SOUTH DAKOTA PERFORMANCE RAM TESTING PROGRAM

FINAL REPORTS: 1994-95 AND 1995-96

Jeff Held

Extension Sheep Specialist

Department of Animal and Range Sciences

SHEEP 97-6

 

Introduction

The South Dakota Performance Ram Testing program was established primarily to identify differences in wool traits for rams managed under the same environmental conditions and plane of nutrition. Secondly, to measure postweaning growth rate as indicated by weight gain. An added feature is evaluation of animal carcass merit using real-time ultrasound technology.

Test Procedures

Fleece weight and staple length were calculated on a 365-day basis. Side and britch wool samples were sent to the Yocum-McColl Testing Laboratory to determine fiber diameter and variability, and clean wool yield. Average daily gain was calculated based on the total weight gain (including fleece) during a period of 140 days.

Fiber Diameter: Determined for each sample using laserscan technology method. The diameter is estimated by measuring four hundred clean fibers to determine an average (mean). In addition, the variation within a sample is determined. The standard deviation (std. dev.) and coefficient of variation (C.V.) are given to provide numerical indications of the variation. A fleece sample with a small C.V. should be considered more uniform than one with a large C.V. (C.V.= std. dev./mean fiber dia.).

Staple Length: Determined by measuring with a ruler at the shoulder, side, and britch. Values were adjusted (less 1/8") for the stubble remaining after the initial shearing and an average calculated from these three sites.

Clean Wool: Determined from the laboratory scoured clean yield estimates on side samples. Analytical procedures meet ASTM standards.

Face Cover and Body Skin Fold Scores: Determined by averaging subjective scores from a three person committee selected by the ram test committee. Scores were assigned from 1 to 4 for each trait. The lower the value the more open faced or freedom from skin folds.

Average Daily Gain: Calculated by dividing the total gain by the number of days in the test period (140 days).

Index: Utilized the following formula established by the Texas and Wyoming Ram tests and the approved index for the American Rambouillet Sheep Association's register of merit program (ROM) [Revised July 8, 1993].

Index = 60 (average daily gain in pounds) + 4.0 (365-day adjusted staple length in inches up to 5.5 inches) + 4.0 (365-day adjusted clean wool in pounds) ± fiber diameter and variability points according to the following schedule:

Fiber diameter (micron) of side

3 (22 - actual microns) = + points up to 9

3 (actual microns - 22) = - points up to -6

Variability-Britch compared to side

2.5 deduction for each micron the britch is coarser than the side. No points given if britch is finer than side.

Index Ratios: To compare one ram with another an index ratio was calculated by the following formula. The average index ratio for all rams is 100; an individual with an index ratio of 130 would be 30% higher than the average and so on.

Actual Ram Index

Ram Index Ratio = Avg Ram Index Value x 100

Certified Ram Classification: The top 30% of the registered Rambouillet rams as indicated by index are eligible for the Certified Ram Classification. In addition to the above requirement, a ram must meet acceptable standards from the standpoint of body type, amount of body skin folds, freedom from anatomical weaknesses and wool defects, including extremely hairy britch or excessive amount of belly type wool. All certified rams must have a minimum of 4.0 inches staple length, 9 lb clean wool, a wool grade of 60's or finer on the side and 56's or finer on the britch, a maximum of 2.7 face cover score, and must have gained at least .55 lb per day on test.

Carcass Merit: At the beginning and end of the test, fat cover and rib eye area were measured at the 12-13th rib by real-time ultrasound. This information is not included in the index. However, these measures may help producers identify rams with superior carcass merit. Rib eye area is a good indicator of overall muscling, rams with larger rib eyes would be expected to be more muscular compared to those with smaller rib eyes. More muscular individuals would be expected to exhibit high growth rated relative to those with less muscularity. Fat cover is an indicator of maturity pattern, i.e., frame-size. Those rams carrying less fat (finish) would likely be later maturing, or perhaps younger, than those with greater amounts of fat cover. For fat cover, the only valid comparison for this set of rams is the final measurement (Tables 1 and 2).

