Effect of chokeberry pomace as a feed additive for high-producing dairy goats on oxidative stress parameters and quality of milk

Fig. 1.

Physicochemical parameters of milk in the control and experimental groups at the start and finish of chokeberry supplementation to dairy goats

Physicochemical parameters of milk	Amount of additive	Mean ± standard deviation		Statistical significance (P-value)
		Start	Finish	Within group A1, A2 and C	Between C and A1 and C and A2	Between C and A1	Between C and A2	Between A1 and A2
				Start to finish	Finish	Start to finish		Finish
Log somatic cell count	15g (A1)	2.65 ± 0.57	2.68 ± 0.17	0.831
	30g (A2)	2.63 ± 0.24	2.61 ± 0.20	0.912	0.184	0.992	0.619	0.626
					0.070
	control (C)	2.68 ± 0.39	2.90 ± 0.20	0.187
Fat (%)	15g (A1)	2.94 ± 0.42	2.73 ± 0.20	0.251
	30g (A2)	3.30 ± 0.41	2.56 ± 0.36	<0.001*	0.757	0.403	0.066	0.316
					0.511
	control (C)	2.88 ± 0.32	2.68 ± 0.50	0.264
Protein (%)	15g (A1)	2.85 ± 0.24	2.82 ± 0.14	0.793
	30g (A2)	2.76 ± 0.20	2.94 ± 0.27	0.106	0.883	0.162	0.013*	0.271
					0.359
	control (C)	2.66 ± 0.27	2.74 ± 0.29	0.093
Casein (%)	15g (A1)	2.01 ± 0.22	1.87 ± 0.19	0.189
	30g (A2)	1.98 ± 0.18	2.06 ± 0.26	0.482	0.438	0.604	0.227	0.085
					0.371
	control (C)	1.93 ± 0.27	1.96 ± 0.25	0.784
Lactose (%)	15g (A1)	4.80 ± 0.25	4.76 ± 0.20	0.708
	30g (A2)	4.83 ± 0.14	4.82 ± 0.22	0.828	0.550	0.184	0.418	0.573
					0.946
	control (C)	4.89 ± 0.15	4.82 ± 0.19	0.484
Total solids (%)	15g (A1)	10.97 ± 0.64	10.86 ± 0.32	0.707
	30g (A2)	11.28 ± 0.60	10.84 ± 0.62	0.112	0.946	0.777	0.835	0.934
					0.881
	control (C)	10.79 ± 0.54	10.88 ± 0.73	0.732
Solids not fat (%)	15g (A1)	8.13 ± 0.41	7.99 ± 0.25	0.404
	30g (A2)	8.08 ± 0.29	8.15 ± 0.45	0.671	0.684	0.877	0.389	0.309
					0.566
	control (C)	8.01 ± 0.31	8.06 ± 0.34	0.797
Urea (mg/L)	15g (A1)	241.56 ± 76.05	257.67 ± 92.03	0.652
	30g (A2)	234.89 ± 67.15	199.50 ± 46.60	0.312	0.202	1.000	0.100	0.100
					0.765
	control (C)	257.67 ± 102.27	210.25 ± 52.78	0.202
Freezing point (°C)	15g (A1)	-0.592.89 ± 11.59	-0.584.11 ± 20.34	0.187
	30g (A2)	-0.589.8 ± 99.09	-0.600.80 ± 17.55	0.094	0.026*	0.010*	0.893	0.012*
					0.859
	control (C)	-0.601.67 ± 4.12	-0.599.63 ± 13.78	0.764
Free fatty acids (mmol/100 g fat)	15g (A1)	0.61 ± 0.11	0.79 ± 0.43	0.140
	30g (A2)	0.60 ± 0.10	0.63± 0.17	0.780	0.113	0.084	0.630	0.191
					0.713
	control (C)	0.58 ± 0.38	0.59 ± 0.17	0.923
Density (g/mL)	15g (A1)	1023.96 ± 1.65	1023.37 ± 1.48	0.416
	30g (A2)	1023.24 ± 0.85	1024.75 ± 1.95	0.036*	0.691	0.518	0.011*	0.054
					0.138
	control (C)	1022.90 ± 1.60	1023.66 ± 1.25	0.308
Natural acidity (0T)	15g (A1)	16.89 ± 1.62	14.44 ± 2.01	0.001*
	30g (A2)	16.78 ± 0.67	15.80 ± 1.32	0.170	0.354	<0.001*	0.023*	0.059
					0.007*
	control (C)	17.44 ± 1.42	13.75 ± 1.83	<0.001*
Citric acid (%)	15g (A1)	0.10 ± 0.03	0.09 ± 0.01	0.849
	30g (A2)	0.09 ± 0.02	0.09 ± 0.03	0.953	0.863	1.0	0.953	0.953
					0.815
	control (C)	0.09 ± 0.03	0.09 ± 0.03	0.863

The activity of aminopeptidases in milk in the control and experimental groups at the start and finish of chokeberry supplementation to dairy goats

Enzymes	Amount of additive	Mean ± standard deviation		Statistical significance (P-value)
		Start	Finish	Within group A1, A2 and C	Between C and A1 and C and A2	Between C and A1	Between C and A2	Between A1 and A2
				Start to finish	Finish	Start to finish		Finish
Alanyl-aminopeptidase (nmol/mg protein/h)	15g (A1)	2.96 ±0 .37	3.65 ± 0.40	<0.001*
	30g (A2)	2.91 ± 0.13	3.80 ± 0.40	<0.001*	0.248	<0.001*	<0.001*	0.302
					0.853
	control (C)	2.85 ± 0.24	3.83 ± 0.23	<0.001*
Leucyl-aminopeptidase (nmol/mg protein/h)	15g (A1)	2.98 ± 0.35	3.53 ± 0.25	<0.001*
	30g (A2)	2.90 ± 0.12	3.87 ± 0.36	<0.001*	0.014*	<0.001*	<0.001*	0.011*
					0.965
	control (C)	2.87 ± 0.23	3.88 ± 0.31	<0.001*
Arginyl-aminopeptidase (nmol/mg protein/h)	15g (A1)	3.01 ± 0.37	3.59 ± 0.42	0.001*
	30g (A2)	2.94 ± 0.15	3.66 ± 0.41	<0.001*	0.676	<0.001*	<0.001*	0.642
					0.982
	control (C)	2.88 ± 0.24	3.66 ± 0.29	<0.001*

