|
|
||||||||
Department of Animal Science, University of Minnesota, St. Paul 55108
Corresponding author: hein0106{at}umn.edu
| ABSTRACT |
|---|
|
|
|---|
Key Words: crossbreeding heterosis production
| INTRODUCTION |
|---|
|
|
|---|
Numerous research studies have documented the potential role of crossbreeding in the dairy industry, but most studies are dated (Fohrman, 1946; Fohrman et al., 1954; Bereskin and Touchberry, 1966; Brandt et al., 1974; Rincon et al., 1982; Touchberry, 1992). A USDA crossbreeding study was initiated in 1939 at Beltsville, MD (Fohrman et al., 1954). Holstein, Jersey, Red Dane, and Guernsey foundation females were bred to Holstein, Jersey, and Red Dane sires to produce 3 generations of crossbreds. Crossbred groups averaged about 30% more than foundation purebred cows for milk production and about 35% more for fat production. Using results of Fohrman et al. (1954), Touchberry (1992) estimated heterosis for milk production (21.6%) and fat production (18.8%). Fohrman et al. (1954) concluded "there is sufficient evidence presented here to indicate that female progeny of crossbred cows when sired by production proved bulls will develop into very satisfactory dairy animals."
From 1949 to 1969, a study of crossbreeding of Holsteins and Guernseys was conducted at the University of Illinois. Pure Holsteins were superior to crossbreds for milk production, but crossbreds had an advantage for income per lactation. Income produced per cow per year was 11.4% greater for crossbreds than the average of the purebreds (Touchberry, 1992).
McAllister et al. (1994) reported greater than 20% heterosis for lifetime performance in crossbreds of Holstein and Ayrshire. They also reported that moderate heterosis was observed during first lactation for milk, fat, and protein production. In the same crossbreeding study at Agriculture Canada, McAllister (1986) indicated that first-lactation crossbreds of Holstein and Ayrshire were not significantly different from pure Holsteins for milk production, but the crossbreds were significantly higher for fat production.
The Animal Improvement Programs Laboratory (AIPL) of USDA conducted an analysis of DHI data to determine breed differences in herds containing both purebred and crossbred cows (VanRaden and Sanders, 2003). In this study, protein production of Brown Swiss/Holstein crossbreds equaled protein production of pure Holsteins. Fat production was slightly greater for crossbreds of Jersey and Holstein, as well as crossbreds of Brown Swiss and Holstein, than for pure Holsteins. With the milk pricing scenarios Net Merit$ and Cheese Merit$ from USDA, they concluded that first-generation crosses of 2 pure breeds (F1), Brown Swiss and Jersey with Holstein, were more profitable than pure Holsteins. In another study with DHI data, Lesmeister et al. (2000) showed Holstein crossbreds could be more profitable than pure Holsteins under commercial conditions.
In New Zealand, crossbreeding has grown substantially in popularity, and numerous studies have been performed to assess the benefits of crossbreeding in pastoral production systems. Ahlborn-Breier and Hohenboken (1991) reported heterosis of 6% for fat production and 7% for protein production of crossbreds of Holstein and Jersey compared to the 2 pure breeds. They also noted that F1 crossbreds of Holstein and Jersey were superior to pure Holsteins for fat production. Lopez-Villalobos et al. (2000) evaluated the profitability of alternative breeding systems under New Zealand pastoral conditions. The aim of the study was to evaluate the profitability of dairying under 3 mating systems involving the Holstein-Friesian, Jersey, and Ayrshire breeds. The results suggested that rotational cross-breeding could increase profitability under New Zealand conditions.
A Swedish study (Ericson et al., 1988) determined the effects of crossbreeding the Swedish Red Breed (SRB) and the Swedish Holstein Breed (SLB) on several traits. The F1 offspring of SRB and SLB were superior to pure SRB or SLB for all production traits except lactational milk production.
Crossbreeding might become more advantageous in the future for commercial milk production to avoid the consequences of inbreeding depression as the genetic relationships of the global Holstein population continue to increase. Increase of relationships within dairy breeds is inevitable with continuous selection, especially with BLUP methods for prediction of genetic worth.
Background
The decline in fertility and survival of pure Holsteins led the managers of 7 large dairies in California to mate Holstein heifers and cows with imported AI semen of the Normande and Montbeliarde breeds from France, as well as the SRB and Norwegian Red Breed (NRF). The SRB and NRF breeds share similar ancestry, mostly Ayrshire and Shorthorn, and exchange sires of sons; therefore, the breeds are collectively regarded as Scandinavian Red (SR) for this study. Crossbred cows began calving in June 2002, and some cows in the 7 dairies continued to be pure Holstein, which permitted comparison of pure Holsteins and crossbreds. Holstein cows were randomly assigned to breed of service sire.
