| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
1 Department of Animal Sciences, The Ohio State University, Columbus, OH 43210
In animal agriculture, the need to understand complex biological, environmental, and management relationships is increasing. In addition, as knowledge increases and profit margins shrink, our ability and desire to predict responses to various management decisions also increases. Therefore, the purpose of this review is to help show how improved mathematical and statistical tools and computer technology can help us gain more accurate information from published studies and improve future research. Researchers, in several recent reviews, have gathered data from multiple published studies and attempted to formulate a quantitative model that best explains the observations. In statistics, this process has been labeled meta-analysis. Generally, there are large differences between studies: e. g., different physiological status of the experimental units, different experimental design, different measurement methods, and laboratory technicians. From a statistical standpoint, studies are blocks and their effects must be considered random because the inference being sought is to future, unknown studies. Meta-analyses in the animal sciences have generally ignored the Study effect. Because data gathered across studies are unbalanced with respect to predictor variables, ignoring the Study effect has as a consequence that the estimation of parameters (slopes and intercept) of regression models can be severely biased. Additionally, variance estimates are biased upward, resulting in large type II errors when testing the effect of independent variables. Historically, the Study effect has been considered a fixed effect not because of a strong argument that such effect is indeed fixed but because of our prior inability to efficiently solve even modest-sized mixed models (those containing both fixed and random effects). Modern statistical software has, however, overcome this limitation. Consequently, meta-analyses should now incorporate the Study effect and its interaction effects as random components of a mixed model. This would result in better prediction equations of biological systems and a more accurate description of their prediction errors.
Key Words: meta-analysis • mixed-model • regression
Submitted on September 1, 2000
Accepted on November 10, 2000
This article has been cited by other articles:
|
|
 |
|
  M. Carriquiry, W. J. Weber, and B. A. Crooker Administration of Bovine Somatotropin in Early Lactation: A Meta-Analysis of Production Responses by Multiparous Holstein Cows J Dairy Sci, July 1, 2008; 91(7): 2641 - 2652. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. T. Socha, C. G. Schwab, D. E. Putnam, N. L. Whitehouse, B. D. Garthwaite, and G. A. Ducharme Extent of Methionine Limitation in Peak-, Early-, and Mid-Lactation Dairy Cows J Dairy Sci, May 1, 2008; 91(5): 1996 - 2010. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
Q. Zebeli, J. Dijkstra, M. Tafaj, H. Steingass, B. N. Ametaj, and W. Drochner Modeling the Adequacy of Dietary Fiber in Dairy Cows Based on the Responses of Ruminal pH and Milk Fat Production to Composition of the Diet J Dairy Sci, May 1, 2008; 91(5): 2046 - 2066. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
G. I. Zanton and A. J. Heinrichs Analysis of Nitrogen Utilization and Excretion in Growing Dairy Cattle J Dairy Sci, April 1, 2008; 91(4): 1519 - 1533. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
P. Huhtanen, M. Rinne, and J. Nousiainen Effects of Silage Soluble Nitrogen Components on Metabolizable Protein Concentration: A Meta-Analysis of Dairy Cow Production Experiments J Dairy Sci, March 1, 2008; 91(3): 1150 - 1158. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 J. C. Marini, D. G. Fox, and M. R. Murphy Nitrogen transactions along the gastrointestinal tract of cattle: A meta-analytical approach J Anim Sci, March 1, 2008; 86(3): 660 - 679. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
O. AlZahal, E. Kebreab, J. France, M. Froetschel, and B. W. McBride Ruminal Temperature May Aid in the Detection of Subacute Ruminal Acidosis J Dairy Sci, January 1, 2008; 91(1): 202 - 207. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. T. Schonewille, H. Everts, S. Jittakhot, and A. C. Beynen Quantitative Prediction of Magnesium Absorption in Dairy Cows J Dairy Sci, January 1, 2008; 91(1): 271 - 278. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 C. D Hunt and L. K Johnson Calcium requirements: new estimations for men and women by cross-sectional statistical analyses of calcium balance data from metabolic studies Am. J. Clinical Nutrition, October 1, 2007; 86(4): 1054 - 1063. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
E. M. Ungerfeld, R. A. Kohn, R. J. Wallace, and C. J. Newbold A meta-analysis of fumarate effects on methane production in ruminal batch cultures J Anim Sci, October 1, 2007; 85(10): 2556 - 2563. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. R. Roche, D. P. Berry, J. M. Lee, K. A. Macdonald, and R. C. Boston Describing the Body Condition Score Change Between Successive Calvings: A Novel Strategy Generalizable to Diverse Cohorts J Dairy Sci, September 1, 2007; 90(9): 4378 - 4396. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
G. B. Huntington, J. C. Burns, and S. L. Archibeque Urea metabolism in beef steers grazing Bermudagrass, Caucasian bluestem, or gamagrass pastures varying in plant morphology, protein content, and protein composition J Anim Sci, August 1, 2007; 85(8): 1997 - 2004. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. Schulin-Zeuthen, E. Kebreab, W. J. J. Gerrits, S. Lopez, M. Z. Fan, R. S. Dias, and J. France Meta-analysis of phosphorus balance data from growing pigs J Anim Sci, August 1, 2007; 85(8): 1953 - 1961. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
G. I. Zanton and A. J. Heinrichs The Effects of Controlled Feeding of a High-Forage or High-Concentrate Ration on Heifer Growth and First-Lactation Milk Production J Dairy Sci, July 1, 2007; 90(7): 3388 - 3396. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. L. Ellis, E. Kebreab, N. E. Odongo, B. W. McBride, E. K. Okine, and J. France Prediction of Methane Production from Dairy and Beef Cattle J Dairy Sci, July 1, 2007; 90(7): 3456 - 3466. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
R. A. Zinn, A. Barreras, L. Corona, F. N. Owens, and R. A. Ware Starch digestion by feedlot cattle: Predictions from analysis of feed and fecal starch and nitrogen J Anim Sci, July 1, 2007; 85(7): 1727 - 1730. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
D. Pacheco, C. G. Schwab, R. Berthiaume, G. Raggio, and H. Lapierre Comparison of Net Portal Absorption with Predicted Flow of Digestible Amino Acids: Scope for Improving Current Models? J Dairy Sci, December 1, 2006; 89(12): 4747 - 4757. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. J. McPhee, J. W. Oltjen, T. R. Famula, and R. D. Sainz Meta-analysis of factors affecting carcass characteristics of feedlot steers J Anim Sci, November 1, 2006; 84(11): 3143 - 3154. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
C. D Hunt and L. K Johnson Magnesium requirements: new estimations for men and women by cross-sectional statistical analyses of metabolic magnesium balance data. Am. J. Clinical Nutrition, October 1, 2006; 84(4): 843 - 852. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
B. Vlaeminck, V. Fievez, S. Tamminga, R. J. Dewhurst, A. van Vuuren, D. De Brabander, and D. Demeyer Milk odd- and branched-chain Fatty acids in relation to the rumen fermentation pattern. J Dairy Sci, October 1, 2006; 89(10): 3954 - 3964. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
D. H. Kleinschmit and L. Kung Jr. A Meta-Analysis of the Effects of Lactobacillus buchneri on the Fermentation and Aerobic Stability of Corn and Grass and Small-Grain Silages. J Dairy Sci, October 1, 2006; 89(10): 4005 - 4013. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M. Vazquez-Anon, R. Gonzalez-Esquerra, E. Saleh, T. Hampton, S. Ritcher, J. Firman, and C. D. Knight Evidence for 2-Hydroxy-4(Methylthio) Butanoic Acid and DL-Methionine Having Different Dose Responses in Growing Broilers Poult. Sci., August 1, 2006; 85(8): 1409 - 1420. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
B. Vlaeminck, V. Fievez, D. Demeyer, and R. J. Dewhurst Effect of forage:concentrate ratio on fatty acid composition of rumen bacteria isolated from ruminal and duodenal digesta. J Dairy Sci, July 1, 2006; 89(7): 2668 - 2678. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. Seo, L. O. Tedeschi, C. G. Schwab, B. D. Garthwaite, and D. G. Fox Evaluation of the passage rate equations in the 2001 Dairy NRC model. J Dairy Sci, June 1, 2006; 89(6): 2327 - 2342. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
G. B. Huntington, D. L. Harmon, and C. J. Richards Sites, rates, and limits of starch digestion and glucose metabolism in growing cattle J Anim Sci, April 1, 2006; 84(13_suppl): E14 - E. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
C. R. Krehbiel, J. J. Cranston, and M. P. McCurdy An upper limit for caloric density of finishing diets J Anim Sci, April 1, 2006; 84(13_suppl): E34 - E. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
H. Lapierre, D. Pacheco, R. Berthiaume, D. R. Ouellet, C. G. Schwab, P. Dubreuil, G. Holtrop, and G. E. Lobley What is the True Supply of Amino Acids for a Dairy Cow? J Dairy Sci, March 1, 2006; 89(e_suppl_1): E1 - E14. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. L. Firkins, A. N. Hristov, M. B. Hall, G. A. Varga, and N. R. St-Pierre Integration of Ruminal Metabolism in Dairy Cattle J Dairy Sci, March 1, 2006; 89(e_suppl_1): E31 - E51. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
E. Charbonneau, D. Pellerin, and G. R. Oetzel Impact of Lowering Dietary Cation-Anion Difference in Nonlactating Dairy Cows: A Meta-Analysis J Dairy Sci, February 1, 2006; 89(2): 537 - 548. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
Q. Zebeli, M. Tafaj, H. Steingass, B. Metzler, and W. Drochner Effects of Physically Effective Fiber on Digestive Processes and Milk Fat Content in Early Lactating Dairy Cows Fed Total Mixed Rations J Dairy Sci, February 1, 2006; 89(2): 651 - 668. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
