Growth rate and changes of the somatotropic axis in beef cattle administered exogenous bovine somatotropin beginning at two hundred, two hundred fifty, and three hundred days of age1

2007 ◽  
Vol 85 (11) ◽  
pp. 2866-2872 ◽  
Author(s):  
B. T. Velayudhan ◽  
K. E. Govoni ◽  
T. A. Hoagland ◽  
S. A. Zinn
Keyword(s):  
Growth Rate ◽  
Beef Cattle ◽  
Bovine Somatotropin ◽  
Somatotropic Axis

The effect of level of environment on sex differences in pre-weaning growth rate in beef cattle

1977 ◽  
Vol 25 (1) ◽  
pp. 47-51 ◽  
Author(s):  
I. R. Hopkins
Keyword(s):  
Growth Rate ◽  
Sex Differences ◽  
Beef Cattle ◽  
Growth Rates ◽  
Additive Models ◽  
Regression Equations ◽  
Male And Female ◽  
Breed Differences ◽  
Per Se ◽  
Simple Regression

SUMMARYUsing pre-weaning records of 3822 calves from 11 Victorian herds, mean male and female growth rates and corresponding sex differences were calculated for each dam age and herd-year class. From these means simple regression equations relating sex differences and growth rates were calculated. There was a close similarity between equations based on dam age means and those based on herd-year means while correlations between sex differences and male growth rates were high.These results showed that sex differences and female growth rates could be predicted reliably from the level of environment as measured by male growth rate. Sex differences predicted by these regression relationships differed markedly from those predicted by the simple multiplicative and simple additive models generally used in adjusting for sex differences in selection.The results also suggested that other differences such as breed differences may be predictable in the same way and that such differences are determined primarily by the level of environment per se rather than differences in the nature of the components contributing to that level.

scholarly journals Genetic aspects of growth and maturing rate in trypanotolerant beef cattle: N'Dama

2021 ◽  
Vol 30 (2) ◽  
pp. 149-156
Author(s):  
O. O Mgbere ◽  
O. Olutogun
Keyword(s):  
Growth Rate ◽  
Beef Cattle ◽  
Growth Traits ◽  
Physiological Stress ◽  
Genetic Parameter ◽  
High Standard ◽  
Parameter Estimates ◽  
Production Environment ◽  
Genetic Progress ◽  
Animal Management

Genetic parameters for Absolute Growth Rate (AGR), Relative Growth Rate (RGR) and Absolute Maturing Rate (AMR) at various age interval from birth to maturity in N 'Dama beef cattle raised in the humid Tropics of Nigeria were estimated. Performance data used were accumulated between 1948 and 1964 at Fasola cattle ranch in Oyo, Nigeria and the number of records analysed ranged from 44 to 678. prewering (B - W) growth and maturing rates in N’Dama calves were 0.377 ± 0.009 kg/day (AGR), 0.643 ± 0.006 %/day (RGR) and 0.120 ± 0.003% A/day (AMR) and fluctuated subsequently, following the animals' state of development and certain physiological stress conditions.  At post weaning (W-12), these rates decreased to 0.249 ± 0.049 kg/day, 0.204 ± 0.029 %/day and 0.075 ± 0.014 % A/day for AGR, RGR and AMR respectively. Estimates of heritability at the various age intervals were considered low in these growth traits with values obtained ranging from 0.03 to 0.24 for AGR, 0.03 to 0.21 for RGR and 0.02 to 0.42 for AMR, with high standard errors. The low estimates though, consistent with literature reports were attributed to the poor standard of animal management and production environment at Fasola. It was evident from this study that selection of N'Dama calves based on post weaning (W-12) growth or maturing rates would yield substantial genetic progress. However, improved animal management and production environment on the ranch would not only improve precision of the genetic parameter estimates but would also enhance N 'Dama growth performance generally.

scholarly journals Real-Time Monitoring of Self-Fed Supplement Intake, Feeding Behaviour, and Growth Rate as Affected by Forage Quantity and Quality of Rotationally Grazed Beef Cattle

Animals ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 1129 ◽  
Author(s):  
José A. Imaz ◽  
Sergio García ◽  
Luciano A. González
Keyword(s):  
Growth Rate ◽  
Beef Cattle ◽  
Real Time ◽  
Temporal Variability ◽  
Feeding Behaviour ◽  
Nutritional Management ◽  
Feeding Frequency ◽  
High Feed ◽  
Supplement Intake

