COMPARATIVE GROWTH RATES OF SHORTHORN AND CROSSBRED BEEF CALVES FROM BIRTH TO 1 YEAR OF AGE

1966 ◽  
Vol 46 (3) ◽  
pp. 217-224 ◽  
Author(s):  
M. Hidiroglou ◽  
W. A. Jordan ◽  
G. M. Carman ◽  
C. Bernard ◽  
L. A. Charette
Keyword(s):  
Growth Rates ◽  
Significant Source ◽  
Beef Calves ◽  
Sources Of Variation

During the 3 years 1959, 1960, and 1961 the purebred Shorthorn herds at the Experimental Farms at Ottawa, Lennoxville, and Kapuskasing were randomly bred to Shorthorn, Angus, Hereford, and Charolais bulls. Three bulls per breed were used each year. Birth weights and rate of gain from birth to 1 year of age were measured in the 254 calves produced. Breed of sire, sex, year of birth, and age of dam were found to be significant sources of variation contributing to weight at birth, but only breed of sire was a significant source of variation in the rate of gain from birth to 1 year of age. Charolais-sired calves were heaviest at all ages, and Hereford next heaviest at all ages. Angus-sired calves were lightest at birth two years of three, but at weaning they were heavier than the purebred Shorthorn calves. The purebred Shorthorns were lightest at weaning and at 1 year of age.

Concentrations of glucose, albumin, inorganic phosphate and sodium in the blood of beef calves at 2 ½ months of age and their relationships with subsequent weight gain

1980 ◽  
Vol 94 (1) ◽  
pp. 95-104 ◽  
Author(s):  
G. J. Rowlands
Keyword(s):  
Growth Rate ◽  
Blood Glucose ◽  
Growth Rates ◽  
Inorganic Phosphate ◽  
The Body ◽  
The Other ◽  
Growth Depression ◽  
Blood Samples ◽  
Beef Calves ◽  
Body Weights

SummaryBlood samples were taken at 9, 10 and 11 weeks of age from 230 male Hereford × Friesian calves, the progeny of 12 Hereford bulls. Concentrations of blood glucose, serum albumin, inorganic phosphate and sodium were measured and correlated with body weights and growth rates until slaughter at 19½ months of age.Correlations between growth rates and glucose concentrations (0·44) and between growth rates and albumin concentrations (0·38) were observed until 4 months of age. Similar correlations between body weights and blood glucose or albumin concentrations persisted until 6 months of age. By 10 months, however, the correlations had begun to decline, and by slaughter they had become insignificant.Correlations between growth rates and inorganic phosphate or sodium concentrations were smaller, and also decreased with age.The effect of hypoglycaemia on growth rate was compared with the effect of enzootic pneumonia. Although the 10% of calves with the lowest glucose concentrations were growing 24% more slowly than the other calves at the time of sampling, this growth depression was not related to pneumonia, and they subsequently made up for most of the early loss of growth.Three blood samples were also taken from 22 Hereford bulls. No significant correlations were observed between the blood composition of the bulls and the body weights or weight gains of their progeny.

INFLUENCE OF RESHEARING JUST PRIOR TO BREEDING ON REPRODUCTIVE PERFORMANCE OF A SOUTHDOWN FLOCK SELECTED FOR DATE OF BIRTH

1973 ◽  
Vol 53 (3) ◽  
pp. 399-403
Author(s):  
F. A. THRIFT ◽  
R. H. DUTT
Keyword(s):  
Statistical Model ◽  
Breeding Season ◽  
Reproductive Performance ◽  
Significant Source ◽  
Breeding Period ◽  
Sources Of Variation ◽  
Treatment Interaction

Data involving 130 ewe-yr observations were collected over a 2-yr period from a flock of purebred Southdown sheep that had closed to outside breeding since 1957 and selected for date of birth. Three treatments were imposed on the flock just prior to the breeding season: (1) rams unsheared, ewes unsheared; (2) rams sheared, ewes unsheared; and (3) rams sheared, ewes sheared. All ewes and rams were shorn each year during the 2nd wk of May. The ewes and rams were reshorn according to treatment each year on 28 July and a 120-day breeding period began immediately thereafter. The ewe traits studied were date of first estrus, date of conception, lambing date, lambs born per ewe lambing, and lambs reared per ewe lambing. The data were analyzed using a statistical model that included year, treatment, year by treatment interaction, and sire within year and treatment. Year, treatment, and the year by treatment interaction were all nonsignificant sources of variation influencing the various traits. However, sire to which the ewes were bred was a significant source of variation for date of first estrus, date of conception, lambing date, and lambs born per ewe lambing, but was nonsignificant for lambs reared per ewe lambing.

