Effect of cooling rate on the survival of cryopreserved rooster sperm: Comparison of different distances in the vapor above the surface of the liquid nitrogen.

The aim of the present trial was to study the effect of different freezing rates on the survival of cryopreserved rooster semen packaged in straws. Slow and fast freezing rates were obtained keeping straws at different distances in the vapor above the surface of the nitrogen during freezing. Adult Lohmann roosters (n=27) were used. Two experiments were conducted. In Experiment 1, semen was packaged in straws and frozen comparing the distances of 1, 3 and 5cm in nitrogen vapor above the surface of the liquid nitrogen. In Experiment 2, the distances of 3, 7 and 10cm above the surfaces of the liquid nitrogen were compared. Sperm viability, motility and progressive motility and the kinetic variables were assessed in fresh and cryopreserved semen samples. The recovery rates after freezing/thawing were also calculated. In Experiment 1, there were no significant differences among treatments for all semen quality variables. In Experiment 2, the percentage of viable (46%) and motile (22%) sperm in cryopreserved semen was greater when semen was placed 3cm compared with 7 and 10cm in the vapor above the surface of the liquid nitrogen. The recovery rate of progressive motile sperm after thawing was also greater when semen was stored 3cm in the vapor above the surface of the liquid nitrogen. More rapid freezing rates are required to improve the survival of rooster sperm after cryopreservation and a range of distances from 1 to 5cm in nitrogen vapor above the surface of the liquid nitrogen is recommended for optimal sperm viability.

Egg quality and productive performance of laying hens fed different levels of skimmed milk powder added to a diet containing Lactobacillus acidophilus.

The current trial was carried out on a commercial poultry farm to study the effect of skim milk powder (SMP) added to a diet containing Lactobacillus acidophilus on performance and egg quality of laying hens from 20 to 49 wk of age. A total of 2,400 Hy-Line W-36 laying hens were housed in 600 unenriched cages (4 hens each) located over 4 tier levels. Animals were assigned to 1 of 3 experimental treatments (0, 3, and 4). The laying hens assigned to treatments 3 and 4 received a diet enriched respectively with 3 and 4% SMP, whereas the animals in treatment 0 were fed a diet without SMP. All diets, moreover, were supplemented with L. acidophilus D2/CSL. Hen performance was determined throughout the experimental period and egg quality was measured on 30 eggs per treatment every week. Results showed that productive performance in terms of egg production, egg weight, and feed conversion ratio was not influenced by SMP at 3 or 4% of the diet. Egg quality was significantly affected by SMP included at 3 or 4% of the diet. Eggs from treatments 3 and 4, in fact, displayed higher shell thickness than those from treatment 0 (P < 0.0001). Likewise, specific gravity, Haugh unit, and shell percentage were significantly affected by the addition of SMP. In conclusion, in our study, SMP added to a diet containing L. acidophilus had no significant effects on the productive parameters of hens during the laying period, whereas significant improvements were found in certain egg quality characteristics.

Egg related parameters affecting fertility and hatchability in the Italian bantam breed Mericanel della Brianza.

Local chicken breeds are a vital reservoir of gene resources and their conservation has a technical role related to the future development of the productive system, as well as a social-cultural role. The aim of this study was to evaluate the effects of egg weight, egg storage period and egg weight loss on hatchability of fertile eggs in the Italian bantam breed Mericanel della Brianza. Fourteen females and eight males were kept in floor pens and divided in 8 families (1M:1 or 2F) during the reproductive season (March-June). Birds received a photoperiod of 14L:10D and were fed ad libitum. Egg production and egg weight were recorded daily. Eggs were divided in 4 weight groups: EW1 =< 33 g, EW2 = 33-36 g, EW3 = 36-39 g and EW4 =≥ 39 g. Eggs were stored at 18 °C and classified in 3 egg storage groups: ES1 = 0-4, ES2 = 5-9 and ES3 = 10-15 days. Egg weight loss was recorded and distributed in 5 different classes: EWL1 =< 10%, EWL2 = 10-15%, EWL3 = 16-20%, EWL4 = 21-25%, EWL5 => 25%. Fertility, embryo mortality and hatchability were recorded. The mean values during the reproductive season were 82% fertility and 50% hatchability of fertile eggs. The best combination of fertility and hatchability values were recorded in EW2 and lower fertility was recorded in EW1 (P < 0.05). Hatchability decreased under 50% after 10 day storage period before incubation and the best hatchability was recorded in EWL1. The present results contribute to the knowledge on reproductive parameters necessary to improve the reproductive efficiency of this Italian breed within a conservation plan.

