Sperm-egg penetration in laying breeder flocks: a technique for the prediction of fertility.

1. An experiment was conducted to evaluate indices of fertility including the sperm penetration (SP) assay as a technique for the prediction of fertility. Forty-eight males consisting of White Leghorn (WL), New Hampshire (NH), Iraqi Brown (IBr) and Iraqi Barred (IBa) (12 males each) and 64 WL hens were divided at random into 4 groups of 4 replicates of 3 males and 4 females each. 2. At the beginning of each week semen was collected from males and pooled by breed of male. Hens in each breeding group were inseminated once weekly, by breeding group, for 4 consecutive weeks with pooled semen from WL, NH, IBr and IBa males (WLxWL, NHxWL, IBrxWL and IBaxWL). 3. The differences in percentage of dead sperm, acrosomal abnormalities, mass motility, individual motility and spermatocrit between the experimental breeds demonstrated the superiority of WL and NH males in all these quantitative characters of the semen. On the other hand, WL hens inseminated with spermatozoa from NH males had significantly more sperm-egg penetration (SP) holes than WL hens inseminated with spermatozoa from other breeds of males. The breed of males used for insemination affected fertility, hatchability and embryonic mortality. 4. The highest fertility and hatchability and lowest embryonic mortality were observed in eggs laid by hens inseminated with spermatozoa from WL and NH males in comparison with hens inseminated with spermatozoa from Iraqi males. 5. There was a strong positive correlation between SP values and fertility for WLxWL, NHxWL, IBrxWL and IBaxWL. The correlation for all breeds combined was also significant. In addition, SP was also positively correlated with hatchability and negatively correlated with embryonic mortality.     

Effect of vaginal douching and different semen extenders on bacterial load and fertility in turkeys

1. A study on artificial insemination of Beltsville Small White turkeys investigated the effect on bacterial load and fertility of vaginal douching with diluents containing Gentamicin 400 microg/ml and different semen extenders. 2. Irrespective of the extenders used, vaginal douching with Gentamicin reduced the microbial load of the vagina with resultant improvement in fertility and hatchability and corresponding reduction in embryonic mortality. 3. Eggs from hens inseminated with semen extended with Beltsville Poultry Semen Extender (BPSE) diluent along with vaginal douching showed a trend towards higher per cent fertility and per cent hatchability of total and fertile eggs set compared to other extenders, though this was non-significant.     

Preservation of fowl semen in liquid nitrogen: Application to breeding programmes

1. A method of freezing semen of individual males was adapted for use under farm conditions using an automated freezing apparatus.

2. An insemination programme to produce high fertility and hatchability with semen which had been deep frozen for 2 months was devised.

3. Over 90% fertile eggs with a 90% hatch of all eggs set was obtained with frozen and thawed semen over a period from the 2nd to the 12th day after the first of four inseminations. The persistency of fertility was also tested and 93, 86.6 and 30.7% of the eggs were fertile during days 2 to 6, 2 to 8 and 9 to 15 after the last insemination.

4. Corresponding with the high fertility rate, chicks were produced by every hen that was inseminated and from every male whose semen was frozen and stored. The implications for future breeding practices of this successful result are discussed.     

Improving the quality of rooster semen frozen in straws by screening the glycerol concentration and freezing rate

ABSTRACT

• 1. This study examined different glycerol concentrations (GC) and freezing rates to improve the quality of rooster spermatozoa frozen in straws, and to determine the effect of varying GC on post-thawed spermatozoa quality, as evaluated by fertility and hatchability.

• 2.The experiment included two tests. In test 1, rooster semen straws containing 2, 4, 6, 8 and 11% glycerol were put in a rack (nine tiers with a 1 cm interval between every two tiers, 1 to 9 cm above liquid nitrogen (LN) source), and gradually frozen. The semen straws located in different tiers experienced different temperatures and freezing rates. The straws were then thawed and live sperm numbers determined. In test 2, rooster semen straws containing 2, 4, 6, 8 and 11% glycerol were put on optimal tiers (identified in test 1) for freezing, and stored at ?196°C. Hens were inseminated with the frozen semen (post-thawed and glycerol removed, about 4.0 × 10⁸ sperm per hen), and eggs incubated.

• 3. The numbers of live sperm in the 11% glycerol group was higher than that in 2, 4 or 6% glycerol group (P < 0.05) for the semen straws on tiers 1 to 9, while that on tiers 1 to 5 was lower than that on tier 6 to 8 (P < 0.05). GC, freezing rate and the interaction between GC and freezing rate had a significant effect on live sperm numbers (P < 0.01). The highest fertility was in the 6% glycerol group and occurred on day 5 after insemination. The lowest fertility occurred in the 2% glycerol group on day 10 after insemination.

