DENTITION OF FARM ANIMALS

DENTITION OF FARM ANIMALS

Among farm animals it is reasonably possible to estimate their age by examining their teeth, however, while such an estimate is reasonably reliable, it may not be always accurate.

Presented below are the conventional formulae for temporary and permanent dentition of commonly used farm animals. In addition, the average periods of eruption of milk as well as permanent teeth have also been tabulated, while variations from them will certainly be met with, the majority of animals will be observed to cut their teeth at the periods stated or within a narrow margin of time before or after.

DENTITION OF HORSE
3		0	3	0
Temporary teeth:							=		24
3		0	3	0
76
3		1	3	or	4		3
Permanent teeth:								=	40 or 42
3		1	3	or	4		3

This means that on the right and left sides of the mouth there are three INCISORS, one CANINE, three or four PREMOLARS and three MOLARS. The numbers above the line are for the teeth in the upper jaw; those below for the lower jaw. In the horse, upper and lower jaws carry the same number of teeth, but this is not so in buffalo, cattle sheep and goat. The variation in the number of premolars depends upon whether wolf teeth are, or are not, present. These are small rudimentary teeth situated in front of the first premolars. Incisor teeth (nipper or pincers), are six in number in the upper and lower jaws; they are found in front of the mouth in each jaw and are exclusively referred to for the purpose of estimating the ages of animals. The incisors are named centrals, laterals or intermediates and corners, according to their situation in the mouth.

Canines (‘tushes’, ‘eye-teeth or ‘dog-teeth’) number two in each of the jaws−one on the right and one on the left side. In equine species, canines are only typically present in male animals, although they may be found in mares upon occasions. If present in the mare they are as a rule either small or rudimentary.

Molars (‘grinder’ or cheek- teeth’) number six or seven in each of the four jaws. The first three permanent molars are represented in the milk dentition and are therefore sometimes called premolars.

Table 1. Eruption of teeth in the horse

Time of eruption	Incisors								Canines				Molars
Birth to one week	2 temporary centrals								-				-
2 to 4 weeks	2 temporary laterals								-				Nos. 1,2,3 temporary molars
7 to 9 months	2 temporary corners								-				No. 4 permanent molar
1 year 6 months to 1	-								-				No.5 permanent molar
year 8 months
2 years 6 months	2 permanent centrals								-				Nos. 1&2 permanent molars
3 years 6 months	2 permanent laterals								-				No.3 permanent molar
4 years	-								All 4 canines				No. 6 permanent molar
4 years 6 months	2 permanent corners								-				-
BUFFALO AND CATTLE
	0			0	3	0			0			0	3	0
Temporary teeth:									or							=	20
	3			1	3	0			4			0	3	0
	0			0	3	3			0			0	3	3
Permanent teeth:									or						=		32
	3			1	3	3			4			0	3	3

Incisors are absent from the upper jaws of buffalo, cattle, sheep and goat; their place being taken by the ‘dental-pad’, a hard mass of dense fibrous tissue covered by tough mucosa developed in the upper incisor region, against which the eight lower incisor teeth bite. The teeth are loosely embedded in the jaw so that a slight amount of movement is normally possible. They are named centrals, first intermediates or medials, second intermediates or laterals and corners. However, it is more convenient to enumerate them from the central pair as Ist pair, 2^nd pair, etc. Canines are absent unless corner incisors are considered as modified canines. Molars are like those of the horse in number and arrangement.

Table 2. Eruption of teeth in buffalo and cattle

Time of eruption	Incisors	Molars
Birth to one month	All 8 temporaries	All twelve temporaries
Six months	-	4th permanent
1 year 3 months to 1 year 6 months	-	5th permanent
1 year 9 months to 2 years	Ist pair permanent	-
2 years	-	6th permanent
2 years 6 months	2nd pair permanents	Ist and 2nd permanents
3 years	3rd pair permanents	3rd permanent
3 years 6 months to 4 years	4th pair permanents	-

SHEEP AND GOAT

The terms used for describing various teeth of buffalo and cattle may be taken to hold good for sheep and goats as well. Sheep and goats have eight lower incisor teeth but none

in the upper jaw. There are twenty-four molar teeth, twelve in each jaw. Of these numbers, half are represented in the temporary dentition.

Temporary teeth:		0			0	3	0		=	20
		3			1	3	0
Permanent teeth:		0			0	3	3	=		32
		3			1	3	3
Table 3. Eruption of teeth in sheep and goat
Time of eruption		Incisors									Molars
Birth to one month		All 8 temporaries									All 12 temporaries
3 months		-									4th permanent
9 months		-									5th permanent
1 year to 1 year 3 months		First pair permanents									-
1 year 6 months		-									6th permanent
1 year 9 months		2nd pair permanents									Ist & 2nd permanents
2 years		-									3rd permanent
2 year 3 months		3rd pair permanents									-
2 year 9 months to 3 years		4th pair permanents									-

DETERMINING THE AGE OF SHEEP AND GOATS BY THEIR TEETH

Mature sheep and goats have thirty-two (32) teeth of which 24 are molars and 8 are incisors. As in buffalo and cattle all incisors are in the lower jaw. The two central incisors are called pinchers, the adjoining ones, first intermediates, the third pair, second intermediates, and the outer ones, corners. There are no tusks.

Until sheep and goats are four years of age, the front teeth of the lower jaw furnish a fairly reliable guide as to their development. The lamb/kid has small narrow teeth that are known as milk teeth (temporary teeth). At twelve to fourteen months of age, the two central incisors are replaced by two large, broad, permanent teeth. Each succeeding year, an additional pair of permanent teeth appears, one on either side of the first pair, until four years of age when there is full mouth. It must be remembered, however, that teeth represent the degree of development rather than the exact age according to birth.

With more advanced age, the teeth merely wear down and spread apart and the degree of wearing or spreading is an indication of age. The normal number of teeth may be retained until about eight years but often some are lost after about the fifth or sixth year, resulting in a ‘broken mouth’. When most of the teeth have disappeared, the animals are known as ‘gummers’.

TEETH OF SHEEP AND GOATS

Figure Side view of 5−, 7−, and 20-year-old horse mouth. Note that as the horse advances in age the teeth change from nearly perpendicular to slanting sharply toward the front. The reverse is true in case of camels.

Your are referred to pertinent text books for more details on dentition of various farm animals.

CAMEL

1			1	3	0
Permanent teeth:						=		22
3			1	2	0
1			1	3	3
Permanent teeth:							=	34
3			1	2	3

Table 4.	Age determination in 1 to 7 years old camels
Teeth		11	12	13	C	P1	P2	P3	M1	M2	M3
Age and jaw
1 and 2 years
Upper		-		D	D	D	D	D	P	-	-
Lower		D	D	D	D	D	D	-	P	-	-
13 teeth
3 and 4 years
Upper		-	-	D	D	D	D	D	P	P	-
Lower		D	D	D	D	D	D	-	P	P	-
15 teeth
5 years
Upper		-	-	P	D	D	P	P	P	P	P
Lower		P	P	D	D	D	P	-	P	P	P
17 teeth
6 and 7 years
Upper		-	-	P	P	P	P	P	P	P	P
Lower		P	P	P	P	P	P	-	P	P	P

17 teeth, all permanent; 34 in all, including right and left of both the upper and lower jaws.

I = incisor; C = canine; P = premolar; M = molar; D = deciduous; P = permanent.

EXERCISES

1.                  Give temporary dentition of various species of animals in a tabulated form making separate columns for incisors, etc.

2.                  Give permanent dentition of various species of animals in a tabulated form making separate columns for incisors, molars, etc.

3.                  Prepare a table showing periods of eruption of temporary and permanent teeth of the camel.

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