F. G. Silversides

Production performance and egg quality of four strains of laying hens kept in conventional cages and floor pens

Production performance and egg quality were compared between 4 strains of beak-trimmed layers: 3 commercial strains-Lohmann White (LW), H&N White (HN), Lohmann Brown (LB)-and a noncommercial cross between Rhode Island Red (male) and Barred Plymouth Rock (female) in conventional cages and in floor pens. All chicks were reared and 857 pullets were housed at 18 wk of age in their respective environments. Body weight, hen-day egg production, feed consumption and efficiency, and egg quality were measured at wk 20, 30, 40, and 50. In floor pens, the location of eggs was recorded for 4 consecutive days at 4-wk intervals between 20 and 50 wk of age. Eggs from cages, nest-boxes, and the floor were tested for Escherichia coli and coliform contamination at 38 and 42 wk of age. Mortality was recorded during the rearing and laying periods. Housing systems significantly influenced BW and mortality but not feed consumption or feed efficiency. The interaction between environment and strain was significant for hen-day egg production at wk 20 to 30 and for BW at wk 30, 40, and 50. Hens in floor pens had greater BW, egg and yolk weights, and yolk color than those in cages. Commercial hens produced more eggs than the cross hens. Overall, HN hens had the best production performance, whereas cross hens had better egg quality. In floor pens, LW and HN hens laid most of their eggs in nest boxes, whereas LB and cross hens laid half of their eggs on the floor. Eggs from cages had lower E. coli and coliform contamination than those from nest-boxes and the floor, and E. coli contamination was greater for LB eggs than for LW eggs. Significant strain differences were found for the use of nest-boxes, with a high percentage of floor eggs for brown egg strains. This study suggests that genotype x environment interactions should be considered when alternative housing systems are proposed.

Growth performance, meat quality, and gut microflora of broiler chickens fed with cranberry extract

Cranberry fruit components have been reported to have antimicrobial activities against a variety of pathogenic bacteria and to be beneficial for human health. Studies on their effects are very limited in animals and especially in chickens. This study investigated the effect of feed supplementation with a commercial cranberry fruit extract (CFE) on the performance, breast meat quality, and intestinal integrity of broiler chickens. Twelve hundred male 1-d-old broiler chicks were allocated randomly to CFE treatments at 0, 40, 80, or 160 mg/kg of feed from d 0 to 35. Cloacal and cecal samples were collected weekly to evaluate the influence of treatments on the intestinal population of generic Escherichia coli, Clostridium perfringens, Enterococcus spp., and Lactobacillus spp. At d 35, BW were 1.62, 1.60, 1.61, and 1.64 kg for the control birds and birds fed 40, 80, and 160 mg of CFE/kg of feed, respectively. Feed intake ranged from 2.7 to 2.8 kg and feed efficiency from 1.8 to 1.9 g of feed/g of BW. However, the treatment effects on bird performance were not statistically significant (P > 0.05). The mortality rate tended to be lower (P = 0.09) in birds fed 40 mg of CFE/kg of feed. Feed supplementation with CFE did not significantly alter any broiler meat properties evaluated when compared with the control diet (P > 0.05). At d 28, the populations of Enterococcus spp. in cecal and cloacal samples were significantly lower (P < 0.05) in birds receiving CFE at 160 mg/kg of feed than the other groups. No significant differences were noted between the control and the treatment groups for general health and intestinal integrity (P > 0.05). These findings suggest that more studies are needed to investigate potential beneficial effects of CFE or its derivatives in broiler production.

Evaluation of glycerol removal techniques, cryoprotectants, and insemination methods for cryopreserving rooster sperm with implications of regeneration of breed or line or both

