Effects of stocking density on growth performance, digestive function and immune performance of Matou goats

Figures & data

Table 1. Ingredients and chemical composition of the diets (DM basis, %).

Ingredients	Content	Chemical composition^b	Content
Corn	29.50	DE, MJ/kg	12.91
Wheat bran	28.30	DM	88.18
Mixture of rice chaff and husk	18.50	CP	18.17
Soya bean meal	14.00	CF	7.88
Rapeseed meal	6.20	EE	1.90
Limestone	1.77	NDF	33.67
Calcium hydrogen carbonate	0.18	ADF	17.12
Salt	0.50	Ca	0.97
Sodium bicarbonate	0.05	Total phosphorus	0.36
Premix^a	1.00	Lysine	0.85
		Methionine	0.29

^aComposition (per kg premix): Vitamin A 120-500 KIU, Vitamin D3 75-200 KIU, Vitamin E > 550 U, Fe 1500–5000 mg, Cu 500–620 mg, Mn 1000–3000 mg, Zn 1500 3500 mg, I 20–100 mg, Se 5–12 mg, Co 8–40 mg.

^bAbbreviations: DE: Digestive energe; DM: Dry matter; CP: Crude protein; CF: Crude fiber; EE: Ether extract; NDF: Neutral detergent fiber; ADF: Acid detergent fiber; Ca: Calcium.

Table 2. Primers for qPCR assay.

Items^b	Primer sets^a (5’→3’)	Product size, bp
Feed-related genes
Goat-GAPDH	F: CAAGTTCCACGGCACAGTCAA	249
	R: TGGTTCACGCCCATCACAAA
Goat-POMC	F: ATGGAAGTGCGTGGTTGGTG	184
	R: GGAAATGGCCCATGACGTACT
Goat-CART	F: TCTGCTGCTGCTGCTACCTTTG	126
	R: AGCGCTTCAATCAGCTCCTTCT
Goat-AgRP	F: CTGAAGCGGATAACGGAGGAAC	213
	R: GCAGTAGCAGAAGGCGTTGAAG
Goat-NPY	F: TGCTGGGTAGCAAGCGACTG	184
	R: TGCCTGGTGATGAGATTGATGT
Goat-MC4R	F: CGCGGTGGACAGGTACTTCA	127
	R: GATGAACAAGACGCCCGACAC
Rumen-related genes
Goat-β-Actin	F: GGCAATGAGCGGTTC	141
	R: CGTGTTGGCGTAAAG
Goat-Claudin-1	F: AATTTGGTCAGGCSTCT	112
	R: CTGGGTGTTGGGTAAG
Goat-GHR-1	F: ATGGTGGTATTGTGGAT	149
	R: TGTATTGGGTGGTGGTT
Goat-IGF-1	F: ATGCSCAGTCACATCCT	112
	R: CATCCACCAACTCAGCS

^aPrimers for qPCR assay were designed by Wuhan Servicebio technology CO., LTD.

^bAbbreviations: GAPDH: Glyceraldehyde-3-phosphate dehydrogenase; POMC: Pro-opiomelanocortin; CART: Cocaine and amphetamine regulated transcript peptide; AgRP: Agouti aelated peptide; NPY: Neuropeptide Y; MC4R: Melanocortin receptor-4; GHR: Growth hormone releaser; IGF: Insulin-like growth factor.

Table 3. Effects of stocking density on production performance.

Items^c	Stocking density			SEM	p Value
	Low	Medium	High
Feed intake, kg/d	1.14	1.13	1.12	–	–
ADG, g/d	151.97^a	129.83^a	57.67^b	14.09	.01
Dressing percentage, %	38.36	37.63	40.69	0.78	.28
Liver index	2.52	2.71	2.79	<0.01	.21
Kidney index	0.36	0.34	0.36	<0.01	.73
Spleen index	0.30	0.28	0.28	<0.01	.54
Lung index	1.21	1.15	1.27	<0.01	.56
Heart index	0.46	0.44	0.44	<0.01	.24

^a,bMeans with different superscripts within a row are significantly different (p < .05). The specific feed intake of each goat cannot be counted so there is no SEM and p value about feed intake, and the data of feed intake is the average feed intake of test goats in each group.

