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Teat Shape and Production Associated with Opening and Prolapse of the Teat Orifice in Friesian Cows
Br. vet.}. (1977 ), 13:1, 258
TEAT SHAPE AND PRODUCTION ASSOCIATED WITH OPENING AND PROLAPSE OF THE TEAT ORIFICE IN FRIESIAN COWS By A. K.
RATHORE
Dairy Research Centre, Richmond, N.S . W . 2753, Australia
SUMMARY
One hundred and fifty-two Friesian cows were grouped by teat shape categories. Size of the teat orifice on one hind and one fore teat on individual cows was scored visually from 1 (smallest opening) to 5 (largest opening) twice, before and after milking. The teat end was scored for the prolapse (eversion) of the orifice immediately after milking. None of the teat orifice size scores (except for the orifice of the fore teat before milking) was significantly different between cows with funnel and cylindrical shaped teats. Milk yield was 15·4% higher in the cows with funnel shaped teats than in cows with cylindrical shaped teats. Teat orifice prolapse was significantly higher in cows with cylindrical shaped teats than in the cows with funnel shaped teats. Teat orifice size (average of hind and fore) was significantly larger after milking than before milking, and fore teat orifice size was significantly larger than the hind teat. INTRODUCTION
Several workers have attempted to gauge the size of the teat orifice from the diameter of the stream of milk squeezed from it. Murphy (1944) found an association between mastitis and large teat orifice. So far, no true measure of teat patency has been discovered, but once it was demonstrated that milking rate gave a measure of orifice size, its relationship with susceptibility to infection could be measured objectively. Baxter, Clarke, Dodd & Foot (1950) found that the maximum rate of milk flow was controlled by the size of the teat orifice and that orifice size varied between cows. Extensive mucosal haemorrhage has been observed in the sinus of most teats when they were subjected to prolonged machine stripping with increased tension on the teat cups (Petersen, 1944). Stevenson (1946) found the mucous membrane of each teat was everted in a herd where the vacuum used was 19 in (48 em) . Baxter et al. (1950) suggested that the teat opening is stretched further open at high vacuum with an increased amount of stripping. Oliver (1955) reported that slowest milkers invariably had severely eroded teats while the fastest milkers rarely showed even slight erosion. Thus, slow milkers which are slow because their teat orifice is small, are the animals having vacuum applied to their teats for the longest time. Round and pointed teat tips are more prone to evert
259
TEAT SHAPE IN COWS
than Rat teat-ends (johansson, 1961). Morse, Hubben & Mitchell (1970) reported that teat keratin lipids may playa role in the anti-streptococcal effect of the teat canal. As the rate of milking begins to decline, depending on the shape of the teat, the cups crawl upward (Ra thore, 1975b). This occurrence was observed in 27·4% o f cows with cylindrical shaped teats compared with 8· 1% of cows with funnel shaped teats, and milk Row ceased although the gland was not evacuated. Cows with funnel shaped teats produced more milk and had a significantly lower incidence of mastiti s (Rathore, 1976). The present investigation was conducted to determine changes in the size o f the teat orifice due to milking, and to establish relationship between shape of the teat a nd the prolapse (eversion ) of the teat orifice. MATERIALS AND METHODS
The experimental animals consisted of 152 lactating Friesian cows from a comme rcial dairy farm. All the cows were scored visually for teat shape into two categories, funnel and cylindrical (Rathore, 1976 ). Each of the four teats was classified independently after udder preparation prior to milking. The teat orifice was scored (Fig. 1) according to the degree of the size of the teat orifice ranging from 1 (smallest opening) to 5 (larges t opening) on one hind and one fore teat on individual cows twice, before a nd after m ilking.
1
2
5
4 Fig. 1. Diagrammatic standards for size of the teat ori fice (score 1-5).
Immediately after milking the incidence of teat orifice prolapse (Fig. 2) was also recorded on individual cows (one hind and one fore teat only). No machine stripping was done on any of the cows. All the milking machines on the farm were tested and adjusted where necessary prior to milking for pulsation ratios and reserve air and for the uniformity of their operation. Milk.yield from each individual cow was recorded to the nearest 0·23 kg using 'Tru-test' milk meters.