• 4. The optimal combination was 11% glycerol in straws located 6 cm above the LN surface (on tier 6). The 6% glycerol group achieved the highest fertility (77.6%), which surpassed that reported in recent years.

     

Quantitation of the fertilising ability of fresh compared with frozen and thawed fowl spermatozoa

The fertilising abilities of freshly-diluted and frozen and thawed fowl semen were compared by inseminating a wide range (0.2 to 1600 X 10(6] of doses of spermatozoa. These data demonstrated that there was a non-linear relationship between numbers of spermatozoa and the probability of fertilisation. It was concluded that a typical fertility trial, which assesses the percentage of fertile eggs laid by groups of hens inseminated with a fixed dose of semen, was inadequate for comparing the quality of semen samples. An alternative fertility trial is described, which involves assessing the numbers of spermatozoa required to fertilize a particular percentage of eggs laid. This modified method showed that the quality of frozen and thawed semen, in terms of its fertilising ability, was reduced to 1.6% of that of fresh semen.     

Early body-weight selection of broiler breeder males in relation to reproductive and growth performance of their offspring

1. The effectiveness of selection of broiler breeder males for body weight at 3 weeks of age on later growth, semen quality and performance of progeny has been tested. 2. Correlation between 3- and 20-week body weights in the breeders was poor but significant. 3. On the basis of 3-week body weight males were divided into heavy birds (mean + 0.5 standard deviation) and all birds. 4. Semen quality was not different between the two groups, but some selection for semen quality was practised within groups. 5. There were no differences in fertility and hatchability of eggs produced from hens artificially inseminated with diluted, stored semen from both groups. 6. There was a small, positive, but non-significant, effect of selection of breeder males on body weight of progeny at 6 weeks of age.     

Intrauterine and intravaginal insemination with frozen canine semen using an extender consisting of orvus ES paste-supplemented egg yolk tris-fructose citrate

Our previous report indicated that addition of Orvus ES Paste (OEP) to the extender of frozen canine semen protected acrosomes and maintained sperm motility after thawing. In this study, artificial insemination (AI) using the frozen semen was carried out. The frozen semen was prepared using egg yolk Tris-fructose citrate, and the final concentrations of glycerol and OEP were 7% (v/v) and 0.75% (v/v), respectively. AI was performed during the optimal mating period predicted from the peripheral plasma progesterone level. In intrauterine insemination (IUI), the bitches were laparotomized and 1 x 10(8) spermatozoa were infused into one of the uterine horns. In insemination of non-OEP supplemented semen, 3 x 10(8) spermatozoa were inseminated. In intravaginal insemination (IVI), 10-40 x 10(8) spermatozoa were inseminated. Conception was obtained in nine of 10 bitches (90.0%) that underwent IUI. The number of newborns was from 1 to 7 (mean 3.6 +/- 0.9). The mean ratio of the number of puppies to the number of ovulations in the inseminated uterine horn was 71.8%. The number of puppies did not exceed the number of ovulation in the inseminated uterine horn. Conception using non-OEP supplemented frozen semen was unsuccessful in all four bitches. In IVI, conception was not obtained in any of the six bitches that received insemination of 10 x 10(8) or 40 x 10(8) spermatozoa, but two of three bitches that received insemination of 20 x 10(8) spermatozoa were fertilized. It was shown that a high conception rate can be obtained by IUI using OEP-supplemented frozen canine semen. Developmenmt of a non-surgical method of IUI and a method of freezing canine sperm applicable to IVI is necessary.     

Fertility and sperm quality of broiler breeder males infected with subgroup J avian leukosis virus

In order to assess the effects of subgroup J avian leukosis virus (ALV-J) on semen quality, broiler breeder males were separated by ALV-J status (ALV-J positive = POS, ALV-J negative = NEG) at 44 wk of age. Of the 249 males originally placed at 1 day of age, 101 (40.6%) died by 43 wk of age. Observations of tumor expression and high mortality suggest that many of the males that died prior to 44 wk of age were infected with ALV-J. From 47 to 56 wk of age, hens were inseminated every third week with 7.5 x 10(7) sperm. Fertility and hatch data were collected by incubating eggs laid during the 2 wk postinsemination (WPI). The number of sperm that penetrated the perivitelline membrane of the ovum was determined from eggs laid on the eighth day postinsemination. Sperm mobility index (SMI) was determined at 58 and 60 wk of age from all males producing semen. Whereas SMI and sperm hole penetration measurements indicated that the sperm quality from treatments POS and NEG were similar, fertility was significantly greater in the POS treatment during the first (89.0% vs. 79.0%) and second WPI (59.3% vs. 45.0%). However, because of numerically higher hatch of fertile from the NEG group, the percentage of hatch of eggs set was similar between groups. These data suggest that ALV-J status of caged males has no influence on sperm quality or hatchability of eggs.     