A series of experiments was designed to evaluate the quality of cryopreserved rooster sperm and its fertility so that programs needing to bank germplasm and recreate animals can do so utilizing a minimal amount of cryopreserved semen. In experiment 1, rooster semen from the National Animal Germplasm Program genebank was thawed and glycerol was removed using a discontinuous Accudenz column or by stepwise dilution. The postthaw sperm motilities, plasma membrane integrity, and concentration were determined before and after deglycerolization. Line differences in postthaw sperm concentration and progressive motility were observed before deglycerolization (P<0.05). After glycerol removal, the sperm that was centrifuged through Accudenz had greater total motility (37 vs. 33% sperm; P<0.05), but use of the stepwise dilution method recovered more sperm per milliliter (320.4x10(6)) compared with the Accudenz method (239.2x10(6) sperm; P<0.05; range across 6 lines of 165.7 to 581.0x10(6) sperm/mL). In experiment 2, rooster semen was cryopreserved using Lakes diluent containing either dimethyl acetamide (DMA) or glycerol as the cryoprotectants. Postthaw analysis revealed that the samples cryopreserved with glycerol survived freezing better, determined by total motility (47.8 and 15.1% glycerol and DMA samples, respectively; P<0.05) and annexin V analyses (1.6 and 11.3% membrane-damaged sperm for glycerol and DMA samples, respectively; P<0.05). Differences in sperm motilities (total and progressive motility) and velocities (path velocity, straight-line velocity, curvilinear velocity) were observed between the 2 cryoprotectant treatments once the glycerol had been removed from those samples cryopreserved with glycerol, of which the glycerol samples had significantly more motile sperm and higher velocities (P<0.05). The fertility of the samples frozen using the 2 cryoprotectants was tested using a single insemination (intravaginal or intramagnal) of 200x10(6) sperm and the fertility (number of live embryos) was evaluated over 18 d. Overall, the intravaginal inseminations had lower fertility than the intramagnal inseminations (P<0.05). In the intravaginal inseminations, the sperm cryopreserved using DMA resulted in lower fertility, but there were no differences in fertility in the intramagnal inseminations due to cryoprotectant (P>0.05). These results indicate that reasonable postthaw sperm quality and fertility can be derived using cryopreserved rooster semen. By utilizing this information, estimations can be made for storing sufficient material for line or breed, or both, recreation programs.

Production of Live Offspring from Testicular Tissue Cryopreserved by Vitrification Procedures in Japanese Quail (Coturnix japonica)

ABSTRACT Cryopreservation of testicular tissue can be used for ex situ conservation of male germplasm of avian species. The possibility of using vitrification and transplantation of testicular tissue for fertility preservation and recovery was tested in Japanese quail. Testes were removed from 1-wk-old Japanese quail; transfixed on acupuncture needles; equilibrated with dimethyl sulphoxide, ethylene glycol, and sucrose; plunged into liquid nitrogen; and stored in 2-ml straws. Cryopreserved tissue was warmed in sucrose solution at room temperature or at 40°C. Fresh and cryopreserved tissue were transplanted subcutaneously into castrated, 1-wk-old recipients. Twenty of 21 recipients survived the surgery, and 18 had viable transplants at maturity, with no difference in transplantation success between fresh and cryopreserved tissue. Fluid extrusion from 11 of the transplants was collected and inseminated surgically into the magnum of 22 quail hens, and 10 inseminations included foam from the proctodeal gland of the same recipients. Egg production in the 2 wk after insemination was reduced, and none of the hens inseminated with foam produced fertile eggs. Five hens inseminated without foam produced a total of eight live offspring; four of these hens had been inseminated with fluid extrusion from cryopreserved tissue. Histological examination showed spermatogenesis in the transplants, and the tubules, lumens, and epithelium of the seminiferous tubules were of comparable size to those of testicular tissue from intact males. These results demonstrate that testicular tissue of Japanese quail can be preserved using vitrification procedures and recovered through transplantation.

Comparison of bones of 4 strains of laying hens kept in conventional cages and floor pens

The maintenance of bone strength has been an important issue in the debate over cage use for laying hens. Bone strength depends on adequate mechanical load and cages restrict movement. Four laying crosses (Lohmann White, Lohmann Brown, H&N White, and Rhode Island Red × Barred Plymouth Rock cross hens) were housed in conventional cages or in floor pens equipped with perches and nest boxes to measure the effect of the housing system on bone strength. Approximately 15 hens of each genotype from each housing system were killed at 50 wk of age and the radius and tibia of each were removed for analysis. There were no differences between the Lohmann White and H&N White (White Leghorn) hens, likely because of their similar genetic background. The Lohmann Brown and the cross hens (brown-egg layers) were larger and they had heavier bones, but the bone density was not different from that of the other lines. The radius was heavier for hens kept in floor pens than for those kept in cages, but the tibia was not. When hens were kept in floor pens, both bones had greater cortical bone density and cross-sectional area, but the difference between housing systems in cortical bone cross-sectional area was much greater for the radius than it was for the tibia. Although the movement of hens in cages is limited, they spend a great deal of time standing, which puts a mechanical load on the tibia. Hens in floor pens are able to stretch their wings or fly, in contrast to hens kept in cages, which likely explains why the difference between housing systems in cortical bone was greater for the radius than for the tibia.