BRITISH VETERINARY JOURNAL, 133,3
260
Fig. 2. Photograph of prolapsed teat orifice.
RES ULTS
Table I summarizes mean values for various scores and measurements relating to cows by teat shape categories. Teat orifice size score for fore teat before milking was significantly larger in the cows with cylindrical shaped teats than in the cows with funnel shaped teats. Differences for the rest of the teat orifice scores for hind and fore teats (before as well as after milking) were non-significant between the cows with funnel and cylindrical shaped teats.
TABLE I MEAN VALUES FOR MEASUREMENTS RELATING TO TEAT SHAPE IN 152 FRIESIAN
Variables
cows
Funnel shape teats
Cylindrical shape teats
No. of cows Hind teat orifice (Before milking) Fore teat orifice (Before milking)
84 1·3510 ·48 1·50 ± 0·55*
68 1·3510 ·5 1 1·7510·63
Hind teat orifice (After milking) Fore teat orifice (After milking)
1·84±0·66 2·04±0·77
1·85±0·67 2·06±0·73
1·69±0·42
1·7510·38
J.42± 0·39
1·5510 ·43
Average teat orifice/cow (Before and after milking) Average hind + fore teat orifice (Before milking) Average hind + fore teat orifice (After milking)' M ilk yield/cow/day (kg) Stage oflactation (months) No. of cows with teat orifice prolapse % of cows with teat orifice prolapse
* Significant at I% level.
1·96± 0·61
1·96±0·53
20·53±5·56*
17 ·36±5·88
4·33± 2·45
4·86±2·39
6
15
7 ·14*
2206
261
TEAT SHAPE IN COWS
Milk yield was 15·4% higher in the cows with funnel shaped teats than in the cows with cylindrical shaped teats, this was significant at the 1% level. Cows in both teat shape categories were at a similar stage oflactation. The percentage of prolapsed teat orifice was significantly higher in cows with cylindrical shaped teats (22%) than in the cows with funnel shaped teats (7%). Table II shows analysis of variance for teat orifice score. Differences were significant at the 1% level for between cows, treatments (i.e. before and after milking), quarters (hind and fore) and cow x treatment interaction. The rest of the interactions were no n-significant.
TABLE II M EA N SQUARES FOR TEAT ORIFICE SCORE IN 152 FRIESIAN COWS
Source rif variance Cow Treatment (Before v . after milking) Quarters (Hind v. fore) Cow x treatments Cow x quarters Treatments x quarters Residual
D .F.
Mean squares
151
0·67" 34·58 " 8· 76· 0·43" 0· 28 0·08 0·24
I 15 1 15 1 151
* Significant at 1% level.
DISCUSSION
Most of the differences between teat shapes for the teat orifice were non-significant. Milk yield was significantly higher in the cows with funnel shaped teats than in the cows with cylindrical shaped teats, in agreement with earlier reports (Rathore, 197 5, 1976). Cows with cylindrical shaped teats had a significantly higher incidence of prolapsed teat orifice than cows with funnel shaped teats. Possibly the cows with cylindrical shaped teats milked slower and as such, the milking machine was on for a longer duration and accompanied by teat cup crawl. This is in agreement with Espe & Cannon (1942) and Petersen (1944) who reported that the continuous vacuum caused erosion and greater opportunity for bacterial infection. Rathore (1976 ) reported that the funnel shaped teats offer greater resistance to being drawn into the teat cup, and milked out more completely. Peterson ( 1964) suggested that the teat canal could remain partly open if the milking machine was left on the teat after the end of milk flow and that over-milking results in injury to the mucosal lining of the teat sinus and to the epithelium and sub-epithelial tissue of the teat canal. When the vacuum within the teat is identical to that in the milk line, the occlusion between the gland sinus and the teat sinus leads to traumatization of the teat orifice (Petersen, 1944). The higher incidence of prolapsed teat orifice in the cows with cylindrical shaped teats could be due to this identical vacuum.
