Efficacy of Endofeed DC in broilers fed diets based on corn and soybean meal

Introduction

The beneﬁcial effects of enzyme supplementation (ES) of poultry diets based on cereals, such as wheat, barley and rye, are well established. However, the data available on the inﬂuence of enzymes on performance and digestive characteristics of broilers fed maize are limited and controversial. In general, the response to enzymes is lower for maize than for more viscous cereal diets. The purpose of the current trial was to assess the effect of enzyme supplementation of corn-SBM diets on performance and digestibility of broilers from 1 to 42 days of age.

Materials & Methods

A total of 1,056 one-day-old male Ross 308 chicks was used and allocated at random to the 4 experimental treatments. The experiment was carried out in 48 pens (replicates) of a 96-pen broiler house. The experimental design was completely randomised with 4 dietary treatments (Table 1) arranged factorially, with two different types of basal diet and two levels of Endofeed DC supplementation (0 vs 125 g/t), a commercial enzyme supplement that contains ß-glucanase and ß-xylanase. Each treatment was replicated 12 times and 22 male broilers housed together formed the experimental unit. Replicates (pens) were allocated to the treatments for a homogeneous distribution of treatments within the house.

Table 1. Study design

Treatment	Basal diet	Endofeed DC
T1 Control High	High protein (23% CP starter, 21% CP finisher)	-
T2 Endofeed DC High	125 g/t
T3 Control Low	Low protein (21% CP starter, 19% CP finisher)	-
T4 Endofeed DC Low	125 g/t

The experimental diets were formulated by Imasde Agroalimentaria, S. L. For each feeding period (starter and finisher) and type of basal diet, all the diets were calculated to be isonutritive, and met or exceeded the nutrient requirements recommended by NRC (1994) for broiler chickens. The composition and the calculated analyses of the basal diets according to FEDNA (2003) values for composition of feed ingredients are presented in Table 2. Starter diets were offered to all birds from day-old until 21 days of age, and finisher diets from 22-42 days. The diets and water were provided ad libitum. The diets were presented to the birds as mash.

Table 2. Composition and calculated analyses of the basal diets

Ingredients, %	Starter (0-21 d)	Finisher (22-42 d)
T1 &T2 High protein	T3&T4 Low protein	T1 &T2 High protein	T3&T4 Low protein
Maize	46.30	51.16	51.23	55.81
Soybean meal, 44 % CP	43.29	37.02	35.68	32.64
Lard	6.14	5.41	8.56	7.02
Wheat middlings	-	2.00	-	-
Others¹	4.27	4.41	4.53	4.53
Calculated analyses²
AME_n, kcal/kg	3,000	3,000	3,200	3,150
Crude protein, %	23.0	21.0	20.0	19.0
Total lysine, %	1.41	1.33	1.20	1.13
Dig. lysine, %	1.23	1.16	1.04	0.98
Dig. methionine	0.62	0.58	0.56	0.52
Total met+cys, %	1.04	0.98	0.93	0.88
Dig. met+cys	0.93	0.87	0.83	0.78
Total threonine, %	0.95	0.89	0.84	0.80
Dig. threonine, %	0.80	0.75	0.71	0.67
Total tryptophan, %	0.27	0.25	0.23	0.22
Calcium, %	1.00	1.00	0.90	0.90
Av. phosphorus, %	0.45	0.45	0.45	0.45
Sodium, %	0.18	0.18	0.17	0.17

^{1DL-Methionine, L-Lysine HCl 78, L-Threonine, 98%, Calcium carbonate, Monocalcium phosphate, Salt and Vitamin & mineral Premix.
2Based on FEDNA (2003) values for feed ingredients.}

