Test 5.1

Recommendation on scoring conformation defects in cattle

Introduction

In many conformation systems for cattle defects are scored when scoring animals for linear traits and general characteristics. Most of the time defects are used to determine the score for general characteristics.

This chapter describes characteristics of defects for dairy, dual purpose and beef cattle and contains a list of proposed defects which could be used. They are considered to be important for one of the breed types (dairy, dual purpose and/or beef) and could be considered by countries or organizations, that do not score them up to now. If a country or organization has already a list of defects, they could consider to reduce the list according to the ICAR list

Description of defect

Defects are not there to describe the whole variation in the population, but only a problematic trait (e.g. side leak) or a trait with a high enough frequency in the population.

The number of defects scored should be kept as low as possible as more defects means also more labor.

The easiest way to score conformation defects in a digital system is when a cow is scored for a group of the linear traits (frame, dairy strength, mammary system, legs/feet), the classifier is requested by the system if there are any defects within this particular group.

A conformation defect could be scored when it has the following characteristics:-

• Heritable
• Not rare
• Is problematic for functionality
• Is clearly described and visible
• Should be scored as 0/1/2 (as soon as there is more variation and the frequency in population is considerable, one could/should consider to score this trait as a linear trait (scale 1-9)
• Is used to come up with a score for a general characteristic

Defects have no value to be scored when it is not used in determining general characteristics or when it is not used in a genetic evaluation.

The advantages of scoring defects are:

• Get overview what the status of a specific defect is in the population
• Could be used for determining the score for general characteristics
• Could be used to present figures per bull

Disadvantage of scoring defects:

• Difficult to harmonize classifiers as definitions are not always clear and for training sessions it is very hard to find a group of cows representing all defects.

Defects can be scored with 0 (not present), 1 (slightly present) or 2 (pronounced defect). More practical is that classifier score defects only when they are present, 1 (slightly present) or 2 (pronounced defect).

Approved standard defects

The list with approved conformation defects is chosen such that they satisfy the characteristics mentioned in 6.2.

Per defect a definition is given in table 2 and it is indicated in which type of breed the defect can have added value.

Table 2. List of approved conformation defects.

No.	Defect	Dairy	Dual purpose	Beef
1	Open shoulder	X	X
2	Weak crops	X
3	Weak back including loin	X
4	Weak Back		X
5	Weak Loin		X
6	Advanced anus	X
7	High tail	X		X
8	Inset tailhead	X
9	Rump roof-shaped		X
10	Open claws	X	X	X
11	Cork screw		X
12	Crampy	X
13	Boggy hock-s	X		X
14	Thurls too far back	X
15	Weak pasterns	X
16	Front toes out		X
17	Rear toes out		X
18	Thin teats	X
19	Teat-s orientation not down	X
20	Webbed teats	X	X
21	Side leak	X	X
22	Extra functional teats	X	X
23	Bulgy fore udder	X
24	Blind quarter	X
25	Front teat spread forward		X
26	Front teat spread out		X
27	Short teats behind		X
28	Oedema udders		X
29	Udder tilt		X
30	Two stage teats		X

Body defects

1. Open shoulder

A significant gap between the tip of the shoulder and the side of the body. Shoulder blades are not well attached to the body causing a significant gap between shoulder blade and body/ribs.

Figure 1. Open shoulder

2. Weak crops

The part of the animal behind the shoulder (just below the chine) is a lot narrower than the shoulder.

Figure 2. Weak crops

3. Weak back including loin

Weakness in the topline in the middle of the back and/or loin

Figure 3. Weak back including loin

4. Weak Back

Figure 4. Weak Back

5. Weak Loin

Figyre 5. Weak Loin

6. Advanced anus

Anus is ahead of pin bone. Tendency for the anus and vagina to be pulled forward

7. High tail

Evaluated by considering the tailhead in relation to the pins viewed from the rear. It could be considered as a defect when tailhead is noticeably over pins.

Figure 7. High tail

8. Inset tailhead

Tailhead is located between the pin bones and can therefore not be seen from side

Figure 8. Inset tailhead

9. Rump roof-shaped

Figure 9. Rump roof-shaped

Feet and legs defects

10. Open Claw-s

Large gap between claws of any leg

Figure 10. Open Claw-s

11. Cork screw

Figure 11. Cork screw

12. Crampy

Unnatural or irregular contraction of muscles of one or both rear legs independent from source (crampy/Spastic Paresis).

Table 12.Crampy

13. Boggy hock-s

Hocks are very coarse and show bumps on the inside of the hock

Table 13. Boggy hock-s

14. Thurls too far back

Distance of thurl position to rump bone is much higher compared to distance of thurl position to pin bone. On a horizontal line thurl position is much closer to pin as to rump bone.

Table 14. Thurls too far back

15. Weak pasterns

Too much angle of the pastern joint.

Table 15. Weak pasterns

16. Front toes out

Figures 16. Front toes out

17. Rear toes out

Figure 17. Rear toes out

Mammary defects

18. Thin teats

Teat with very small diameter.

Figure 18. Thin teats

19. Teat-s orientation not down

One or more teats are not pointing down, but significantly outside/inside or forward/backward.

Figure 19. Teat-s orientation not down

20. Webbed teats

An extra teat is attached to functional teat.

Figure 20. Webbed teats

21. Teat(s) with side leak

Little function hole on the side wall of the teat.

Figure 21. Teat(s) with side leak

22. Extra functional teat-s

Extra teat-s which produce milk.

Figure 22. Extra functional teat-s

23. Bulgy fore udder

The shape of the fore udder is very round.

Figure 23. Bulgy fore udder

24. Blind quarter-s

Quarter never gives milk.

Figure 24. Blind quarter-s

25. Front teat spread forward

Figure 25. Front teat spread forward

26. Front teat spread out

Figure 26. Front teat spread out

27. Short teats behind

Figure 27. Short teats behind

28. Oedema udders

Figure 28. Oedema udders

29. Udder tilt

Figure 29. Udder tilt

30. Two stage teats

Figure 30. Two stage teats