Intake of milk and pasture and growth rate of calves reared by cows with high or low potential for milk production

2018 ◽  
Vol 58 (3) ◽  
pp. 523 ◽  
Author(s):  
F. J. Roca Fraga ◽  
N. Lopez-Villalobos ◽  
N. P. Martin ◽  
P. R. Kenyon ◽  
S. T. Morris ◽  
...  

Milk production of cows influences calf weaning weight, which is the major driver for economic return in a cow–calf operation. The growth trajectory of 64 steer calves resulting from a terminal cross between Angus or Simmental bulls with Angus, Angus cross Holstein Friesian, Angus cross Jersey and Angus cross KiwiCross cows was examined during the pre-weaning period from birth (D0) to weaning (D148) and during the post-weaning period until a year of age (D365). Random regression models were used to model milk intake and liveweight of calves throughout lactation. These models were a good fit to the data (r2 = 0.77 for milk intake and r2 = 0.99 for liveweight). Total energy intake from milk was greater (P < 0.05) for the Angus cross Holstein Friesian-, Angus cross Jersey- and Angus cross KiwiCross-reared steers than for those reared by Angus dams. Additional milk intake increased liveweight of steers from D90 to D365, but the magnitude of the effect decreased as the calves aged. Simmental-sired steers had a greater liveweight response to additional milk intake than Angus-sired steers at D120 and D148, probably reflecting greater growth potential from out-crossed calves.

2013 ◽  
Vol 12 (1) ◽  
pp. 143-153 ◽  
Author(s):  
D.J.A. Santos ◽  
M.G.C.D. Peixoto ◽  
R.R. Aspilcueta Borquis ◽  
R.S. Verneque ◽  
J.C.C. Panetto ◽  
...  

2016 ◽  
Vol 46 (9) ◽  
pp. 1649-1655
Author(s):  
Mariana de Almeida Dornelles ◽  
Paulo Roberto Nogara Rorato ◽  
Luis Telo Lavadinho da Gama ◽  
Fernanda Cristina Breda ◽  
Carlos Bondan ◽  
...  

ABSTRACT: The objective of this study was to compare the functions of Wilmink and Ali and Schaeffer with Legendre polynomials in random regression models using heterogeneous residual variances for modeling genetic parameters during the first lactation in the Holstein Friesian breed. Five thousand eight hundred and eighty biweekly records of test-day milk production were used. The models included the fixed effects of group of contemporaries and cow age at calving as covariable. Statistical criteria indicated that the WF.33_HE2, LEG.33_HE2, and LEG.55_HE4 functions best described the changes in the variances that occur throughout lactation. Heritability estimates using WF.33_HE2 and LEG.33_HE2 models were similar, ranging from 0.31 to 0.50. The LEG.55_HE4 model diverged from these models, with higher estimates at the beginning of lactation and lower estimates after the 16th fortnight. The LEG55_HE4, among the three better models indicated by the index, is the one with highest number of parameters (14 vs 34) and resulted in lower estimation of residual variance at the beginning and at the end of lactation, but overestimated heritability in the first fortnight and presented a greater difficulty to model genetic and permanent environment correlations among controls. Random regression models that used the Wilmink and Legendre polynomials functions with two residual variance classes appropriately described the genetic variation during lactation of Holstein Friesians reared in Rio Grande do Sul.


2014 ◽  
Vol 49 (5) ◽  
pp. 372-383 ◽  
Author(s):  
Maria Gabriela Campolina Diniz Peixoto ◽  
Daniel Jordan de Abreu Santos ◽  
Rusbel Raul Aspilcueta Borquis ◽  
Frank Ângelo Tomita Bruneli ◽  
João Cláudio do Carmo Panetto ◽  
...  

The objective of this work was to compare random regression models for the estimation of genetic parameters for Guzerat milk production, using orthogonal Legendre polynomials. Records (20,524) of test-day milk yield (TDMY) from 2,816 first-lactation Guzerat cows were used. TDMY grouped into 10-monthly classes were analyzed for additive genetic effect and for environmental and residual permanent effects (random effects), whereas the contemporary group, calving age (linear and quadratic effects) and mean lactation curve were analized as fixed effects. Trajectories for the additive genetic and permanent environmental effects were modeled by means of a covariance function employing orthogonal Legendre polynomials ranging from the second to the fifth order. Residual variances were considered in one, four, six, or ten variance classes. The best model had six residual variance classes. The heritability estimates for the TDMY records varied from 0.19 to 0.32. The random regression model that used a second-order Legendre polynomial for the additive genetic effect, and a fifth-order polynomial for the permanent environmental effect is adequate for comparison by the main employed criteria. The model with a second-order Legendre polynomial for the additive genetic effect, and that with a fourth-order for the permanent environmental effect could also be employed in these analyses.


