Potential relationships between physical traits and male broiler breeder fertility.

Genetic selection in primary broiler breeders may modify skeletal structure, possibly impeding semen transfer, and could alter the size and degree of fluctuating asymmetry (FA) of bilateral traits associated with fertility. Hence, we hypothesized specific morphometric traits could predict differential fertility. Sixty primary broiler breeder males from Strains A and B (n = 30/strain) were individually housed with an average of 10 females per male. Male fertility and sperm penetration (SP) through the perivitelline layer were estimated on fresh eggs. At 50 wk, BW, keel length (KL), posterior pelvic width and length (PPW, PPL), dorsal pelvic width and length (DPW, DPL), tarsometatarsal length and width (TL, TW), comb length and width (CL, CW), and wattle length, width, and area (WL, WW, WA) were measured. Results indicated that Strain A had smaller BW, KL, WL, WW, WA, CL, CW, PPL, DPL, and DPW. A higher degree of FA was found in Strain A TL and WL (P < 0.05), yet DPW FA was greater for Strain B (P < 0.001). In addition, DPW FA negatively correlated with Strain B fertility (r = -0.369; P < 0.01); however, other FA measurements did not correlate with estimated fertility or SP. Strain A WL correlated with SP (r = 0.383; P < 0.01) and fertility (r = 0.346; P < 0.01). Results indicate DPW alteration may impact semen transfer upon copulation, as Strain A fertility negatively correlated with DPW (r = -0.298; P < 0.05). This research provides evidence that morphometric traits might be useful to predict fertility in broiler breeders.

Phenotypic traits as reliable indicators of fertility in male broiler breeders.

Genetic selection procedures applied to improve broiler performance may negatively impact the subsequent reproductive efficiency of breeders, particularly in males. Identification of traits that reliably indicate individual male fertility would facilitate selection for reproduction. We hypothesized that physical traits, such as comb area, relative testicular weight, and testicular weight asymmetry, may correlate with fertility in two male-selected primary broiler breeder strains (A and B). Thirty males per strain, individually housed with an average of 10 females, were evaluated at five age periods within the 30-to-50-wk breeding cycle. Flock fertility by candling eggs at Day 19 of incubation and sample fertility by visual assessment of the germinal disc were determined. Sperm penetration (SP) through the perivitelline layer was assessed. Comb area was evaluated by image analysis at 40 and 50 wk, and relative testicular weight was measured at 50 wk. Strain A sample and flock fertility (P < 0.001) and SP values (P < 0.0001) were significantly lower than Strain B. Both strains had a significant decline of fertility and SP with age (P < 0.0001). Strain A comb area correlated with sample fertility (P < 0.05), flock fertility (P < 0.05), and relative testicular weight (P < 0.01). Conversely, Strain B relative testicular weight correlated with sample fertility (P < 0.0001) and flock fertility (P < 0.001). Significant correlations were not found between testicular weight asymmetry and other reproductive traits. Results suggest comb area may be a reliable indicator of male fertility in Strain A.

Impact of vinclozolin on reproductive behavior and endocrinology in Japanese quail (Coturnix coturnix japonica).

The impact of endocrine-disrupting chemicals (EDCs) has been demonstrated in mammalian models, but less research is available for avian species. The effects of vinclozolin (VIN), an antiandrogenic fungicide, on sexual differentiation and maturation were investigated in Japanese quail (Coturnix coturnix japonica). On day 4 of incubation, embryos were exposed to no treatment, oil, or 25, 50, or 100 ppm of VIN. Endpoints measured included adult male reproductive behavior, hypothalamic gonadotropin-releasing hormone I (GnRH-I) content in hatchlings and adults, plasma steroid levels in hatchlings and adults, proctodeal gland growth during maturation, and relative testicular weight at seven weeks of age. Results showed that exposure to VIN significantly (p < 0.05) altered GnRH-I in male hatchlings, whereas GnRH-I levels in females remained unaffected. Although steroid levels were unaltered by any VIN treatment, the display of male reproductive behavior seemed delayed, with the number of mounts and the number of cloacal contacts being significantly (p < 0.05) lower in the VIN-treated males. This could have an extreme negative impact on wild avian species that are routinely exposed to similar EDCs.

Neuroendocrine and behavioral implications of endocrine disrupting chemicals in quail.

