The effects of genotype (line) by preinsemination semen treatment interaction on fertility and spermatozoal motility were also examined. When semen was frozen (Treatments 1 and 2), the selected line had significantly (P less than .01) higher duration of fertility, percent fertility for 7 days postinsemination, and percent fertility for the duration of fertility and spermatozoal motility than the control line. For fresh semen (Treatments 3 and 4), the selected line had significantly (P less than .01) higher fertility estimates and spermatozoal motility than the control line except for percent fertility for the duration of fertility (P greater than .05) of undiluted semen. For stored semen (Treatments 5 and 6), the selected line only had significantly (P less than .05) higher duration of fertility after 24 hr storage and percent fertility for the duration of fertility after 48 hr storage than the control line.(ABSTRACT TRUNCATED AT 250 WORDS)

Seminal plasma proteins of a line of chickens selected for fertility of frozen-thawed semen and the control line.

The seminal plasma from individual ejaculates of 13 males of a line of chickens selected for increased duration of fertility of frozen-thawed semen for 7 generations and 12 males of the control line were analyzed for proteins. The mean +/- SE total seminal plasma protein of the selected and control lines were 8.74 +/- .55 micrograms and 7.52 +/- .92 micrograms/microliter seminal plasma (P greater than .05). Crossed immunoelectrophoretic analysis of the seminal plasma generated, in general, 11 precipitant peaks in both lines. The protein corresponding to peak 11 of the electrophoretic pattern was significantly (P less than .01) higher in the selected line than in the control line, the mean +/- SE being 1.80 +/- .21 and .85 +/- .19 micrograms/microliter seminal plasma.

Semen production, sperm quality, and their heritabilities as influenced by selection for fertility of frozen-thawed semen in the chicken.

Ejaculate volume, sperm concentration, and sperm number per ejaculate were measured six times from 8 to 15 months of age, and testes and body weight at 15 months of age, on Generation 9 males of a line of broiler breeders selected for fertility of frozen-thawed semen and those of a randombred control line. Sperm quality (percent normal, percent abnormal, and percent dead sperm) was determined on Generation 10 males at 11 months of age. Selection decreased (P less than .01) ejaculate volume and sperm number per ejaculate. The control line had 4.9% more abnormal (P less than .05) sperm than the selected line. The differences between the lines for sperm concentration, testes and body weights, and percent dead sperm were not significant (P greater than .05). The correlation coefficients of fertility of frozen-thawed semen with percent abnormal and percent dead sperm were negative but were positive with percent normal sperm. The heritability and repeatability estimates of ejaculate volume, sperm concentration, and sperm number per ejaculate ranged from .34 to .73 and .33 to .51, respectively.

Ultrastructure of fresh and frozen-thawed spermatozoa of high and low fertility lines of chickens.

Level of damage caused by freezing and thawing to four spermatozoal organelles (individual mitochondrion, midpiece, nucleus, and perforatorium) and the relationships of the integrity of these organelles in fresh and frozen-thawed semen with fertility were examined. Semen sample from 10th generation males of a line of chickens selected for increased duration of fertility of frozen-thawed semen and the corresponding randombred control line were used. In both the selected and control lines, the freeze-thaw process caused significant (P less than .05) detrimental damage to the ultrastructure of the mitochondria, midpiece, and perforatorium but not to the nucleus. Types of damage were identical in both lines. Granulated nuclei were observed in both frozen-thawed and freshly ejaculated spermatozoa and were referred to as a nuclear defect. This nuclear defect was associated with reduced fertility, the effect being more severe with frozen-thawed semen. Where the incidence of the nuclear defect was greater than 2% in frozen-thawed semen, fertility was found to be very low or nil regardless of the degree of structural integrity of the mitochondria, midpiece and perforatorium. Highly significant (P less than .01) positive correlation coefficients were observed for percentage fertility 2 to 8 days postinsemination and duration of fertility in days with percentages of normal mitochondria (.80 and .92), midpiece (.79 and .87), nucleus (.86 and .94), and perforatorium (.84 and .97) for fresh semen. With frozen-thawed semen, the positive correlation coefficients were significant (P less than .05) for midpiece (.64 and .69) and nucleus (.63 and .71) and nonsignificant for mitochondria (.52 and .50) and perforatium (.20 and .30).(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of floor and cage housing of male turkeys on semen production and fertility of fresh and stored semen.

Broiler-type male turkeys housed in individual cages were compared with those housed in litter floor pens with respect to fertility, semen volume, concentration of spermatozoa, body weight, foot abnormality, and mortality. The effect of short-term storage of semen on fertility was also examined. There was no significant difference (P greater than .05) between the fertilities of the males in cages and those on floor when semen was diluted and inseminated fresh (92 vs. 88%) or diluted and stored for 6 hr at 15 (79 vs. 84%) or 3 C (77 vs. 85%). The males in cages produced as much semen as those on floor and with similar concentrations of spermatozoa. Those in cages had significantly (P less than 01) reduced body weight, higher incidence of foot abnormality, and higher percent mortality. Storage of semen for 6 hr reduced fertility.

Artificial insemination of individually caged broiler breeders. II. The relationships of juvenile male traits with subsequent reproductive traits.

The relationship of the reproductive performance and semen characteristics of commerical broiler parent males with their body weight at 6, 8, 10, and 12 weeks of age, keel length, shank length, breast angle at 8 weeks of age, and packed erythrocyte volume at 6 and 8 weeks of age were examined. Phenotype correlations of juvenile traits with subsequent reproductive traits were generally of low magnitude, except for the significant positive correlations of 6- and 8-week body weight with fertility. Positive correlations existed between fertility and semen quality traits which were significant in some cases. Six-week body weight and spermatozoal motility appeared to be the most useful traits in predicting a male's fertility.

Artificial insemination of individually caged broiler breeders. 1. Reproductive performance of males in relation to age and strain of females.

Studies were conducted to evaluate the reproductive capacity of male broiler breeders used for artificial insemination over an extended period and mated to females of six strains. Biweekly determinations were made of semen volume, semen concentration, and spermatozoal motility for each of the 47 males caged individually from their 39th to 63rd week of age. The percent fertility, duration of fertility, and percent hatchability were determined at five-week intervals (periods) using three young and three force-molted broiler female strains. With young female strains, the mean percent fertility for a 7-day collection of eggs following a single insemination (1 to 7 days) ranged from 95.7 to 81.1 over six consecutive periods. The mean duration of fertility (days) and the mean percent hatchability of fertile eggs was 13.3 and 13.0, and 92.5 and 84.9 respectively, for the first two periods. With force-molted hens, the mean percent fertility (1 to 7 days) ranged between 97.2 and 86.0 over the first three periods, and the mean duration of fertility and the mean percent hatchability was 13.2 and 12.8, and 91.5 and 84.1, respectively, for the first two periods. Fertility of eggs collected for 10 days following a single insemination was slightly but consistently lower than fertility over 7 days for both female groups. Significant differences among males and between periods existed for each semen trait. The effects of male, young female strain and period on fertility and duration of fertility were significant. Hatchability was significantly affected by period only. No male by female strain interaction existed for percent fertility or hatchability. A significant male by period interaction existed for percent fertility, semen volume and concentration. The results obtained are considered to support the feasibility of maintaining broiler breeders in cages and the use of artificial insemination (AI) to produce broiler hatching eggs.