Efficacy of sperm mobility assessment in commercial flocks and the relationships of sperm mobility and insemination dose with fertility in turkeys.

Our objectives were to evaluate: 1) the efficacy of the Sperm Mobility Test on commercial turkey farms, and 2) the influence of sperm mobility phenotype on fertility when insemination parameters are varied. In research flocks, differences in sperm mobility among toms are predictive of fertility. We wanted to test the efficacy of this sire selection test in practical, real-world situations, evaluating its usefulness in terms of assessing large numbers of toms, different strains of turkeys, and variable management practices. Utilizing field study results, controlled studies were then conducted to improve test parameters. For the field trials, semen from each of 405 breeder toms (11 strains or lines) was evaluated either in duplicate (n = 285) or in triplicate (n = 120). Sperm mobility was normally distributed among all toms tested, except for one strain. Because the sperm mobility indices for toms evaluated in these field trials were higher than those observed in research flocks, the Sperm Mobility Test was modified to increase the separation between high and low sperm mobility phenotypes by increasing the concentration of Accudenz. To determine the effects of sperm mobility and insemination dose on sustained fertility through time, hens from a research flock were inseminated twice before the onset of lay with sperm from toms classified as high-, average-, or low-mobility in concentrations of 25 to 400 million sperm per artificial insemination dose, and egg fertility was evaluated over a 5-wk period. Toms with the high-mobility sperm phenotype maintained higher fertility (P < 0.05) over the 5-wk period at all insemination doses compared with toms with low-mobility sperm. Toms with high-mobility sperm sired equal numbers of poults in a sperm competition study in which numbers favored low-mobility toms by 3:1. These results demonstrate that the Sperm Mobility Test can be used for on-farm evaluation of semen quality of toms in commercial flocks and that sperm mobility influences fertility and sire fitness.

Where the boys aren't.

Many causative factors have been cited for our present national nursing shortage. Some of these are: the "baby bust" of the late sixties and seventies, the women's movement, inadequate salaries, and shift work. Yes, an untapped pool of potential applicants exists--men. This article asks why nursing is "where the boys aren't."

Divergent selection for growth in Japanese quail under split and complete nutritional environments. 2. Water and feed intake patterns and abdominal fat and carcass lipid characteristics.

A study was conducted to investigate water and feed intake patterns, abdominal fat and carcass lipid levels, feed efficiency and growth in high (H) and low (L) body weight lines of Japanese quail divergently selected under complete diet (CD) or split diet (SD) environments. Birds under the SD environment could self-select from high-protein low-energy or low-protein high-energy diets. Progeny from both the selected and control (C) lines were evaluated under the SD environment in Generations 6 and 10, and under the CD environment in Generation 10. Under the SD environment, body weights of the H lines were similar as were body weights of the L lines; however, under the CD environment, there were significant differences between H lines and between L lines. Body weights were higher under the CD than under the SD environment. Differences between H and L lines in body weights and 1-wk relative growth rates within SD and CD environments were attributed to differences in water and feed consumption and feed efficiency. Water consumption was greater in the SD than CD environments. Feed consumption was greater in the SD than CD environment from 0 to 2 wk of age; thereafter, feed consumption was higher in the CD environment. Abdominal fat and carcass lipid levels were greater in H than L lines, with the magnitude of the difference greater in the SD environment, indicating that the SD may be a better environment than the CD environment for the study of abdominal fat and carcass lipids in Japanese quail.

Divergent selection for growth in Japanese quail under split and complete nutritional environments. 1. Genetic and correlated responses to selection.

Japanese quail were divergently selected for 4-wk body weight under two different nutritional environments. In one environment quail were divergently selected for high and low body weight (H and L) under a split diet (SD) with quail having the opportunity to self-select feed from high protein and high energy diets. In the other environment, quail were similarly selected (H and L) under a normal (28% protein) complete diet (CD). After 11 generations of selection, H-SD and H-CD lines were 48.9 and 49.7% higher in 4-wk body weight than controls. Quail from L-SD and L-CD lines were 46.5 and 45.4% lower in 4-wk body weight than controls. Realized heritabilities for 4-wk body weight were .36 +/- .03, .30 +/- .03, .52 +/- .02, and .47 +/- .03 for H-SD, L-SD, H-CD, and L-CD lines, respectively. Selection differentials were significantly higher in the SD than in the CD environment. Changes in 2-wk, adult body, and egg weight across generations paralleled that of the trait under selection (4-wk body weight). Selection also resulted in decreased hatchability and egg production with increased age to sexual maturity in both environments. The SD environment was determined to be a stress environment because of birds' inferior growth there compared with growth in the CD environment. Rate of growth, however, to reach adult body size was superior for L-SD quail once the stress environment was removed. There was also evidence that eggs were larger for quail in the SD than the CD environment.

The influence of dietary salt on water consumption and carcass lipids in Japanese quail.

Studies were conducted to investigate the influence of dietary salt on water consumption and subsequent carcass lipids in Japanese quail at various ages. In Experiment 1, randombred nongrowth-selected (C) quail were fed 28% protein diets containing .0, .4, .8, 1.6, and 3.2% added salt. In Experiment 2, growth-selected P- and C-line quail were fed 20%-protein diets containing .4% and 3.2% added salt. The different dietary salt levels did not exert a consistent effect on body weight in Experiment 1. There was no adverse effect of salt level on feed consumption and efficiency and no direct effect on abdominal fat or carcass lipid levels. High salt (1.6 and 3.2%) stimulated water consumption and increased water:feed ratios. Water:feed ratios were higher for quail than for broilers, suggesting a species difference. In Experiment 2, C-line quail demonstrated similar effects to the high-salt (3.2%) diet in Experiment 1. High salt (3.2%) adversely affected body weight, feed consumption, abdominal fat, and carcass lipid in P-line quail. There was no affect on feed efficiency, and a substantial stimulation of water consumption with concomitantly increased water:feed ratios. The relatively low abdominal fat observed at 4 weeks of age indicate that nongrowth-selected quail may not be a good model for the study of abdominal fat in broilers.