scholarly journals The Columbian Restriction Gene, Co, and Early Growth Rate in the Domestic Fowl

1984 ◽  
Vol 63 (3) ◽  
pp. 586-588
Author(s):  
THOMAS W. FOX ◽  
J. ROBERT SMYTH
1951 ◽  
Vol 30 (3) ◽  
pp. 343-361 ◽  
Author(s):  
John W.A. Brant
Keyword(s):  

2014 ◽  
Vol 30 (1) ◽  
pp. 1-13 ◽  
Author(s):  
M. Sahraei

Continuous genetic selection and improvement in nutrition have led to a very fast growth rate in modern strains of broiler chickens. Metabolic disorders such as ascits, sudden death syndrome and leg problems are related to a rapid early growth rate in poultry, especially in broilers, and their incidence can be decreased by slowing early growth. The use of management tools to reduce metabolic disorders that rely primarily on decreasing feed consumption, The feed restriction programs is on of the main techniques in growth curve manipulation for increasing production efficiency in broiler chicken in alleviate the incidence of some metabolic disorders and can be used to reduction the unfavorable effects of fast growth rate in broiler chicken production industry, and could be profitable in broiler chickens production efficiency. This article implicated on new findings in about different feed restriction programs effects on these problems in broiler chickens.


Author(s):  
A.J. Morris ◽  
G.E. Pollott

To date commercial broiler breeders have focused primarily on increasing early growth rate in selection programmes aimed at improving overall production efficiency. In commercial programmes, early growth rate is simplified to a single body weight measure taken at a fixed age during the growth phase approaching common slaughter weights. Most recent selection studies report heritabilities from experimental populations that are at best, synthesised from crossing modern broiler material from several different sources (Leenstra et al, 1986; Wang et al, 1991). Therefore, such populations are likely to exhibit greater heterozygosity than many commercial lines which have undergone many generations of intense selection in closed populations. This paper reports heritabilities estimated using both least squares and derivative-free maximum likelihood techniques for data from a commercial breeder dam line which has remained closed since its inception in 1975.


1989 ◽  
Vol 37 (3) ◽  
pp. 207 ◽  
Author(s):  
IR Noble

The genus Eucalyptus L'Hérit. dominates most of the forests and woodlands of Australia. Many stands consist of intimate mixtures of species from different subgenera. The ecological traits of the two largest subgenera, Symphyomyrtus and Monocalyptus, are reviewed. Consistent differences in herbivore and parasite damage to leaves; in water relations; in tolerance to waterlogging, flooding, salinity and frost; in nutrient usage; in response to Phytophthora cinnamorni; and in early growth patterns are described. These can be summarised as differences in leaf chemistry; in root morphology, chemistry and activity; and in early growth rates. It is suggested that the differences in the ecological traits, and especially in the early growth rate, may help explain the coexistence of closely related species of similar habits in eucalypt communities.


1979 ◽  
Vol 59 (1) ◽  
pp. 81-85 ◽  
Author(s):  
S. FREYMAN ◽  
G. A. KEMP ◽  
D. B. WILSON

Growth and rates of photosynthesis of two accessions and two cultivars (Great Northern 1140 and Sutter Pink) of bean (Phaseolus vulgaris L.) were compared at 10, 15, and 23 °C in a controlled environment cabinet. The leaf area, dry matter, and rate of total apparent photosynthesis of one of the accessions was significantly higher after growth for 13 days at 10 °C than that of the commercial cultivars. This advantage was not maintained at 23 °C. In another experiment, growth of the same four cultivars was compared at light/dark temperatures of 10/10, 15/12, and 23/18 °C. The two accessions established a higher leaf area and accumulated more dry matter at the cooler temperatures than the commercial cultivars, but lost this advantage at the highest temperatures. In a field trial, the accessions had a similar rapid early growth but fell behind later in the season. Ideally, a bean cultivar for the Canadian prairie should incorporate the accession’s ability for rapid growth and leaf expansion at cool temperatures with a growth rate during mid-summer comparable to that of Great Northern 1140.


2017 ◽  
Vol 67 (3-4) ◽  
pp. 239-249 ◽  
Author(s):  
Yuleimis T. Martínez-Caballero ◽  
Brian C. Bock ◽  
Isabel Pérez ◽  
Ángela M. Ortega-León ◽  
Vivian P. Páez

Large initial body size and rapid early growth rate are important in many species, both because predation rates decline as individuals grow and because females that attain a larger adult body size are more fecund. To identify possible factors contributing to size and growth rate variation in hatchling green iguanas, we artificially incubated six clutches at three constant temperatures to test for effects of incubation temperature and/or clutch effects on initial size and growth rate. Higher incubation temperatures resulted in significantly shorter incubation periods but did not influence initial body size. There were significant differences among clutches in egg size, and also in initial hatchling body size, even after correcting for differences in egg size among clutches. A subset of hatchlings from each nest was reared in semi-natural conditions for four months, with individuals from the high incubation temperature condition exhibiting the slowest longer-term growth rates. No clutch effects were detected in the growth rate analyses. The observed variation in early growth rate of juvenile iguanas seems to be selectively important and this variation may be due in part to the conditions the eggs experience during incubation, but clutch effects in this study were limited to egg size and initial hatchling body size variation, but were not found for subsequent growth rates.


Author(s):  
E. M. Abubakar ◽  
E. K. Rabo

Khaya senegalensis (Desr) A. Juss is a perennial deciduous tree which has many uses in developing nations. The population of the tree is rapidly declining due to no conservation efforts to prevent the species from endanger and extinction. At the moment there is dearth information on manure types required to raise healthy seedlings of the tree species in the study area. To conserve this genetic resource, germination and early growth rate experiment was carried out using seeds collected from three locations (eco-zones) (Alkaleri, Bauchi and Toro). Matured seeds of K. senegalensis were collected from mother tree stand in the three locations. One hundred and fifty seeds (150) from each location were sown in perforated polythene pots at an average depth of 2-3 cm. After germination i.e. 30 days after planting, different manures were applied to the seedlings. The experiment was laid out in a Completely Randomized Design (CRD) with three treatments, namely: poultry dung, cow dung and NPK manures; the experiment was replicated four times. Data on seeds germination variables of interest (seedling heights, number of leaves, collar diameter, leaf area, leaf width, leaf length and fresh weights) were measured. Seedlings height were measured using meter rule, collar diameters using a venier caliper, numbers of leaves were determined by manual counting the number of leaves on the seedlings, leaf area was measured by tracing leaves of seedling on a graduated graph sheet. Data collected on seed germination and early growth rate were subjected to descriptive statistics and inferential statistics (ANOVA). Where significant differences occurred, Tukey test was used to separate the means. Based on this finding, germination of seeds commenced after 10 to 14 days. Locations and manure types had significant effects on the mean heights, number of leaves, collar diameter, leaf area, leaf width, length and fresh weights of K. senegalensis seedlings in the study area. Thus, for species conservation and genetic heredity, seeds sourced from Bauchi eco-zone was the best with poultry manure as the best performed manure for the raising of K. senegalensis seedlings in the study area.


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