Health effects following chronic dosing with tungsten-iron and tungsten-polymer shot in adult game-farm mallards.

Permanent approval of shot composed of tungsten-iron and tungsten-polymer for waterfowl hunting by the U.S. Fish and Wildlife Service was pending the results of the present study that examined the health and reproductive effects of the two shot types on mallards (Anas platyrhynchos) over a 150-day period. We collected data pertaining to the effects of tungsten-iron and tungsten-polymer shot on mortality, body weight, organ weight, tissue pathology, and shot erosion. Thirty-two bird groups (sexes equal) of adult mallards were dosed orally with eight #4 steel shot (control), eight #4 tungsten-iron shot, or eight #4 tungsten-polymer shot on days 0, 30, 60, 90, and 120 of a 150-day trial (26 January 1998 to 25 June 1998). An additional 12 mallards (sexes equal) were dosed orally with eight #4 lead shot (positive control) on day 0 of the study. All lead-dosed ducks died by day 25, whereas no ducks died in the other treatment groups. Significant liver hemosiderosis was present in all control and tungsten-iron-dosed males, in five of eight control and three of eight tungsten-iron-dosed females, and in one tungsten-polymer-dosed male examined. The rate of shot erosion was highest for tungsten-polymer shot (99%), followed by tungsten-iron (72%), and steel (55%) shot. Tungsten-iron or tungsten-polymer shot repeatedly administered to adult mallards did not have deleterious health effects during the 150-day trial based on mortality, body weights, organ weights, and histology of the liver and kidneys.

Reproductive effects and duckling survivability following chronic dosing with tungsten-iron and tungsten-polymer shot in adult game-farm mallards.

Tungsten-iron and tungsten-polymer shot were given conditional approval for waterfowl hunting by the U.S. Fish and Wildlife Service based partly on the results of a 30-day acute toxicity trial utilizing mallards (Anas platyrhynchos). Final approval of the two tungsten-containing shot was contingent on the results of a 150-day study that assessed the health and reproductive effects of tungsten-iron and tungsten-polymer shot in adult mallards. Reproductive data are presented in this paper. Sixteen male and 16 female adult mallards were dosed orally with eight #4 steel shot (control), eight #4 tungsten-iron shot, or eight #4 tungsten-polymer shot on days 0, 30, 60, 90, and 120 of a 150-day trial (26 January 1998 to 25 June 1998). Reproductive performance was assessed during the last 90 days (day 61 to day 150) of the trial. There were no significant differences in egg production and fertility and hatchability of eggs from tungsten-iron- and tungsten-polymer-dosed ducks compared to control ducks. There was no evidence of differences in percent survivability and body weight of ducklings from tungsten-iron and tungsten-polymer mallards compared to ducklings from control ducks. Tungsten-iron or tungsten-polymer shot repeatedly administered to adult mallards during the 150 day trial did not adversely affect reproduction or their offspring.

Hematological effects and metal residue concentrations following chronic dosing with tungsten-iron and tungsten-polymer shot in adult game-farm mallards.

The U.S. Fish and Wildlife Service required a chronic dosing study that assessed the health and reproductive effects of tungsten-iron and tungsten-polymer shot in adult game-farm mallards (Anas platyrhynchos) prior to granting permanent approval of the shot for waterfowl hunting. Herein, we present the effects of tungsten-iron and tungsten-polymer shot on various hematologic parameters and metal residue concentrations in the femur, liver, kidneys, and gonads. Thirty-two-bird groups (sexes equal) of adult mallards were dosed orally with eight #4 steel shot (control), eight #4 tungsten-iron shot, or eight #4 tungsten-polymer shot on days 0, 30, 60, 90, and 120 of a 150 day trial (26 January 1998 to 25 June 1998). An additional 12 mallards (sexes equal) received eight #4 lead shot (positive control) on day 0 of the study. Lead-dosed mallards had significantly decreased hematocrit, hemoglobin concentration, and whole-blood delta aminolevulinic acid dehydratase activity on day 7, as well as significant changes in a number of plasma chemistry parameters compared to ducks in the control, tungsten-iron, or tungsten-polymer groups. Mallards dosed with tungsten-iron or tungsten-polymer shot had occasional significant differences in hematocrit and plasma chemistry values when compared to control mallards over the 150 day period, but these changes were not considered to be indicative of deleterious effects. Low concentrations of tungsten were detected in gonad and kidney samples from males and females and in liver samples from females dosed with tungsten-polymer shot. Tungsten was also detected in femur samples from tungsten-polymer-dosed mallards. Higher concentrations of tungsten were detected in femur, liver, kidney, and gonad samples from tungsten-iron-dosed ducks. Tungsten-iron or tungsten-polymer shot repeatedly administered to adult mallards did not cause adverse hematological effects during the 150 day trial. Concentrations of tungsten in the femur, liver, kidneys, and gonads were generally higher in tungsten-iron-dosed ducks when compared to tungsten-polymer-dosed ducks.

Acute effects of lead, steel, tungsten-iron, and tungsten-polymer shot administered to game-farm mallards.

