Performance of french hillbilly gray rolled chickens fed various energy levels in the starter phase^

Introduction

The Brazilian poultry industry has grown at an accelerated speed in recent years, due to the advances in several areas like nutrition, genetic improvement, health, facilities, etc. This progress now allows the industry to offer the consumer with an optimum protein source at very affordable prices, as compared with products from other industries (Silva and Camargo, 2010). The objective of producing hick-type chickens is using a more natural farming system for a higher value added, well differentiated product, to meet the demands of producers searching for alternative higher quality products. The production of these hillbilly chickens is one of most promising sectors in alternative animal agriculture focusing the market niche of tastier, firmer meat products, with a more pronounced flavor (Madeira et al., 2010).

Feed energy is primarily used by animals us used for maintenance of vital processes such as breathing, body temperature, and blood circulation (Oliveira Neto et al., 2000). Literature shows that performance is directly related dietary energy levels. nevertheless, limited studies exist on the energy levels required by slow-growing birds. In this context, the theoretical basis is represented by studies focusing metabolizable energy (ME) requirements. It is important to know the performance of peasant chickens fed various ME levels, since ME exerts a direct influence on both production cost and animal development. The objective of this study was to evaluate the effects of feed ME levels on the performance of French Hillbilly Gray Rolled chickens, in the starter phase.

Materials and Methods

The study was carried out in an experimental house located in Parauapebas Show Park, State of Pará, Brazil. One hundred and nine two (192) as hatched, one-day-old, chickens of the above-mentioned rustic broilers, in an intensive production system.

For the preparation of the feeds, conventional ingredients were used including corn, soybean meal, soybean oil, meat meal, limestone, dicalcium phosphate, sodium chloride, and vitamin/mineral premix (Table 1).

Table 1. Percent composition and calculated analysis of the starter feeds (1-28 days)

Ingredients	T1	T2	T3
Corn	58.83	56.54	54.25
Soybean meal	32.60	32.90	33.33
Plant oil	1.80	3.70	5.60
Meat meal	5.50	5.60	5.60
Calcium carbonate	0.37	0.36	0.35
Salt, NaCl	0.30	0.30	0.30
*Vitamin/mineral premix^()**	0.60	0.60	0.60
Total	100	100	100
Calculated nutritional composition
ME, Kcal/Kg	3.000	3.100	3.200
Crude protein, %	22.00	22.00	22.00
Ether extract, %	4.89	6.70	8.51
Crude fiber, %	3.54	3.52	3.49
Mineral matter, %	5.31	5.31	5.31
Lysine, %	1.21	1.22	1.23
Calcium, %	1.00	1.00	1.00
Total phosphorus, %	0.68	0.68	0.68
Available phosphorus, %	0.48	0.48	0.48
Sodium, %	0.17	0.17	0.17

^{(*) Composition per kg product: Vit. A - 1,835.000 IU; Vit. D3 - 335,000 IU; Vit. E - 2,835 mg; Vit. B1 - 335 mg; Vit. B2 - 1,000 mg; Vit. B6 - 335 mg; Vit. K3 - 417 mg; Vit. B12 - 2.500 μg; Biotin - 17 mg; Folic acid- 135 mg; Niacin - 6,670 mg; Selenium - 35 mg; Antioxidant - 2,000 mg; Calcium pantotenate- 1,870 mg; Copper - 1,000 mg; Cobalt 35 mg; Iodine- 170 mg; Iron 8,335 mg; Manganese - 10,835 mg; Zinc - 8,335 mg; Choline chloride 50% - 135,000; Methionine - 267,000 mg; Coccidiostat - 13,335 mg; Growth promoter- 16,670.}

The experimental design was completely at random, with 3 treatments and 4 repetitions. The experimental unit was one 16-bird pen. Treatments (T) consisted of various ME levels in the starter (1-28 days) feeds, as follows: T1: 3,000 Kcal ME/Kg; T2: 3,100 Kcal ME/Kg; T3: 3,200 Kcal ME/Kg. The houses was cleaned and disinfected and after placement, chickens were selected and weighed. Homogenous, 16-chicken lots were weighed then randomly distributed among the pens, as per treatment/repetition identifications. Water was given ad libitum. Drinkers were washed and refilled twice per day, in order to avoid decreases in water intake that could result in reduced feed intakes. The feeds were prepared once per week and offered ad libitum, assuring that feed be present in the feeders at all times. Twice per day, feed in the feeders was mixed in order to promote feed intake, and any litter particles were removed from the feed. Variables studied included start weight, end weight, feed intake (FI) weight gain (WG), feed conversion rate (FCR), crude protein intake, ME consumed, protein efficiency and energy efficiency. Results were statistically analyzed using the ANOVA procedure, for a completely-at-random model, with the "Statistical and Genetic Analysis System" (SAEG, 2007). Differences among means were analyzed using Tukey´s test (P<0.05).

Results and Discussion

Data analysis showed that start weight, end weight, FI, daily WG, and FCR were not influenced by dietary ME levels (Table 2). A different result was obtained by Reginatto et al. (2000) who, testing a high (3,200 Kcal/ME) or low (2,900 Kcal/ME) energy levels in Ross broilers (1-21 days of age), reported decreased performance in the birds fed the low energy level.

Table 2. Performance of French Hillbilly Gray Rolled chickens fed rations containing different metabolizable levels during the starter phase (1-28 days of age)

Treatments	Start weight (g)	End weight (g)	Feed Intake (g)	Weight gain (g/bird/day)	Feed Conversion Rate
T1 - 3,100 Kcal ME/Kg	33.75	444.00	913.00	14.65	2.27
T2 - 3,200 Kcal ME/Kg	34.25	506.00	953.25	16.85	2.03
T3 - 3,300 Kcal ME/Kg	33.25	490.75	858.75	16.34	1.92
CV (%)	3.73	11.48	16.53	12.52	22.40

^{Means showed no statistical differences, as per Tukey''''s test (P>0.05).}

Oliveira Neto et al. (2000), analyzing five different ME levels (3,000, 3,075, 3,150, 3,225 and 3,300 Kcal ME/Kg feed) on the performance, carcass quality, and some physiological variables of Hubbard broilers from 22 to 42 days of age, found that the level of 3,232 Kcal ME yielded the best results in terms of performance and carcass protein deposition.

Regarding crude protein intake, ME intake, protein efficiency, and energy efficiency, no significant effects from the diets containing any of the 3 different ME levels (Table 3). Nazareno (2008), evaluating confinement and semi-confinement production systems with Cobb 508 broilers fed 3,119 or 3,161 Kcal/Kg ME, found that these production systems did not result in significant performance changes nor they affected protein/energy efficiency.

Table 3. Energy efficiency and protein efficiency in French Hillbilly Gray Rolled chickens, in the starter phase (1 - 28 days of age)

Variables	Treatments
T1 3,100 Kcal EM/Kg	T2 3,200 Kcal EM/Kg	T3 3,300 Kcal EM/Kg	CV (%)
Crude protein intake (Kg/bird)	6.98	7.29	6.55	14.30
Metabolizable energy intake (g/bird)	95.14	102.77	95.28	14.67
protein efficiency	0.49	0.43	0.41	21.70
Energy efficiency	0.15	0.16	0.18	26.72

^{Means showed no statistical differences, as per Tukey''''s test (P>0.05).}

Conclusions

Dietary metabolizable energy did not affect the performance of French Hillbilly Gray Rolled chickens in the starter phase. Energy efficiency was not influenced by dietary energy levels.

Bibliography

Madeira LA, Sartori JR, Araujo PC, Pizzoalante CC, Saldanha PB, Pezzato AC. 2010. Avaliação do desempenho e do rendimento de carcaça de quatro linhagens de frangos de corte em dois sistemas de criação. R. Bras. Zootec. 39(10):2214-2221.

Nazareno AC. 2008. Influência de diferentes sistemas de criação na produção de frangos de corte industrial com ênfase no bem-estar animal. Dissertação (Mestrado em Engenharia Agrícola) - Universidade Federal Rural de Pernambuco. Departamento de Tecnologia Rural.

Oliveira Neto AR, Oliveira RFM, Donzele JL, Rostagno HS. 2000. Níveis de energia metabolizável para frangos de corte no período de 22 a 42 dias de idade mantidos em ambiente termoneutro. Revista Brasileira Zootecnia 29(4):1132-1140.

Reginatto MF, Ribeiro AM, Penz AM. 2000. Efeito da Energia, Relação Energia: Proteína e Fase de Crescimento sobre o desempenho e composição de carcaça de frangos de corte. Revista Brasileira de Ciência Avícola 2(3):229-237.

SAEG - Sistema para Análises Estatísticas e Genéticas. 2007. Versão 9.1: Fundação Arthur Bernardes-UFV- Viçosa.

Silva MG & Camargo AM. 2010. Desempenho produtivo e características da carcaça de frangos caipiras em diferentes sistemas de criação. Em: Anais do XIV Seminário de Iniciação Científica da Universidade Estadual de Feira de Santana, UEFS, Feira de Santana.

PA Andrade¹*, MSV Santos², FB Tavares⁴, AS Moreira³, SS Vieira¹, CS Aguiar¹^ Project Financed by Pará State Research Protection Foundation (FAPESPA); ¹Academicians, Animal Husbandry Graduate Course, Federal Rural University of Amazonia, Parauapebas Campus, Brazil; ²Professor, Animal husbandry Graduate Course, Federal Rural University of Amazonia, Parauapebas Campus, Brazil; ³Masters Undergraduate Amazonia''''s Animal Health and Production, Animal Husbandry Professional, Municipal Secretariat of of Rural Production,, Parauapebas, Brazil; ⁴Masters Undergraduate Amazonia''''s Animal Health and Production, Animal Husbandry Professional, Federal Rural University of Amazonia ( UFRA), Brazil.