Effect of lycopene on semen quality, fertility and native immunity of broiler breeder.

1. The effect of drinking water supplementation with lycopene on the semen quality, fertility and immunity of broiler breeders was evaluated. 2. Broiler breeder males were individually caged from 25 to 42 weeks old and divided into two group: L group, treated birds (lycopene 0.5 g/l) and C group, control birds. Laying hens were divided into two groups and artificially inseminated. 3. Semen variables were evaluated and daily fertility recorded. Serum bactericidal activity was tested. 4. Semen production and viability were affected by lycopene supplementation. Serum bactericidal activity was better in L than in C group. The fertility rate curve of the L group displayed a positive trend.

Effect of restricted and ad libitum feeding on semen production and fertility in broiler breeder males.

1. The effect of food restriction on the quality of semen production and fertility in broiler breeder males was studied. 2. Seventy-two Ross broiler breeder males, from 20 to 54 weeks of age, were divided into 4 groups and fed as follows: group 1 = 110 g/bird/d; group 2 = 120 g/bird/d; group 3 = 130 g/bird/d; group 4 = ad libitum. 3. Body weight, sperm quality (volume, concentration, % motility and % live cells) and fertility were measured. The birds were slaughtered at 55 weeks of age; the abdominal fat pad and testicles were weighted. 4. Groups 2 and 3 produced the highest volume of semen. The quality of semen was very similar in all the restricted groups. 5. Males fed ad libitum produced semen with the best motility and percentage of live cells. Groups 3 and 4 showed the best fertility percentage (79%) against group 1 and 2 (59 and 72% respectively).

Heritabilities and genetic correlations of conformation and plumage characteristics in pheasant (Phasianus colchicus).

Data were obtained from 588 pedigreed pheasants of an unselected population. Body weight, shank length (SL), plumage measurements, and plumage score were analyzed to estimate heritabilities and genetic and phenotypic correlations. All measurements were made at 28 and 120 d of age. The h2 estimates (sire component) were the following: .27 and .30 for BW at 28 (BW28) and at 120 d (BW120), respectively; .34 and .79 for SL at 28 (SL28) and at 120 d (SL120), respectively; .30 and .13 for rectrices length (RL) at 28 (RL28) and at 120 d (RL120), respectively; .14 for primary remex at 28 d (PR); .21 for primary remex 1 at 28 d (PR1); .23 for secondary remiges length (SRL); .34 for body weight gain (BWG); .35 for shank length gain (SLG). Negative genetic correlations between BW and SL with plumage traits at 120 d were found. The magnitude of heritability indicates that selection for BW is possible but the negative association with plumage traits must be carefully considered. The improvement of housing conditions could lead to birds with a well-developed plumage, because environment influenced variability of plumage traits.

Evaluation of pheasant semen production during the reproductive season.

The aim of this research was to evaluate the quality and quantity of semen production of pheasants during the reproductive season. Fifty-five male pheasants (Phasianus colchicus mongolicus) were used from 37-59 weeks of age. Semen samples were collected manually on a biweekly basis. At 45 weeks of age, pheasants which had never produced (n = 22) or only produced occasionally (n = 7) were discarded from the study. The volume of the ejaculate from each male was measured upon each semen collection. Sperm concentration and motility were measured for every semen collection from the 41st week of age. Body weight was recorded at 38 and 39 weeks and then every 2 weeks. The largest percentage (55%) of males producing semen was reached at 44 weeks of age. Semen variables showed the following mean values during the reproductive season: volume = 105 mg, concentration = 5.86 x 10(9)/ml, and motility scale = 2.45 (modest-good). Semen variables were significantly influenced by bird and age but not by day of collection.