Association between electrical conductivity and milk production traits in Dairy Gyr cows

Figures & data

Table 1. Pearson's correlation coefficient (above the diagonal) and estimated linear regression coefficients (below the diagonal in bold type) for EC of milk , SCS, TDMY and fat (%F), protein (%P), lactose (%L) and total solids (%TS) content in Dairy Gyr cows.

Trait	EC^a	SCS^b	TDMY	%F	%P	%L	%TS
EC	1	0.41*	−0.32*	−0.18*	0.14*	−0.65*	−0.40*
SCS	0 . 094	1	−0.22*	0.36*	0.31*	−0.66*	−0.19*
TDMY	−2 . 01*	−0 . 26*	1	−0.02^NS	−0.31*	0.30*	−0.03^NS
%F	−0 . 54*	0 . 18*	–	1	0.25*	−0.32*	0.03^NS
%P	0 . 07*	0 . 01^NS	–	–	1	−0.26*	0.63*
%L	−0 . 36*	−0 . 09*	–	–	–	1	0.45*
%TS	−0 . 32*	−0 . 08*	–	–	–	–	1

NS, not significant.

*Significant at the 1% probability level.

^aLinear regression coefficients (Model 1a).

^bLinear regression coefficients (Model 1b).

Table 2. Records number (N) and frequency of records (%) of somatic cell count (SCC), EC of milk, lactose content (%) and TDMY and their respective standard deviations, according to SCS in Dairy Gyr cows.

SCS	N	Frequency of records (%)	SCC^a	EC (mS/cm)	Lactose (%)	TDMY (kg)
1	47	6.91	16.43 (±5.64)	4.69 (±0.42)	4.93 (±0.15)	14.56 (±4.38)
2	53	7.79	37.62 (±7.06)	4.68 (±0.29)	4.87 (±0.14)	15.55 (±4.59)
3	90	13.24	71.23 (±14.50)	4.59 (±0.34)	4.83 (±0.18)	16.26 (±6.04)
4	98	14.41	143.77 (±28.03)	4.78 (±0.45)	4.72 (±0.18)	15.14 (±5.72)
5	89	13.09	287.37 (±56.42)	4.86 (±0.48)	4.67 (±0.24)	14.13 (±5.20)
6	91	13.38	593.57 (±116.28)	4.97 (±0.50)	4.53 (±0.30)	13.42 (±5.72)
7	81	11.91	1122.46 (±219.29)	5.16 (±0.62)	4.47 (±0.31)	13.37 (±6.37)
8	57	8.38	2252.04 (±485.08)	5.08 (±0.62)	4.35 (±0.32)	12.89 (±6.43)
9	59	8.68	4702.10 (±890.70)	5.40 (±0.77)	4.10 (±0.42)	11.81 (±4.61)
10	15	2.21	8601.93 (±1200.97)	5.32 (±0.46)	4.07 (±0.28)	10.27 (±3.58)

^aValues of SCC were divided by 1000.

Table 3. Linear regression coefficients and means for TDMY on EC of milk within the classes (250,000; 400,000; 600,000 and 750,000 cells/mL) of somatic cell count (SCC).

SCC level/mL	Linear regression coefficient	Mean TDMY
Below 250,000	−1.25*	15.04^a
Above 250,000	−2.26**	14.62^a
Below 400,000	−1.06^NS	15.03^a
Above 400,000	−2.38**	14.57^a
Below 600,000	−1.00^NS	15.00^a
Above 600,000	−2.53**	14.55^a
Below 750,000	−1.03*	15.01^a
Above 750,000	−2.72 **	14.55^a

Note: NS, not significant.

**, *Significant at the 1% and 5% probability level, respectively. Means followed by the same superscript letter do not differ significantly at the 5% level (Tukey test).

Table 4. Proportion of records distributed by classes of EC (EC – mS/cm) and limits of somatic cell count (SCC) in Dairy Gyr cows.

Classes of EC (mS/cm)	SCC Below 250^a	SCC Above 250	SCC Below 400	SCC Above 400	SCC Below 600	SCC Above 600	SCC Below 750	SCC Above 750
Below 4.20	8	3	7	3	8	3	7	3
4.21–4.40	14	6	12	5	13	5	11	5
4.41–4.60	22	12	22	10	21	9	20	10
4.61–4.80	24	15	23	15	24	12	23	11
4.81–5.00	15	18	16	17	16	18	16	17
5.01–5.20	7	11	7	12	7	12	8	10
5.21–5.40	6	8	7	7	6	8	6	9
5.41–5.60	1	10	2	11	2	12	4	11
5.61–5.80	1	5	1	6	1	6	2	6
5.81–6.10	1	4	1	5	1	5	1	7
Above 6.11	1	8	2	9	1	10	2	11
Number total and (%)	316 (46)	364 (54)	377 (55)	303 (45)	422 (62)	258 (38)	461 (67)	219 (33)

^aValues of SCC were divided by 1000.

Figure 1. Linear regression of EC of milk on SCS.