The objectives of this study were to determine differences between pure Holsteins and crossbreds of Normande/Holstein, Montbeliarde/Holstein, and SR/Holstein during first lactation for actual 305-d production of milk, fat, protein, and combined fat plus protein in the 7 commercial dairies in California.
| MATERIALS AND METHODS |
|---|
|
|
|---|
The number of cows remaining in the data following successive steps of editing is provided in Table 1
. Edits were made to test-day observations, and they were similar to those used by the USDA for routine genetic evaluation. Lactations of cows were required to be at least 40 d in milk. If a cow left the herd, the lactation had to be at least 15 d. A first test day by 90 d in milk was required. For individual test days, days in milk were required to be from 5 to 365 d. Test days after 305 d are used to improve prediction of 305-d production (Schaeffer and Jamrozik, 1996). The first test after 305 d, but not beyond 365 d, was included in the data file. Each test day was required to have an observation for milk, fat, and protein production. Fat percentage was required to be at least 1.0%, but no more than 9.9%. Protein percentage was required to be at least 1.0%, but no more than 6.0%. Test-day milk weights were required to be
4.54 kg.
|
Following all edits, 380 pure Holsteins and 245 Normande/Holstein, 494 Montbeliarde/Holstein, and 328 SR/Holstein crossbreds remained for comparison. The pure Holstein, Normande/Holstein, Montbeliarde/Holstein, and SR/Holstein crossbred cows were daughters of 69, 24, 23, and 13 sires, respectively. The 13 SR sires were 4 SRB and 9 NRF. The distribution of cows by herd and breed group is in Table 2
. The 7 herds were variable in number of cows and in extent of use of cross-breeding. Only 20 cows passed edits from herd 5, however, these observations were spread across only 4 herd-year-seasons, so they contributed meaningful information for breed group comparisons.
|
Lactation Curves of Cows
Actual sample-day production for milk and fat (kg) plus protein (kg) was used to provide a preliminary assessment of the lactation curves of breed group. Sample-day production across 20-d intervals (5 to 24, 25 to 44, etc.) postpartum was adjusted for fixed effects age of calving (linear and quadratic), herd-year-season, and breed group with the GLM procedure of SAS (SAS Institute, 2004). All fixed effects were significant (P < 0.01). The GPLOT procedure of SAS (SAS Institute, 2004) was then used to plot lactation curves with a cubic spline method for smoothing. Figure 1
has lactation curves for milk (kg) and Figure 2
has lactation curves for fat (kg) plus protein (kg) for pure Holsteins and Normande/Holstein, Montbeliarde/Holstein, and SR/Holstein crossbred cows. The production curves in both Figures 1
and 2
suggest that breed groups were similar for persistency of production through lactation.
|
|
A BP algorithm was obtained from Agri-Tech Analytics (Visalia, CA), and was based on the BP methods used by AIPL of USDA. The BP was applied separately to each of the 7 dairies in this study and herd-specific lactation curves were used to calculate 305-d actual production. Also, BP adjusted for age at calving and milking frequency with factors developed by AIPL. Production from test days for cows milked 3 times daily was adjusted to twice-daily milking. Records less than 305 d were projected to 305 d.
Statistical Analyses
Dependent variables for the statistical model were 305-d milk, fat, and protein production, as well as fat plus protein production, from BP. Independent variables were effects of herd-year-season, breed group, and linear regression on the PTA of each cows maternal grandsire. The PTA for the respective production trait of the cows maternal grandsire was included as a covariable in the analysis to account for the genetic level of dams of cows. The PTA for production traits were obtained from the May 2005 genetic evaluation of USDA via the AIPL website (http://aipl.arsusda.gov/). The GLM procedure of SAS (SAS Institute, 2004) was used to obtain solutions and conduct the ANOVA.
| RESULTS AND DISCUSSION |
|---|
|
|
|---|
Table 3
shows probability levels for contrasts of pure Holsteins versus crossbreds for production, and Table 4
shows least squares means and standard errors for breed groups. Pure Holstein cows (9,757 kg) were superior (P < 0.01) to all of the crossbred groups for milk production, which is consistent with the results of Touchberry (1992) and McAllister et al. (1994).
|
|
For protein production, Holsteins (305 kg) were significantly higher (P < 0.01) than Normande/Holstein (277 kg) and Montbeliarde/Holstein (293 kg) cross-breds. Pure Holsteins also surpassed the SR/Holstein (297 kg) crossbreds for protein production, but at a lower level of significance (P < 0.05). Protein percentage for the pure Holsteins was 3.13% compared to 3.24% for Normande/Holstein crossbreds, 3.20% for Montbeliarde/Holstein crossbreds, and 3.20% for SR/Holstein crossbreds.
