Evaluation of growth traits in captive red-winged tinamou ( Rhynchotus rufescens ) raised in
different production environments
Luiz Eduardo Cruz dos Santos Correia
*1,Cristiane Sella Paranzini
2, Édina de Fátima Aguiar
3, Kelry Mayara da Silva
2, Keylla Helena Nobre Pacifico Pereira
4, Fabiana Ferreira de Souza
2, Nabor Veiga
5and Josineudson Augusto II de Vasconcelos Silva
3.
1 Departamento de Zootecnia, FCAV, Universidade Estadual Paulista, Via de Acesso Prof. Paulo Donato Castellane, s/n, 14884-900, Jaboticabal, São Paulo, Brazil.
2 Departamento de Reprodução Animal e Radiologia Veterinária, FMVZ, Universidade Estadual Paulista, Rua Prof. Doutor Walter Mauricio Correa, s/n, 18618-681, Botucatu, São Paulo, Brazil.
3 Departamento de Melhoramento e Nutrição Animal, FMVZ, Universidade Estadual Paulista, Rua Jose Barbosa de Barros, nº 1780, 18618-307, Botucatu, São Paulo, Brazil.
4 Departamento de Clínica Veterinária, FMVZ, Universidade Estadual Paulista, Prof. Doutor Walter Mauricio Correa, s/n, 18618-681, Botucatu, São Paulo, Brazil.
5 Departamento de Produção Animal, FMVZ, Universidade Estadual Paulista, Rua José Barbosa de Barros, n°
1780, 18618-307, Botucatu, São Paulo, Brazil.
*Corresponding author email: luiz.edcsc@gmail.com , Tel: +55 14 98102-4009 Key words: Nonlinear model, tinamidae, width, weight.
1 ABSTRACT
The objective of the present study was to evaluate the growth of red-winged tinamou (Rhynchotus rufescens) in different production environments (FCAV and FMVZ sector) in order to provide technical information for future commercial farming. The following growth traits were evaluated: birth weight, weight, breast width (BIW), and thigh width (TW) at specific ages. Eight age classes were established (28, 56, 84, 112, 140, 168, 200, and > 300 days of age), considering weights at less or more than 12 days of age per class. The SAS program was used for statistical analysis. The nonlinear Gompertz model was used to describe the growth of the animals, using the NLIN procedure. Analysis of variance of body weights in the different age classes was performed by the least square method, using the GLM procedure. The asymptotic value and lowest growth rate for weight, BrW and TW were: 758 g, 23.9 cm, 8.8 cm and 0.0197 g, 0.0164 cm and 0.021 cm, respectively, The observed means of birth weight and the eight age classes 28, 56, 84, 112, 140, 168, 200, and >
300 were 41.2 g, 1392 g, 2733 g, 4401 g, 558.7 g, 633.3 g, 6838 g, 724.7 g and 750.0 g respectively. The red-winged tinamou requires a longer time to reach mature weight than other birds, and measures should be taken to shorten this period for commercial production.
2 INTRODUCTION
Breeding birds for food production has been increasing over the last three decades in Brazil, which has become the first and third largest country in terms of export and global
production, respectively. These advances in poultry farming are due to major changes in performance indices, including egg laying and meat production, based on genetic breeding
and improvement in nutrition and health (Martins, 2002). Although Gallus gallus domesticus is the most common bird species used in poultry farming. Wild birds have become an alternative for commercial meat and egg production. The main attributes that distinguish the meat of exotic birds from domestic chickens are flavour, texture and versatility (various qualities), providing a different and expensive meat that attracts consumers with a high purchasing power and knowledge of gastronomy (Avicultura industrial, 2003). As the introduction of ostrich, turkey and quail was well accepted by consumers, the red-winged tinamou (Rhynchotus rufescens) (Figure 1) has the potential to be explored zootechnically for the sale of noble meats. The scientific community, especially growth studies, has investigated economically important traits related to this
species (Tholon and Queiroz, 2008: Tholon et al., 2008). According to Moro et al. (2006), the red-winged tinamou has an average carcass and breast meat yield of 74.4% and 36.6%, respectively. Queiroz et al. (2013), evaluating tinamou meat, observed greater tenderness, lower acidity, higher protein content and low cholesterol levels when compared to broiler chickens. These data highlight the importance of red-winged tinamou by demonstrating its similarity or superiority compared to domestic or wild species, a reason to conduct genetic selection programs for the production of noble meats. The objective of the present study was to evaluate the growth of red-winged tinamou in different production environments in order to provide technical information for future commercial farming.