T. D. Nennich, J. H. Harrison, L. M. VanWieringen, N. R. St-Pierre, R. L. Kincaid, M. A. Wattiaux, D. L. Davidson, and E. Block Prediction and Evaluation of Urine and Urinary Nitrogen and Mineral Excretion from Dairy Cattle J Dairy Sci, January 1, 2006; 89(1): 353 - 364. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
G. I. Zanton and A. J. Heinrichs Meta-Analysis to Assess Effect of Prepubertal Average Daily Gain of Holstein Heifers on First-Lactation Production J Dairy Sci, November 1, 2005; 88(11): 3860 - 3867. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
T. D. Nennich, J. H. Harrison, L. M. VanWieringen, D. Meyer, A. J. Heinrichs, W. P. Weiss, N. R. St-Pierre, R. L. Kincaid, D. L. Davidson, and E. Block Prediction of Manure and Nutrient Excretion from Dairy Cattle J Dairy Sci, October 1, 2005; 88(10): 3721 - 3733. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 F. E. Miguez and G. A. Bollero Review of Corn Yield Response under Winter Cover Cropping Systems Using Meta-Analytic Methods Crop Sci., September 23, 2005; 45(6): 2318 - 2329. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. N. Hristov, W. J. Price, and B. Shafii A Meta-Analysis on the Relationship Between Intake of Nutrients and Body Weight with Milk Volume and Milk Protein Yield in Dairy Cows J Dairy Sci, August 1, 2005; 88(8): 2860 - 2869. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
W. P. Weiss and M. T. Socha Dietary Manganese for Dry and Lactating Holstein Cows J Dairy Sci, July 1, 2005; 88(7): 2517 - 2523. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. Bach, S. Calsamiglia, and M. D. Stern Nitrogen Metabolism in the Rumen J Dairy Sci, May 1, 2005; 88(e_suppl_1): E9 - E21. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
I. R. Ipharraguerre and J. H. Clark Impacts of the Source and Amount of Crude Protein on the Intestinal Supply of Nitrogen Fractions and Performance of Dairy Cows J Dairy Sci, May 1, 2005; 88(e_suppl_1): E22 - E37. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
R. A. Kohn, M. M. Dinneen, and E. Russek-Cohen Using blood urea nitrogen to predict nitrogen excretion and efficiency of nitrogen utilization in cattle, sheep, goats, horses, pigs, and rats J Anim Sci, April 1, 2005; 83(4): 879 - 889. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
W. P. Weiss and D. J. Wyatt Macromineral Digestion by Lactating Dairy Cows: Estimating Phosphorus Excretion via Manure J Dairy Sci, July 1, 2004; 87(7): 2158 - 2166. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
W. P. Weiss Macromineral Digestion by Lactating Dairy Cows: Factors Affecting Digestibility of Magnesium J Dairy Sci, July 1, 2004; 87(7): 2167 - 2171. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. N. Hristov, W. J. Price, and B. Shafii A Meta-Analysis Examining the Relationship Among Dietary Factors, Dry Matter Intake, and Milk and Milk Protein Yield in Dairy Cows J Dairy Sci, July 1, 2004; 87(7): 2184 - 2196. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
W. Hu and M. R. Murphy Dietary Cation-Anion Difference Effects on Performance and Acid-Base Status of Lactating Dairy Cows: A Meta-Analysis J Dairy Sci, July 1, 2004; 87(7): 2222 - 2229. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
L. Doepel, D. Pacheco, J. J. Kennelly, M. D. Hanigan, I. F. Lopez, and H. Lapierre Milk Protein Synthesis as a Function of Amino Acid Supply J Dairy Sci, May 1, 2004; 87(5): 1279 - 1297. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. Nousiainen, K. J. Shingfield, and P. Huhtanen Evaluation of Milk Urea Nitrogen as a Diagnostic of Protein Feeding J Dairy Sci, February 1, 2004; 87(2): 386 - 398. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
R. J. Tempelman Experimental design and statistical methods for classical and bioequivalence hypothesis testing with an application to dairy nutrition studies J Anim Sci, January 1, 2004; 82(13_suppl): E162 - 172. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. A. N. Mills, E. Kebreab, C. M. Yates, L. A. Crompton, S. B. Cammell, M. S. Dhanoa, R. E. Agnew, and J. France Alternative approaches to predicting methane emissions from dairy cows J Anim Sci, December 1, 2003; 81(12): 3141 - 3150. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
I. R. Ipharraguerre and J. H. Clark Soyhulls as an Alternative Feed for Lactating Dairy Cows: A Review J Dairy Sci, April 1, 2003; 86(4): 1052 - 1073. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. L. Galyean and P. J. Defoor Effects of roughage source and level on intake by feedlot cattle J Anim Sci, February 1, 2003; 81(14_suppl_2): E8 - 16. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
F. Bargo, L. D. Muller, E. S. Kolver, and J. E. Delahoy Invited Review: Production and Digestion of Supplemented Dairy Cows on Pasture J Dairy Sci, January 1, 2003; 86(1): 1 - 42. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
O. Martin and D. Sauvant Metaanalysis of Input/Output Kinetics in Lactating Dairy Cows J Dairy Sci, December 1, 2002; 85(12): 3363 - 3381. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