The trial was carried out at the Broiler Floor Pen Unit of Imasde experimental facilities (Murcia, Spain). The birds were kept in 48 floor pens of a clean house equipped with 96 floor pens, each an area of 1.82 m2 (1.58 x 1.16 m), with fresh wood ss as bedding. Stocking density was around 13 chicks/m2 (22 chicks per pen), similar to that practised commercially.
Weight gains, feed intakes and feed conversion ratios of each pen of birds were determined at the end of each feeding period (i.e. at 21, and 42 days of age). EPEFs at 42 days were calculated by replicate: EPEF (European Production Efficiency Factor) [(mean daily gain (g))/(FCR*10)] x (100 - % mortality). Ileal apparent digestibility of dry matter and crude protein were determined at 42 days of age.
The basic statistical technique applied was Analysis of Variance (ANOVA). The data were analysed as a completely randomised factorial design by GLM of SAS v. 9.0 (SAS, 2002). The results are presented by periods in tables by using least squares corrected means. Statistical significance is declared at P ≤ 0.05, with 0.05

Results & Discussion

Endofeed DC supplementation of diets increased body weight of birds at 21 days of age (671 vs 698 g; P = 0.0042), but differences disappeared thereafter (Table 3). Protein level of the diet affected body weight of broilers and chicks fed the high protein diets were 3.8 % heavier than birds fed the low protein diets at the end of the trial (2,767 vs 2,666 g; P = 0.0061). No significant Endofeed x Protein level interaction was detected for body weight. During the starter period (from 1 to 21 days of age), broilers fed Endofeed DC grew 4.3 % more and exhibited 3.8 % improvement in feed conversion rate over the non-supplemented birds (29.9 vs 31.2 g/d; P = 0.0041 and 1.82 vs 1.75 g feed/g gain; P = 0.0392 for daily gain and feed conversion, respectively). Birds receiving the high protein diets tended to grow more than birds fed the low protein diets (30.9 vs 30.0 g/d; P = 0.0717). During the finisher period (from 22 to 42 days of age) no significant differences were observed with Endofeed DC supplementation for any of the parameters studied. Protein level of the diets had an effect in growth and feed conversion, and chickens fed the high protein diets grew more (98.8 vs 94.8 g/d; P = 0.0138) and had better feed conversion rate (1.74 vs 1.80 g feed/g gain; P = 0.0246) than birds fed the low protein diets. An interaction (Endofeed DC x Protein level) for feed intake and feed conversion rate was detected; the impairment caused by the low protein diet in feed conversion was diminished when Endofeed DC was added to the diet (P < 0.01).

Table 3. Effect of dietary treatment on body weight (BW), average daily gain (ADG), average daily feed intake (ADFI) and feed conversion rate (FCR)

Treatment	Enzyme	Protein	BW, g	1-21 days	21-42 days
21 d	42 d	ADG, g/d	ADFI, g/d	FCR, g/g	ADG, g/d	ADFI, g/d	FCR, g/g
T-1	-	High	677	2,742	30.2	54.9	1.82	98.4	166.6	1.69
T-3	-	Low	665	2,656	29.6	53.7	1.82	94.9	172.9	1.83
T-2	Endofeed	High	709	2,792	31.7	54.3	1.71	99.2	176.5	1.78
T-4	Endofeed	Low	687	2,676	30.7	54.6	1.78	94.7	166.7	1.76
SEM (n=12)	9.1	34.93	0.43	0.90	0.04	1.56	2.80	0.03
Endofeed DC suppl.
Control diets	671^b	2,699	29.9^b	54.3	1.82^b	96.6	169.7	1.76
Endofeed DC diets	698^a	2,734	31.2^a	54.4	1.75^a	96.9	171.6	1.77
SEM (n=24)	6.43	24.7	0.31	0.64	0.03	1.10	1.98	0.02
Probability (P value)
Endofeed DC supplementation	0.0042	0.3284	0.0041	0.8793	0.0392	0.8300	0.5070	0.8146
Protein level	0.0723	0.0061	0.0717	0.5729	0.4031	0.0138	0.5300	0.0246
Endofeed DC x Protein level	0.6021	0.6688	0.6014	0.4011	0.3505	0.7550	0.0059	0.0045

For the whole experimental period (1 to 42 days of age), no significant differences were observed for average daily gain, average daily feed intake, feed conversion rate or European Production Efficiency Factor with Endofeed DC supplementation (Table 4). Broilers fed the high protein diets grew more (64.9 vs 62.5 g/d; P=0.0061) and exhibited better feed conversion rate (1.74 vs 1.80 g feed/g gain; P = 0.0242) than chicks fed the low protein diets. An interaction (Endofeed DC x Protein level) for feed intake and feed conversion was detected; the impairment caused by the low protein in feed conversion was diminished when Endofeed DC was added to the diet (P < 0.05).

Broilers fed diets supplemented with Endofeed DC showed higher ileal digestibility of dry matter than Control chicks (62.5 vs 65.4 %, P = 0.0168). Furthermore, birds fed the low protein diets showed higher ileal apparent digestibility coefficients for dry matter and crude protein than birds fed the high protein diets (P < 0.05). No significant Endofeed DC x Protein level interaction was detected.

Table 4. Average daily gain (ADG), average daily feed intake (ADFI), feed conversion rate (FCR), EPEF (European Production Efficiency Factor) and apparent ileal digestibility (AID) of dry matter (DM) and crude protein (CP) of broilers at 42 days of age

Treatment	Enzyme	Protein	1-42 days	AID, %
ADG, g/d	ADFI, g/d	FCR, g/g	EPEF	DM	CP
T-1	-	High	64.3	110.7	1.72	343	60.4	76.2
T-3	-	Low	62.2	113.3	1.83	313	63.2	75.2
T-2	Endofeed	High	65.4	115.4	1.76	340	64.7	77.2
T-4	Endofeed	Low	62.7	110.6	1.76	343	67.6	78.6
SEM (n=12)	0.83	1.60	0.02	10.6	1.13	1.02
Main effects: Endofeed DC suppl.
Control diets	63.2	112.0	1.77	327.81	62.5	76.7
Endofeed DC diets	64.1	113.0	1.76	341.69	65.4	76.9
SEM (n=24)	0.59	1.13	0.02	7.47	0.80	0.72
Probability (P value)
Endofeed DC supplementation	0.3283	0.5344	0.6230	0.1953	0.0168	0.8450
Protein level	0.0061	0.4806	0.0242	0.2130	0.0005	0.0383
Endofeed DC x Protein level	0.6688	0.0272	0.0309	0.1320	0.9805	0.2633

Conclusions

a)      Endofeed DC supplementation of diets significantly increased body weight at 21 d (P<0.01) and improved growth and feed conversion (P<0.05) during the starter period, from 1-21 days of age, but differences disappeared thereafter and no significant differences in performance were observed over the global trial period, from 1-42 days of age.
b)      Broilers fed diets supplemented with Endofeed DC showed better ileal apparent digestibility of dry matter than Control chicks (P<0.05).
c)      Over the global trial period, from 1-42 days of age, birds fed the high protein diets grew significantly more and had better feed conversion rate than birds fed the low protein diets (P<0.05).
d)      Broilers fed the low protein diets showed higher ileal apparent digestibility coefficients for dry matter and crude protein than birds fed the high protein diets (P<0.05).

Bibliography

FEDNA. 2003. Guidelines of the Spanish Foundation for Development of Animal Nutrition for the formulation of compound feeds. de Blas C, García P, Mateos GG (eds). Fundación Española para el Desarrollo de la Nutrición Animal. ETSIA (Madrid Polytechnical University), Spain.

National Research Council. 1994. Nutrient Requirements of Poultry. 9^th Rev. Ed. National Academy Press. Washington DC. USA.

SAS Institute. 2002. SAS^® User's Guide: Statistics. SAS Institute, Cary, NC, USA.