Studies in our laboratory have focused on endocrine, neuroendocrine, and behavioral components of reproduction in the Japanese quail. These studies considered various stages in the life cycle, including embryonic development, sexual maturation, adult reproductive function, and aging. A major focus of our research has been the role of neuroendocrine systems that appear to synchronize both endocrine and behavioral responses. These studies provide the basis for our more recent research on the impact of endocrine disrupting chemicals (EDCs) on reproductive function in the Japanese quail. These endocrine active chemicals include pesticides, herbicides, industrial products, and plant phytoestrogens. Many of these chemicals appear to mimic vertebrate steroids, often by interacting with steroid receptors. However, most EDCs have relatively weak biological activity compared to native steroid hormones. Therefore, it becomes important to understand the mode and mechanism of action of classes of these chemicals and sensitive stages in the life history of various species. Precocial birds, such as the Japanese quail, are likely to be sensitive to EDC effects during embryonic development, because sexual differentiation occurs during this period. Accordingly, adult quail may be less impacted by EDC exposure. Because there are a great many data available on normal development and reproductive function in this species, the Japanese quail provides an excellent model for examining the effects of EDCs. Thus, we have begun studies using a Japanese quail model system to study the effects of EDCs on reproductive endocrine and behavioral responses. In this review, we have two goals: first, to provide a summary of reproductive development and sexual differentiation in intact Japanese quail embryos, including ontogenetic patterns in steroid hormones in the embryonic and maturing quail. Second, we discuss some recent data from experiments in our laboratory in which EDCs have been tested in Japanese quail. The Japanese quail provides an excellent avian model for testing EDCs because this species has well-characterized reproductive endocrine and behavioral responses. Considerable research has been conducted in quail in which the effects of embryonic steroid exposure have been studied relative to reproductive behavior. Moreover, developmental processes have been studied extensively and include investigations of the reproductive axis, thyroid system, and stress and immune responses. We have conducted a number of studies, which have considered long-term neuroendocrine consequences as well as behavioral responses to steroids. Some of these studies have specifically tested the effects of embryonic steroid exposure on later reproductive function in a multigenerational context. A multigenerational exposure provides a basis for understanding potential exposure scenarios in the field. In addition, potential routes of exposure to EDCs for avian species are being considered, as well as differential effects due to stage of the life cycle at exposure to an EDC. The studies in our laboratory have used both diet and egg injection as modes of exposure for Japanese quail. In this way, birds were exposed to a specific dose of an EDC at a selected stage in development by injection. Alternatively, dietary exposure appears to be a primary route of exposure; therefore experimental exposure through the diet mimics potential field situations. Thus, experiments should consider a number of aspects of exposure when attempting to replicate field exposures to EDCs.

An electrically powered total artificial heart. Over 1 year survival in the calf.

An electric motor driven orthotopic artificial heart was implanted in a 110 kg female Holstein calf as part of a series of 12 such implants intended to demonstrate the in vivo durability and compatibility of the device. The device uses pusher plates set into motion by a reversing brushless DC motor and roller screw to alternately eject two cylindrical sac type blood pumps. The pumps use Bjork-Shiley Delrindisc convexo-concave or monostrut valves. The left pump provides an 88-90 ml dynamic stroke volume. Woven Dacron grafts and polyurethane coated Dacron/Lycra cuffs are used to attach the device to the major arteries and atria, respectively. A polyurethane conduit and anchoring skin button bring motor wires percutaneously to an extracorporeal controller. The controller provides balanced cardiac output sensitive to atrial or aortic pressures, without operator intervention. The system is hermetically sealed and uses a simple compliance sac to maintain thoracic pressure between the pumps. The calf recovered uneventfully from surgery and thrived thereafter. She was killed on the 388th post-operative day because of worsening cardiac insufficiency. The previous three operative survivors in this series lived 131, 134, and 204 days. These results indicate the device's good potential for durability and body compatibility.

Development of malignant hyperthermia during mitral valve replacement.

Malignant hyperthermia is a genetically predisposed, potentially fatal disorder triggered by anesthetic agents. The early diagnosis and treatment of malignant hyperthermia is essential, yet often difficult, because the signs and symptoms of this disorder are not unique to the disease. When the patient is also undergoing cardiopulmonary bypass this disorder may be very difficult to recognize. In this article, we report a case of malignant hyperthermia diagnosed during mitral valve replacement and discuss the preoperative and postoperative management possibilities. The unusualness of this case stems from the fact that the patient had centronuclear myopathy. Although reported with other types of myopathies, centronuclear myopathy has rarely been associated with malignant hyperthermia. This episode of malignant hyperthermia was diagnosed by intraoperative measurements showing increased oxygen consumption despite hypothermic cardiopulmonary bypass.