scholarly journals Broiler Production Under Varying Population Densities

1992 ◽  
Vol 71 (3) ◽  
pp. 427-433 ◽  
Author(s):  
T.L. CRAVENER ◽  
W.B. ROUSH ◽  
M.M. MASHALY
2014 ◽  
Vol 107 (4) ◽  
pp. 1496-1501 ◽  
Author(s):  
Damon J. Crook ◽  
Joseph A. Francese ◽  
Michael L. Rietz ◽  
David R. Lance ◽  
Helen M. Hull-Sanders ◽  
...  

Author(s):  
Riccardo Pansini ◽  
Davide Fornacca

AbstractCOVID-19 has spread in all continents in a span of just over three months, escalating into a pandemic that poses several humanitarian as well as scientific challenges. We here investigated the geographical expansion of the infection and correlate it with the annual indexes of air quality observed from the Sentinel-5 satellite orbiting around China, Italy and the U.S.A. Controlling for population size, we find more viral infections in those areas afflicted by Carbon Monoxide (CO) and Nitrogen Dioxide (NO2). Higher mortality was also correlated with poor air quality, namely with high PM2.5, CO and NO2 values. In Italy, the correspondence between poor air quality and SARS-CoV-2 appearance and induced mortality was the starkest. Similar to smoking, people living in polluted areas are more vulnerable to SARS-CoV-2 infections and induced mortality. This further suggests the detrimental impact climate change will have on the trajectory of future epidemics.SignificanceWe found a significant correlation between levels of air quality and COVID-19 spread and mortality in China, Italy and the United States. Despite the infection being still ongoing at a global level, these correlations are relatively robust not being influenced by varying population densities. Living in an area with low air quality seems to be a risk factor for becoming infected and dying from this new form of coronavirus.


2013 ◽  
Vol 106 (6) ◽  
pp. 2407-2414 ◽  
Author(s):  
Joseph A. Francese ◽  
Michael L. Rietz ◽  
Damon J. Crook ◽  
Ivich Fraser ◽  
David R. Lance ◽  
...  

1980 ◽  
Vol 35 (5-6) ◽  
pp. 390-398 ◽  
Author(s):  
Ernst Priesner ◽  
Hermann Bogenschütz ◽  
Heinrich Am

Traps baited with 100 μg (Z)-9-dodecenyl acetate and 10|ig (Z)-ll-tetradecenyl acetate are highly effective in attracting C. murinana males at varying population densities. The attractive mixture was established by electrophysiological and Field screening studies combined with chemical analysis of the female pheromone secretion. (Z)-9-dodecenyl acetate is a major constituent in washes of pheromone glands of calling C. murinana females. This compound, the first dodecenyl ester pheromone known for a species of the Archipini tribe, is moderately attractive on its own at low doses. Attraction is strongly synergized by 10% (Z)-11-tetradecenyl acetate but is inhibited by small amounts of (Z)-9- tetradecenyl acetate. Each of the three compounds acts upon a separate type of receptor cell in hair sensilla of the male antenna.


1997 ◽  
Vol 05 (02) ◽  
pp. 191-201 ◽  
Author(s):  
Veijo Kaitala

The evolutionary stability of delayed maturity and suppressed breeding, including a possibility of reproductive gaps, in an age-structured population breeding more than once within a breeding season was studied. In this study I show that breeding strategies may depend strongly on intra-specific competition (population density), in which case the breeding strategies will also modify the overall growth rates of the population. Consequently, breeding strategies may fluctuate from year to year when the individuals adjust their breeding behaviors according to chaotically varying population densities.


2019 ◽  
Vol 17 (1) ◽  

Background: Commercial broiler is a rapidly growing sector in Bangladesh. The broilers are supplied with the balanced ration prepared from a number of ingredients which are not available uniformly throughout the years. On the other hands, manufactured feeds are costly and inconvenient for the rural farmers. This study is undertaken to use unconventional feed ingredients aiming to decrease the broiler production cost. Method: A total of ninety-nine day- old broiler chicks (Hubbard) of either sex were used in this study in 3 treatment groups to assess processed unconventional feed item (shoti, blood meal, poultry dropping and molasses) on growth and profitability upon rearing for 60 days. Broilers were reared in dip litter system and were fed ad libitum on conventional and unconventional diet dividing into 3 treatment diets namely, treatment diet 1 (T1: Conventional as control), treatment diet 2 (T2: unconventional with blood meal and shoti), and treatment diet 3 (T3: unconventional with blood meal, shoti, poultry droppings and molasses) throughout the trial period. Treatment group 1 (T1) was used as control. Results: Broilers fed on control diet (conventional feed) achieved higher (P<0.01) body weight, while the broilers offered diets with the highest amount of unconventional feed had the lowest body weight. Increased (P<0.01) feed intake was observed during 21days and 49 days of age when broilers fed diets with the supplementation, but no significant differences were found among the groups in terms of feed consumption during 33 day of age. FCR differed significantly (P<.01) throughout the trial period with the broilers fed diets without supplementation of unconventional feed item had the superior FCR than the others. Mortality rate was 6.06%,9.09%, and 9.09% in treatment group I, treatment group II, and treatment group III respectively while live weights, feed conversion and feed consumption was unaffected by all the dietary groups with/without incorporation of unconventional feed item up to day 60 days of age. Statistically significant (P<0.01) decreased live weight was observed among the treatment groups in 60-day-old birds. Productivity and cost-benefit analysis were performed. Conclusion: Use of unconventional feed ingredients in broiler production greatly reduces the feed cost with little hampering the growth rate and hence, it is profitable for the farmers.


Author(s):  
Gregory L. Tylka ◽  
Mychele Batista da Silva ◽  
Joel L. DeJong ◽  
Joshua L. Sievers ◽  
Ryan Rusk

Sign in / Sign up

Export Citation Format

Share Document