Selection responses in duration of fertility and its consequences on hatchability in the intergeneric crossbreeding of ducks

1. From 1992 to 2003, selected (S) and control lines (C) of the laying Brown Tsaiya duck (Anas platyrhynchos) were simultaneously maintained under the same standardised conditions of feeding and management. 2. The selection objective was to increase the number of fertile eggs after a single artificial insemination (AI) with pooled Muscovy semen. From generations G1 to G11, 2452 and 2022 female ducks, in S and C lines, respectively, were measured and recorded. In the S line, the percentage selected varied between 20.2 and 34.3% in females and between 7.2 and 20.8% in males. 3. Selection for number of fertile eggs had a correlated effect of increasing the parameter tau of the logistic curves which fitted the daily variations (d 2 to 15) in fertility or hatchability on the basis of eggs set. The differences S-C for the estimates of the times of half maximal fertility and hatchability increased by 0.41 and 0.37 d per generation between G1 and G11, respectively. 4. The highest increases of fertility per day rates after a single AI were observed between d 5 and 11. Moreover, in the selected line, fertility rate was higher than, or equal to, 90% in d 2 from G8. The same tendencies were observed for the changes in the evolution of hatchability on the basis of eggs set. 5. Selection increased fertility and hatchability according to the egg set rates, especially for d 2 to 8 after AI. Hatchability of fertile eggs was not impaired, confirming that selection for one AI per week was possible in this strain of laying ducks.     

Influence of pre-insemination douching and different semen extenders on fertility and hatchability of white Leghorn eggs.

1. White Leghorn hens were artificially inseminated twice weekly with undiluted semen or semen diluted (1:3) in Tris buffer, pH 6.8 or saline solution (9 g NaCl/l); with or without pre-insemination douching of the vagina with a solution of ampicillin. 2. Pre-insemination douching reduced the bacterial load of the vagina, resulting in an improvement in fertility and hatchability, with a proportionate reduction in the embryonic mortality. 3. The fertilising and hatching abilities of saline-diluted semen were comparable with those of undiluted semen. 4. Dilution of semen with Tris buffer significantly reduced fertility, but not hatchability.     

Quantifying sperm egg interaction to assess the breeding efficiency through artificial insemination in guinea fowls

• 1. Guinea fowl hens were inseminated weekly once with two doses of spermatozoa (75 million and 100 million) in two different diluents, Beltsville poultry semen extender (BPSE), and Instruments for Veterinary Medicine (IMV), each with and without pre-insemination vaginal douching. Per cent fertility, hatchability, dead germ, dead in shells along with data on sperm egg interaction and vaginal microbial counts were recorded.

• 2. Artificial insemination had significantly improved the per cent fertility and hatchability compared to natural mating. Dose dependent improvement in fertility was noticed with both diluents.

• 3. There was a beneficial effect of vaginal douching, which was more pronounced at lower insemination doses.

• 4. For optimum fertility and hatchability in guinea fowl, insemination of 75 million spermatozoa diluted in BPSE once in 4 d and 100 million spermatozoa diluted in BPSE or IMV once in 5 d coupled with vaginal douching is recommended.

     

Effect of semen storage time and number of spermatozoa inseminated on the fertility and hatchability of eggs from dwarf broiler breeder hens

Semen from commercial breeder males was diluted two-fold and stored for 6 and 24 h at 2 to 3 degrees C. For each storage period, groups of caged dwarf broiler breeder hens from the same strain were inseminated with 300, 200 or 100 x 10(6) spermatozoa. Three replicates of 15 birds were inseminated per treatment. Control hens were inseminated with 150 x 10(6) fresh, undiluted spermatozoa. Inseminations were performed for 5 consecutive weeks during a first (32 to 36 weeks of age) and for 6 consecutive weeks during a second experimental period (42 to 47 weeks). During weeks 33 to 36 of the first period, only 24 h storage and 100 x 10(6) spermatozoa produced lower (P less than 0.05) hatchability of all eggs set than the control (84.4 compared to 88.6%). During weeks 43 to 47 of the second period, no significant differences between treatments were observed. Embryonic mortality, measured at different periods during incubation, was not affected by the storage time or the number of spermatozoa inseminated.     

