EFFECTS OF CORRECTING FOR FEEDING LEVELS ON ESTIMATES OF GENETIC PARAMETERS OF MILK YIELD AND COMPOSITION

1976 ◽  
Vol 56 (3) ◽  
pp. 523-529 ◽  
Author(s):  
A. K. W. TONG ◽  
B. W. KENNEDY ◽  
J. E. MOXLEY
Keyword(s):  
Energy Intake ◽  
Milk Fat ◽  
Genetic Parameters ◽  
Genetic Relationships ◽  
Protein Yield ◽  
Net Energy ◽  
Yield Traits ◽  
Genetic And Phenotypic Correlations ◽  
Net Energy Intake ◽  
Quadratic Effects

A total of 13,561 Holstein 305-day lactation records were studied to examine the effects of correcting records for linear and quadratic effects of 305-day net energy intake from silage, hay, pasture and meal feeding on estimates of genetic parameters of milk, fat and protein yield and fat and protein percent. Correcting records for net energy intake reduced variances of yield traits, but had little effect on composition trait variances. When expressed as a percentage of the total variance, the relative importance of sire and sire–herd components were unchanged using corrected records, and heritabilities, except for that of protein yield, were unaltered. Cow components of yield traits were reduced relative to other components after records were corrected for feeding levels. Consequently, repeatabilities were reduced as well, suggesting that a large portion of the permanent environmental effects on yield traits may be of nutritional origin. Genetic and phenotypic correlations between yield traits were also reduced appreciably after records were corrected for feed intake. Genetic relationships between milk, fat and protein yield may not be as great as commonly believed.

Genetic and phenotypic correlations between linear type traits and production traits in Holstein-Friesian dairy cattle

1994 ◽  
Vol 59 (2) ◽  
pp. 183-187 ◽  
Author(s):  
S. Brotherstone
Keyword(s):  
Milk Fat ◽  
Genetic Correlations ◽  
Protein Yield ◽  
Yield Traits ◽  
Production Traits ◽  
Linear Type ◽  
Phenotypic Correlations ◽  
Holstein Friesian ◽  
Type Traits ◽  
Genetic And Phenotypic Correlations

AbstractFirst lactation production and linear type records of 72 559Holstein-Friesian cows, calving from 1982 to 1989, were analysed by multivariate restricted maximum likelihood, using a sire model. The data comprised offspring of 1066 randomly used sires, and 91 proven i.e. widely used bulls. All phenotypic correlations between the type traits and the yield traits were small, but moderate genetic correlations were obtained between milk, fat and protein yield and angularity (~—0·43) and between the yield traits and udder depth (~0·44), indicating that higher yielding heifers are more angular and have deeper udders. The heritabilities of the type traits were in line with previous analyses, but those for milk, fat and protein yield were rather high at 0·47, 0·52 and 0·45 respectively

scholarly journals Phenotypic and genetic parameters of milk yield traits in first-calf heifers of Holstein-Friesian breed

2020 ◽  
Vol 70 (2) ◽  
pp. 93-102
Author(s):  
Mladen Popovac ◽  
Aleksandar Miletić ◽  
Nenad Đurić ◽  
Nenad Mićić ◽  
Mihailo Radivojević ◽  
...  
Keyword(s):  
Animal Model ◽  
Milk Fat ◽  
Genetic Parameters ◽  
Yield Traits ◽  
Production Traits ◽  
Age At First Calving ◽  
Holstein Friesian ◽  
Genetic And Phenotypic Correlations ◽  
Positive Correlations