Discussion

The index system used to rank the rams within a breed takes into account growth rate, wool, and anatomical traits. In most cases the higher indexing rams are those which produced the most pounds of clean wool (CFW). The data would indicate that the pounds of clean wool was a function of grease fleece weight, yield, and staple length. Growth rate and anatomical measures have less impact on the index value in most instances since there was less variation between rams for these parameters. The index system fits the objectives of our testing program quite well since it ranks rams on the most economically important traits.

The average values for the wool traits measured were similar across both tests (Tables 3 and 4). A comparison between side and britch fiber diameter shows that for most rams these measures differ by less than 2 microns, indicating good fleece uniformity. Perhaps as important, fiber uniformity within a location was excellent as indicated by a relatively small coefficient of variation (COV) [Tables 5 and 6]. However, for the traits measured, there are considerable differences among rams.

Wool Grading Systems
American Grade Spinning count grade Micron diameter
Fine Finer than 80s Under 17.70
Fine 70s 19.15 - 20.59
Fine 64s 20.60 - 22.04
1/2 62s 22.05 - 23.49
1/2 60s 23.50 - 24.94
3/8 58s 24.95 - 26.39
3/8 56s 26.40 - 27.84
1/4 54s 27.85 - 29.29
1/4 50s 29.30 - 30.99
Low 1/4 48s 31.00 - 32.69
Low 1/4 46s 32.70 - 34.39

The ram testing committee would like to thank the following sponsors for their contributions to the program:

Zip Feed Mills, Huron, SD

Mid-States Wool, Belle Fourche, SD

Center of the Nation Wool, Belle Fourche, SD

TABLE 1. 1993-94 CARCASS MERIT RESULTS

 

Beginning (10-1-93)

End (3-1-94)

Ram ID

Flock Tag #

Producer

REA (sq in)

FAT (in)

REA (sq in)

FAT (in)

5

1300

Benz, Matt

2.29

0.24

3.53

0.35

12

A3165

 Erk, George

1.02

0.16

2.20

0.31

24

3618

Cook Sisters

1.08

0.16

2.80

0.24

13

A3095

 Erk, George

1.57

0.20

2.96

0.43

15

A7040

 Erk, Paul & Teri

1.71

0.16

3.00

0.35

25

3648

Cook Sisters

0.88

0.16

2.18

0.24

1

463

Riesland, Kurt

0.98

0.16

3.22

0.35

23

3660

Cook Sisters

1.49

0.12

2.94

0.31

28

4254

Chapman, Lenard

1.02

0.16

3.18

0.31

37

497

Reid, Clarence

1.51

0.16

2.37

0.39

11

A2994

 Erk, George

1.27

0.20

2.80

0.28

16

A7015

 Erk, Paul & Teri

1.55

0.16

2.51

0.35

26

3679

Cook Sisters

1.29

0.12

2.37

0.24

10

A2957

 Erk, George

1.45

0.16

2.78

0.20

19

1084

Circle Cross

1.73

0.20

3.35

0.28

14

A3063

 Erk, George

1.53

0.20

2.86

0.31

39

1193

Funell, Dean

0.86

0.16

2.61

0.28

4

900

Anderson, Burt

1.06

0.12

2.18

0.24

29

4296

Chapman, Lenard

1.22

0.16

2.49

0.24

38

93-87

 Kitzan, Dwight

1.16

0.16

2.20

0.24

30

4274

Chapman, Lenard

0.92

0.16

2.08

0.31

18

A6859

 Erk, Paul & Teri

1.69

0.20

2.53

0.43

35

B264

 Chapman, Lenard

1.10

0.08

2.80

0.28

40

583

Funell, Robert

1.14

0.20

2.59

0.31

9

3241

Erk, Joe

1.63

0.12

2.80

0.28

21

4099

Gano, Tamra

1.00

0.16

1.86

0.20

6

387

Benz, Darold

1.49

0.16

3.02

0.24

17

A7007

 Erk, Paul & Teri

1.18

0.20

2.71

0.31

27

4241

Chapman, Lenard

1.00

0.12

2.88

0.35

2

183

Anderson, Burt

0.94

0.12

2.00

0.35

20

1112

Circle Cross

1.29

0.12

2.63

0.24

33

202

Chapman, Lenard

1.02

0.20

2.10

0.28

7

3247

Erk, Joe

1.33

0.16

2.47

0.35

36

B268

 Chapman, Lenard

1.14

0.16

2.20

0.24

8

3397

Erk, Joe

1.61

0.16

2.80

0.39

32

200

Chapman, Lenard

1.27

0.20

2.31

0.31

3

20

Anderson, Burt

1.04

0.12

2.43

0.28

34

230

Chapman, Lenard

1.10

0.16

1.90

0.24

22

3608

Cook Sisters

1.41

0.12

2.78

0.24

31

4240

Chapman, Lenard

1.10

0.12

Out

Out
REA = Rib eye area (square inches) at 12-13th rib.

FAT = Fat cover at 12-13th rib.

 

TABLE 2. 1994-95 CARCASS MERIT RESULTS

 

Beginning (10-6-94)

End (3-1-95)

Ram ID

Flock Tag #

 Producer

FAT (in)

REA (sq in)

FAT (in)

REA (sq in)

2

3750

Cook Sisters

0.08

1.57

0.29

3.31

9

0021

 Anderson Family

0.16

1.98

0.29

3.37

38

4243

Circle Cross

0.12

1.29

0.29

2.47

13

A7092

 Paul & Teri Erk

0.20

2.18

0.21

2.76

17

0105

 Robert Mertz

0.16

1.84

0.21

3.02

43

539

Clarence Reid

0.16

1.73

0.21

3.51

5

3552

Gary Haiwick

0.24

2.63

0.29

3.41

14

A7136

 Paul & Teri Erk

0.16

1.82

0.16

2.49

8

0040

 Anderson Family

0.20

1.73

0.29

3.27

10

0039

 Anderson Family

0.20

1.67

0.21

2.57

29

4057

Murl Patrick

0.16

2.39

0.29

2.61

7

3569

Gary Haiwick

0.20

2.16

0.31

3.02

16

0139

 Robert Mertz

0.12

2.24

0.17

3.47

42

589

Clarence Reid

0.16

2.14

0.14

2.67

37

4254

Circle Cross

0.12

1.29

0.14

2.78

18

3664

Joseph Erk

0.16

1.84

0.14

2.53

20

3596

Joseph Erk

0.16

1.53

0.29

2.29

6

3407

Gary Haiwick

0.20

1.43

0.26

3.06

3

3775

Cook Sisters

0.16

2.14

0.21

2.82

4

3409

Gary Haiwick

0.20

2.39

0.29

3.20

34

4058

Murl Patrick

0.16

2.06

0.29

2.86

23

0285

 Lenard Chapman

0.08

1.49

0.14

2.18

19

3703

Joseph Erk

0.16

1.41

0.21

2.55

35

4054

Murl Patrick

0.12

1.61

0.21

2.96

41

46

Reid Sisters

0.12

2.35

0.26

2.86

24

B371

 Lenard Chapman

0.12

1.76

0.26

2.14

36

4051

Murl Patrick

0.12

2.02

0.17

2.96

22

467

Darold Benz

0.16

1.76

0.21

3.47

32

4055

Murl Patrick

0.12

2.31

0.21

2.45

44

106

A & T Girard

0.20

2.04

0.21

2.47

28

4056

Murl Patrick

0.16

1.80

0.26

2.14

40

94-80

 Dwight Kitzan

0.24

2.86

0.29

3.96

25

4385

Lenard Chapman

0.16

1.55

0.26

2.57

33

4059

Murl Patrick

0.08

2.35

0.29

2.84

31

4053

Murl Patrick

0.16

1.86

0.29

2.45

45

189

A & T Girard

0.24

2.51

0.29

2.67

1

3763

Cook Sisters

0.12

1.33

0.29

2.69

27

65

T.W. Schalesky

0.12

1.57

0.16

2.08

11

A7261

 Newell FFA

0.16

1.80

0.26

2.65

26

4394

Lenard Chapman

0.12

1.33

0.14

2.45

39

1174

Circle Cross

0.08

1.43

0.14

2.45

21

476

Darold Benz

0.12

1.71

0.00

0.00

12

029

 John H. Erk

0.16

1.98

0.00

0.00

15

A7070

 Paul & Teri Erk

0.00

1.57

0.00

0.00

30

4052

Murl Patrick

0.12

2.02

0.00

0.00

AVERAGE

0.15

2.06

0.23

2.79
REA = Rib eye area (square inches) at 12-13th rib.

FAT = Fat cover at 12-13th rib.

 

TABLE 3. 1993-1994 RAM PERFORMANCE SUMMARY

Ram ID #

Flock Tag #

P/H

INT WT #

END WT #

Test Gain

ADG (lb)

GFW 365-d

SL 365-d

LSY

CFW 365-d

Side fiber Grade Micron

Britch fiber
Grade Micron

FS AVG

BSF AVG

Index

Index Ratio

 Producer

5

1300

P

136

264

128

0.91

21.40

5.6

64.30

13.76

54'S

28.78

48'S

31.29

1.0

1.0

121.30

128.15

 Benz, Matt

12

A3165

P

125

238

113

0.81

24.88

5.6

56.00

13.93

62'S

22.82

60'S

24.89

1.0

1.0

119.10

125.83

 Erk, George

24

3618

H

99

214

115

0.82

20.32

5.8

65.40

13.29

60'S

24.62

54'S

28.97

1.0

1.0

114.64

121.12

 Cook Sisters

13

A3095

H

136

240

104

0.74

23.83

5.6

53.90

12.84

64'S

21.94

58'S

25.47

1.0

1.0

113.53

119.95

 Erk, George

15

A7040

P

132

238

106

0.76

18.34

5.3

63.90

11.72

64'S

21.37

62'S

22.68

2.7

1.0

112.12

118.46

 Erk, Paul & Teri

25

3648

H

87

196

109

0.78

18.98

5.6

62.10

11.79

62'S

23.48

58'S

25.83

1.0

1.0

106.82

112.86

 Cook Sisters

1

463

P

102

208

106

0.76

23.95

5.6

50.90

12.19

58'S

25.46

56'S

27.78

1.0

1.0

105.59

111.56

 Riesland, Kurt

23

3660

H

94

204

110

0.79

18.54

5.3

62.20

11.53

58'S

26.30

54'S

27.98

1.0

1.0

104.27

110.16

 Cook Sisters

28

4254

H

100

212

112

0.80

18.80

4.7

57.00

10.72

58'S

26.20

56'S

26.79

1.0

1.0

102.19

107.97

 Chapman, Lenard

37

497

P

153

270

117

0.84

21.29

5.0

48.10

10.24

58'S

25.09

58'S

25.17

1.0

1.0

101.63

107.38

 Reid, Clarence

11

A2994

H

123

228

105

0.75

21.05

5.2

55.20

11.62

58'S

25.33

54'S

28.82

1.0

1.0

101.28

107.00

 Erk, George

16

A7015

H

117

230

113

0.81

18.68

5.0

53.00

9.90

60'S

23.82

60'S

24.48

2.7

1.0

100.92

106.62

 Erk, Paul & Teri

26

3679

H

109

222

113

0.81

20.37

4.7

54.70

11.14

58'S

26.10

50'S

29.48

1.0

1.5

100.80

106.50

 Cook Sisters

10

A2957

H

118

208

90

0.64

17.71

5.2

65.00

11.51

62'S

22.05

58'S

25.49

1.0

1.0

100.27

105.93

 Erk, George

19

1084

H

114

228

114

0.81

17.83

5.0

58.70

10.47

60'S

24.16

56'S

26.82

1.0

1.0

99.72

105.36

 Circle Cross

14

A3063

P

115

210

95

0.68

19.68

5.8

59.30

11.67

60'S

24.76

54'S

28.25

1.0

1.0

99.60

105.22

 Erk, George

39

1193

P

105

222

117

0.84

17.50

5.4

54.20

9.49

62'S

23.41

58'S

25.91

1.0

1.0

99.20

104.81

 Funell, Dean

4

900

P

100

206

106

0.76

20.54

5.4

51.10

10.50

60'S

23.71

50'S

29.55

1.0

1.0

98.88

104.47

 Anderson, Burt

29

4296

H

113

214

101

0.72

19.13

5.3

57.30

10.96

60'S

23.53

56'S

26.98

1.0

1.0

98.74

104.32

 Chapman, Lenard

38

93-87

H

112

220

108

0.77

19.02

5.3

62.00

11.79

56'S

27.52

56'S

27.72

1.0

1.0

97.60

103.11

 Kitzan, Dwight

30

4274

H

100

196

96

0.69

19.78

5.3

58.10

11.49

56'S

26.93

50'S

30.09

1.0

1.0

97.31

102.81

 Chapman, Lenard

18

A6859

H

126

228

102

0.73

20.51

5.0

54.30

11.14

60'S

24.88

54'S

28.66

1.0

1.0

97.26

102.76

 Erk, Paul & Teri

35

B264

P

101

222

121

0.86

19.37

4.4

52.20

10.11

58'S

25.60

56'S

26.70

1.0

1.5

96.35

101.80

 Chapman, Lenard

40

583

H

117

236

119

0.85

14.44

5.0

58.20

8.40

62'S

23.34

58'S

25.06

1.0

1.0

96.30

101.74

 Funell, Robert

9

3241

P

116

224

108

0.77

19.98

4.7

52.50

10.49

60'S

24.54

54'S

28.59

3.0

1.0

96.04

101.47

 Erk, Joe

21

4099

H

109

200

91

0.65

21.39

5.3

51.50

11.02

54'S

28.11

50'S

29.32

1.0

1.0

95.24

100.62

 Gano, Tamra

6

387

P

150

248

98

0.70

18.78

4.7

52.80

9.92

58'S

25.18

58'S

25.73

1.0

1.0

93.09

98.35

 Benz, Darold

17

A7007

P

129

208

79

0.56

21.54

5.0

54.00

11.63

60'S

24.07

58'S

25.83

1.0

1.0

89.98

95.07

 Erk, Paul & Teri

27

4241

H

118

230

112

0.80

16.10

3.9

52.70

8.48

62'S

23.11

58'S

25.93

1.0

1.0

89.21

94.25

 Chapman, Lenard

2

183

P

86

198

112

0.80

17.10

4.7

48.80

8.34

60'S

24.61

56'S

26.84

1.0

1.0

89.18

94.22

 Anderson, Burt

20

1112

H

107

210

103

0.74

17.17

4.4

53.80

9.24

60'S

24.59

56'S

27.64

1.0

1.0

87.69

92.65

 Circle Cross

33

202

P

103

200

97

0.69

19.61

5.6

62.10

12.18

58'S

26.23

48'S

31.95

1.0

1.0

85.69

90.54

 Chapman, Lenard

7

3247

P

114

198

84

0.60

17.39

5.0

55.50

9.65

58'S

25.46

56'S

26.69

3.0

1.0

85.53

90.37

 Erk, Joe

36

B268

P

104

210

106

0.76

18.02

5.5

59.20

10.67

58'S

26.30

48'S

31.00

1.0

1.0

85.45

90.28

 Chapman, Lenard

8

3397

P

126

222

96

0.69

18.78

4.7

48.20

9.05

58'S

25.78

50'S

30.20

2.0

1.0

85.15

89.96

 Erk, Joe

32

200

P

110

218

108

0.77

18.93

4.8

55.60

10.53

54'S

28.06

50'S

29.97

1.0

1.0

84.63

89.41

 Chapman, Lenard

3

20

P

94

196

102

0.73

16.15

4.4

51.70

8.35

58'S

25.01

56'S

26.96

1.0

1.0

83.84

88.58

 Anderson, Burt

34

230

P

110

200

90

0.64

22.27

5.6

57.60

12.83

54'S

28.07

44'S

35.21

1.0

1.2

76.22

80.53

 Chapman, Lenard