262
BRITISH VETERINARY JOURNAL, 133 , 3
Baxter et al. (1950) reported that the maximum rate of milk flow is controlled by the size of the teat orifice. In the present investigation the teat orifice (before and after milking) was not significantly different between the cows with funnel and cylindrical shaped teats, although the cows with funnel shaped teats milked faster (Rathore, 197 5 unpublished data), possibly the size of the teat orifice does not provide a measure of milk flow . Studying teat orifice size during milking might, however, provide some measure of milk flow rate . ACKNOWLEDGEMENTS
The author wishes to acknowledge the assistance of Mr F. Braat and Mr F. Payne. REFERENCES
BAXTER, E. S., CLARKE, P. M ., DODD, F. M . & FOOT, A. S. (]950 ).). Dairy Res. 17 , 117 . ESPE, D . & CANNON, c. Y. (]942).j. Dairy Sci. 25,155. JOH ANNSON, l. (] 96 I) . In Genetic Aspects of Dairy Cattle Breeding, p. 122, ed. Oliver & Boyd. London. MORSE, G. E., H UBBEN, K. & MITCHELL, K. (1970 ). Proceedings 7th International Conference on Cattle Diseases, Philadelphia, Pennsylvania. August 1970, 108 . M URPHY,]. M. (1944 ). Cornell Vet. 34, 64. OLIVER,]. (J955). Diary Sci . Abstr. 17,355 & 447. PETERSEN, W. E. ( I 944 ). j. Dairy Sci. 27,433 . PETERSON, K.]. ( 1964). Am.). vet. Res. 25, 1002. RATHOR E, A. K. (J 97 5 ).). agric. Sci., Camb ., 85,377. RATHORE, A . K. (1976 ). Br. vet.}., 132,389. STEVENSON, W . G . ( 1946 ). Can.]. compo Med. 10, 115.
(Acceptedfor publication 23 February 19 76)
TEAT SHAPE AND PRODUCTION ASSOCIATED WITH OPENING AND PROLAPSE OF THE TEAT ORIFICE IN FRIESIAN COWS By A. K.
RATHORE
Dairy Research Centre, Richmond, N.S . W . 2753, Australia
SUMMARY
One hundred and fifty-two Friesian cows were grouped by teat shape categories. Size of the teat orifice on one hind and one fore teat on individual cows was scored visually from 1 (smallest opening) to 5 (largest opening) twice, before and after milking. The teat end was scored for the prolapse (eversion) of the orifice immediately after milking. None of the teat orifice size scores (except for the orifice of the fore teat before milking) was significantly different between cows with funnel and cylindrical shaped teats. Milk yield was 15·4% higher in the cows with funnel shaped teats than in cows with cylindrical shaped teats. Teat orifice prolapse was significantly higher in cows with cylindrical shaped teats than in the cows with funnel shaped teats. Teat orifice size (average of hind and fore) was significantly larger after milking than before milking, and fore teat orifice size was significantly larger than the hind teat. INTRODUCTION
Several workers have attempted to gauge the size of the teat orifice from the diameter of the stream of milk squeezed from it. Murphy (1944) found an association between mastitis and large teat orifice. So far, no true measure of teat patency has been discovered, but once it was demonstrated that milking rate gave a measure of orifice size, its relationship with susceptibility to infection could be measured objectively. Baxter, Clarke, Dodd & Foot (1950) found that the maximum rate of milk flow was controlled by the size of the teat orifice and that orifice size varied between cows. Extensive mucosal haemorrhage has been observed in the sinus of most teats when they were subjected to prolonged machine stripping with increased tension on the teat cups (Petersen, 1944). Stevenson (1946) found the mucous membrane of each teat was everted in a herd where the vacuum used was 19 in (48 em) . Baxter et al. (1950) suggested that the teat opening is stretched further open at high vacuum with an increased amount of stripping. Oliver (1955) reported that slowest milkers invariably had severely eroded teats while the fastest milkers rarely showed even slight erosion. Thus, slow milkers which are slow because their teat orifice is small, are the animals having vacuum applied to their teats for the longest time. Round and pointed teat tips are more prone to evert
