Effect of feeding less shell, extruded and enzymatically treated palm kernel cake on expression of growth-related genes in broiler chickens

Figures & data

Table 1. Feed composition of experimental diets.

Ingredients	0%	Untreated PKC	LSPKC	ETPKC	EXPKC
Corn	59.24	47.00	49.90	49.00	47.60
PKC	0.00	25.00	25.00	25.00	25.00
Soybean meal	29.30	0.00	0.00	0.00	0.00
Corn gluten	0.00	12.80	12.00	12.20	12.80
Fish meal	0.00	4.50	4.50	4.50	4.50
Wheat pollard	3.50	0.00	0.00	0.00	0.00
Palm oil	4.80	6.90	4.80	5.50	6.30
Dicalcium phosphate	1.40	1.00	1.00	1.00	1.00
Limestone	0.90	0.65	0.65	0.65	0.65
K2Co3	0.00	0.50	0.50	0.50	0.50
Na2SO4	0.00	0.50	0.50	0.50	0.50
NaCl	0.45	0.00	0.00	0.00	0.00
Choline Cl-70%	0.05	0.15	0.15	0.15	0.15
Vitamin premix^a	0.05	0.05	0.05	0.05	0.05
Mineral premixb	0.10	0.10	0.10	0.10	0.10
L-Lysine	0.07	0.66	0.66	0.66	0.66
DL-Methionine	0.14	0.02	0.02	0.02	0.02
L-Threonine	0.00	0.09	0.09	0.09	0.09
L-Tryptophan	0.00	0.08	0.08	0.08	0.08
Total	100.00	100.00	100.00	100.00	100.00
Calculated
Metabolisable energy, ME kcal/kg	3102.00	3098.00	3100.00	3105.00	3099.00
Crude protein	19.01	19.02	19.01	19.01	19.05
DEB,mEq/kg	247	203	205	204	203
Ether extract	7.68	11.78	9.80	10.46	11.21
Crude fibre	2.92	5.23	3.55	4.33	4.34
Ca	0.76	0.76	0.76	0.76	0.76
avP	0.38	0.38	0.38	0.38	0.38
Lysine	1.05	1.05	1.06	1.06	1.05
Methionine	0.43	0.43	0.43	0.43	0.44
Tryptophan	0.22	0.19	0.19	0.19	0.19
Threonine	0.72	0.71	0.71	0.71	0.71

Palm kernel cake (PKC): Untreated PKC; LSPKC Less-shell PKC; ETPKC: enzyme-treated PKC; EXPKC: Extruded PKC; DEB: dietary electrolyte balance.

^aVitamin premix supplied per ton of diet: 10.000 MIU; vitamin E: 75.000; vitamin K₃: 20.000 g; vitamin A: 50.000 MIU; vitamin D₃, vitamin B₁: 10.000 g; vitamin B₆: 20.000 g; vitamin B₂: 30.000 g; calcium D-pantothenate: 60.000 g; vitamin B₁₂: 0.100 g; folic acid: 5.000 g; nicotinic acid: 200.000 g; biotin: 235.000 mg.

^bMineral premix supplied per ton of diet: Fe: 80 g; Cu: 15 g; Zn: 80 g; Mg: 100 g; Se: 0.20 g; KCl: 4 g; MgO₂: 0.60 g; NaHCO₃: 1.5 g.

Table 2. List of genes with their respective biological functions and pathways.

NCBI Gene ID	Symbol	Description	Functional pathway
386572	GRB2	Growth factor receptor-bound protein 2	mTOR signalling pathway
420948	GRB10	Growth factor receptor-bound protein 10	mTOR signalling pathway
415832	SLC7A5	Solute carrier family 7 (amino acid transporter light chain, L system), member 5	mTOR signalling pathway
415783	GPI	Glucose-6-phosphate isomerase	Glycolysis / Gluconeogenesis
396017	ENO1	Enolase 1, (alpha)	Glycolysis / Gluconeogenesis
373889	HK1	Hexokinase 1	Fructose and mannose metabolism
769765	MPI	Mannose phosphate isomerase	Fructose and mannose metabolism
769850	PFKL	Phosphofructokinase, liver	Fructose and mannose metabolism
417989	PMM1	Phosphomannomutase 1	Fructose and mannose metabolism
418090	IGF1	Insulin-like growth factor 1 (somatomedin C)	FoxO signalling pathway
395337	IL6	Interleukin 6 (interferon, beta 2)	FoxO signalling pathway
100857767	LOC100857767	Forkhead box protein O3-like	FoxO signalling pathway
374231	FOXO1	Forkhead box O1	FoxO signalling pathway
421769	FOXO3	Forkhead box O3	FoxO signalling pathway
428703	FOXO4	Forkhead box O4	FoxO signalling pathway
395274	FAS	Fas (TNF receptor superfamily, member 6)	Apoptosis
418325	TNFRSF1A	Tumor necrosis factor receptor superfamily, member 1A	Apoptosis
396337	NTRK1	Neurotrophic tyrosine kinase, receptor, type 1	Apoptosis
771315	CSF2RB	Colony stimulating factor 2 receptor, beta, low-affinity (granulocyte-macrophage)	Apoptosis
101750363	LOC101750363	Perforin-1-like	Apoptosis
23221	RHOBTB2	Rho-related BTB domain containing 2	Apoptosis
419399	PRKCZ	Protein kinase C, zeta	Insulin signalling pathway
423572	SOS2	Son of sevenlesshomologue 2 (Drosophila)	Insulin signalling pathway
395114	RHOQ	Ras homologue gene family, member Q (Gallus gallus)	Insulin signalling pathway
422703	EIF4E	Eukaryotic translation initiation factor 4E	Insulin signalling pathway
396148	RPS6	Ribosomal protein S6	Insulin signalling pathway
374015	FABP1	Fatty acid binding protein 1, liver	PPAR signalling pathway

