Effect of liner design, pulsator setting, and vacuum level on bovine teat tissue changes and milking characteristics as measured by ultrasonography

Table 1 Effect of plant vacuum levels (40, 44 and 50 kPa) on mean teat tissue changes (mm)*, and mean milk yield (kg) with WB and NB clusters - Experiment 1

Vacuum level - kPa	40 low-level		44 low-level		50 mid-level
Cluster Type	NB	WB	NB	WB	NB	WB	s.e.d
Canal length	3.18	3.45	3.46	3.33	3.51	3.73	0.41
Canal length (15 min)	2.73	3.42	3.10	4.05	3.03	3.37	0.45
Teat diameter	0.21^b	1.26^a	0.67^ab	1.55^a	0.52^b	0.19^b	0.47
Teat diameter (15 min)	-0.03^d	1.22^a	0.70^ad	1.50^a	0.68^d	0.06^d	0.32
Cistern diameter	-7.33	-8.01	-7.03	-8.85	-7.73	-7.75	0.52
Cistern diameter (15 min)	-6.67^b	-7.82^a	-6.42^b	-8.40^a	-7.10^b	-7.62^ab	0.40
Wall thickness	2.63	3.65	2.86	4.38	2.94	3.43	0.34
Wall thickness (15 min)	2.30^b	3.43^a	2.78^b	3.90^a	2.95^b	3.20^b	0.24
Teat length	11.62	8.75	11.17	5.17	10.42	9.12	1.83
Teat length (15 min)	4.50	2.92	4.67	0.67	4.42	2.50	1.43
Mean milk yield (kg)	18.05	17.27	17.05	18.15	18.38	17.58	0.63

s.e.d.: standard error difference
* Tissue changes were recorded directly after milking and 15 minutes later.
Values with different superscripts, within rows, differ significantly, ^ab P < 0.05, ^ac P < 0.01, ^ad P < 0.001.

ISSN: 2046-0481