Fat (kg) plus protein (kg) was used to gauge the overall productivity of pure Holsteins vs. crossbreds. Pure Holsteins (651 kg) were significantly higher (P < 0.01) than the Normande/Holstein (596 kg) and the Montbeliarde/Holstein (627 kg) crossbreds for fat plus protein production. On a percentage basis, the Normande/Holstein crossbreds had 8.6% less fat plus protein production than pure Holsteins. The Montbeliarde/Holstein crossbreds (3.8%) were much closer to the pure Holsteins for fat plus protein production, and the SR/Holstein crossbreds (2.2%) did not differ significantly (P > 0.05) from pure Holsteins. The mating system did not permit the separation of additive genetic and heterotic effects.
The means of breed groups for 305-d production in this study were not adjusted for differences in days open for cows. Days open in current lactation has been documented to have a significant effect on lactational production (Lee et al., 1997); however, appropriate adjustment for current days open is difficult. Fewer days open causes decreased lactational production, but increased lactational production causes more days open. Consequently, the cause-and-effect relationship of lactational production and reproductive status is not easily disentangled. Appropriate adjustment for breed group differences in days open might bring the production of the crossbred groups closer to the production of pure Holsteins. The major reason that dairy producers in this study were exploring the potential of crossbreeding was to improve the fertility, health, and survival of cows.
| CONCLUSIONS |
|---|
|
|
|---|
No adjustment was made to production for differences in days open of cows. Cows with fewer days open are penalized for 305-d production. Therefore, if appropriate adjustment for days open had been possible, production of crossbreds might have been closer to that of pure Holsteins. Crossbreeding of dairy cattle is being explored mostly for its potential to improve the fertility, health, and survival of cows, and advantages for these traits might compensate for loss in production of cross-breds compared to pure Holsteins.
| ACKNOWLEDGEMENTS |
|---|
|
|
|---|
Received for publication August 22, 2005. Accepted for publication February 3, 2006.
| REFERENCES |
|---|
|
|
|---|
This article has been cited by other articles:
![]() |
S. Walsh, F. Buckley, K. Pierce, N. Byrne, J. Patton, and P. Dillon Effects of Breed and Feeding System on Milk Production, Body Weight, Body Condition Score, Reproductive Performance, and Postpartum Ovarian Function J Dairy Sci, November 1, 2008; 91(11): 4401 - 4413. [Abstract] [Full Text] [PDF] |
||||
![]() |
B. J. Heins, L. B. Hansen, A. J. Seykora, A. R. Hazel, D. G. Johnson, and J. G. Linn Crossbreds of Jersey x Holstein Compared with Pure Holsteins for Body Weight, Body Condition Score, Dry Matter Intake, and Feed Efficiency During the First One Hundred Fifty Days of First Lactation J Dairy Sci, September 1, 2008; 91(9): 3716 - 3722. [Abstract] [Full Text] [PDF] |
||||
![]() |
B. J. Heins, L. B. Hansen, A. J. Seykora, D. G. Johnson, J. G. Linn, J. E. Romano, and A. R. Hazel Crossbreds of Jersey x Holstein Compared with Pure Holsteins for Production, Fertility, and Body and Udder Measurements During First Lactation J Dairy Sci, March 1, 2008; 91(3): 1270 - 1278. [Abstract] [Full Text] [PDF] |
||||
![]() |
C. D. Dechow, G. W. Rogers, J. B. Cooper, M. I. Phelps, and A. L. Mosholder Milk, Fat, Protein, Somatic Cell Score, and Days Open Among Holstein, Brown Swiss, and Their Crosses J Dairy Sci, July 1, 2007; 90(7): 3542 - 3549. [Abstract] [Full Text] [PDF] |
||||
![]() |
P. M. VanRaden, M. E. Tooker, J. B. Cole, G. R. Wiggans, and J. H. Megonigal Jr. Genetic Evaluations for Mixed-Breed Populations J Dairy Sci, May 1, 2007; 90(5): 2434 - 2441. [Abstract] [Full Text] [PDF] |
||||
![]() |
B. J. Heins, L. B. Hansen, and A. J. Seykora Fertility and Survival of Pure Holsteins Versus Crossbreds of Holstein with Normande, Montbeliarde, and Scandinavian Red J Dairy Sci, December 1, 2006; 89(12): 4944 - 4951. [Abstract] [Full Text] [PDF] |
||||
![]() |
B. J. Heins, L. B. Hansen, and A. J. Seykora Calving difficulty and stillbirths of pure Holsteins versus crossbreds of Holstein with Normande, Montbeliarde, and Scandinavian Red. J Dairy Sci, July 1, 2006; 89(7): 2805 - 2810. [Abstract] [Full Text] [PDF] |
||||
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |