Management practices and milk quality in dairy goat farms in Northern Italy

Figures & data

Figure 1(a–c). Change in milk yield, milk fat/protein ratio and milk somatic cell count (as log₁₀ cells/mL) throughout lactation by month of kidding (LS means) for goats which kidded in season (goats = 5559).

Table 1. Description of the 173 dairy goat farms: main characteristics (percentage of farms).

Categories	Variable	Levels	%
Herd size	No. lactating goats	<45 lactating goats	52.0
		45–70 lactating goats	20.2
		>70 lactating goats	27.8
Breeds	Main breeds	Saanen	36.1
		Alpine	37.2
		Saanen and Alpine	15.7
		Local breeds*	6.4
		Half-breeds	4.7
Barn equipment and herd management	Fans	Yes	11.6
	Type of bedding material	Straw	96.3
		Sawdust	3.7
	Frequency of bedding material addition	Daily	24.9
		Weekly	38.2
		When necessary	37.0
	Frequency of complete bed replacement	Monthly	34.7
		Less than monthly	65.3
	Bedding disinfection	Yes	51.2
	Exercise outdoor paddock	Yes	41.2
	Type of outdoor paddock**	paved	7.5
		ground	68.7
		grassed	23.9
	Pasture grazing	Yes	28.9
	Out-of-season breeding	Yes	13.3
Milk utilisation		Farm-made cheese	82.0
		Milk sold to cheese factories	18.0
Farm-made cheese processing**	Use of raw milk	Yes	71.9
	Use of starters	Yes	92.0
	Use of commercial starters	Yes	80.4

* Main local breeds: Bionda dell’Adamello, Frisa, Nera di Verzasca, and Orobica.

** Expressed as percentage of farms which have outdoor paddocks or make cheese on-farm, respectively.

Table 2. Description of the 173 dairy goat farms: milking facilities and routine (percentage of farms).

Categories	Variables	Levels	%
Milking	Type of milking	Hand milking	8.7
		Machine milking	91.3
	No. daily milkings	1	2.3
		2	86.1
		From 2 to 1*	11.6
	Milking location	Bedded area	12.1
		Barn	39.9
		Separate milking room	48.0
Milking machine	Type of milking machine	Bucket	38.0
		Portable	20.9
		Pipeline	41.1
	Vacuum	<40 kPa	53.8
		>40 kPa	46.2
	Pulsation ratio	50:50	13.7
		60:40	37.7
		65:35	4.1
		Unknown	44.5
	Automatic cluster removal	Yes	5.1
	Type of liner	Short	81.6
		Long	18.4
	Liner shape	Flat	50.0
		Rounded	50.0
	Liner material	Silicone	71.7
		Rubber	28.3
Milking machine cleaning	Type of cleaning process	Manual	56.9
		Semi-automatic	8.13
		Automatic	35.0
	Pre-rinse	Yes	52.1
	Water temperature (main wash)	<45 °C	54.8
		>45 °C	45.2
Milking routine	Paper udder cleaning	Yes	72.6
	Forestripping	Yes	69.4
	Teat pre-dipping	Yes	12.1
	Teat post-dipping	Yes	40.2
	Udder squeezing with milking unit on	Yes	41.1
	Milkers wearing gloves	Yes	18.8

* Farms which milked twice a day except during grazing periods and/or at the end of lactation.

Table 3. Average herd traits, milk production and quality of the sample of 91 farms (6981 goats; individual and bulk tank milk controls).

Variable		N	Mean	SD	Minimum	Maximum
Parity	No	46545	2.89	1.81	1.00	13.00
Primiparous goats	% controls	11216	24.10	–	–	–
Secondiparous goats	% controls	12873	27.70	–	–	–
Multiparous goats	% controls	22456	48.30	–	–	–
Milk yield	kg/milking	46545	1.25	0.57	0.06	5.27
Fat	%	44653	3.49	0.77	2.01	6.00
Protein	%	37856	3.59	0.47	3.01	6.99
Milk fat/protein reversion	% samples	19019	51.40	–	–	–
Somatic cell count	log10/mL	46097	5.86	0.63	3.00	7.89
Standard plate count	log10 CFU/mL	760	4.47	0.66	3.00	7.01
Lactose	%	748	4.36	0.23	2.08	5.12
Casein	%	711	2.66	0.40	1.72	4.81
Urea	mg/dL	744	39.70	9.15	11.40	90.90

Table 4. Logistic analysis of risk factors associated to the presence of more than 50% of lactating goats with milk fat/protein reversion.

Effect	Odds ratio estimate	95% confidence intervals		p
Udder squeeze with milking unit on: yes vs no	1.860	1.250	2.780	.002
Herd size: >70 goats vs <45 goats	0.530	0.330	0.840	.027
Herd size: 45–70 goats vs <45 goats	0.689	0.430	1.110	.805
Milk yield/milking: <1.4 kg vs ≥1.4 kg	0.660	0.430	1.010	.055
SCC*: ≥5.8 log10 cell/mL vs <5.8 log10 cell/mL	2.720	1.810	4.100	<.001

* SCC: somatic cell count.

Table 5. Logistic analysis of risk factors associated to the presence of more than 50% of lactating goats with SCC* > 5.8 log10 cell/mL.

Effect	Odds ratio estimate	95% confidence intervals		p
Herd size: >70 goats vs <45 goats	2.620	1.580	4.370	<.001
Herd size: 45–70 goats vs <45 goats	0.780	0.480	1.280	.001
Milk protein: ≥3.4% vs <3.4%	2.040	1.330	3.130	.001
Post-dipping procedure: yes vs no	2.240	1.440	3.480	<.001
Milking vacuum: ≤40 kPa vs >40 kPa	1.800	1.170	2.750	.007
Milk fat/protein reversion: yes vs no	1.740	1.140	2.660	.010
Milk yield/milking: <1.4 kg vs ≥1.4 kg	3.940	2.530	6.120	<.001
SPC**: >4.5 log10 CFU/mL vs ≤4.5 log10 CFU/mL	2.410	1.570	3.690	<.001

* SCC: somatic cell count.

** SPC: standard plate count.

Table 6. Regression model for milk yield, milk fat and milk protein percentages.

	Milk production, kg/milking		Milk fat, %		Milk protein, %
Parameter	Estimate	p	Estimate	p	Estimate	p
Intercept	2.34	<.001	2.98	<.001	2.37	<.001
DIM*: <100 vs 200 d	0.31	<.001	0.05	<.001	−0.28	<.001
DIM*: 100–200 vs 200 d	0.18	<.001	−0.24	<.001	−0.32	<.001
Out-of-season vs in-season kidding	−0.02	.02	0.10	<.001	0.07	<.001
Local breeds vs Alpine and Saanen	−0.32	<.001	0.21	<.001	0.02	.14
Alpine vs Alpine and Saanen	0.11	<.001	0.14	<.001	0.18	<.001
Saanen vs Alpine and Saanen	0.39	<.001	−0.05	<.001	0.01	.03
Herd size**: Small farms vs Large farms	−0.01	.18	−0.03	.01	0.07	<.001
Herd size**: Medium farms vs Large farms	0.05	<.001	0.07	<.001	0.13	<.001
Primiparous vs Multiparous goats	−0.22	<.001	0.27	<.001	0.09	<.001
Secondiparous vs Multiparous goats	−0.06	<.001	0.13	<.001	0.05	<.001
Somatic cell count, log10 cells/mL	−0.23	<.001	0.07	<.001	0.21	<.001

* DIM: days in milk.

Herd size**: Small farms: <45 lactating goats; Medium farms: 45–70 lactating goats; Large farms: >70 lactating goats.