Crossbred or Composite Seedstock, Crossbred or Composite Seedstock, What are the OpportunitiesWhat are the Opportunities

Larry V. CundiffLarry V. CundiffMARC-ARS-USDAMARC-ARS-USDA

Clay Center, NEClay Center, NE

American Simmental Association SeminarAmerican Simmental Association SeminarBIF Annual MeetingBIF Annual Meeting

Choctaw, MSChoctaw, MSApril 18, 2006April 18, 2006

Cross breeding or composite populations can be used to Cross breeding or composite populations can be used to exploit: exploit:

• HETEROSISHETEROSIS

• COMPLEMENTARITY among breeds optimize COMPLEMENTARITY among breeds optimize performance levels for important traits and to match performance levels for important traits and to match genetic potential with:genetic potential with:

Market preferencesMarket preferencesFeed resourcesFeed resourcesClimatic environmentClimatic environment

BREED DIFFERENCES an important genetic resource

Weight of Calf Weaned Per Cow Weight of Calf Weaned Per Cow Exposed To BreedingExposed To Breeding

8.58.5

14.814.8

8.58.5

23.323.3

Straightbredcows

straightbredcalves

Straightbredcows

X-bredcalves

X-bredcows

X-bredcalves

Per

cen

t

• Heterosis increased Heterosis increased production per cow 20 to 25% production per cow 20 to 25% in in Bos taurus x Bos taurus Bos taurus x Bos taurus crosses and at leastcrosses and at least 50% in 50% in Bos indicus x Bos taurus Bos indicus x Bos taurus crosses in subtropical crosses in subtropical regions.regions.

• More than half of this effect More than half of this effect is dependent on use of is dependent on use of crossbred cows.crossbred cows.

HeterosisHeterosis

• Increased herd life per cow 1.36 yr or 16.2%.

• Increased life time production of calf wt weaned 600 lb or 25.3%.

• Reduced break even cost of production about 9.5%.

HETEROSISHETEROSIS

Rotational Crossbreeding Rotational Crossbreeding SystemsSystems

MARC I¼ Limousin, ¼

Charolais,¼ Brown Swiss,

c Angus and c Hereford

Limousin

Charolais

Angus Hereford

Brown Swiss (Braunvieh)

MARC II ¼ Simmental, ¼ Gelbvieh,¼ Hereford and ¼ Angus

Angus

Simmental

Gelbvieh

Hereford

MARC III ¼ Pinzgauer, ¼ Red Poll,¼ Hereford and ¼ Angus

Pinzgauer

Red Poll

Angus

Hereford

HETEROSIS EFFECTS AND RETAINED HETEROSISIN COMPOSITE POPULATIONS VERSUS CONTRIBUTING

PUREBREDS (Gregory et al., 1992)

Composites minus purebredsComposites minus purebreds

TraitTrait F F11 F F22 F F3&43&4

Birth wt., lbBirth wt., lb 3.63.6 5.05.0

5.1 5.1

200 d wn. wt., lb200 d wn. wt., lb 42.442.4 33.433.4

33.733.7

365 d wt., females, lb365 d wt., females, lb 57.357.3 51.451.4

52.052.0

365 d wt., males, lb365 d wt., males, lb 63.563.5 58.658.6

59.859.8

Age at puberty, females, dAge at puberty, females, d -21-21 -18-18

-17-17

Scrotal circumference, inScrotal circumference, in .51.51 .35.35

.43.43

200 d weaning wt., (mat.), lb200 d weaning wt., (mat.), lb 3333 3636

Calf crop born, (mat.), %Calf crop born, (mat.), % 5.45.4 1.71.7

Calf crop wnd., (mat.), %Calf crop wnd., (mat.), % 6.36.3 2.12.1

200 d wn. wt./cow exp. (mat.), lb200 d wn. wt./cow exp. (mat.), lb 5555 3737

Composite populations Composite populations maintain heterosismaintain heterosis

proportional to heterozygosityproportional to heterozygosity

(n-1)/n or 1 – (n-1)/n or 1 – P Pii22

MODEL FOR HETEROZYGOSITY IN A TWO BREED COMPOSITE

Breed Breed of sireDam ½ A ½ B

½ A AA AB½ B BA BB

(n-1)/n or 1 – (n-1)/n or 1 – P Pii2 2 = .50= .50

MODEL FOR HETEROZYGOSITY IN A THREE BREED COMPOSITE

Breed Breed of sireDam .50 A .25 B .25 C

.50 A .25 AA .125 BA .125 CA

.25 B .125 BA .0625 BB .0625 CB

.25 C .125 AC .125 BC .0625 CC

1 – 1 – P Pii2 2 = (1 - .375) = .625= (1 - .375) = .625

Weaning Wt Marketed Per Cow Exposed for Alternative Weaning Wt Marketed Per Cow Exposed for Alternative Crossbreeding Systems Relative to Straightbreeding (%)Crossbreeding Systems Relative to Straightbreeding (%)

Straight breeding 0 0 0

2-breed rotation (A,B) .67 .67 15.53-breed rotation (A,B,C) .86 .86 20.04-breed rotation (A,B,C,D) .93 .93 21.7

2-breed composite (5/8 A, 3/8 B) .47 .47 11.02-breed composite (.5 A, .5 B) .5 .5 11.73-breed composite (.5A, .25 B, .25C) .625 .625 14.64 breed composite (.25A,.25B,.25C,.25D) .75 .75 17.5

F1 bull rotation (3-breed: AB, AC) .67 .67 15.5F1 bull rotation (4-breed: AB, CD) .83 .83 19.3

Wean. wt H i Hm marketed System (+ 8.5%) (+14.8%) per cow exp

Weaning Wt Marketed Per Cow Exposed for Alternative Weaning Wt Marketed Per Cow Exposed for Alternative Crossbreeding Systems Relative to Straightbreeding (%)Crossbreeding Systems Relative to Straightbreeding (%)

Straight breeding 0 0 0 0

2-breed rotation (A,B) .67 .67 15.5 20.83-breed rotation (A,B,C) .86 .86 20.0 24.14-breed rotation (A,B,C,D) .93 .93 21.7 25.4

2-breed composite (5/8 A, 3/8 B) .47 .47 11.0 17.32-breed composite or F1 bulls (.5 A, .5 B) .5 .5 11.7 17.83-breed composite (.5A, .25 B, .25C) .625 .625 14.6 20.34 breed composite (.25A,.25B,.25C,.25D) .75 .75 17.5 22.2

F1 bull rotation (3-breed: AB, AC) .67 .67 15.5 20.8F1 bull rotation (4-breed: AB, CD) .83 .83 19.3 23.6

Wean. wt Terminal H i Hm marketed crossa

System + 8.5% +14.8% per cow exp (+5% wt/calf)

a Assumes 66 % of calves marketed (steers and heifers) are by terminal sire breed out of more mature age dams and 33% are by maternal breeds (steers only).

Heterosis Retention in Heterosis Retention in Bos taurusBos taurus X X Bos indicusBos indicus

Results are mixed:

Consistent with dominance model:Consistent with dominance model:(B x H, P, backcross, F1 , F2) Cartwright et al., (1964)(B x A, backcross) Turner and MacDonald (1969)(B x Sh, rotations) Koger et al., 1975(B x A, B x C, backcrosses) Peacock and Koger (1979)(B x H, P, F1 , F2) Sanders et al. (2005)

Not consistent with dominance model:Not consistent with dominance model:(B x H, backcrosses) Arthur et al. (1999)(B x A, P, F1 , F2) Sanders et al. (2005)

Matching GeneticMatching GeneticPotential to the Potential to the

Climatic EnvironmentClimatic Environment

(Olson et al., 1991)(Olson et al., 1991)

Composite populationsComposite populations provide for provide for effective use ofeffective use of

• HeterosisHeterosis• Breed differencesBreed differences• Uniformity and end product Uniformity and end product

consistencyconsistency

Genetic Variation in Alternative Mating SystemsGenetic Variation in Alternative Mating Systems

OptimumOptimum

Assumes that the Two FAssumes that the Two F11’s Used are of Similar Genetic Merit’s Used are of Similar Genetic Merit

COEFFICIENTS OF VARIATION IN PUREBRED AND COMPOSITE POPULATIONS (Gregory et al., 1992)

TraitTrait Purebreds Composites Purebreds Composites

Gestation length, dGestation length, d .01.01

.01.01

Birth wt. Birth wt. .11.11

.12 .12

200 d wn. wt.200 d wn. wt. .09.09

.09.09

365 d wt., females365 d wt., females .08 .08

.08.08

365 d wt., males365 d wt., males .09.09

.09.09

Age at puberty (females)Age at puberty (females) .08 .08

.07.07

Scrotal circumferenceScrotal circumference .07.07

.07.07

5 yr cow wt, lb5 yr cow wt, lb .07.07

.08.08

5 yr height, in5 yr height, in .02.02

.02.02

Steer carcass wt, lbSteer carcass wt, lb .08.08

.08.08

Rib-eye areaRib-eye area .10.10

.10.10

Retail product, %Retail product, % .04.04

.06.06

Retail product, lbRetail product, lb .19.19

.20.20

Breed differences for growth traitsare not as great today as

30 years ago

SIRE BREED MEANS FOR FINAL WEIGHT AND CARCASS SIRE BREED MEANS FOR FINAL WEIGHT AND CARCASS TRAITS OF FTRAITS OF F11 STEERS WITH HEREFORD, ANGUS, STEERS WITH HEREFORD, ANGUS,

OR MARC III DAMS (445 DAYS) OR MARC III DAMS (445 DAYS)

Hereford 97 1322 60.7 480 526 70 9.1Angus 98 1365 59.2 488 584 95 8.9Red Angus 93 1333 59.1 474 590 93 9.2

Simmental 92 1363 63.0 522 528 66 9.5Gelbvieh 90 1312 63.8 509 506 58 9.9Limousin 84 1286 63.7 504 504 57 9.5Charolais 95 1349 63.7 523 517 62 9.6

LSD < .05 40 1.3 16 17 0.7 0.6

Final Retail Marb- USDA WBSire wt product ling Choice shearBreed N lb % lb sc % lb

• Sire breed differences in reproduction rate and calf survival to weaning not significant.

• Contrasts between British (H and A) and Continental European breeds (S, G, L, and C) are about 1/4th as great for direct (5.5 vs 22 lb) and 4/10th as great for maternal (10 vs. 24 lb) breed effects in the current evaluation as they were to 30 years ago.

Hereford 56 135.4 7.0 1496 1419Angus 62 134.4 7.2 1501 1411Red Angus 68 134.4 7.4 1510 1409

Simmental 70 137.4 7.0 1476 1406Gelbvieh 68 135.0 6.8 1381 1323

Limousin 80 137.4 6.9 1462 1393Charolais 69 137.4 7.1 1474 1372

LSD < .05 0.8 0.3 64 57

Act. Adj. Height Condition Weight Weighta

Breed No. cm score lb lb

SIRE BREED MEANS FOR HEIGHT, CONDITION SCORE, WEIGHT AND WEIGHT ADJUSTED FOR CONDITION

SCORE AT 5 YEARS OF AGE

a Adjusted to condition score of 5.5

• Advantages of terminal sire crossing systems Advantages of terminal sire crossing systems are not as great today as 30 years ago due to are not as great today as 30 years ago due to similarity of breeds for rate and efficiency of similarity of breeds for rate and efficiency of growthgrowth.

Implications for Crossbreeding

• Similarity in mean performance of British and Continental Similarity in mean performance of British and Continental European breeds means they are more suited for use in rotational European breeds means they are more suited for use in rotational cross-breeding systems today than 30 years ago.cross-breeding systems today than 30 years ago.

• Performance levels are not expected to fluctuate as much with Performance levels are not expected to fluctuate as much with rotational crossing for growth traits and cow size. Growth rate can rotational crossing for growth traits and cow size. Growth rate can be stabilized by using Across-breed EPDs. be stabilized by using Across-breed EPDs.

• Differences in birth weight are still significant and warrant use of Differences in birth weight are still significant and warrant use of sire breeds with lighter birth weight on first calf heifers (i.e., Angus, sire breeds with lighter birth weight on first calf heifers (i.e., Angus, Red Angus, etc.).Red Angus, etc.).