The objective of this paper was to study variability, heritability and correlation of the three production traits in 1409 first-calf heifers of Holstein-Friesian breed; including the determination of the quantity of milk during lactation (ML), the quantity of milk fat during lactation (MM) and the quantity of protein during lactation (PR). According to the obtained results it could be concluded that there were statistically significant differences (P<0.01, P<0.05, P<0.001) between ML, MM and PR regarding the effect of season of the first calving and the length of the first lactation. In addition, there were also significant differences (P<0.01, P<0.001) between ML and PR with respect to the effect of farm on which animals were raised, while on MM variability the year and age at first calving had a significant effect (P<0.05). A share of Holstein genes and the ration which animals were fed had no effect (P>0.05) on variability of any of the examined traits, while the farm on which animals were raised had no effect (P>0.05) on MM, and year and age at first calving did not demonstrate (P>0.05) statistically significant effect on ML and PR. By applying the animal model, based on the use of kinship matrix which involved 3867 animals, by help of REML methodology following heritability coefficients were evaluated: ML h2= 0.25; MM h2= 0.40; PR h2= 0.37. Coefficients determined for genetic and phenotypic correlations indicated existence of complete and positive correlations between these traits the interval of values being from rg = 0.96 between ML and MM to rg = 1.00 between ML and PR.

The effect of increasing the interval between recordings on genetic parameters of test day yields of British Holstein-Friesian heifers

1993 ◽  
Vol 56 (2) ◽  
pp. 159-164 ◽  
Author(s):  
B. L. Pander ◽  
R. Thompson ◽  
W. G. Hill
Keyword(s):  
Milk Fat ◽  
Genetic Parameters ◽  
Covariance Structure ◽  
Protein Yield ◽  
Breeding Value ◽  
Holstein Friesian ◽  
Wide Range ◽  
Genetic And Phenotypic Correlations ◽  
Additional Variance ◽  
Daily Milk

AbstractThe effect of increasing the interval between recordings from 1 month to 2 months was studied by analysis of milk, fat and protein yield records obtained in alternate monthly herd visits. The data comprised records on over 34 000 daughters of 40 proven and 705 young sires which were analysed by multivariate restricted maximum likelihood.Heritability estimates of bimonthly test day records were similar to the average of the estimates for the two corresponding monthly test day records, as were genetic and phenotypic correlations between bimonthly test day and lactation records. A quartic regression removed most of the additional variance due to the wide range of days to first test and therefore the variance-covariance structure of bimonthly test day records could be predicted from that of monthly test day records.The accuracies of prediction of breeding value for 305-day yields of milk, fat and protein using the sum of five bimonthly test day records and the sum of seven 6-weekly tests were estimated to be at least 0·97 and 0·99, respectively, of the accuracy of using 10 monthly test day records.If milk yield were recorded daily, prediction of lactation fat or protein yield from the product of the sum of daily milk yields and the average fat or protein content would be more accurate than using yield and content records solely from test days.

A DAIRY RECORDS STUDY OF THE EFFECTS OF FEEDING LEVELS ON MILK YIELD AND COMPOSITION

1976 ◽  
Vol 56 (3) ◽  
pp. 513-522
Author(s):  
A. K. W. TONG ◽  
B. W. KENNEDY ◽  
J. E. MOXLEY
Keyword(s):  
Milk Yield ◽  
Milk Fat ◽  
Variance Components ◽  
Dairy Herd ◽  
Error Variance ◽  
Energy Concentration ◽  
Net Energy ◽  
Linear Effects ◽  
Net Energy Intake ◽  
Quadratic Effects

A total of 139,720 Holstein and 17,259 Ayrshire 305-day lactation records from the Dairy Herd Analysis Service were studied to estimate linear and quadratic effects of net energy intakes from silage, hay, pasture and meal and effects of silage:hay ratio, roughage:meal ratio and energy concentration on milk yield and composition. Effects of correcting for feeding levels on estimates of herd and cow variance components were studied also. Linear effects of increased net energy intakes from silage, hay, pasture and meal on milk, fat and protein yields were positive (P <.01) for both breeds. For Holsteins, all quadratic effects on milk yield were also positive (P <.01). Quadratic effects of each roughage source on fat and protein yield were negative, but meal had a positive quadratic effect (P <.01). Quadratic effects were inconsistent for the Ayrshires. Both linear and quadratic effects of feeding levels on fat and protein percent were inconsistent for the two breeds. For both breeds, greater silage:hay ratios and energy concentrations increased yields, and greater roughage:meal ratios decreased yields and fat percent (P <.01). Correcting records for net energy intake reduced estimates of herd, cow and error variance components. Repeatability estimates of yield traits were also reduced, but percentage trait repeatabilities were not altered.

scholarly journals Genetic parameters estimates for milk, fat and protein yield analyzed by test day models for Murrah buffaloes in Brazil

2007 ◽  
Vol 6 (sup2) ◽  
pp. 368-371 ◽  
Author(s):  
R. Aspilcueta-Borquis ◽  
A. Tanaka ◽  
L. Albuquerque ◽  
R. Sesana ◽  
L. Seno ◽  
...  
Keyword(s):  
Milk Fat ◽  
Genetic Parameters ◽  
Protein Yield ◽  
Murrah Buffaloes

Position Choice by Drift-Feeding Salmonids: Model and Test for Arctic Grayling (Thymallus arcticus) in Subarctic Mountain Streams, Interior Alaska

1990 ◽  
Vol 47 (10) ◽  
pp. 2039-2048 ◽  
Author(s):  
Nicholas F. Hughes ◽  
Lawrence M. Dill
Keyword(s):  
Energy Intake ◽  
Water Depth ◽  
Focal Point ◽  
Water Velocity ◽  
Net Energy ◽  
Intake Rate ◽  
Arctic Grayling ◽  
Thymallus Arcticus ◽  
Net Energy Intake ◽  
Energy Intake Rate

We develop a model to predict position choice of drift-feeding stream salmonids, assuming a fish chooses the position that maximizes its net energy intake rate. The fish's habitat is represented as a series of stream cross-profiles, each divided into vertical strips characterized by water depth and velocity. The fish may select a focal point in any of these strips, and include several neighbouring strips in its foraging area. The number of prey the fish encounters depends on its reaction distance to prey, water depth, and water velocity; the proportion of detected prey the fish is able to capture declines with water velocity. The fish's net energy intake rate is its gross energy intake rate from feeding minus the swimming cost calculated by using water velocity at the fish's focal point. There was a close match between the positions predicted by this model and those chosen by solitary Arctic grayling (Thymallus arcticus) in the pools of a mountain stream in Alaska.

scholarly journals Schätzung genetischer Parameter für Testtagsergebnisse von Milchleistungsmerkmalen bei Bunten Deutschen Edelziegen

2004 ◽  
Vol 47 (2) ◽  
pp. 193-202
Author(s):  
D. Bömkes ◽  
H. Hamann ◽  
O. Distl
Keyword(s):  
Protein Content ◽  
Milk Yield ◽  
Milk Fat ◽  
Genetic Parameters ◽  
Genetic Correlations ◽  
Protein Yield ◽  
Lower Saxony ◽  
Genetic Progress ◽  
Performance Traits ◽  
Milk Performance

Abstract. Title of the paper: Estimation of genetic parameters for test day records of milk performance traits in German Improved Fawn The objectives of this study were to estimate genetic parameters for milk performance traits of German Improved Fawn by using univariate und multivariate animal models. The analysis was based on 27,778 test day records of 1,848 German Improved Fawn with 3,574 lactation records distributed over 229 flocks in Lower Saxony, Saxony and Baden-Wuerttemberg. Milk records were sampled between 1988 and 2002. The animals in our analysis were the progeny of 455 sires and 1.148 does. Heritabilities estimated with a multivariate test day model with fixed regression were h2 = 0.19, 0.16 and 0.15 for milk, fat and protein yield. For fat and protein content and Somatic Cell Score (SCS) heritabilities were h2 = 0.17, 0.14 and 0.16, respectively. The additive genetic correlations between milk yield and fat as well as protein yield of German Improved Fawn were very high and positive (rg = 0.84 and rg = 0.77). Milk yield and milk contents were genetically negative correlated with rg = −0.28 for fat and rg = −0.22 for protein content. A moderate additive genetic correlation (rg = 0.48) between fat and protein content was estimated. There were no considerable additive genetic correlations between fat yield and protein content as well as between fat content and protein yield (rg = 0.05 and rg = 0.09). Additive genetic correlations between milk, fat or protein yield and SCS were high and negative, whereas additive genetic correlations between fat or protein content and SCS were low and positive. The genetic parameters estimated from field test records allow to achieve genetic progress in milk performance traits of German Improved Fawn.