Supplement intake and liveweight (LW) data were collected daily and remotely by digital in-paddock technologies (electronic feeder (EF) and walk-over-weighing scale (WOW)) to study the effect of forage quantity and quality on the intake of a self-fed supplement (molasses-lick blocks (MLB)), LW, liveweight change (LWC), and feeding behaviour of grazing beef cattle. Fifty-two crossbred weaners were rotationally grazed or fed for 254 days on different forages: sudangrass (SG), autumn pastures (P), winter pastures with concentrate (P+C), oat crops (OC), lucerne hay (LH), and oaten hay (OH). Forage quantity and quality were measured on the day of entry (high feed availability) and exit (low feed availability) stages of grazing or hay delivery. The intake of MLB was 111% higher (p < 0.05) at low compared to high feed availability, and this was also reflected in the feeding behaviour of animals (e.g., greater feeding frequency and rate). Moreover, there was a large temporal variability of daily MLB intake (Coefficient of variation (CV) = 146.41%). Supplementing MLB improved LWC only with SG, P, or OH (p < 0.05). The behaviour of animals around MLB reflects changes in feed quantity and quality and could be used to enhance cattle grazing and nutritional management in real time.

Effect of Synovex-S on Growth Rate and Plasma Thyroid Hormone Concentrations in Beef Cattle

1978 ◽  
Vol 46 (1) ◽  
pp. 232-237 ◽  
Author(s):  
S. Kahl ◽  
J. Bitman ◽  
T. S. Rumsey
Keyword(s):  
Growth Rate ◽  
Thyroid Hormone ◽  
Beef Cattle

The significance of coat type in cattle

1960 ◽  
Vol 11 (4) ◽  
pp. 645 ◽  
Author(s):  
HG Turner ◽  
AV Schleger
Keyword(s):  
Growth Rate ◽  
Body Weight ◽  
Beef Cattle ◽  
Heat Dissipation ◽  
Metabolic Efficiency ◽  
Body Temperatures ◽  
Potential Value ◽  
Respiration Rates ◽  
Different Seasons ◽  
Age And Sex

A system of subjective scoring of cattle coats, ranging from very sleek to very woolly, is described. It has been applied to about 1600 animals, of which 500 were Hereford and Shorthorn cows and the rest their progeny from matings in four years to British breed and Zebu bulls. Consistency of scoring within and between observers is satisfactory. Highly significant differences between animals of the same breed persist through different seasons. The repeatability of coat score is 0.6 or more over intervals of up to 17 months. Effects of season, age, and sex are described. Heritability of coat score is estimated at 0.63. Coat scores are well correlated with body temperatures and respiration rates. Coat score and post-weaning growth rate of British breed calves are correlated to such a degree that coat score can be superior to a record of body weight as an estimate of growth capacity. The genetic correlation between coat score and growth rate is high in the British breeds. Evidence of the relation between coat score and growth rate in Zebu cross calves is inconclusive. The observed relationships are discussed with particular reference to their physiological causes. The results indicate the potential value of coat characters in selecting tropical beef cattle. The degree to which these results may be applicable to other populations in other environments is discussed. It is concluded that a sleek coat is important in favouring heat dissipation, but it may have even greater significance as an indicator of metabolic efficiency or of capacity to react favourably to stress.

Comparison of genetic and phenotypic parameters in a purebred and a synthetic beef cattle population

1991 ◽  
Vol 71 (2) ◽  
pp. 279-285 ◽  
Author(s):  
M. F. Liu ◽  
M. Makarechian ◽  
R. T. Berg
Keyword(s):  
Growth Rate ◽  
Birth Weight ◽  
Beef Cattle ◽  
Variance Components ◽  
Growth Traits ◽  
Cattle Population ◽  
Coefficients Of Variation ◽  
Sib Families ◽  
Phenotypic Variations ◽  
Two Populations

Genetic and phenotypic parameters of growth traits from birth to 1 year of age were compared in a multibreed Beef Synthetic (SY) and a purebred Hereford (HE) population managed together under the same environmental conditions and selected for growth rate from 1961 to 1979. Growth traits studied were birth weight, preweaning and postweaning gains. Records of 2077 calves of 70 HE and 100 SY paternal half-sib families were used for analysis. Except for birth weight, phenotypic variances of growth traits were similar for the synthetic (SY) and purebred (HE) populations, but genetic variances were larger in SY than in HE for all growth traits except postweaning gain in males. The coefficients of variation were comparable for all the traits studied in the two populations, indicating that phenotypic variations in the multibreed population and the purebred population were similar. Key words: Variance components, heritability, beef cattle

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