Dietary net energy levels for growing barrows from 30 to 70 kg

Rodrigues, Gabriela Puhl; Kiefer, Charles; Nascimento, Karina Márcia Ribeiro de Souza; Corassa, Anderson; Marçal, Danilo Alves; Bonin, Marina de Nadai; Santos, Alexandre Pereira dos; Santos, Luana Cristiane dos

doi:10.1590/0103-8478cr20201033

ABSTRACT:

This study evaluated the effect of dietary net energy (NE) levels on growth performance and carcass characteristics of barrows from 30 to 70 kg of body weight (BW). Sixty barrows with initial body weight (IBW) of 31.94 ± 3.54 kg and final body weight (FBW) of 71.98 ± 5.99 kg were allotted to one of five dietary NE levels (2.40, 2.45, 2.50, 2.55, and 2.60 Mcal kg^-1), using a completely randomized block design with six replicates and two barrows per replicate. The experimental period was divided into phase I: 30 to 50 kg and phase II: 50 to 70 kg. The variables analyzed were average daily feed intake (ADFI), net energy intake (NEI), digestible lysine intake (LysI), average daily gain (ADG), feed conversion (FC), FBW, digestible lysine conversion:gain (LysI:G), Cost:Gain (C:G), loin eye area (LEA), muscle depth (MD), first backfat layer (BF₁), second backfat layer (BF₂), total backfat (BFt), lean meat percentage, and carcass bonus index (BI). In phase I, there was a linear increase (P < 0.05) in FBW, ADG, NEI, and LysI with increasing NE levels in the diet. In phase II, increasing dietary NE levels also increased (P < 0.05) FBW, ADG, NEI, LysI, and FC linearly. Overall, there was a linear increase (P < 0.05) in ADG, NEI, LysI, and FC with increasing NE levels in the diet. The other performance variables were not affected (P > 0.05) by the NE levels. There was an increase (P < 0.05) in BF₂ with increasing NE levels, but the other carcass characteristics were not altered (P > 0.05). We recommended 2.60 Mcal of NE kg^-1 in the diet for growing barrows from 30 to 70 kg.

Keywords:
calorie:nutrient ratio; energy intake; nutritional density; requirements

[1] E-mail: charles.kiefer@ufms.br. ^*Corresponding author

Ingredients,%	-------------------------------Diets, NE (Mcal kg^-1)----------------------------
	2.40	2.45	2.50	2.55	2.60
Corn (7.88%)	65.96	65.96	65.96	65.96	65.96
Soybean meal (46.5%)	26.74	26.74	26.74	26.74	26.74
Kaolin (inert)	3.200	2.427	1.657	0.888	0.115
Soybean oil	0.977	1.632	2.288	2.944	3.599
Dicalcium phosphate	1.347	1.397	1.448	1.498	1.548
Limestone	0.662	0.669	0.673	0.678	0.685
L-Lysine HCl	0.277	0.305	0.333	0.360	0.388
L-Threonine	0.094	0.108	0.123	0.138	0.153
DL-Methionine	0.100	0.113	0.126	0.138	0.151
L-Tryptophan	0.014	0.020	0.023	0.027	0.032
Vitamin-mineral premix¹	0.150	0.150	0.150	0.150	0.150
Tiamulin	0.050	0.050	0.050	0.050	0.050
Salt	0.432	0.432	0.432	0.432	0.432
---------------------------------------------------------------Calculated nutritional composition²-------------------------------------------------------------
Net energy, Mcal kg^-1	2.40	2.45	2.50	2.55	2.60
Metabolizble energy, Mcal kg^-1	3.19	3.24	3.30	3.36	3.42
Crude protein, %	18.00	18.05	18.09	18.14	18.19
SID lysine, %	1.026	1.048	1.069	1.090	1.112
SID met+cys, %	0.605	0.618	0.631	0.643	0.656
SID threonine, %	0.667	0.681	0.695	0.709	0.723
SID tryptophan, %	0.205	0.210	0.214	0.218	0.222
Calcium, %	0.693	0.708	0.722	0.736	0.751
Digestible phosphorus, %	0.332	0.339	0.346	0.353	0.360
Sodium, %	0.190	0.190	0.190	0.190	0.190

Ingredients, %	-----------------------------Diets, NE (Mcal kg^-1)------------------------------
	2.40	2.45	2.50	2.55	2.60
Corn (7.88%)	73.49	73.49	73.49	73.49	73.49
Soybean meal (46.5%)	20.61	20.61	20.61	20.61	20.61
Kaolin (inert)	3.371	2.617	1.864	1.112	0.354
Soybean oil	0.000	0.659	1.318	1.977	2.635
Dicalcium phosphate	0.917	0.953	0.996	1.032	1.076
Limestone	0.594	0.603	0.604	0.610	0.614
L-Lysine HCl	0.271	0.294	0.317	0.340	0.365
L-Threonine	0.073	0.085	0.098	0.111	0.123
DL-Methionine	0.062	0.072	0.083	0.094	0.105
L-Tryptophan	0.017	0.021	0.024	0.028	0.032
Vitamin-mineral premix¹	0.150	0.150	0.150	0.150	0.150
Tiamulin	0.050	0.050	0.050	0.050	0.050
Salt	0.396	0.396	0.396	0.396	0.396
-----------------------------------------------------------Calculated nutritional composition²----------------------------------------------------------------
Net energy, Mcal kg^-1	2.40	2.45	2.50	2.55	2.60
Metabolizble energy, Mcal kg^-1	3.16	3.21	3.27	3.33	3.38
Crude protein, %	15.70	15.74	15.78	15.82	15.86
SID lysine, %	0.876	0.894	0.912	0.930	0.949
SID met+cys, %	0.517	0.527	0.538	5.49	0.560
SID threonine, %	0.569	0.581	0.593	0.605	0.617
SID tryptophan, %	0.175	0.179	0.182	0.186	0.190
Calcium, %	0.543	0.555	0.566	0.577	0.589
Digestible phosphorus, %	0.264	0.269	0.275	0.280	0.286
Sodium, %	0.176	0.176	0.176	0.176	0.176

Variables	----------------------Diets, NE (Mcal kg^-1)-----------------------			----------P value---------			CV, %
	2.40	2.45	2.50	2.55	2.60	L	Q
-------------------------------------------------------------------------Phase I (30 to 50 kg)-------------------------------------------------------------------
IBW, kg	32.01	31.91	31.97	31.99	31.83	0.129	0.133	3.21
FBW, kg^*	49.46	49.43	49.68	49.82	49.89	0.020	0.250	3.14
ADG, kg^*	0.92	0.92	0.93	0.94	0.95	0.027	0.785	5.33
AADFI, kg	1.90	1.91	1.95	1.89	1.86	0.953	0.131	6.81
FC	2.07	2.07	2.09	2.01	1.96	0.055	0.133	6.20
NEI, Mcal d^-1*	4.56	4.69	4.87	4.81	4.84	0.006	0.129	6.94
LysI, g d^-1*	19.50	20.06	20.82	20.56	20.71	0.006	0.127	6.95
LysI:G	21.22	21.71	22.35	21.91	21.79	0.208	0.136	6.32
------------------------------------------------------------------------Phase II (50 to 70 kg)-------------------------------------------------------------------
BFW kg^**	71.11	70.68	72.10	72.88	73.32	0.001	0.655	3.59
ADG, kg^**	1.03	1.01	1.07	1.10	1.12	<0.001	0.698	6.84
AADFI, kg	2.65	2.59	2.67	2.70	2.66	0.395	0.817	8.91
FC^**	2.56	2.55	2.51	2.46	2.38	<0.001	0.222	4.43
NEI, Mcal d^-1**	6.35	6.34	6.68	6.89	6.92	0.003	0.835	9.02
LysI, g d^-1**	23.19	23.13	24.35	25.14	25.24	0.003	0.840	9.01
LysI:G	22.46	22.84	22.85	22.90	22.53	0.722	0.196	4.45
------------------------------------------------------------------------Overall (30 to 70 kg)--------------------------------------------------------------------
ADG, kg^***	0.98	0.97	1.00	1.02	1.04	<0.001	0.817	4.73
AADFI, kg	2.29	2.27	2.33	2.31	2.28	0.564	0.504	7.66
FC^***	2.33	2.33	2.31	2.25	2.18	<0.001	0.096	4.31
NEI, Mcal d^-1***	5.50	5.56	5.82	5.90	5.93	0.002	0.502	7.80
LysI, g d^-1***	21.44	21.67	22.68	22.97	23.09	0.003	0.470	7.70
LysI:G	21.90	22.32	22.62	22.43	22.19	0.328	0.094	4.37
Cost:G, R$	0.20	0.21	0.20	0.20	0.20	0.167	0.401	4.76

	---------------------------------Diets, NE (Mcal kg^-1)-----------------------------			----------P value--------		CV, %
Variables	2.40	2.45	2.50	2.55	2.60	L	Q
LEA, cm²	31.06	31.30	31.10	30.96	31.10	0.960	0.978	14.85
MD, mm	40.07	40.11	39.75	40.46	39.19	0.745	0.759	10.39
BF_1, mm	3.37	3.97	3.40	3.19	3.98	0.616	0.586	26.32
BF_2, mm^*	4.21	4.79	4.93	5.09	6.09	0.019	0.688	32.98
BF_t, mm	7.58	8.76	8.33	8.28	10.07	0.060	0.614	27.17
Lean, %	59.61	58.93	59.15	59.24	58.08	0.081	0.599	2.60
BI	103.87	102.52	103.37	103.65	103.02	0.752	0.721	2.29

Brasil

Brasil

Dietary net energy levels for growing barrows from 30 to 70 kg

Níveis de energia líquida para suínos machos castrados dos 30 aos 70 kg

ABSTRACT: