Effect of Dietary Supplementation of Melon (Citrallus Lanatus) Seed Oil on the Growth Performance and Antioxidant Status of Growing Rabbits

Singh, A.S*, Alagbe, J.O**, Sharma, S***, Oluwafemi, R.A****, Agubosi, O.C.P***** 1 University of Mysore, India 2 Department of Animal Nutrition and Biochemistry, Sumitra Research Institute, Gujarat, India 3Osmania University, India 4,5 Department of Animal Science, University of Abuja, Nigeria P.O.Box 5205, Garki Area 10, Abuja, Nigeria (900001) E-mail: drmusabas@gmail.com ------------------------------------------------------------------------***----------------------------------------------------------------Abstract: This study was carried out to determine effect of dietary supplementation of melon (Citrallus lanatus) seed oil (WMO) on the growth performance and immune response of growing rabbits. Thirty six (36), 5-6 weeks weaner rabbit of mixed breed and sex with an average weight of 435 g – 438 grams were randomly divided into four (4) treatments of nine rabbits per group and each rabbit served as a replicate in a completely randomized design (CRD). The experiment lasted for 12 weeks and all other management practices were strictly observed. Basal diet was formulated according to the nutrient requirements of rabbit according to NRC (1977). Treatment (T1) were fed basal diet with 0 % WMO, T2, T3 and T4 were fed basal diet supplemented with WMO at 0.2 %, 0.4 % and 0.6 % respectively. Results obtained were used to examine the average daily weight gain (ADWG), average daily feed intake (ADFI), feed: gain, mortality, activities of superoxide dismutase (SOD), glutathione-S-transferase (GST), reduced glutathione (GSH) and malonyldialdehyde (MLA). ADWG, feed: gain and mortality were significantly different (P˂0.05) among the treatments. ADFI increased as the level of WMO increases, though not at a significant level (P˃0.05). Highest mortality was recorded among animals in T1 (1.00 %), none was recorded in the other treatments (P˂0.05). Activities of SOD, GST, GSH and MLA were significantly (P˃0.05) influenced by WMO. It was concluded that dietary supplementation of WMO up to 0.6 % enhanced growth performance, improved feed: gain and had no negative effect on the antioxidant parameters of rabbits, it is safe and could be used to bridge the gap between food safety and production.


Introduction
Animals encounter numerous stressors during their lives. These stressors cause hormonal changes, decrease in feed intake, altered nutrient metabolism and suppressed immune function (Gary and Richard, 2002). Animal performance is a function of genetic potential and the environment. Immune stress is loss of immune homeostatis caused by various factors including different production and environmental stressors (Sripathy, 2009). Nutrients are known to influence responses of rabbits to a disease challenge, thus immune system benefits largely from proper nutrition or feeding of animals ( (Gilani, 2005). Among the potential underutilized plant are melon seeds. Melon (Citrullus lanatus) is an herbaceous creeping plant belonging to the family Cucurbitaceae. It can be grown in most part of the world and mainly propagated by seeds and thrives best in warm areas (Betty et  Collection and processing of test material Fresh, healthy and mature melons were harvested within Sumitra Research Institute, Gujarat, India. It was identified and authenticated by a certified crop taxonomist of the institute, thereafter the fruits were sliced open with a clean knife; the removed seeds were washed and sundried for 10 days. The dried samples were grinded into powder using a blender and stored into a well labeled air tight container for further analysis. Extraction of melon seed oil (WMO) was carried out according to the methods outlined by Oyeleke et al. (2012). Crude fibre, crude protein, moisture, ether extract and moisture content were determined according with the official methods of the association of official analytical chemist (AOAC, 2000). Mineral analyses of calcium, phosphorus, potassium, sodium, magnesium, manganese, zinc, iron, cobalt, copper, chromium selenium, cadmium and lead were determined using Atomic Absorption Spectrophotometer (AAS -Model 156Y) based on (AOAC, 2000). Amino acid analysis was carried out using methods reported by Kundan (2017).

Animals and their management
Thirty six (36), 5-6 weeks weaner rabbit of mixed breed and sex with an average weight of 435 g -438 g were purchased from a local market in India. It was randomly distributed to four treatments of nine rabbits per treatment in a completely randomized design (CRD). Animals were housed individually in a locally constructed wire cage measuring (15 × 12 × 25 cm) with provisions of clay feeding and water troughs. Rabbits were given prophylactic treatment and acclimatized for two weeks during which they fed commercial growers mash before the commencement of the experiment. Rabbits were fed twice daily at 8:00 am and 4:00 pm while clean water was given ad libitum, all other management practices were strictly observed throughout the experimental period which lasted for 12 weeks.

Measurements
Feed intake (FI) was determined by difference between feed offered and left over. Weight gain (g) = final weight -initial weight eed o g in io feed in e g weigh g in (g) Antioxidant parameters Blood samples were collected from the marginal veins of the ears of three randomly selected rabbits per treatment to determine the antioxidant status of the animal. Activities of superoxide dismutase (SOD), glutathione-Stransferase (GST), reduced glutathione (GSH) and malonyldialdehyde (MLA) were carried out using method outlined by Singh et al. (2011).

Statistical analysis
All data were subjected to one -way analysis of variance (ANOVA) using SPSS (18.0) and significant means were separated using Duncan multiple range tests (Duncan, 1955). Significant w s decl ed if P ≤ 0.05. Table 1  when Bambara nut waste meal were fed to growing rabbits. According to Omokore and Alagbe (2019) Essential nutrients required by rabbits are those which will be able to maintain normal physiological processes of the body such as growth, health, digestion, reproduction and lactation. Inadequate energy, protein or micronutrients in the diet may impair ep oduc ion of bbi s Niyi, 1997 . R bbi 's nutrition and requirements for feed intake vary with age and particularly with reproductive status (Aduku and Olukosi, 1990; Alagbe and Akintayo, 2020). Proteins play a vital role in biological processes, catalyze reactions in the body, transport molecules such as oxygen, keep the body healthy as part of the immune system and transmit messages from cell to cell   (NRC, 1994). The ash content gives an indication of the amount of minerals present in a particular sample, which are important in many biochemical reactions functioning as co-enzyme and aid physiological functioning of major metabolic processes in the body (Onwuka, 2005). The energy result thus suggests that water melon seeds may not be able to supply adequate amount of calorie to animals.  . Iron is an essential trace element for haemoglobin formation and normal functional of the central nervous system and in the oxidation of carbohydrates, protein and fats (Adeyeye and Otokiti, 1999). Magnesium is major intracellualar cations in cells; they were catalyst to enzymatic reactions and assimilation of phosphorus (Vasudevan and Sreekumari, 2007;Ryan, 1991). Sodium is the major cation which is involved in maintaining osmotic pressure, controlling water balance and acid-base balance (Akpanyung, 2005). It also functions in muscle contractions, nerve impulse transmission and glucose / amino acid transport (Oduye and Fasanmi, 1971). Zinc serves as a cofactor in many enzyme systems, including arginase, enolase, several peptidases, and oxalacetic decarboxylase (Alagbe, 2016). Manganese is a cofactor or component of several key enzyme systems, manganese is essential for bone formation (re. mucopolysaccharide synthesis), the regeneration of red blood cells, carbohydrate metabolism, and the reproductive cycle (Okwu, 2005). Copper is involved with iron metabolism, and therefore haemoglobin synthesis and red blood cell production and maintenance (Ishida et al., 2000).

Amino acid of dried melon seeds
The amino composition of melon seeds is presented in  Table 5. Initial body weight (IBW), final body weight (FBW), weight gain (WG), average daily weight gain (ADWG) and feed: gain ranged between 435.0 -438.0 g, 986.1 -1170.6 g, 548.4 -735.6 g, 9.14 -12.51 g and 7.18 -7.62 respectively. Total feed intake (TFI) and average daily feed intake (ADFI) ranged between 7200.1 -7308.4 g and 120.7 -123.0 g. WG and feed: g in we e signific n ly P˂0.05 diffe en among the treatments. The result obtained is in agreement with the findings of Olatunji et al. , phytochemicals are performs multiple biological activities such as: antimicrobial, antifungal, antiviral, antiinflammatory and antioxidant properties. In addition, the inclusion of phytochemicals in the diets alters and stabilizes the intestinal microbiota and reduces microbial toxic metabolites in the gut, owing to their direct antimicrobial properties on various pathogenic bacteria, which results in relief from intestinal challenge and immune stress, thus improving performance. Average daily feed intake increased from diet 1 to 4 though not at a signific n level P˃0.05 . This is cle indication that WMO is capable of improving the palatability of feed (Akintayo and Alagbe, 2020). Highest mortality was recorded in T1 and none w s eco ded in he o he e men s P˂0.05 .