scholarly journals Description and evaluation of a net energy intake model as a function of dietary chewing index

2016 ◽  
Vol 99 (11) ◽  
pp. 8699-8715 ◽  
Author(s):  
L.M. Jensen ◽  
B. Markussen ◽  
N.I. Nielsen ◽  
E. Nadeau ◽  
M.R. Weisbjerg ◽  
...  
Keyword(s):  
Energy Intake ◽  
Net Energy ◽  
Net Energy Intake

scholarly journals 53 Young Scholar Presentation: Diet starch concentration and starch fermentability affect energy intake and production of dairy cows during the postpartum period

2019 ◽  
Vol 97 (Supplement_2) ◽  
pp. 26-26
Author(s):  
Rodrigo I Albornoz ◽  
Michael Allen
Keyword(s):  
Energy Intake ◽  
Milk Fat ◽  
Treatment Effects ◽  
Block Design ◽  
Net Energy ◽  
High Moisture ◽  
Starch Concentration ◽  
Randomized Block Design ◽  
Early Postpartum ◽  
Main Effects

Abstract Our objective was to evaluate the effects of starch concentration and starch fermentability of diets fed during the early postpartum (PP) period on DM and energy intake and production. Fifty-two multiparous Holstein cows were used in a completely randomized block design with a 2 X 2 factorial arrangement of treatments. Treatment diets were formulated to 22% (LS) or 28% (HS) starch with dry-ground corn (DGC) or high-moisture corn (HMC) as starch source. Treatments were fed from 1 to 23 d PP, and cows were switched to a common diet until 72 d PP to measure carryover (CO) effects. Throughout the experiment, DMI and MY were measured daily, and milk components and BW were measured weekly. During the TP, feeds, refusals, and fecal samples were collected and digestibility was determined weekly. During the TP, HMC decreased intakes of DM and net energy of lactation (NEL) more when included in the HS (3.9 kg/d and 3.2 Mcal/d) than in the LS (0.9 kg/d and 0.6 Mcal/d) diets and HMC decreased yields of milk, fat, protein, 3.5% FCM and milk NEL by 4.3, 0.19, 0.18, 4.8 kg/d and 2.8 Mcal/d, respectively. Energy balance was improved by HS compared with LS (-14.7 vs. -16.8 Mcal/d). During the CO period, treatment effects on DMI diminished over time with no main effects of treatment for the entire period. Treatments interacted to affect yields of milk, milk fat and FCM during the CO period, which were greater for HS-DGC and LS-HMC (54.8 and 52.8, 1.76 and 1.81, and 51.3 and 52.2 kg/d, respectively) than for LS-DGC and HS-HMC (51.2 and 51.0, 1.68 and 1.64, and 48.4 and 48.6 kg/d, respectively). Feeding a highly fermentable starch source during the early PP period decreased DM and energy intake and production, with treatment effects diminishing during the CO period.

Microhabitat variables explain patch switching by wintering Bewick’s swans through giving-up net energy intake rates

2020 ◽  
Vol 27 (15) ◽  
pp. 18843-18852
Author(s):  
Chao Yu ◽  
Lizhi Zhou ◽  
Nazia Mahtab ◽  
Shaojun Fan ◽  
Yunwei Song
Keyword(s):  
Energy Intake ◽  
Net Energy ◽  
Net Energy Intake
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