Sixteen-bird groups (sexes equal) of adult mallards (Anas platyrhynchos) were orally dosed with eight #4 steel short, eight #4 lead shot, eight BB-size tungsten-iron shot, eight BB-size tungsten-polymer shot, or were sham-dosed and maintained for 30 days (16 January 1996 to 15 February 1996). Half of the lead-dosed ducks (five males, three females) died during the study, whereas no ducks died in the other dosage groups. For lead-dosed ducks, hematocrit and hemoglobin concentration were decreased on day 15 of the trial, but not on day 30. Delta aminolevulinic acid dehydratase activity in lead-dosed ducks was lower when compared to steel-dosed ducks only. Plasma activities of selected enzymes were elevated in lead-dosed ducks when compared to enzyme activities of ducks in the other groups. For lead-dosed ducks, relative heart, liver, and kidney weights increased in comparison to relative weights of those organs of ducks in other groups. Histology of tissues indicated that renal nephrosis accompanied by biliary stasis was present in the eight lead-dosed ducks that died. For the eight lead-dosed ducks that survived, six had mild to severe biliary stasis. Mild biliary stasis was noted in five tungsten-iron dosed ducks and three tungsten-polymer dosed ducks. Amounts of lead in the femur, liver, and kidneys were higher in lead-dosed ducks than in ducks of the other four groups. Small amounts of tungsten were detected in the femur and kidneys of two tungsten-polymer dosed ducks. Higher concentrations of tungsten were detected in the femur, liver, and kidneys of all tungsten-iron dosed ducks. The rate of shot erosion was highest (80%) for the tungsten-polymer shot, followed by tungsten-iron (55%), lead (50%), and steel shot (33%). Results indicated that tungsten-iron or tungsten-polymer shot (8 shot/duck) orally administered to mallards did not adversely affect them during a 30-day trial.

Mating behavior and brain biogenic amine concentrations in chickens treated with parachlorophenylalanine (PCPA).

Four experiments were conducted to determine the effect of parachlorophenylalanine (PCPA) on the male mating behavior of a line of chickens genetically selected for low mating frequency and to determine the effect on brain concentrations of 5-hydroxytryptamine, dopamine (DA) and norepinephrine (NE). Mating behavior was not affected by moderate levels (less than 64 mg/kg) of PCPA, and decreased significantly when higher levels (100 mg/kg) of the drugs were administered. Results suggest that elevated brain serotonin titers were not causing the low mating frequency associated with the selected line. Birds receiving higher levels of PCPA exhibited a lethargy which persisted for approximately ten days after withdrawal of the drug. Serotonin, DA, and NE were all significantly reduced in the brains of birds receiving PCPA (30 mg/kg).

Testosterone aromatization in high and low mating lines of gallinaceous birds.

Capons from high (HML) and low (LML) mating lines of Japanese quail and chickens received testosterone propionate, 5 alpha-dihydrotestosterone (5 alpha-DHT) or estradiol benzoate injections after which copulatory behavior was observed during exposure to live females and to a female model. With live females, the testosterone-treated HML capons mated significantly more than the other HML groups. All LML capons mated infrequently and at comparable levels. When tested with the model, estrogen-treated LML capons mated significantly more frequently than testosterone-treated LML capons, suggesting testosterone aromatization rate was affecting mating activity. This possibility was tested with HLM and LML intact cocks and capons receiving silastic implants of either testosterone, 5 alpha-DHT or a combination of estradiol and 5 alpha-DHT (E + DHT). Mating activity of intact HML cocks, T-treated, and E + DHT-treated HML capons were similar, and all groups mated significantly more than the control or 5 alpha-DHT-treated capons. There were no significant differences between any of the LML groups. The data suggested that limited testosterone aromatization was not the cause of relatively reduced sexual activity in the LML males.

Storage and evacuation of spermatozoa from the uterovaginal sperm-host glands in domestic fowl.

Autoradiography with 3H-labeled spermatozoa was utilized to study spermatozoal oviductal interrelationships. Results demonstrated that sperm displacement from the uterovaginal sperm-host glands did not occur in domestic fowl. Furthermore, there was no indication that phagocytosis of labeled spermatozoa by sperm gland epithelium occurred. Associated studies demonstrated that extensive head-to-head agglutination occurred between freshly ejaculated spermatozoa, but the ability to agglutinate was lost as the sperm cells aged. On the basis of these observations, it was proposed that agglutination may be the basic mechanism controlling sperm storage and release from the uterovaginal sperm-host glands. A working model to this effect was presented.

The effects of exogenous steroidal hormones on the testes of quail from selected high and low mating lines.

Several steroid hormones were tested for their effects on the testes of lines of Japanese quail selected for high and low mating frequency. Estradiol benzoate and testosterone propionate caused a complete and partial regression of the testes, respectively, while dihydrotestosterone did not affect testicular weight. Spermatogenesis was adversely affected by both estradiol benzoate and testosterone propionate but not by dihydrotestosterone. Dihydrotestosterone caused a significant increase in the diameter of the seminiferous tubules while estradiol benzoate and testosterone propionate caused a significant decrease in tubular diameter. Significant line differences were found; the high mating line exceeded the low mating line for each of the treatments except extradiol benzoate. Extradiol benzoate caused testicular regression in both lines.