259
TEAT SHAPE IN COWS
than Rat teat-ends (johansson, 1961). Morse, Hubben & Mitchell (1970) reported that teat keratin lipids may playa role in the anti-streptococcal effect of the teat canal. As the rate of milking begins to decline, depending on the shape of the teat, the cups crawl upward (Ra thore, 1975b). This occurrence was observed in 27·4% o f cows with cylindrical shaped teats compared with 8· 1% of cows with funnel shaped teats, and milk Row ceased although the gland was not evacuated. Cows with funnel shaped teats produced more milk and had a significantly lower incidence of mastiti s (Rathore, 1976). The present investigation was conducted to determine changes in the size o f the teat orifice due to milking, and to establish relationship between shape of the teat a nd the prolapse (eversion ) of the teat orifice. MATERIALS AND METHODS
The experimental animals consisted of 152 lactating Friesian cows from a comme rcial dairy farm. All the cows were scored visually for teat shape into two categories, funnel and cylindrical (Rathore, 1976 ). Each of the four teats was classified independently after udder preparation prior to milking. The teat orifice was scored (Fig. 1) according to the degree of the size of the teat orifice ranging from 1 (smallest opening) to 5 (larges t opening) on one hind and one fore teat on individual cows twice, before a nd after m ilking.
1
2
5
4 Fig. 1. Diagrammatic standards for size of the teat ori fice (score 1-5).
Immediately after milking the incidence of teat orifice prolapse (Fig. 2) was also recorded on individual cows (one hind and one fore teat only). No machine stripping was done on any of the cows. All the milking machines on the farm were tested and adjusted where necessary prior to milking for pulsation ratios and reserve air and for the uniformity of their operation. Milk.yield from each individual cow was recorded to the nearest 0·23 kg using 'Tru-test' milk meters.
BRITISH VETERINARY JOURNAL, 133,3
260
Fig. 2. Photograph of prolapsed teat orifice.
RES ULTS
Table I summarizes mean values for various scores and measurements relating to cows by teat shape categories. Teat orifice size score for fore teat before milking was significantly larger in the cows with cylindrical shaped teats than in the cows with funnel shaped teats. Differences for the rest of the teat orifice scores for hind and fore teats (before as well as after milking) were non-significant between the cows with funnel and cylindrical shaped teats.
TABLE I MEAN VALUES FOR MEASUREMENTS RELATING TO TEAT SHAPE IN 152 FRIESIAN
Variables
cows
Funnel shape teats
Cylindrical shape teats
No. of cows Hind teat orifice (Before milking) Fore teat orifice (Before milking)
84 1·3510 ·48 1·50 ± 0·55*
68 1·3510 ·5 1 1·7510·63
Hind teat orifice (After milking) Fore teat orifice (After milking)
1·84±0·66 2·04±0·77
1·85±0·67 2·06±0·73
1·69±0·42
1·7510·38
J.42± 0·39
1·5510 ·43
Average teat orifice/cow (Before and after milking) Average hind + fore teat orifice (Before milking) Average hind + fore teat orifice (After milking)' M ilk yield/cow/day (kg) Stage oflactation (months) No. of cows with teat orifice prolapse % of cows with teat orifice prolapse
* Significant at I% level.
1·96± 0·61
1·96±0·53
20·53±5·56*
17 ·36±5·88
4·33± 2·45
4·86±2·39
6
15
7 ·14*
2206
261
TEAT SHAPE IN COWS
Milk yield was 15·4% higher in the cows with funnel shaped teats than in the cows with cylindrical shaped teats, this was significant at the 1% level. Cows in both teat shape categories were at a similar stage oflactation. The percentage of prolapsed teat orifice was significantly higher in cows with cylindrical shaped teats (22%) than in the cows with funnel shaped teats (7%). Table II shows analysis of variance for teat orifice score. Differences were significant at the 1% level for between cows, treatments (i.e. before and after milking), quarters (hind and fore) and cow x treatment interaction. The rest of the interactions were no n-significant.
TABLE II M EA N SQUARES FOR TEAT ORIFICE SCORE IN 152 FRIESIAN COWS
Source rif variance Cow Treatment (Before v . after milking) Quarters (Hind v. fore) Cow x treatments Cow x quarters Treatments x quarters Residual
D .F.
Mean squares
151
0·67" 34·58 " 8· 76· 0·43" 0· 28 0·08 0·24
I 15 1 15 1 151
* Significant at 1% level.
DISCUSSION
Most of the differences between teat shapes for the teat orifice were non-significant. Milk yield was significantly higher in the cows with funnel shaped teats than in the cows with cylindrical shaped teats, in agreement with earlier reports (Rathore, 197 5, 1976). Cows with cylindrical shaped teats had a significantly higher incidence of prolapsed teat orifice than cows with funnel shaped teats. Possibly the cows with cylindrical shaped teats milked slower and as such, the milking machine was on for a longer duration and accompanied by teat cup crawl. This is in agreement with Espe & Cannon (1942) and Petersen (1944) who reported that the continuous vacuum caused erosion and greater opportunity for bacterial infection. Rathore (1976 ) reported that the funnel shaped teats offer greater resistance to being drawn into the teat cup, and milked out more completely. Peterson ( 1964) suggested that the teat canal could remain partly open if the milking machine was left on the teat after the end of milk flow and that over-milking results in injury to the mucosal lining of the teat sinus and to the epithelium and sub-epithelial tissue of the teat canal. When the vacuum within the teat is identical to that in the milk line, the occlusion between the gland sinus and the teat sinus leads to traumatization of the teat orifice (Petersen, 1944). The higher incidence of prolapsed teat orifice in the cows with cylindrical shaped teats could be due to this identical vacuum.
262
BRITISH VETERINARY JOURNAL, 133 , 3
Baxter et al. (1950) reported that the maximum rate of milk flow is controlled by the size of the teat orifice. In the present investigation the teat orifice (before and after milking) was not significantly different between the cows with funnel and cylindrical shaped teats, although the cows with funnel shaped teats milked faster (Rathore, 197 5 unpublished data), possibly the size of the teat orifice does not provide a measure of milk flow . Studying teat orifice size during milking might, however, provide some measure of milk flow rate . ACKNOWLEDGEMENTS
The author wishes to acknowledge the assistance of Mr F. Braat and Mr F. Payne. REFERENCES
BAXTER, E. S., CLARKE, P. M ., DODD, F. M . & FOOT, A. S. (]950 ).). Dairy Res. 17 , 117 . ESPE, D . & CANNON, c. Y. (]942).j. Dairy Sci. 25,155. JOH ANNSON, l. (] 96 I) . In Genetic Aspects of Dairy Cattle Breeding, p. 122, ed. Oliver & Boyd. London. MORSE, G. E., H UBBEN, K. & MITCHELL, K. (1970 ). Proceedings 7th International Conference on Cattle Diseases, Philadelphia, Pennsylvania. August 1970, 108 . M URPHY,]. M. (1944 ). Cornell Vet. 34, 64. OLIVER,]. (J955). Diary Sci . Abstr. 17,355 & 447. PETERSEN, W. E. ( I 944 ). j. Dairy Sci. 27,433 . PETERSON, K.]. ( 1964). Am.). vet. Res. 25, 1002. RATHOR E, A. K. (J 97 5 ).). agric. Sci., Camb ., 85,377. RATHORE, A . K. (1976 ). Br. vet.}., 132,389. STEVENSON, W . G . ( 1946 ). Can.]. compo Med. 10, 115.
(Acceptedfor publication 23 February 19 76)