Invasive and noninvasive measurement of stress in laying hens kept in conventional cages and in floor pens

Measurements of the heterophil:lymphocyte (H/L) ratio (invasive technique) and corticosterone in yolk and albumen (noninvasive techniques) were used to measure stress in 3 commercial laying strains, Lohmann White (LW), H&N White (HN), Lohmann Brown (LB), and a noncommercial cross (CR) between Rhode Island Red (male) and Barred Plymouth Rock (female), kept in conventional cages or floor pens. All chicks were reared in their respective environments, and 450 and 432 pullets were placed at 18 and 7 wk of age in cages and floor pens, respectively. Blood from 12 hens per strain was taken at 19, 35, and 45 wk of age in each housing system. A total of 100 heterophils and lymphocytes were counted and their ratio (H/L ratio) was calculated. Corticosterone was measured in yolk and albumen from 12 hens per strain in each housing system at 22 and 45 wk of age. The H/L ratio was within the normal range. The interaction between environment and strain for the H/L ratio showed that in both environments, LB and CR hens had a higher H/L ratio than LW and HN layers. In cages, there were significant differences in H/L ratios between LW and HN hens that were likely due to genetic differences. The LW hens had significantly lower corticosterone concentrations in yolk than LB hens. In cages but not floor pens, yolk corticosterone concentrations at wk 22 were significantly higher than at wk 45. In floor pens but not cages, albumen corticosterone at wk 22 was higher than at wk 45. The H/L ratios suggest that none of the hens were unduly stressed, and corticosterone levels in yolk and albumen support the suggestion that hens adapted to their environments with age. Although measurement of yolk corticosterone and the H/L ratio may be comparable, the measurement of corticosterone level in the albumen may differ because it is secreted over a short time.

Bone Fracture Incidence in End-of-Lay High-Producing, Noncommercial Laying Hens Identified Using Radiographs

Bone fractures in laying hens are both a welfare and an economic concern for the poultry industry. The aim of this study was to use radiographs to quantify fracture incidence in 6 lines of noncommercial high-producing laying hens. A total of 451 hens (n = 71 to 78) were killed at 47 wk (White Leghorn-Black, White Leghorn-Blue) or 65 wk of age [Barred Plymouth Rock (BR), White Leghorn-Burgundy (WL-BUR), Columbian Plymouth Rock, Rhode Island Red (RIR)]. Radiographs were obtained with hens in 2 positions (lateral and ventrodorsal) and were used to identify fractures in the skeleton. Data on scallop-shaped indentations (possibly fractures) of the keel bone were also collected. After radiography, the left wings were removed for analysis of humeri, radii, and ulnae. Data for the 2 age groups were analyzed separately. The overall incidence of hens with at least 1 fracture was 6.6 and 15.7% in the 47- and 65-wk-old hens, respectively. Fracture incidence in 47-wk-old hens was not different between White Leghorn-Black and White Leghorn-Blue lines. Significant line differences were observed in the 65-wk-old hens, with at least 1 fracture found in 29.5% of RIR hens versus 9.5 and 4.2% observed in Columbian Plymouth Rock and WL-BUR lines, respectively. Fracture incidence in BR hens (18.2%) was greater than in WL-BUR hens. Fractures in RIR hens occurred predominantly in the furculum and wing bones, whereas pubic bones were most affected in BR hens. The proportion of hens with scallop-shaped indentations of the keel ranged from 36.1 to 88.2% and differed between lines in both age groups. High egg production did not seem to be associated with bone fragility in these lines. Two of the older lines (RIR and WL-BUR) had similar egg production, number of eggs to 60 wk, and egg shell weights at 4 ages but had a significantly different fracture incidence. The line differences in fracture incidence may have been affected by calcium metabolism, bone structure, and body weight.