Figure 1: Red-winged tinamou (Rhynchotus rufescens).
3 METHODOLOGY
The experiment was conducted in two production environments, one at the Faculdade de Ciências Agrárias e Veterinárias (FCAV), Unesp, Jaboticabal, São Paulo, Brazil, between October and December 2015 and the other at the Faculdade de Medicina Veterinária e Zootecnia (FMVZ), Unesp, Botucatu, Sao Paulo, Brazil, between September and
December 2016. The period when the study was conducted corresponds to the breeding season of the animals. The initial sample consisted of 181 red-winged tinamous aged 6 to 8 years. Birds without an initial recorded were sexed by cloacal reversal technique (Moro, 1991) and ringed on the right wing with an identification number. All birds were then
weighed, and the mean overall weight was obtained. At the Sector of FCAV in Jaboticabal, the barn used for housing the growing birds
measured about 300 m2 and consisted of 28 pens with a capacity of seven animals by pen (Figure 2).
Figure 2: Red-winged tinamou (Rhynchotus rufescens) in FCAV Sector (Jaboticabal city).
The sides of the barn were covered with blue plastic curtains to protect the animals from cold drafts. At the beginning of 2016, the tinamous were transferred to the Lageado Experimental Farm of FMVZ after the project was approved by the Ethics Committee on Animal Use with protocol CEUA 98/2016. The birds were kept in individual transport boxes and transferred in an air-conditioned vehicle provided by the
university. The facility of the sector of FMVZ in Botucatu was made of brick walls, clay tiles and a concrete floor, with an area of 72 m2. The facility was equipped with six pens, with a capacity of 21 animals by pen, 24-hour monitoring cameras, wood partitions and sliding doors (Figure 3). Each pen measured 6 m2. The windows were 1.45 m wide and 2.10 m high and were covered with blue plastic curtains.
Figure 3: Red-winged tinamou (Rhynchotus rufescens) in FMVZ Sector (Botucatu city).
In both environments, the birds received same diet and water ad libitum (Table 1). However, the physical form of the feed was pellet in Jaboticabal and mash in Botucatu. The feed composition was different for each life stage (initial growth phase= from the second day to the twentieth week of life; pre-laying phase = from the twentieth week of life to the beginning of egg laying; laying phase = egg laying period). At both sites, the concrete floor inside the pens was covered with coastal Bermuda grass (Cynodon dactylon) for comfort of the animals. There were differences in the number of housed birds between pens and in the number of males per female. The birth season comprised the period from October to December 2015 in FCAV and from September to November 2016 in FMVZ. With the beginning of the breeding period, eggs were
collected in all pens twice daily, in the morning and in the afternoon. The eggs were weighed, registered, cleaned and transferred to an artificial incubator (Premium Ecológica IP 70) after six days. After birth, the chicks were weighed on a digital precision scale and identified with a leg ring containing the day of birth and pen of origin. The animals were kept in a breeder for 12 days and were then transferred to a larger pen. The chicks received water with vitamin additive and grower feed in mash form ad libitum. Vaccination was not performed and there was no contact with other birds so there was the absence of symptoms of the main avian diseases (Sousa et al., 1999;
Paulillo et a1., 2005). The birds were identified with a numbered ring on the right wing and sexed at 120 days, the best age for visualization of the phallus in males.
Table 1: Composition of the feeds used during the experimental period.
Ingredients Initial growth phase Pre-laying phase Laying phase
Corn 45.4 63.5 40.4
Soybean meal 48.0 17.0 37.2
Meat meal 5.0 - -
Wheat meal - 13.5 5.6
Soybean oil - - 3.5
Salt 0.5 0.27 0.43
Calcitic limestone 0.5 0.09 5.56
Dicalcium phosphate - 1.74 1.61
Methionine 0.1 0.17 -
Lysine - 0.23 -
Mineral and vitamin mix* 0.5 (1) 3.5 (2) 5.7 (2)
Total 100.0 100.0 100.0
*(1) Composition: vit A: 528,000 mcg, vit D3: 120,000 mcg, vit E: 5 mg, vit K3: 1 mg, vit B1: 0.36 mg, vit B2: 2 mg, vit B6: 0.5 mg, vit B12: 5.6 mg, niacin: 7 mg, biotin: 0.03 mg, pantothenic acid: 5 mg, folic acid: 0.3 mg, choline: 0.2 mg, iron: 11 mg, cupper: 3 mg, manganese: 18 mg, zinc: 12 mg, iodine: 0.24 mg, selenium: 0.03 mg, methionine: 0.2 mg, growth promoter: 20 g, Coccidiostatic: 100 g, Antifungal: 2 mg, BHT: 10 g, inert filler 1,000 g.
*(2) Composition: vit A: 52,800 mcg, vit D3: 12,000 mcg, vit E: 0.5 mg, vit K3: 0.1 mg, vit B1: 0.036 mg, vit B2: 0.2 mg, vit B6: 0.05 mg, vit B12: 0.56 mg, niacin: 0.7 mg, biotin: 0.003 mg, pantothenic acid: 0.5 mg, folic acid: 0.03 mg, choline: 0.02 mg, iron: 1.1 mg, cupper: 0.3 mg, manganese: 0.18 mg, zinc: 0.12 mg, iodine: 0.024 mg, selenium: 0.003 mg, methionine: 0.02 mg, calcium: 0.175 mg, phosphor: 68 g, sodium: 23 g, chlorine: 36 g, growth promoter: 2 g, Coccidiostatic: 10 g, Antifungal: 0.2 mg, BHT: 1 g, inert filler 1,000 g.
The data obtained in 2015 and 2016 were used to complement the weight data file of tinamous obtained in FCAV from 2005 to 2013. The following growth traits were evaluated: birth weight, weight, breast width (BrW), and thigh
width (TW) at specific ages. Weights were measured with a digital precision scale and the other body measures were obtained with a measuring tape. The final dataset contained 1,300 weight records and 272 measures of BrW
and TW of birds aged 1 to 400 days. For the weight records, except for birth weight, eight age classes were established (28, 56, 84, 112, 140, 168, 200, and > 300 days of age), considering weights at less or more than 12 days of age per class (Table 2). The SAS program (SAS, 2011) was used for statistical analysis. The nonlinear Gompertz model (Laird, 1965) was used to describe the growth of the animals. This model is the most widely used and most adequate function for birds, which
permits a data fit similar to that of more complex growth functions (Winsor, 1932;
Freitas et al., 1983; Emmans, 1989). The model is represented by the equation:
yt = Ae-Be(-kt) + ε
Where yt is weight or body measure at age t; A is the asymptotic weight or body measure; B is the constant of integration without biological interpretation, and k is the maturation rate.
Table 2: Age class (in days) used for analysis of variance of weight gain in tinamou (Rhynchotus rufescens).
Class Age (days) No. of birds
1 1 139
28 Between 16 and 40 41
56 Between 44 and 68 39
84 Between 72 and 96 141
112 Between 100 and 124 96
140 Between 128 and 152 129
168 Between 156 and 180 121
200 Between 188 and 212 94
>300 Greater than 300 239
The model was adjusted individually to the weight, BrW and TW series according to the age of each animal using the modified method of Gauss-Newton described by Hartley (1961) for nonlinear models. The NLIN procedure (SAS, 2011) was used to obtain the individual parameter estimates and estimates of the average parameters for all available data.
Analysis of variance of body weights in the different age classes was performed by the least square method using the GLM procedure (SAS, 2011). The following model was
used:
Yt = µ + SB + S + SX + age + ε
Where Yt the body weight in age class t; u is the overall mean; SB is the season of birth (1, September to October; 2, November to January, and 3, February to March); S is the site (FCAV or FMVZ): SX, sex of the individual; age is the linear covariate, and 5 is the random error. The model for birth weight included egg weight instead of the age covariate. The weights in age classes 28, 56, 84 and 112 days corresponded to the growth phase, those in classes 140, 168 and 200 days to the phase close to maturity, and >
300 days to the adult phase of the birds. The Tukey-Kramer test was used to compare means with significance level of 5%.
4 RESULTS AND DISCUSSION
The Gompertz model showed good fit of the weight data for both sexes, with a coefficient of determination (R2) higher than 96%, a value considered to be high (Table 3). The R2 values obtained for the BrW and TW data were less than 90%. The asymptotic value (parameter A) for weight and TW in females was high when
compared to males (Figure 4 and 5). This parameter corresponds to the mature weight (or body measure) of the animal. Studying the same bird species, Tholon and Queiroz (2007) also reported a higher asymptotic weight for females using the Gompertz function. The superiority of female tinamous in terms of body weight has
also been reported by Carnio et al. (1999) and Tholon and Queiroz (2008). However, no difference in BrW was observed between males and females, i.e., both sexes exhibited the same width despite the higher weight of females. The same was evaluated in quail (Coturnix coturnix japonica) by Ojo et al. (2013), in which females were heavier than males starting at 6 weeks of life, while body length did not differ significantly between sexes. For domestic chicken, Ajayi and Ejiofor (2009) found significant differences in body length between the Anak and Ross broiler breeds at 63 days of life, and males were heavier than females.
Egena et al. (2014), studying indigenous
chickens from Africa (Gallus gallus domesticus) showed that body weight and breast length were greater in males than females. Parameter B (scale) models the weights or body measures from birth to adult life and does therefore not possess a biological interpretation (Freitas, 2005;
Tholon and Queiroz, 2009). Among the traits evaluated, TW had the lowest growth rate, represented by parameter k. This parameter can be interpreted as the rate of gain, which corresponds to the slope of the growth curve, i.e., the higher k, the faster the approximation of a given animal to its asymptotic weight or body measure (Neto, 1993; Oliveira et al., 2000).
Table 3: Parameter estimates for weight, breast width, and thigh width of red-winged tinamou (Rhynchotus rufescens) obtained with the Gompertz function.
Y N A B k R2
Weight G 1,300 758 3.11 0.0197 0.97
Weight M 594 737 2.77 0.0183 0.98
Weight F 706 785 2.87 0.0192 0.98
BrW G 272 23.9 0.84 0.0164 0.85
BrW M 112 24.0 0.77 0.0136 0.84
BrW F 160 23.8 0.89 0.0182 0.88
TW G 272 8.8 1.10 0.021 0.82
TW M 112 8.84 0.96 0.017 0.77
TW F 160 9.08 1.18 0.021 0.86
Y, weight (g) or body measure (cm); G, general; M, male; F, female; N, number of observations; A, B and k, adjusted parameters; R2, coefficient of determination; BrW, breast width; TW, thigh width.
The values of k are important for comparison with quail used for meat production (Coturnix coturnix japonica) and domestic broilers, demonstrating inferiority of the growth rate of tinamou. Using the Gompertz function, Narinc et al. (2010) and Drumond et al. (2013) estimated k values (in g) of 0.08 and 0.059, respectively, for quail of both sexes. In broilers,
Rovadoscki (2013) obtained values of 0.049 and 0.061 g for the Carijó Barbado and 7P lines, respectively. Genetic selection should be used to increase the growth rate of red-winged tinamou in commercial farming, providing rapidity with which the animal reaches maturity, greater economic return, and a reduction in feed costs.
Figure 4: Growth curve for weigh based on the parameters fitted with the Gompertz model.
Figure 5: Growth curve for breast (BrW) and thigh width (TW) based on the parameters fitted with the Gompertz model.
The point where the curve changes concavity and the maturation rate changes from increasing to decreasing or stability is called point of inflection (parameter m). This point tends to infinity in the Gompertz function (Silva et al., 2001; Tholon and Queiroz, 2007).
However, it is possible to determine the age at
which maturity is reached based on the significant asymptotic value. The asymptotic confidence intervals (95%) were 744.6 to 771.3 g, 23.4 to 24.3 cm and 8.7 to 9.2 cm for weight, BrW and TW, respectively. The intervals for BrW and TW were short, indicating high reliability of the estimates. According to the
intervals found, the ages at which the birds reached maturity for weight, BrW and TW were 200, l80 and 120 days, respectively. In contrast to tinamou, Santos et al.(2005), who evaluated the growth curve of Cobb, Paraiso Pedrês and ISA Label chickens using the Gormpertz model, identified the inflection points of the curve, respectively, at 37, 44 and 52 days for males and at 36, 48 and 53 days for females. The body weight data shown in Table 4 exhibit high variability because of the formation of age classes, with deviations of i 12 days, except for birth weight. The mean birth weight was higher than that reported by Carnio et al. (l999) and Tholon et al. (2008), which was 38.6 g and 39.16 g, respectively. Ledur et al. (1992) found higher mean birth weights compared to the present study for two broiler lines (43.41 and 44.07 g).
The mean weight at 200 days (W200) was similar to that of birds older than 300 days (W>300). This result shows that, in this
population, the animal does not increase its body weight significantly after 200 days. This age is lower than the slaughter age reported by Moro et al. (2006), who determined a mean carcass weight of 637.3 g in tinamou at 56 weeks of age (392 days). Studying Chilean tinamou (Nothoprocta perdicaria), Aggrey et al.(1992) obtained a post-slaughter weight of 455.8 g for 28 birds at ll2 days of age; however, the mean mature weight of the species studied by these authors is 420 g (Gonzalez et al., 2003;
Skewes et al., 2006). Analysis of variance of birth weight showed no significant effects of site, season or sex. The egg weight covariate was highly significant (P<0.0l). The lack of control of paternity did allow inclusion of the effect of sire or dam. Tholon et al. (2008) estimated a heritability of 0.58 for birth weight of tinamou, in which the sire exerted a significant influence.
Table 4: Number of observations (N), mean and standard deviation, and minimum and maximum values of weight (in g) at specific ages in the red-winged tinamou (Rhynchotus rufescens).
Trait N Mean ± SD Minimum Maximum
Birth weight 139 41.2 ± 3.8 32 54
W28 41 139.2 ± 30.9 76 200
W56 39 273.3 ± 60.0 132 400
W84 141 440.1 ± 80.1 228 628
W112 96 558.7 ± 78.7 365 742
W140 129 633.3 ± 71.9 445 815
W168 121 683.8 ± 65.4 480 832
W200 94 724.7 ± 67.6 554 878
W>300 239 750.0 ± 82.5 565 960
W28 : Weight at 23 days; W56 : weight at 56 days; W84 : weight at 84 days; W112 : weight at 112 days; W140 : weight at 140 days; W168 : weight at 168 days; W200 : weight at 200 days; W>300 : weight at > 300 days.
Table 5: Probability values for effects of body weights trait of red-winged tinamou (Rhymchotus rufescens) in analysis of variance.
Effect W28 W56 W84 W112 W140 W168 W200 W>300
Season <0.05 <0.05 ns ns ns ns ns ns
Site ns ns <0.01 ns ns ns - <0.01
Sex ns ns <0.01 <0.05 <0.01 <0.01 <0.01 ns
Age ns <0.01 <0.01 <0.01 <0.05 ns ns ns
ns: not significant.
Birth weight was not included as a linear effect in the analysis of variance of the other weights (Tables 5) because of the small number of data
for this trait. In addition, the analysis of birth weight is more important for the control of safe births. According to Pinchasov (1991), birth
weight is not a major factor influencing the final weight. The season of birth significantly influenced (P<0.05) W28 and W56, with birds born in November and December being the heaviest (mean of 147.9 g) compared to those born in September and October (l2l.8 g). The site of study had a significant effect (P<0.0l) on W84 and W>300. It was not possible to include this effect in W200 because only data from birds in FCAV were available. At first, weights that were not influenced by the site of study might indicate good adaptation of the birds to the environmental effects of FMVZ, such as luminosity and climate variation. However, the mean W84 was higher in FMVZ (463.3 g) than in FCAV (424.7 2), a finding that could be related to the superior performance of a certain individual. Different from W84, birds raised in FMVZ had a mean W>300 of 709.8 g versus
772.2 g in FCAV. This difference between mean weights may be due to the type of feed used and the consequent influence on weight gain, with the birds receiving mash and pelleted feed in Botucatu and Jaboticabal, respectively.
According to Nakage (2002 apud Toledo et al., 2001), fine food particles adhere to the beak of birds, reducing food intake and increasing waste.
In general, sex exerted a significant effect on weights after 84 days. This finding can be explained by the fact reported above that;
females have a higher body weight than males.
In the study of Tholon et al. (2008), the difference between male and female weights of tinamous occurred before that observed in the present study, with significant differences between 39 and 45 days. The linear age covariate was significant up to W140, emphasizing the stability of weight.
5 CONCLUSION
The red-winged tinamou requires a longer time to reach mature weight than other birds, and measures should be taken to shorten this period for commercial production. The change in
different production environments had no major influence on the body weights of the animals.
6 ACKNOWLEDGMENTS
The authors thank Coordenação de Aperfeiçoamento de Pessoa de Nível Superior (Capes) for research funding.
7 REFERENCES
Aggrey SE, Nichol CR. and Cheng KM: 1992.
The partridge tinamou for commercial meat production: preliminary evaluation.
World’s poultry congress 19: 360 pp.
Ajayi FO. and Ejiofor O: 2009. Effects of Genotype X Sex Interaction on Growth and Some Development Characteristics of Ross and Anak Broiler Strains in the High Rainfost Zone of Nigeria. Asian Journal of Poultry Science 3(2): 51-56.
Avicultura Industrial: 2003. Aves para todos os gostos, held Oct 06-16, 2003, Brazil.
http://www.aviculturaindustrial.com.br /imprensa/aves-para-todos-
osgostos/20030929-114703-0002.
Carnio A, Moro MEG. and Giannoni ML: 1999.
Estudos para a criação e reprodução em
cativeiro da ave silvestre, Rhynchotus rufescens (Tinamiformes), com potencial para exploração zootécnica. Ars Veterinaria 15: 140-143.
Drumond ESC, Gonçalves FM, Veloso RC, Amaral JM, Balotin LV, Pires AV. and Moreira J: 2013. Curvas de crescimento para codornas de corte. Ciência rural 43(10): 1872-1877.
Egena SSA, Ijaiya AT. and Kolawole R: 2014.
An assessment of the relationship between body weight and body measurements of indigenous Nigeria chickens (Gallus gallus domesticus) using path coefficient analysis. Livest. Res.
Rural Dev 26: 29-33.
Emmans GC: 1989. The growth of turkeys.
Technical presentation, Recent Advances in Turkey Science, 1989, London. 135-166.
Freitas AR : 2005. Curvas de crescimento na produção animal. R. Bras. Zootec 34(3) : 786-795.
Freitas AR, Albino LFT and Rosso LA: 1983.
Estimativas do peso de frangos machos e fêmeas através de modelos matemáticos. EMBRAPA-CNPSA. 1-4.
González D, Daugschies A, Pohlmeyer K, Rubilar L, Skewes O. and Mey E: 2003.
Ectoparásitos de la perdiz chilena (Nothoprocta perdicaria) en la provincia de Ñuble, Chile. Parasitología latinoamericana 58(2): 75-77.
Hartley HO: l96l. The modified Gauss-Newton method for the fitting of non-linear regression functions by least squares.
Technometrics 3(2): 269-280.
Ledur MC, Schmidt GS, Avila VS, Figueiredo EAP. and Munari DP: 1992.
Parâmetros genéticos e fenotípicos para peso corporal em diferentes idades em linhagens de frango de corte. Revista Brasileira de Zootecnia 21: 667-673.
Martins EM : 2002. Perspectivas do melhoramento genético de codornas no Brasil. Simpósio internacional de coturnicultura l : 109-112.
More MEG, Ariki J, Souza PA, Souza HBA, Moraes VMB. and Vargas FC : 2006.
Rendimento de carcaga e composigao quimica da came da perdiz nativa (Rhynchotus rufescens). Ciencia Rural 36:
258~262.
Nakage ES, Cardozo JP, Pereira GT, Queiroz SA. and Boleli IC : 2002. Efeito da Forma Física da Ração Sobre a Porosidade, Espessura da Casca, Perda de Água e Eclodibilidade em Ovos de Perdiz (Rhynchotus rufescens). Revista Brasileira de CiÉncia Avicola 4:
227~l34.
Narinc D, Karaman E, Firat MZ. and Aksoy T : 2010. Comparison of non-linear growth
models to describe the growth in Japanese quail. Journal of Animal and Veterinary Advances 9(14): 1961-1966.
Neto JB: 1993. Estudo genético de curvas de crescimento de aves de postura.
Dissertation, Universidade Federal de Pelotas.
Ojo V, Fayeye TR, Ayorinde KL. and Olojede H: 2013. Relationship between body weight and linear body measurements in Japanese quail (Coturnix coturnix japonica).
Journal of Scientific Research 6(1): 175- 183.
Oliveira HN, Lôbo RB. and Pereira CS: 2000.
Comparação de modelos não lineares para descrever o crescimento de fêmeas da raça Guzerá. Pesquisa Agropecuária Brasileira 35(9): 1843-1851.
Paulillo AC, Silva GS, Junior LD, Gama NMSQ, Nishizawa M. and Iturrino FS : 2005. Importância das perdizes (Rhynchotus rufescens) como fonte potencial de vírus patogênico da doença de newcastle para aves domésticas. Arq.
Inst. Biol. (online) 72(3): 313-317.
Pinchasov Y: 1991. Relationship between the weight of hatching eggs and subsequent early performance of broiler chicks.
Poultry Science 32: 1091 15.
Queiroz FA, Carvalho MM, Nunes J, Felipe L, Santos EC, Tonhati H, Boiago MM, Hata ME, Tholon P. and Queiroz SA:
2013. Meat and carcass traits of the red- winged tinamou (Rhynchotus rufescens).
Revista Brasileira de Ciência Avícola 15:
113-118.
Rovadoscki GA : 2013. Modelos de curva de crescimento e regressão aleatória em linhagens nacionais de frango caipira.
Dissertation, Escola Superior de Agricultura Luiz de Queiroz, Universidade de São Paulo.
Santos AL, Sakornura NK, Freitas ER, Fortes CMLS, Carrilho ENVM. and Fernandes JBK: 2005. Comparison of free-range broiler chicken strains raised in confined or semi-confined systems.
Revista Brasileira de Zootecnia 34:
1589-1598.
SAS INSTITUTE : 2011. SAS/l_ML 9.3 user's guide. Sas Institute.
Silva FF, Aquino LH. and Oliveira JA: 2001.
Influência de fatores genéticos e ambientais sobre as estimativas dos parâmetros das funções de crescimento em gado nelore. Ciência e Agrotecnologia 25(5): 1195-1205.
Skewes O, Moraga C. and Bustos N: 2006.
Mortalidad de perdiz chilena (Nothoprocta perdicaria) a causa de maquinaria agrícola en Chillán, Chile.
Ornitologia neotropical 17: 605-607.
Sousa RLM, Cardoso TC, Paulillo AC, Montassier HJ. and Pinto AA: 1999.
Antibody response to Newcastle disease vaccination in a flock of young partridges (Rhynchotus rufescens). Journal of Zoo and Wildlife Medicine 30(3):
459-461.
Tholon P, Freitas EC. and Queiroz SA: 2008.
Estimativas de parâmetros genéticos
para pesos corporais em perdizes (Rhynchotus rufescens) criadas em cativeiro.
Revista Caatinga 21: 48-61.
Tholon P. and Queiroz SA : 2009. Modelos matemáticos utilizados para descrever curvas de crescimento em aves aplicados ao melhoramento genético animal. Ciência Rural 39: 2261-2269.
Tholon P. and Queiroz SA: 2007. Models for the analysis of growth curves for rearing tinamous (Rhynchotus rufescens) in captivity. Revista Brasileira de Ciência Avícola 9: 23-31.
Tholon P. and Queiroz SA : 2008. Utilização de diferentes estruturas de variância residual em modelos de regressão aleatória para descrição da curva de crescimento de perdizes (Rhynchotus rufescens) criadas em cativeiro. Revista Caatinga 21: 3747.
Winsor CP: 1932. The Gompertz curve as a growth curve. Proceedings of the national academy of sciences 18(1): 1-8.