• Intergeneration fluctuations in milk production still persist but they Intergeneration fluctuations in milk production still persist but they are less than half as great as 30 years ago. Milk levels can be are less than half as great as 30 years ago. Milk levels can be stabilized by using Across-breed EPDs.stabilized by using Across-breed EPDs.

• Inter generation fluctuations in mean performance for carcass traits Inter generation fluctuations in mean performance for carcass traits are still large and significant. are still large and significant.

Implications for Crossbreeding

Implications for Crossbreeding

• Rotational SystemsRotational Systems

Provide for more effective use of Provide for more effective use of • HeterosisHeterosis

• Composite populationsComposite populations

Provide for more effective use of Provide for more effective use of • Breed differencesBreed differences• Uniformity and end product consistencyUniformity and end product consistency

• In general, they are not very different

• With only 2 breeds, for commercial customers F1 bulls = Composite bulls

• With multi-breed EPDs, selection can be equally effective

• Adjustments in breed composition and breeding value for specific traits can be made more rapidly producing F1 bulls than in composite populations.

F1 BULLS F1 BULLS oror COMPOSITE BULLS COMPOSITE BULLS

In composite populations, with additional foundation breeds:

• Breed effects can be optimized with greater precision.

• Heterosis effects can be increased to more nearly competitive levels.

• Mating plans are less complex for the commercial customer.

• Seedstock producer benefits from heterosis.

F1 BULLS F1 BULLS oror COMPOSITE BULLS COMPOSITE BULLS

Complementarity

is maximized in terminal crossing systems

Cow HerdSmall to moderate sizeAdapted to climateOptimal milk production

for feed resources

Terminal Sire BreedRapid and efficient growthOptimizes carcass compositionand meat quality in slaughter progeny

ProgenyMaximize high quality lean beefproduced per unit feed consumedby progeny and cow herd

Will terminal crossing decrease or increase?Will terminal crossing decrease or increase?

Weaning Wt Marketed Per Cow Exposed for Alternative Weaning Wt Marketed Per Cow Exposed for Alternative Crossbreeding Systems Relative to Straightbreeding (%)Crossbreeding Systems Relative to Straightbreeding (%)

Straight breeding 0 0 0 0

2-breed rotation (A,B) .67 .67 15.5 +3-breed rotation (A,B,C) .86 .86 20.0 + 4-breed rotation (A,B,C,D) .93 .93 21.7 ++

2-breed composite (5/8 A, 3/8 B) .47 .47 11.0 +++2-breed composite (.5 A, .5 B) .5 .5 11.7 +++3-breed composite (.5A, .25 B, .25C) .625 .625 14.6 ++++4 breed composite (.25A,.25B,.25C,.25D) .75 .75 17.5 +++++

F1 bull rotation (3-breed: AB, AC) .67 .67 15.5 +++F1 bull rotation (4-breed: AB, CD) .83 .83 19.3 ++++

Wean. wt H i Hm marketed Comple-System + 8.5% +14.8% per cow exp mentarity

Angus -1.2 1.6 2.3 2.3 33.8 38.5 2.8 68.3 71.5 0.4 21.4 19.0Hereford -.4 3.0 3.7 4.1 37.2 37.0 3.8 64.6 63.0 2.0 15.2 14.0Red Angus -- -0.7 .4 -- 27.7 29.0 -- 48.3 51.0 -- 13.9 15.0

Simmental 2.9 2.0 1.8 18.5 37.0 34.1 28.9 65.3 59.5 8.8 5.1 5.4Gelbvieh 2.4 0.7 1.9 30.8 36.7 41.0 52.8 69.4 73.0 16.2 19.3 18.0

Charolais 0.3 0.3 1.3 0.5 21.9 20.0 0.5 40.1 35.2 0.3 10.1 6.2Limousin -0.1 2.0 2.1 12.0 35.7 36.3 27.0 70.5 68.2 16.9 15.4 18.3

Breed BWT WNWT YRWT MILKI&II VII Avg I&II VII Avg I&II VII Avg I&II VII Avg.

EPDs from 2006 genetic evaluations for bulls used in Cycles I & II (1970-74), and Cycle VII (1999-2000) compared to current (2004) breed average