A Relation between mature weight and time taken to mature in mammals

Taylor, C. S.

doi:10.1017/s0003356100025629

Cited by 82 publications

(38 citation statements)

References 2 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Selection for body size under different environmental conditions is subject to the above argument since the trait under optimal and sub-optimal environments may have different physiological manifestations (Robertson, , 1960(Robertson, , 1963Taylor, 1965). An examination of growth in Tribolium under different levels of nutrition (Y.…”

Section: Discussionmentioning

confidence: 99%

Selection for larval growth inTriboliumunder two levels of nutrition

Yamada¹,

Bell²

1969

Genet. Res.

View full text Add to dashboard Cite

Selection for large and small 13-day larval weight in Tribolium castaneum was studied for sixteen generations in a replicated experiment to evaluate the effectiveness of various selection methods and the importance of genotype by environment interactions under two levels of nutrition.Direct selection responses generally were larger than correlated ones under both Good and Poor nutritional environments. However, contrary to theoretical expectations, those populations selected on average performance in both environments were not superior for this attribute.Asymmetrical responses were observed to be dependent on the environment of selection. When selection was based on performance in the optimal environment, the asymmetry was observed toward small size. This situation in the sub – optimal environment was completely reversed. This phenomenon was discussed in terms of physiological limits rather than gene frequency and directional dominance.It was proposed that selection of compound traits such as body weight at a fixed age may affect the component characters quite differently. As the latter are differentiated by direction and environment of selection, the compound trait may reflect parametric changes and enhanced genotype by environment interactions. Such changes hamper the precision of current selection theory for predicting response even in the short run.

show abstract

Section: Discussionmentioning

confidence: 99%

Selection for larval growth inTriboliumunder two levels of nutrition

Yamada¹,

Bell²

1969

Genet. Res.

View full text Add to dashboard Cite

show abstract

“…It is referred to as growth rate or maturity rate in relation to mature weight. The value k -1 is the interval of time spent to attain maturity and serves to measure changes in the degree of maturity (Taylor, 1965). 4.…”

Section: Obtaining Growth Parametersmentioning

confidence: 99%

Description and comparison of growth parameters in Chianina and Nelore cattle breeds

Carrijo

Duarte²

1999

Genet. Mol. Biol.

View full text Add to dashboard Cite

Weight data from birth to 18 months of age of Nelore and Chianina, both meat-producing cattle breeds, were analyzed. Data were corrected for significant effects of environment and utilized to estimate genetic parameters through the non-linear von Bertalanffy model. Average values found for growth parameters in Nelore were: mature weight (A), 312.87 kg; integration constant (B), 0.49; maturity rate (k), 0.13; age at inflection point (T (I) ), 3.29 months; weight at inflection point (P (I) ), 92.70 kg, and maturity interval (1/k), 8.04 months. For the Chianina animals, the values were 751.38 kg, 0.59, 0.10, 6.64 months, 222.63 kg, and 10.98 months, respectively. Nelore animals exhibited higher maturity rate, smaller maturity intervals, reaching mature weights younger than Chianina animals, although lighter than these at maturity. Heritability estimates presented low values, mainly for mature weight (0.093 and 0.212), age at inflection point (0.062 and 0.202), weight at inflection point (0.093 and 0.212) and maturity interval (0.057 and 0.309) (for Nelore and Chianina, respectively). The parameters mature weight and weight at inflection point presented positive genetic correlations with weights at different ages and with similar trends, increasing as age increased, in both breeds. Considering the development period analyzed, from birth to 18 months of age, the parameter maturity rate and the weights at different ages showed genetic correlations which increased until the weight at 150 and 205 days in Nelore and Chianina, respectively, and decreased from these ages on, and the genetic correlations among the parameter maturity interval and the weights at different ages were negative. They decreased until the weights at 150 and 205 days, respectively, in Nelore and Chianina, and increased from these ages on.

show abstract

“…First, comparisons between animals within a species or even within a breed at a constant weight or age in terms of body composition or the efficiency of food conversion during growth are dominated by the effect of stage of maturity. The individual having the larger mature size will, by definition, be less mature at a given weight or age (Taylor, 1965) and thus (other things being equal) tend to be leaner. In this example, one would rarely expect to find a healthy, properly-fed Hereford bull to be leaner than a Charolais bull at 400 d. Second, the mean values and correction factors given by the Agricultural Research Council (1980) cannot be used with confidence to predict either the composition of gains in a particular phenotype fed on a particular ration or the age and weight at which its body composition will be ideal for slaughter.…”

Section: Proceedings Of the Nutrition Societymentioning

confidence: 99%

Factors affecting the body composition of growing and adult animals

Webster

1986

Proc. Nutr. Soc.

View full text Add to dashboard Cite

School of Veterinary Science, L a n d i d , Bristol BS18 7DUThe body composition of any animal is the consequence of the effect of nutrition over a period of time on the genetic and physiological factors that, together with nutrition, determine its phenotype. This paper will consider only those aspects of body composition that are of major importance, first in the conversion of animal feed to saleable product in meat animals and, secondly, in the quality of the meat as perceived by the consumer. These are (a) killing-out ratio, i.e. empty carcass weight:total body-weight at the time of slaughter; (b) the proportions of dissectable bone, lean and fat in the carcass; (c) the chemical composition of the lean and adipose tissue.The quantity of published information on the body composition of meat animals (and laboratory species used as models for meat animals) is enormous. This paper deals mainly with beef cattle. The Agriculture and Food Research Council (Agricultural Research Council, 1980) has produced a very comprehensive review of the literature relating to the body composition of ruminants. This brief paper is not intended to compete with this review nor does it attempt to bring it up to date in a bibliographic sense. Its purpose is only to outline the range of genetic, physiological and nutritional factors that affect body composition and explore the interactions between them.

show abstract

A Relation between mature weight and time taken to mature in mammals

Cited by 82 publications

References 2 publications

Selection for larval growth inTriboliumunder two levels of nutrition

Selection for larval growth inTriboliumunder two levels of nutrition

Description and comparison of growth parameters in Chianina and Nelore cattle breeds

Factors affecting the body composition of growing and adult animals

Contact Info

Product

Resources

About