Complete Replacement of Corn by White or Red Sorghum in Japanese Quail Feeds

This study aimed at evaluating the total replacement of corn by white or red sorghum and the inclusion or not of pigment in the diet on the performance and yolk color of Japanese quail eggs. In the trial, 210 Japanese quails were distributed according to a completely randomized experimental design consisting of five treatments with six replicates of seven birds each. Treatments consisted of Corn-based diet (C), white sorghum-based diet (WS), white sorghum-based diet + pigment (WSP), red sorghum-based diet (RS), and red sorghum-based diet + pigment (RSP). Feed intake, feed conversion ratio, egg production, and egg mass were no influenced by the treatments. However, paler egg yolks were produced when corn was replaced by sorghum. When red and white sorghum varieties were compared, there were no differences in yolk color or response to pigment dietary inclusion. It was concluded that the total replacement of corn by sorghum in the feed did not influence the performance of Japanese quails and that yolk color response is not affected by the inclusion of pigments in diets containing sorghum, independently of its variety.


ABStRACt
This study aimed at evaluating the total replacement of corn by white or red sorghum and the inclusion or not of pigment in the diet on the performance and yolk color of Japanese quail eggs. In the trial, 210 Japanese quails were distributed according to a completely randomized experimental design consisting of five treatments with six replicates of seven birds each. Treatments consisted of Corn-based diet (C), white sorghum-based diet (WS), white sorghum-based diet + pigment (WSP), red sorghum-based diet (RS), and red sorghum-based diet + pigment (RSP). Feed intake, feed conversion ratio, egg production, and egg mass were no influenced by the treatments. However, paler egg yolks were produced when corn was replaced by sorghum. When red and white sorghum varieties were compared, there were no differences in yolk color or response to pigment dietary inclusion. It was concluded that the total replacement of corn by sorghum in the feed did not influence the performance of Japanese quails and that yolk color response is not affected by the inclusion of pigments in diets containing sorghum, independently of its variety.

INtRODUCtION
Problems related to corn prices and availability have driven the research on alternative feedstuffs for poultry feeding. Among alternative feedstuffs, sorghum presents adequate nutritional characteristics and it is often used to replace corn, particularly in semi-arid and tropical regions, where sorghum crops present better nutritional yield per area and its price is lower compared with corn (Ligeiro et al., 2009). In terms of nutritional composition, sorghum contains 5% lower metabolizable energy lower digestibility than corn, but its crude protein content is higher (NRC, 1994). Moreover, sorghum also has lower carotenoid pigment levels (xanthophyll and carotenes), which are responsible for egg yolk pigmentation.
Another aspect to be considered when including sorghum in feeds is the presence of tannins. Tannins can form carbohydrate and protein complexes, thereby reducing diet their digestibility and palatability (Rostagno et al., 2005). However, the development of low-tannin sorghum varieties has allowed their increasing inclusion in non-ruminant diets (Moreno et al., 2007), including in layer feeds (Costa et al., 2006;Moreno et al., 2007;Assuena et al., 2008;Ligeiro et al., 2009). To date, the low level of carotenoid pigments in sorghum has been the main limitation for its inclusion in layer diets. When sorghum replaces corn, there is a proportional reduction in the intensity of yellow of the yolks, demanding the dietary inclusion of pigments (Costa et al., 2006;Moreno et al., 2007;Assuena et al., 2008;Ligeiro et al., 2009). Faquinello et al. (2004) evaluated the replacement of corn by graded Complete Replacement of Corn by White or Red Sorghum in Japanese Quail Feeds levels of high-tannin sorghum in Japanese quail diets and concluded that up to 80% corn can be replaced by sorghum, despite the observed worse feed conversion ratio, egg production and paler egg yolks as dietary sorghum levels increased.
The increasing replacement of corn by sorghum both in human and animal feeding has driven genetic research for sorghum with reduced tannin levels and higher crop yield. New sorghum genetic varieties have been launched, and grain color is one of the features that differentiates them.
This study aimed at evaluating the total replacement of corn by white or red sorghum and the inclusion or not of pigment in the diet on the performance and yolk color of Japanese quail eggs.

MAtERIALS AND MEtHODS
In the trial, 210 Japanese quails were distributed according to a completely randomized experimental design consisting of five treatments with six replicates of seven birds each. Birds were housed at a density of fiver birds per cage in (33-cm long x 23-cm wide x 16cm high) metal battery cages equipped with trough feeders and nipple drinkers.
The following sorghum varieties were used: BRS 308 (grain sorghum, no tannin, red grains) and BRS 309 (grain sorghum, no tannin, white grains). The chemical analysis, performed according to the methodology described by Silva & Queiroz (2002), showed the red and white sorghum varieties used in the present experiment contained 88.84 and 88.30% dry matter, 4,071 and 3,946 kcal gross energy/kg, 9.19 and 9.14% crude protein, and 8.21 and 7.72% ether extract on 'as-fed' basis, respectively.
The experimental diets (Table 1) were formulated to supply the nutritional requirements recommended by the NRC (1994) for quails in lay and considering the feedstuff composition proposed by Rostagno et al. (2005), but adjusting sorghum protein and amino acid levels to the average protein content of the sorghum varieties used in the experiment.
Due to their similar composition, red sorghum was isometrically replaced by white sorghum, according to treatment. In the diets with pigment inclusion, the inert material was replaced by the pigment product Sunred-50®, containing more than 5 g xanthophyll/kg. A 64-days experimental period, divided in four 21-d periods, was applied. During the entire experimental period, birds were supplied feed and water ad libitum, and a lighting program of 16h of light (natural+artificial) per day was applied.
The following parameters were evaluated: egg production (%/bird/day), feed intake (g/bird/day), feed conversion ratio per egg mass (g/g), egg mass (g/bird/ day), and yolk color (Roche colorimetric fan). Data were submitted to the analysis of variance using SAS (2000) statistical package, and means were compared by the SNK test at 5% probability level.

RESULtS AND DISCUSSION
There was no effect of the treatments (p>0.05) on feed intake, egg production, egg mass, or feed conversion ratio, indicating that there was no influence of the substitution of corn by sorghum or pigment inclusion in the diets containing sorghum on performance (Table 2).