^cADG: average daily weight gain.

Table 4. Effects of stocking density on morphological parameters of duodenum, jejunum and ileum.

Items^c	Stocking density			SEM	p Value
	Low	Medium	High
Duodenum
VL, μm	679.50^a	728.76^a	529.04^b	33.37	.01
CD, μm	126.83	148.02	123.15	9.32	.57
VL:CD	5.43	5.22	4.32	0.34	.42
Jejunum
VL, μm	593.07	544.16	467.72	26.70	.15
CD, μm	127.81	140.96	153.29	10.12	.65
VL:CD	4.70	3.94	3.27	0.34	.26
Ileum
VL, μm	811.49^a	592.22^b	487.10^b	55.89	.02
CD, μm	142.21	126.26	107.19	7.69	.18
VL:CD	5.80	4.69	4.63	0.32	.29

^a,bMeans with different superscripts within a row are significantly different (p < .05).

^cCD: Crypt depth; VL: villus length.

Table 5. Effects of stocking density on rumen fermentation parameters.

Items^d	Stocking density			SEM	p Value
	Low	Medium	High
pH	6.23^ab	6.42^a	6.09^b	0.06	.05
Ammonia-nitrogen, mg/dL	42.49^c	49.46^b	59.00^a	1.75	<.001
Total VFA, mmol/L	101.35^b	95.47^b	129.16^a	6.11	.03
Acetate, mmol/L	61.35	59.04	72.99	3.33	.21
Propionate, mmol/L	27.12^ab	22.30^b	32.05^a	1.68	.03
Butyrate, mmol/L	12.88^b	14.13^b	24.12^a	1.69	<.001
Acetate/propionate ratio	2.28^b	2.65^a	2.26^b	0.08	.02

^a–cMeans with different superscripts within a row are significantly different (p< .05).

^dVFA: Volatile fatty acid.

Figure 1. Effects of stocking density on the mRNA expression of feeding-related genes in hypothalamus tissues of Matou goats. ^a–cWithin the same row, means with different superscripts differ (p< 0.05).

Figure 2. Effects of stocking density on the mRNA expression of rumen-related genes in rumen tissues of Matou goats. ^a–cWithin the same row, means with different superscripts differ (p< .05).

Table 6. Effects of stocking density on protein content, antioxidant capacity and stress hormone content of serum.

Items^d	Stocking density			SEM	p Value
	Low	Medium	High
serum protein
TP, g/L	90.00^a	89.50^a	76.17^b	2.25	.01
Alb, g/L	35.33^a	33.50^ab	32.67^b	0.45	.04
Glb, g/L	54.67^a	56.00^a	43.50^b	2.04	.01
IgG, μg/mL	25.36^a	18.45^c	20.19^b	0.73	<.001
IgM, μg/mL	16.11^a	13.79^b	15.43^a	0.26	<.001
IgA, μg/mL	24.29^a	22.56^b	19.25^c	0.50	<0.001
serum antioxidant capacity
T-AOC, U/mL	11.04	10.51	11.77	0.74	.83
MDA, nmol/mL	4.83	4.39	3.90	0.40	.70
SOD, U/mL	8.45	9.55	10.22	0.97	.80
serum stress hormones
GCS, pg/mL	109.24^b	122.85^ab	133.45^a	3.01	<.001
β-EP, ng/mL	2.41^b	2.87^a	2.93^a	0.66	<.001
ACTH, pg/mL	141.99	142.35	136.50	1.73	.32
Cortisol, ng/mL	1.86 ^c	2.49 ^a	1.99 ^b	0.07	<.001

^a–cMeans with different superscripts within a row are significantly different (p<.05).

^dTP: total protein; Alb: albumin; Glb: globulin; T-AOC: total antioxidant capacity; SOD: superoxide dismutase; MDA: malondialdehyde; GCS: glucocorticoid; ACTH: adrenocorticotropic hormone; β-EP: β-endorphin.

Data availability statement

Data and materials supporting the results or analyses presented in this paper are available upon reasonable request.