1975 ◽  
Vol 55 (4) ◽  
pp. 565-570 ◽  
Author(s):  
R. HIRONAKA ◽  
G. C. KOZUB ◽  
S. B. SLEN

Forty Holstein–Friesian cows were fed concentrate at one of five levels (0.15, 0.20, 0.25, 0.30, or 0.35 kg concentrate/kg milk produced) and alfalfa hay to appetite. In a 280-day lactation period with twice-a-day milking, average milk production was 19.9 kg/day and increased 0.150 kg/0.01-kg increase of concentrate per kilogram of milk produced (P < 0.05). The rate of change in milk production, feed intake, and milk constituents was not affected by the breed–class–average (BCA) index of the cows over the BCA range studied. For each 0.01-kg increase in concentrate per kilogram of milk produced, daily increase in production of solids-not-fat was 0.0138 kg and of protein was 0.0052 kg (P < 0.05). Total energy secreted in milk increased, but not significantly, as the level of concentrate feeding increased. However, the proportion of energy consumed that was secreted in the milk declined from 26.8 to 23.5% (P < 0.10) as the level of concentrate feeding was increased.


2003 ◽  
Vol 76 (3) ◽  
pp. 455-460 ◽  
Author(s):  
A. A. Degen ◽  
R. W. Benjamin

AbstractWe determined milk intake and growth rate of fat-tailed Awassi ram lambs from birth to 30 days of age when sucking ewes that were grazing natural green pasture in the semi-arid Negev. The conversion of milk and energy intake to body mass and body solids gain in the lambs were calculated. Annual rainfall and, as a consequence, pasture availability were below average during the study. Body mass at birth was 4·22 (s.d. 0·71) kg and at 30 days was 12·10 (s.d.1·22) kg for an average daily gain of 256 (s.d.33) g/day. Of the 256 g/day, 100 (s.d.12·3) g/day were body solids, and for every unit body mass increase, proportionately 0·391 was body solids. Milk and energy intakes averaged 1·34 (s.d.0·23) l/day and 5·66 (s.d.0·97) MJ/day, respectively. The volume of milk intake per kg increase in body mass and body solids were 5·2 l and 13·4 l, respectively, whereas, the energy intake per kg increase in body mass and body solids were 22·1 MJ and 56·6 MJ, respectively. Of the total metabolizable milk energy intake, proportionately 0·46 was converted to body energy of the lamb. Although dry matter intake of the ewes was insufficient to prevent body mass loss, they produced sufficient milk to support a relatively high lamb growth rate, presumably by mobilizing fat reserves in the tail.


1976 ◽  
Vol 87 (1) ◽  
pp. 205-211 ◽  
Author(s):  
Y. L. P. Le Du ◽  
R. D. Baker ◽  
J. M. Barker

SUMMARYTwo trials were conducted to measure the herbage intake of South Devon cross calves suckling Hereford × Friesian cows and to test the validity of applying the relationships established between milk and herbage intake and milk intake and live-weight gain for artificially fed calves to suckled calves. In Expt 1 the milk and herbage intakes of eight calves were monitored. Their average milk consumption was 2250 kg and their growth rate was 1·14 kg/day. Both milk consumption and growth rate were higher than those recorded in other studies with artificially-reared calves. Nevertheless, it was possible to predict the herbage intake and growth rate of the calves from the relationship previously established for artificially reared calves. The nutrition of cows in Expt 2 was manipulated to induce changes in milk production and the consequent effect on the herbage intake of their calves assessed. Milk consumption was at a lower level and herbage intakes fell within the expected range. Herbage intake also responded to changes in the milk production of the cows. The observed herbage intakes and live-weight gains were similar to those predicted from previously established relationships with artificially fed calves.


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