Table 3. Feed intake, weight gain and feed conversion ratio (FCR) of broilers fed with control and PKC containing diets.

Parameter	0% PKC	Untreated PKC	LSPKC	ETPKC	EXPKC
Feed intake, kg/bird
Day 21–39	2.81^bc ± 0.03	2.78^c ± 0.01	2.85^ab ± 0.01	2.88^a ± 0.01	2.87^ab ± 0.01
Day 1–39	4.05^b ± 0.03	4.00^b ± 0.02	4.11^a ± 0.02	4.17^a ± 0.02	4.15^a ± 0.02
Body weight gain, kg/bird
Day 21–39	1.43^b ± 0.01	1.33^c ± 0.01	1.27^c ± 0.02	1.31^c ± 0.04	1.27^c ± 0.01
Day 1–39	2.26^a ± 0.02	2.16^b ± 0.01	2.11^b ± 0.03	2.13^b ± 0.04	2.10^b ± 0.02
FCR
Day 21–39	1.97^c ± 0.01	2.10^b ± 0.02	2.25^a ± 0.04	2.21^a ± 0.05	2.26^a ± 0.02
Day 1–39	1.83^c ± 0.01	1.91^b ± 0.01	2.03^a ± 0.02	1.99^a ± 0.03	2.02^a ± 0.02

Palm kernel cake (PKC): Untreated PKC; LSPKC Less-shell PKC: ETPKC: enzyme-treated PKC; EXPKC: Extruded PKC Means  ±  SEM with different superscripts in a row differ significantly (p < .05).^a,b,cMeans within a column with no common superscripts are significantly different at p < 0.05.

Table 4. Fold changes in expression of liver genes of broilers fed different dietary treatments by PCR array analysis.

Genes	Untreated PKC		LSPKC		ETPKC		EXPKC
	Fold change	p value	Fold change	p value	Fold change	p value	Fold change	p value
GRB2	1.227	.425	3.705	.019	2.837	.306	1.373	.292
GRB10	1.371	.442	7.562	.048	7.113	.285	1.895	.292
SLC7A5	0.659	.815	21.944	.196	50.240	.286	11.719	.308
GPI	1.322	.592	2.947	.078	2.072	.305	2.650	.308
ENO1	1.436	.367	11.217	.005	8.326	.261	2.493	.278
HK1	1.014	.725	1.181	.421	2.953	.139	0.714	.872
MPI	1.444	.492	9.040	.176	4.941	.317	2.750	.340
PFKL	1.452	.269	17.235	.002	9.785	.267	2.228	.249
PMM1	1.329	.590	20.392	.176	6.423	.323	3.597	.320
IGF1	1.344	.362	8.259	.052	13.668	.329	5.120	.329
LOC100857767	1.235	.385	26.318	.212	22.362	.329	8.347	.330
IL6	0.286	.286	0.251	.251	0.333	.333	0.495	.495
FOXO1A	1.035	.704	17.006	.210	17.025	.330	4.844	.335
FOXO3	1.046	.405	13.905	.008	15.917	.187	2.334	.753
FOXO4	1.450	.615	13.928	.137	5.187	.336	1.049	.337
TNFRSF1A	1.186	.521	1.510	.197	1.244	.415	1.691	.130
FAS	1.372	.543	7.163	.092	4.304	.320	4.324	.313
NTRK1	1.876	.198	82.37	.157	71.290	.335	2.086	.346
CSF2RB	1.532	.315	7.055	.075	24.255	.336	3.223	.330
LOC101750363	0.811	.468	8.355	.017	7.124	.167	0.615	.301
PRKCZ	1.251	.368	4.303	.029	3.699	.015	1.910	.208
SOS2	1.215	.673	13.402	.066	8.365	.307	3.196	.303
RHOQ	1.451	.380	5.020	.081	5.894	.322	2.408	.301
RHOBTB2	1.536	.279	10.335	.008	4.717	.024	2.837	.213
RPS6	1.469	.506	10.691	.055	13.041	.333	3.626	.328
EIF4E	1.306	.469	7.800	.097	4.228	.317	4.332	.317
FABP1	1.067	.360	5.167	.208	3.961	.337	9.164	.336

Palm kernel cake (PKC): Untreated PKC; LSPKC Less-shell PKC: ETPCE: enzyme-treated PKC; EXPKC: Extruded PKC.

Expression of genes with ≥2.0 fold change and p < .05 was considered significantly up-regulated.