Heterotopic Transplantation of Testes in Newly Hatched Chickens and Subsequent Production of Offspring via Intramagnal Insemination

Abstract Transplantation of testicular tissue onto the back of immunodeficient nude mice provides a tool to examine testicular development and preserve fertility in mammals. There is no immunodeficient model in birds, but we recently transplanted ovarian tissue between newly hatched chicks from two lines of chickens and produced donor-derived offspring, showing that experimental transplantation is possible in newly hatched chicks. In the present study testicular tissue from newly hatched Barred Plymouth Rock (BPR) chicks was transplanted under the skin of the back, under the skin of the abdomen, or in the abdomen of White Leghorn chicks that had been surgically castrated and immunocompromised. Recipient birds were killed at 10 mo of age. Transplanted tissue was observed in one of five hosts receiving tissue under the skin of the back, two of five hosts receiving tissue under the skin of the abdomen, and three of five chicks with grafts inside the abdominal cavity. In recipients with no regeneration of host testes, testicular transplants grew to the size of normal testes, and histologic analysis showed active spermatogenesis. Subsequent collection of sperm from two successful transplants and surgical insemination of the sperm into the magna of the oviducts of BPR hens resulted in the production of 24 donor-derived chicks. These results demonstrate that the combination of testicular tissue transplantation with intramagnal insemination can produce viable, normal chicks, which could provide a simple approach for the recuperation of live offspring in avian species.

Locally elevated cortisol in lymphoid organs of the developing zebra finch but not Japanese quail or chicken.

Glucocorticoids are important for production of functional lymphocytes and immunity. In altricial neonates, adrenal glands are unresponsive and local glucocorticoid synthesis in lymphoid organs may be necessary to support lymphocyte development. Precocial neonates, in contrast, have fully responsive adrenal glucocorticoid production, and lymphoid glucocorticoid synthesis may not be necessary. Here, we found that in altricial zebra finch hatchlings, lymphoid organs had dramatically elevated endogenous glucocorticoid (and precursor) levels compared to levels in circulating blood. Furthermore, while avian adrenals produce corticosterone, finch lymphoid organs had much higher levels of cortisol, an unexpected glucocorticoid in birds. In contrast, precocial Japanese quail and chicken offspring did not have locally elevated lymphoid glucocorticoid levels, nor did their lymphoid organs contain high proportions of cortisol. These results show that lymphoid glucocorticoids differ in identity, concentration, and possibly source, in hatchlings of three different bird species. Locally-regulated glucocorticoids might have species-specific roles in immune development.

Novel needle-in-straw vitrification can effectively preserve the follicle morphology, viability, and vascularization of ovarian tissue in Japanese quail (Coturnix japonica)

Cryopreservation of ovarian tissue has been the only effective way of ex situ conservation of female germplasm in avian species. A novel needle-in-straw (NIS) vitrification method was developed to store tissue in straws instead of cryovials. Fragments of ovarian tissue from one-week old Japanese quail were transfixed on an acupuncture needle. They were immersed in equilibration and vitrification solutions containing dimethyl sulphoxide, ethylene glycol and sucrose. A layer of tin foil was rolled over the tissue fragments and the tin foil package was plunged into liquid nitrogen and inserted into a pre-cooled, 0.5-ml straw which was stored in liquid nitrogen. Tissue was also preserved using a needle immersed vitrification (NIV) method, in which tissue fragments transfixed on needles without tin foil and were stored in cryovials filled with liquid nitrogen. Cryopreserved tissue was warmed at room temperature (RT) or 37°C and the ratio of normal follicles to total visible follicles was determined by histological methods. In addition, cryopreserved and warmed tissue was cultured on the chorioallantoic membranes of fertilized chicken eggs for 5-6 days. The viability and vascularization of the grafts were evaluated. The tissue cryopreserved by NIS and warmed at RT showed comparable follicle morphology to fresh tissue and to that preserved by NIV and warmed at RT. No significant impairment on the viability or vascularization of the grafted tissue was observed. The NIS method allows tissue to be stored and transported safely and efficiently and can be used instead of cryovials in tissue cryobanking.