4,159 research outputs found
Feather growth, bodyweight and body temperature in broiler lines with different feathering rates
Two early feathering sire lines (B1 and B2), two late feathering dam lines (A1 and A3), and an early feathering dam line were evaluated to determine differences in growth, in lengths of primary feathers, in under-wing and rectal temperatures, and in feed intake until the birds were 20 weeks old. The chicks were hatched from eggs collected from 35-week-old hens of pure line broiler flocks. Data were collected at hatch, and at 1, 2, 4, 6, 8, 12, and 20 weeks old Thirty males and 30 females were evaluated for each line. The early feathering genotypes (A2, B1 and B2) had longer primary feathers until they were six weeks old. They also had higher under-wing and rectal temperatures and higher live weight compared with the late-feathering lines (A1 and A3) at one and two weeks old. The males were heavier than females at all ages. However, under-wing and rectal temperatures were similar in males and females at all ages. A positive correlation was observed between the length of primary feathers and live weight in A2, B1, and B2 at six weeks, whereas a negative correlation was observed between the rectal temperature and the length of primary feathers in A1 and A3 at 4 and 20 weeks old
Effect of production system and slaughter age on some production traits of guinea fowl: Meat quality and digestive traits
Certain meat quality traits of guinea fowl that were reared in two production systems were determined in this study. Grey guinea fowl were reared in free-range and barn conditions. Birds were slaughtered at 14, 16 and 18 weeks old to determine meat quality traits. Some digestive traits were also determined. The type of production system affected the yellowness of breast meat significantly, and guinea fowl reared in the free-range system had yellower breast meat. The pH of both breast and thigh meat increased at older ages. Water-holding capacity, cooking loss and drip loss of breast and thigh meat were not affected by production system. Drip loss of meat decreased at older slaughter ages. The ratios of digestive system organ weights to body weight mostly decreased at older ages.Keywords: Digestive tract, free-range, meat colour, water holding capacity, p
Performance of fast, medium and slow growing broilers in indoor and free-range production systems
This study compared growth and carcass traits of 2 medium-growth crossbred, 4 slow-growth crossbred, 1 commercial slow-growth and 1 commercial fast-growth broiler strains raised in indoor and free-range production systems. One hundred twenty chicks of each strain were raised in each production system. Chicks were raised in indoor pens at a density of 10 chicks per m2. From day 29 until slaughter at 84 days of age, chicks in the free-range system were given outdoor access through doors that were open between 8.00 - 17.00 hours. The study found live weight, feed efficiency, and mortality were significantly affected by strain. However, no significant differences were found between the production systems. Outdoor access varied significantly among strains, with the commercial high-growth and medium-growth crossbred strains making less use of outdoor areas. In terms of performance traits, none of the strains showed any significant differences in performance between the indoor and free-range production systems. However, significant differences among the strains in carcass traits, pH, and colour values of thigh and breast meat were observed in connection with differences in growth rate. Moreover, carcass and breast yields were greater in fast and medium-growth broilers, while ratios of edible inner organs were greater in medium and slow-growth broilers.
Keywords: abdominal fat, animal welfare, breast to thigh ratio, feed efficiency, outdoor access, slaughter and carcass trait
Effects of dietary supplementation of L-carnitine on performance, carcass and meat characteristics of quails
The present study was conducted to determine the effects of feeding diets containing two levels of metabolizable energy (12.13 or 11.72 MJ ME/kg) and two different fat sources (sunflower- and fish-oil) with or without supplemental L-carnitine (0 or 50 mg/kg diet) on growth performance and carcass and meat characteristics of Japanese quails. Two hundred and forty day-old male quail chicks were randomly assigned to eight treatment groups, each subdivided into three replicates of 10 chicks. The chicks were raised from hatch until 5 wks of age. Feeding the diet containing 12.13 MJ ME/kg increases body weight and body weight gain significantly, and improved the feed conversion ratio above that of the lower energy diet. Feed intakes of the birds were unaffected by treatments. The cold carcass yield of quails fed the diet containing sunflower oil was significantly higher than those receiving the diets containing fish oil. After 35 days of feeding the diet containing the standard energy level (12.13 MJ ME/kg) the thigh yield of the birds was significantly higher than that of the chicks on the lower energy diet. Dietary treatments did not affect pH values of edible meat in the quails. Feeding diets containing sunflower oil and L-carnitine significantly decreased malonaldehyde (MA) amounts in the edible meat. The crude protein content of the edible meat fraction was significantly higher when the dietary energy level was decreased from 12.13 to 11.72 MJ ME/kg diet. Decreasing dietary energy levels significantly decreased the “L” (lightness) and “b” values (less yellow) of the meat, while dietary L-carnitine supplementation resulted in a significant increase in “L” value. The total edible meat of the quails on the diets containing fish oil had a higher “a” value (more red) than the quails receiving sunflower oil in their diets. It was concluded that additional studies are required to clarify the role of dietary L-carnitine in the oxidation of long-chain fatty acids, its antioxidant properties and its importance in energy metabolism in Japanese quails. Keywords: L-carnitine; metabolizable energy; fat sources; carcass quality; shelflife of edible meat South African Journal of Animal Science Vol. 37 (3) 2007: pp.189-20
Effect of reusing litter on broiler performance, foot-pad dermatitis and litter quality in chickens with different growth rates
Methods to Determine Neutrino Flux at Low Energies:Investigation of the Low Method
We investigate the "low-" method (developed by the CCFR/NUTEV
collaborations) to determine the neutrino flux in a wide band neutrino beam at
very low energies, a region of interest to neutrino oscillations experiments.
Events with low hadronic final state energy (of 1, 2 and 5 GeV)
were used by the MINOS collaboration to determine the neutrino flux in their
measurements of neutrino () and antineutrino (\nub_\mu) total cross
sections. The lowest energy for which the method was used in MINOS is
3.5 GeV, and the lowest \nub_\mu energy is 6 GeV. At these energies, the
cross sections are dominated by inelastic processes. We investigate the
application of the method to determine the neutrino flux for ,
\nub_\mu energies as low as 0.7 GeV where the cross sections are dominated by
quasielastic scattering and (1232) resonance production. We find that
the method can be extended to low energies by using values of 0.25
and 0.50 GeV, which is feasible in fully active neutrino detectors such as
MINERvA.Comment: 25 pages, 32 figures, to be published in European Physics Journal
Retrograde intrarenal surgery (RIRS), regular and small sized percutaneous nephrolithotomy (PCNL) in daily practice : European Association of Urology Section of Urolithiasis (EULIS) Survey
A wide selection of both anterograde and retrograde mini-invasive procedures exist for stones' treatment. The 2016 European Association of Urology (EAU) guidelines still don't univocally define a best option. Our purpose is to give an overview on some European Stone Centers' customs and to compare real life clinical practice with statements of opinion leaders and Guidelines
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