The activity of lysosomal enzymes in milk in the control and experimental groups at the start and finish of chokeberry supplementation to dairy goats

Enzymes	Amount of additive	Mean ± standard deviation		Statistical significance (P-value)
		Start	Finish	Within group A1, A2 and C	Between C and A1 and C and A2	Between C and A1	Between C and A2	Between A1 and A2
				Start to finish	Finish	Start to finish		Finish
Acid phosphatase (nmol/mg protein/h)	15g (A1)	17.78 ± 2 .87	20.29 ± 1.83	0.005*
	30g (A2)	17.28 ± 0.82	23.28 ± 2.01	<0.001*	0.069	0.001*	<0.001*	0.001*
					<0.001*
	control (C)	17.33 ± 1.36	18.64 ± 1.23	0.146
β-glucuronidase (nmol/mg protein/h)	15g (A1)	0.99 ± 0.14	1.26 ± 0.10	<0.001*
	30g (A2)	0.97 ± 0.05	1.35 ± 0.12	<0.001*	<0.001*	<0.001*	<0.001*	0.051
					<0.001*
	control (C)	0.96 ± 0.08	1.00 ± 0.06	0.413
β-galactosidase (nmol/mg protein/h)	15g (A1)	4.10 ± 0.29	5.08 ± 0.32	<0.001*
	30g (A2)	4.01 ± 0.24	5.50 ± 0.56	<0.001*	<0.001*	<0.001*	<0.001*	0.014*
					<0.001*
	control (C)	3.95 ± 0.41	3.66 ± 0.10	0.092
β-glucosidase (nmol/mg protein/h)	15g (A1)	3.99 ± 1.15	5.10 ± 0.36	<0.001*
	30g (A2)	4.18 ± 0.17	5.67 ± 0.51	<0.001*	0.038*	0.003*	<0.001*	0.050*
					<0.001*
	control (C)	4.17 ± 0.55	4.45 ± 0.50	0.349
α-glucosidase (nmol/mg protein/h)	15g (A1)	4.27 ± 0.26	5.14 ± 0.33	<0.001*
	30g (A2)	4.41 ± 0.22	5.37 ± 0.52	<0.001*	<0.001*	<0.001*	<0.001*	0.230
					<0.001*
	control (C)	4.28 ± 0.46	4.39 ± 0.50	0.566
N-acetylhexosaminidase (nmol/mg protein/h)	15g (A1)	9.00 ± 1.12	10.18 ± 0.81	0.004*
	30g (A2)	9.07± 0.63	11.64 ± 0.95	<0.001*	0.021*	0.001*	<0.001*	<0.001*
					<0.001*
	control (C)	8.77 ± 0.68	9.22 ± 0.60	0.266
Mannosidase (nmol/mg protein/h)	15g (A1)	2.23 ± 0.31	2.53 ± 0.23	0.008*
	30g (A2)	2.19 ± 0.07	2.67 ± 0.21	<0.001*	0.421	0.020*	<0.001*	0.186
					0.038*
	control (C)	2.27 ± 0.24	2.44 ± 0.22	0.133

The activity of antioxidant non-enzymatic compounds in milk in control and experimental groups at the start and finish of chokeberry supplementation to dairy goats

Non-enzymatic compounds	Amount of additive	Mean ± standard deviation		Statistical significance (P-value)
		Start	Finish	Within group A1, A2 and C	Between C and A1 and C and A2	Between C and A1	Between C and A2	Between A1 and A2
				Start to finish	Finish	Start to finish		Finish
(2,2-diphenyl-1-picrylhydrazyl) (% of remaining DPPH)	15g (A1)	80.03 ± 3.60	85.77 ± 2.68	<0.001*
	30g (A2)	80.95 ± 1.54	87.47 ± 1.32	<0.001*	<0.001*	<0.001*	<0.001*	0.097
					<0.001*
	control (C)	80.80 ± 1.49	80.37 ± 1.52	0.684
Vitamin C (mg/100mL)	15g (A1)	1.88 ± 0.22	2.10 ± 0.34	0.059*
	30g (A2)	1.91 ± 0.24	2.11 ± 0.27	0.107	0.978	0.414	0.337	0.901
					0.882
	control (C)	1.99 ± 0.25	2.09 ± 0.28	0.444
Reduced glutation (μM)	15g (A1)	24.46 ± 4.09	55.56 ± 10.60	<0.001*
	30g (A2)	22.84 ± 2.98	66.50 ± 20.59	<0.001*	<0.001*	<0.001*	<0.001*	0.029*
					<0.001*
	control (C)	21.76 ± 2.33	29.64 ± 7.77	0.132
Polyphenols (mg/GAE/mL)	15g (A1)	3.78 ± 0.32	6.97 ± 1.14	<0.001*
	30g (A2)	3.51 ± 0.38	8.11 ± 1.01	<0.001*	<0.001*	<0.001*	<0.001*	0.001*
					<0.001*
	control (C)	3.68 ± 0.44	3.81 ± 0.51	0.712