The concentration of minerals in the blood of genetically diverse groups of sheep:V. Concentrations of copper, calcium, phosphorus, magnesium, potassium, and sodium in the blood of lambs and ewes

1971 ◽  
Vol 76 (3) ◽  
pp. 513-521 ◽  
Author(s):  
Gerald Wiener ◽  
A. C. Field
Keyword(s):  
Blood Plasma ◽  
Whole Blood ◽  
Significant Interaction ◽  
The Other ◽  
Significant Source ◽  
Calcium Phosphorus ◽  
Sources Of Variation ◽  
Mineral Levels ◽  
Diverse Groups ◽  
Birth Type

SUMMARYConcentrations of Cu, Ca, P, Mg, K and Na were examined in the blood plasma (whole blood for P) of 149 adult ewes and their 244, 15-week-old lambs in a grassland flock of sheep. The ewes were 3 or 4 years old and of five crossbred types produced by mating Scottish Blackface females to Border Leicester, dun Forest, Dorset Horn, Finnish Landrace and Tasmanian Merino rams. The lambs in turn were the offspring of these crossbred ewes, and two rams of each of the Oxford Down, Southdown, Soay breeds and one Cheviot ram.Breed of sire (but not sire within breed) was a significant source of variation in the concentration of all the minerals, except Na, in the blood of both ewes and lambs. Other factors considered were age of ewe and sex, birth type, type of rearing, and date of birth of lamb. None of these appeared to be significant sources of variation except that twins and triplets, if reared as such, had higher concentrations of Ca in their blood than lambs born and reared as singles; however the ewes with singles were on different pasture from those rearing 2–3 lambs. For the mineral levels in the blood of the lambs there was no significant interaction of breed of ram with cross-breed of ewe. The lambs had substantially higher concentrations of Cu and P in their blood than their mothers and also significantly higher concentrations of Ca, Mg and possibly K. This may not be attributable to age alone because the lambs and their mothers also differed in genotype.Heritability estimates based on parent-offspring regression were 0·4 ±0·14 for Cu and less than 0·2 for the other minerals.

Factors affecting birth weight and performance to weaning of beef calves in the dry tropics of north Queensland

1978 ◽  
Vol 18 (93) ◽  
pp. 494 ◽  
Author(s):  
L Winks ◽  
PK O'Rourke ◽  
PC Venamore ◽  
R Tyler
Keyword(s):  
Growth Rate ◽  
Birth Weight ◽  
Least Squares ◽  
Growth Rates ◽  
Least Squares Method ◽  
Factors Affecting ◽  
Calf Growth ◽  
Beef Calves ◽  
Dry Tropics ◽  
And Performance

Data from 533 calves from 321 Shorthorn cows at 'Swan's Lagoon', north Queensland, were analysed by the least-squares method. Calves were sired by either Sahiwal or Brahman bulls. Birth weights, growth rates and corrected 180-day weights were comparable in Brahman and Sahiwal cross calves. Age of dam had a significant effect on performance with cows 5-8 years and 9+ years producing heavier calves than cows 3-4 years of age. Calves born early in the season were significantly superior to calves born later and males outperformed females throughout, being 8-9 per cent heavier at 180 days. Pre-calving weight of the cow was positively correlated with calf growth rate and 180 day weight. Calf gains were inversely related to cow gains from birth to weaning. Calf birth weight was significantly correlated with calf growth rate and 180-day weight.

A comparison of the growth rate of single and twin born beef calves

1990 ◽  
Vol 1990 ◽  
pp. 5-5
Author(s):  
M.G. Diskin ◽  
T.G. McEvoy ◽  
J.M. Sreenan
Keyword(s):  
Growth Rate ◽  
Litter Size ◽  
Economic Efficiency ◽  
Simulation Study ◽  
Growth Rates ◽  
Biological Efficiency ◽  
Published Data ◽  
Beef Calves ◽  
Beef Cow ◽  
Birth Type

It is frequently hypothesised that Increasing the litter size of the beef cow would increase output and biological efficiency. Such hypothesis is supported by the simulation study of Guerra-Martlnez et al (1987), which Indicated that twinning would Increase biological and economic efficiency of beef production by 20 to 25%. However, there is little published data on the comparative growth rates of single-born, single-reared and twin-born and twin-reared beef calves. The objective of the present study was to determine the effect of birth type (single or twin) on growth rate from birth through to beef and on final carcase weight, carcase conformation and fatness level.

scholarly journals Minimal variation in eutherian brain growth rates during fetal neurogenesis

2017 ◽  
Vol 284 (1854) ◽  
pp. 20170219 ◽  
Author(s):  
Andrew C. Halley
Keyword(s):  
Growth Rates ◽  
Brain Size ◽  
Early Ontogeny ◽  
Growth Patterns ◽  
Body Growth ◽  
Adult Brain ◽  
Brain Growth ◽  
Physiological Variables ◽  
Sources Of Variation ◽  
Eye Opening

A central question in the evolution of brain development is whether species differ in rates of brain growth during fetal neurogenesis. Studies of neonatal data have found allometric evidence for brain growth rate differences according to physiological variables such as relative metabolism and placental invasiveness, but these findings have not been tested against fetal data directly. Here, we measure rates of exponential brain growth acceleration in 10 eutherian mammals, two marsupials, and two birds. Eutherian brain acceleration exhibits minimal variation relative to body and visceral organ growth, varies independently of correlated growth patterns in other organs, and is unrelated to proposed physiological constraints such as metabolic rate or placental invasiveness. Brain growth rates in two birds overlap with eutherian variation, while marsupial brain growth is exceptionally slow. Peak brain growth velocity is linked in time with forebrain myelination and eye opening, reliably separates altricial species born before it from precocial species born afterwards, and is an excellent predictor of adult brain size ( r 2 = 0.98). Species with faster body growth exhibit larger relative brain size in early ontogeny, while brain growth is unrelated to allometric measures. These findings indicate a surprising conservation of brain growth rates during fetal neurogenesis in eutherian mammals, clarify sources of variation in neonatal brain size, and suggest that slow body growth rates cause species to be more encephalized at birth.

Rearing dairy beef calves by multiple suckling. 2. Effects on liveweight gain of calves

1975 ◽  
Vol 15 (74) ◽  
pp. 314 ◽  
Author(s):  
AG Kaiser ◽  
GH O'Neill
Keyword(s):  
Growth Rate ◽  
Growth Rates ◽  
Early Lactation ◽  
Stocking Rate ◽  
Calf Growth ◽  
Beef Calves ◽  
Significant Difference ◽  
Kikuyu Grass ◽  
Temperate Pastures ◽  
Linear Decline

Three experiments were conducted in which dairy cows multiple suckled beef x dairy cross calves during early lactation. After weaning calves grazed nitrogen fertilized kikuyu grass (Pennisetum clandestinum). In the first experiment each cow suckled two, three or four calves for 12 weeks. Pre-weaning calf growth rate increased significantly (P < 0.01) as the number of calves suckled was reduced, In the second experiment, calves suckled at three per cow for 6, 9 or 12 weeks gained at similar rates to weaning, reaching weaning liveweights of 52, 64 and 72 kg respectively. Neither the number of calves suckled in experiment 1 nor the length of the suckling period in experiment 2 significantly affected post-weaning growth rates. In the third experiment there was no significant difference between the growth rates of calves sired by Friesian and Angus bulls. After weaning, stocking rate treatments were imposed, there being a significant (P < 0.05) but small linear decline in growth rate as stocking rate was increased. The post-weaning growth rates of calves in all three experiments were poor when compared with growth rates reported for calves grazing temperate pastures.

GROWTH PATTERNS OF RANGE BEEF CALVES OVER DISCRETE PREWEANING INTERVALS

1989 ◽  
Vol 69 (4) ◽  
pp. 865-869 ◽  
Author(s):  
K. M. HAVSTAD ◽  
M. J. McINERNEY ◽  
S. B. CHURCH
Keyword(s):  
Key Words ◽  
Growth Rates ◽  
Seasonal Variations ◽  
Growth Patterns ◽  
Seasonal Growth ◽  
Management Performance ◽  
Beef Calves ◽  
Maximum Interval

Suckling range beef calf production demonstrates periodicity despite consistency of management. Performance of calves within 33- to 50-d intervals from birth to weaning over nine seasons demonstrated maximum interval growth of approximately 1 kg d−1, but average seasonal growth rates varied from 0.79 to 0.99 kg d−1. Maximizing available forages for the final 33 d preweaning could minimize seasonal variations in calf production. Key words: Calf production, liveweight gain, rangelands

Sign in / Sign up

Export Citation Format

Share Document