NUTRITIVE VALUE OF MALTED SORGHUM SPROUT IN BROILER CHICKEN DIETS

ABSTRACT

Two studies were carried out to determine the nutritive value of Malted Sorghum Sprouts (MSS) in broiler chickens. The first trial was conducted to determine the effect of graded levels of MSS in a isocaloric- isonitrogenous diets on performance, carcass, and hematological parameters. A total of two hundred and seventy birds were used for both the starter and finisher phases. There were five dietary treatments, replicated three times with eighteen birds per pen and a total of fifty four birds per treatment in a completely randomized design. Five isocaloric-isonitrogenous experimental diets were formulated to contain MSS at 0, 5, 10, 15 and 20% to compliment other energy components in the diets. The experiment lasted for eight weeks. In the second set of experiments, two hundred and seventy birds were allotted to five dietary treatments with three replicates per treatment containing eighteen birds per pen. Birds were fed five’ isocaloric-isonitrogenous diets with Maxigrain® enzyme treatment i.e. MSS at 0% (Trt l), 10% (Trt 2), 10% + Enzyme (Trt 3), 15% (Trt 4) and 15% + Enzyme (Trt 5). Data analysis revealed that dietary treatments had significant (p<0.05) effect on feed intake, body weight gain, feed conversion ratio, feed cost/kg gain, carcass and blood parameters taken. Feed intake was significantly (p<0.05) the lowest for birds fed diet 5 while those on diet 2 had the highest values. Body weight gain significantly (p<0.05) decreased as the percent MSS increased in diets. Feed conversion and cost/kg gain significantly (p<0.05) favored birds on diet 2 compared to those on diet 1, 3, 4 and 5 respectively. Blood parameters were significantly (p<0.05) affected by experimental diets but differences were within expected limits. Feed intake was significantly the highest in Trt l and least in Trt 5. Trtl was numerically the highest in final weight and weight gain but did not differ (p>0.05) from trt3. Trts 2 and 5 recorded the lowest final weight as daily weight gains were least for these treatments. Trt 3 had the best feed conversion ratio and cost/kg gain with Trts 4 being the lowest. Dietary treatments had effect on breast, thighs, and other cuts and organs while drumstick, wings, back and lungs showed no difference. Hb and TP significantly differed but not PCV though values were within recommended range. These studies showed that birds in treatment 1 gave the best results in both experiments but, MSS can be included at 5% or at 10% with enzyme treatment for good performance, reduced feed cost and better feed conversion ratio. Mortality was not significantly (P>0.05) affected by MSS inclusion. It is therefore recommended that MSS in broiler diets should not exceed 10% levels of inclusion as the overall performance of birds become poorer with increased levels in the diet.

CHAPTER ONE

1.0         INTRODUCTION

The poultry industry has suffered more than any other livestock industry as a result of inadequate supply and high cost of feed (Hill, 1989; Mtimuni, 1995; Leplaideur, 2004). Cereal grains constitute the major sources of energy in poultry diets in the tropics (Oluyemi and Roberts, 2000). However, maize has remained the chief energy source in compounded diets and constitutes about 50% of poultry ration (Ajaja et al., 2002). Pressure on maize, wheat and recently cassava has been on the increase worldwide with emphasis being placed on export and other diversified uses mostly in flour based foods and ethanol production as an alternative source of fuel (Doki, 2007; Thornton, 2007). According to Etuk (2008), these trends require serious diversification of energy and protein feedstuffs for poultry, because the availability of cheap and good quality protein and energy sources remain the single most important limiting factor in poultry production in Nigeria (Bawa et al., 2003; Abeke et al., 2008). The fact that feed alone accounts for 70–80% of the recurrent production input in intensive monogastric animal production makes the utilization of multiple feed ingredients expedient (Mtimuni, 1995; Marie-Agnés, 2004). Field observations in Nigeria revealed the inclusion of sorghum and possibly wheat in poultry and rabbit diets (Ojo et al., 2005a; Abubakar et al., 2006; Etuk and Ukaejiofo, 2007) as alternatives.

Sorghum bicolor (L) Moench is widely grown in the semi-arid and arid savannah regions of Nigeria. Maunder (2002) reported that sorghum is a traditional crop in Africa and Asia and an introduced or hybridized crop in the western hemisphere. Sorghum is the world’s fifth most important cereal and is grown in semi-arid regions of Africa being well adapted to the harsh climate and naturally resistant to many pests (Belton et al., 2003).

It benefits from an ability to tolerate drought, soil toxicities and temperature extremes effectively than other cereals. In terms of the nutritive value, cost and availability, sorghum grain is the next alternative to maize in poultry feed (Subramanian and Metta, 2000). Several varieties of sorghum have been developed and introduced in Nigeria (IAR, 1999). However, the diversity of chemical composition and anti-nutritional factors, mainly tannin resulting in variability in digestibility from 35 – 60% or more have been reported (Becker, 1992). Varieties of sorghum, climatic and soil conditions, fertilizer types are listed among the factors responsible for the variations in chemical composition of sorghum (Aduku, 1993; Tacon, 1995; Ngoka, 1997; Etuk and Ukaejiofo, 2007; Etuk, 2008). The usefulness of sorghum by-products has been reported world-wide (Mosimanyana and Kiflewahid, 1987; Mahabile et al., 1990; Dowling et al., 2003; Macedo and Aguilar, 2005; Nyannor et al., 2007). Some varieties of sorghum have phenols concentrated in the outer layers of the kernel which serves as natural source of antioxidants for foods (Awika et al., 2001). Taylor and Da Silva (2004) reported that sorghum bran could be a source of protein for industrial uses. Apart from serving as a staple food in Nigeria, sorghum grain is used for the production of beverages.

Malting of sorghum, like barley, involves steeping or soaking, germination, drying and curing in Kiln and polishing. The resultant malt extract is a useful inp ut in breweries and food processing companies where it is utilized for the manufacture of malt drinks, syrups, beverages, baby foods, microbiological media and other useful products. Malted sorghum sprout (MSS) is a by-product of sorghum malting. The separated roots and shoots which are left after malt extraction from the young germinating sorghum seedlings are collectively called sorghum sprout (Aletor et al., 1998). Malted sorghum sprout has a lot of prospect as a feed stuff of the livestock industry. It is rich in organic nitrogen (Ikediobi, 1989). Malted sorghum sprout contains (g/kg); 226 crude protein, 48 crude fibre, 33 ether extract, 16 ash, 522 nitrogen free extract and 16.26 MJ/kg DM gross energy (Aning et al., 1998). Aning et al. (1998) reported that magnesium was the most abundant mineral while potassium was the least in MSS. Among the trace minerals, Zinc is the most abundant while copper is the least. Sorghum sprout is reported to contain a considerable number of amino acids with low level of methionine, lysine and threonine (Aning et al., 1998).

The anti- nutritional factors in MSS are tannin and hydrogen cyanide (Omogbai and Ojeaburu, 2010). Van Buren and Robinson (1969) reported that tannins affect the growth of animals in three main ways: they have an astringent taste, which affects palatability and decreases feed consumption; they form complexes with proteins which reduce its digestibility and they act as enzyme inactivators. Processing of Malted sorghum sprout was shown to have no significant (P>0.05) effect on growth (Fanimo and Akinola, 2006) but inclusion of enzymes in feed have shown positive results in counteracting the effects of anti- nutritional factors. This study was conducted to determine inclusion level of malted sorghum sprout on its utilization by broiler chickens and subsequent effect of enzyme treatment.

1.3         Objective

Objectives of the study were to;

1. Determine the proximate and anti- nutritional factor components of malted sorghum sprout.
2. Determine the effect of MSS based diet on performance and carcass characteristics of broiler chicken.
3. Determine the effect of enzyme treatment of malted sorghum sprouts on the performance and nutrient digestibility by broiler Chicken.
4. Evaluate the cost effectiveness of MSS inclusion in broiler diets.

1.4         Hypotheses

Experiment 1

H_o: Malted sorghum sprout cannot be effectively included and utilized in broiler chicken diets

H_A : Malted sorghum sprout can be effectively included and utilized in broiler chicken diets Experiment

H_o: Enzyme treatment cannot increase efficient utilization of malted sorghum sprouts in broiler diets

H_A : Enzyme treatment can increase efficient utilization of malted sorghum sprout in broiler chicken diets

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