Artificial insemination and fertility in turkeys

Large‐type White turkey hens from a flock with a record of low “fertility” (live embryos at 7 to 10 days’ incubation) were distributed randomly into four groups of 50 hens each and were given treatments involving antibiotic and inseminations on a weekly or fortnightly schedule. During the first 5 weeks of the experiment, semen was introduced, via a plastic tube, at least 5 cm. into the oviduct of all birds in each group. Irrespective of the type of treatment, there was a significant rise in “fertility” in all groups. This was sustained for a 4‐week period, with the highest “fertility” occurring in the group inseminated weekly. When shallow insemination was used with two groups, “fertility” over a second 4‐week period was lowest in these two groups. Since percentage infertile eggs could account for the major share of the decline in percentage live embryos, it is postulated that the low live embryo percentage existing previously in the flock resulted from insufficient numbers of spermatozoa being inseminated rather than from a reaction to an unidentified pathogenic agent, as frequently suspected.     

The effect of n‐6/n‐3 fatty acid ratios on broiler breeder performance,hatchability, fatty acid profile and reproduction

This experiment was conducted to study the effect of dietary omega6 (n‐6) to omega3 (n‐3) fatty acid (FA) ratios on performance and reproduction of broiler breeders. In experiment 1, 400 females and 40 males (30 week age) of Ross 308 broiler breeder (20 females and two males in each pen) were randomly assigned to one of the four diets with n‐6/n‐3 FA ratios of 4, 6, 8 and 16 (control). As a measure of hatchability, fertility of eggs and general incubation traits, 1,200 eggs (60 eggs from each pen) were collected and incubated for 21 days and embryo liver and brain fatty acid profile in 14 and 21 days were determined. In experiment 2, 48 males (three males in each pen) randomly assigned to one of the four diets with n‐6/n‐3 FA ratios of 4, 6, 8 and 16 (control). Semen was collected twice weekly, and semen volume, spermatozoa concentration and motility and alive and dead spermatozoa were estimated. Egg production and egg mass were decreased by n‐6/n‐3 FA ratios of 4:1 and 6:1 (p < .05). There were no significant differences between treatments on breeder's body weight, eggs fertility and hatchability, embryonic mortality and semen features. Linolenic acid, eicosapentaenoic acid, docosahexaenoic acid and total n‐3 of egg yolk, semen, testis and liver and brain of embryo and day‐old chicken were increased while concentration of linoleic acid, arachidonic acid and docosatetraenoic acid of mentioned tissues were decreased by increasing n‐6/n‐3 FA ratios (p > .05). In conclusion, absolute amount of n‐3 and n‐6 FAs in broiler breeder diet may be more important than n‐6/n‐3 FA ratios and to consider reproductive and performance traits of breeders, it is necessary to supply higher levels of n‐3 and n‐6 FA with respect to n‐6/n‐3 FA ratios.     

Relationship of the number of spermatozoa inseminated to fertility of turkey semen stored 6 h at 5 degrees C

The relationship was investigated between turkey hen fertility and the total number and the number of viable spermatozoa inseminated, after semen storage for 6 h at 5 degrees C. The minimum numbers of total and viable spermatozoa necessary for high fertility during the first 15 weeks of production were respectively 175 and 150 X 10(6) weekly. The number of viable spermatozoa produced by breeding males decreased with age. Adjusting the insemination dose of viable spermatozoa weekly over 15 weeks resulted in a consistent high rate of fertility.     

Dam and Sire Effects on Sperm Penetration of the Perivitelline Layer of Eggs Produced by Two Strains of Commercial Turkeys

The reproductive performance of 2 commercial turkey breeder lines was examined using reciprocal crosses between sires and dams of each line. One line had been selected using artificial inseminations performed at biweekly intervals, whereas the second line had been selected using inseminations performed at weekly intervals. The hypothesis was proposed that sires and dams of the 2 lines differ because of different abilities for sperm to penetrate the inner perivitelline layer (IPVL) and fertilize eggs.Fertilized eggs to hatch poults for the experiment were obtained from the primary breeders and were incubated using conditions recommended by the industry. Hens (n = 72) and toms (n = 15) from each strain were identified and reared in preparation for a reproductive cycle using commercially accepted standards. Beginning just prior to the onset of egg production and at weekly intervals thereafter, half of the hens were inseminated with semen from males of the same line, whereas the remaining half received semen from the opposite line. Eggs were collected from the pens daily and set in incubators to determine fertility and embryo survival. At biweekly intervals 3 eggs per pen were used for counting sperm penetration holes in the IPVL. Data were collected for fertility, hatchability, and time that embryos died for each of the pens. Dam and sire affected IPVL penetration independently. A dam by sire interaction influenced fertility, whereas hatchability was affected only by dam. Thus, it is concluded that selection of dam and sires for commercial breeders alters IPVL sperm penetration ability of hens as well as egg-binding ability of sires.     

An exploration of Cryoprotective compounds for fowl spermatozoa

1. Glycerol is an effective cryoprotective for fowl spermatozoa, but after thawing the frozen semen it must be reduced in concentration from the level adequate to protect spermatozoa during freezing, otherwise it has a contraceptive action.

2. A series of alternative cryoprotective compounds were tested for their effect on fertility when fowl spermatozoa were inseminated fresh in their presence. Under these circumstances dimethylsulphoxide, dimethylaceta‐mide, ethane‐diol, propane‐diol and methylpyrrolidone did not depress fertility when used in concentrations equivalent to that of glycerol or in amounts reported previously to be non‐toxic and adequate to protect cells during freezing.

3. Dimethylacetamide was compared with propane‐diol for use in freezing fowl semen and the former enabled encouraging levels of fertility to be obtained.     

Artificial insemination of Bobwhite quail

The purpose of this study was to determine whether fertilisation of Bobwhite quail could be secured by artificial insemination. After this proved to be feasible, the period between insemination and the onset of laying fertile eggs, the time during which fertile eggs were laid and levels of fertility and hatchability of eggs obtained from hens inseminated at weekly intervals over an extended period of time were determined.

Semen was collected from Bobwhite quail males by simultaneously applying pressure to both the left and right sides of the vent without prior stimulation. Upon collection, the semen was diluted with 0.9 per cent saline solution to prevent dehydration. Semen volume measurements were made with a tuberculin syringe to which was attached a piece of graduated, fine‐bore plastic tubing. Females were artificially inseminated by placing the diluted semen in the posterior opening of the everted oviduct.

Mean duration of fertility of the eggs from six trials, two of which utilised only a single insemination, one of which was the final insemination of a series of weekly inseminations and three of which utilised two inseminations within a period of 24 hr, was 9.3 days. Percentage fertility of eggs improved considerably after the first trial probably due to improvement of technique and gain in experience. Average fertility of eggs for the six trials was 64–9 per cent.

The average time interval between insemination and the appearance of the first fertile egg was 3.4 days. Peak fertility was reached by the fourth day following insemination.

Fertility of eggs averaged 62.2 ±3.5 per cent and their hatchability averaged 77.2 ±1.4 per cent over a period of 31 weekly inseminations. These values were comparable to 60.2 per cent fertility and 78.9 per cent hatchability which were obtained from natural matings.     

Influence of chicken native breeds on some physical and biochemical characteristics and short-term storage of semen

1. The major objective of this study was to examine the influence of 24-h storage of semen at low temperature on semen characteristics and fertilising ability of spermatozoa in two native breeds (Kadaknath-KN, Aseel Peela-AP) and White Leghorn (WL) chicken. 2. Various physical and biochemical properties of freshly ejaculated semen of KN and AP were investigated. Fertility was examined in freshly-ejaculated as well as 24-h-stored (3°C) semen diluted (1:3) with Beltsville Poultry Semen Extender. 3. No significant difference was observed in sperm motility among the different breeds whereas live counts were higher in WL than the native breeds. Body weight, semen volume and sperm concentration were highest in AP, followed by KN and WL. A similar trend was observed in the percentage of dead and morphologically-abnormal spermatozoa. 4. The activity of acid and alkaline phosphatase in seminal plasma were higher in WL than KN, whereas the opposite trend was recorded for glutamic oxaloacetic and pyruvic transaminases. The cholesterol content of semen was highest in AP, followed by KN and WL. Cholesterol was much lower in seminal plasma compared with whole semen but there were no differences between breeds. Mean values of the methylene blue reduction time test were higher in WL than in the native breeds. 5. Fertility and hatchability, using freshly-diluted semen, were poorer in the native breeds than in WL. The pattern of fertility deteriorated further, especially in native fowls, when the birds were inseminated with 24-h-stored semen. 6. In conclusion, variation in physical and biochemical characteristics of semen in native breeds compared to WL correlated with poor fertility after short-term storage of semen.     

Fertility and hatchability results with fowl spermatozoa stored in fresh and freeze-dried diluent

Semen obtained from Rhode Island Red males was stored for 3 and 24 h in fresh and freeze‐dried diluent. Fertility and hatchability of eggs laid from the 2nd to 8th d inclusive after a single insemination was tested with hens of proven fertility. The fertilising power of diluted semen after storage did not differ significantly from the undiluted control, but the hatchability of the fertile eggs was significantly reduced after 24 h storage in the freeze‐dried diluent.