Kanthi Annamalai

Effects of age on composition and quality of muscle Longissimus thoracis of the Omani Arabian camel (Camelus dromedaries)

The aim of this study was to determine the effects of age on chemical composition and quality characteristics of the Arabian one-humped camels meat. Samples of longissimus thoracis (between the 10th and the 13th rib of the left side) were randomly collected from 21 Omani intact male camels of three different age groups: group 1 (1-3 years), group 2 (3-5 years) and group 3 (6-8 years). Samples were chilled (1-3°C) for 48h. Moisture, crude protein, fat and ash were determined on freeze dried ground muscle. Mineral contents were determined using an Inductively coupled plasma emission spectrometer (ICP). Meat quality including ultimate muscle pH, Warner-Bratzler shear force, sarcomere length, myofibrillar fragmentation index, expressed juice, cooking loss percent, and colour L(∗), a(∗), b(∗) were measured using standard methods. The moisture, protein, fat and ash ranged from 64.4% to 76.7%; 18.6% to 25.0%, 1.1% to 10.5% and 1.0% to 1.4% on dry matter basis, respectively. The Ca, Mg, Na, K, P, Cad, Cr, Ni, Pb, Co, Mo, Be and V ranged from, 9.2 to 46.6, 24.7 to 57.3, 104.7 to 257.0, 471.4 to 1053.0, 249.9 to 584.0, 0.005 to 0.024, 0.020 to 0.410, 0.016 to 0.187, 0.010 to 0.299, 0.010 to 0.018, 0.050 to 0.470, 0.005 to 0.030 and 0.013 to 0.141mg/100g on dry matter basis, respectively. The percentage of protein decreased and that of fat increased with increasing camel age. The ultimate pH, shear force, sarcomere length, fragmentation index, expressed juice, cooking loss, lightness (L(∗)), redness (a(∗)) and yellowness (b(∗)) ranged from 5.46 to 6.64, 4.25 to 17.82, 0.96 to 2.50, 55.91 to 94.81,19.50 to 33.63, 13.18 to 29.88, 27.86 to 43.21, 10.46 to 22.81, and 4.63 to 10.11, respectively. Muscles of younger camels (group 1) had significantly (P<0.05) lower shear force value, ultimate pH and higher sarcomere length, fragmentation index, expressed juice, cooking loss, and lightness color (L(∗)) by 48%, 3.4%, 43%, 25%, 28%, 14%, and 16% than those collected from older camels (group 3), respectively. Values of middle age camels (group 2) camels were in-between. This study confirmed that camel meat is healthy and nutritious as it contains low fat as well as being a good source of minerals. Age is an important factor in determining meat quality and composition.

Fatty acid composition of muscle and fat tissues of Omani Jebel Akhdar goats of different sexes and weights

This paper describes the fatty acid (FA) composition of muscle and fat tissue in Omani Jebel Akhdar buck, wether and does slaughtered at 11, 18 or 28 kg body weight (BW). The fat percentage in dry matter (DM) of the subcutaneous and kidney fats ranged between 85 and 98% and that of muscle ranged between 17 and 21%. Subcutaneous fat tended to have lower DM than kidney fat. Palmitic (C16:0), stearic (C18:0) and oleic (C18:1) acids comprised the largest proportions of FA in the muscle tissue (approximately 80%) with oleic acid being the most abundant. Ninety-one percent of the total FA were contributed by the C16 and C18 fatty acids being 31.6 and 58.5%, respectively. C19 and C20 were not detected in the muscle tissue. The essential FA, C20:2, C20:3 and C20:4 contributing about 1%. Muscle tissue of the Jebel Akhdar goat contained an average 51.3% and 48.7% of saturated (SFA) and unsaturated fatty acids (UFA), respectively. Polyunsaturated FA (PUFA) constituted about 5% and monounsaturated (MFA) 43.5% of the total FA. Subcutaneous fat contained more total FA (68.08%) than kidney fat (48.14%) in the whole tissue. Kidney fat contained higher percentages of C16 and C18 but less C:18:1 than subcutaneous fat. The proportions of SFA to UFA was high in both fat depots with the SFA being much higher in the kidney than subcutaneous fats. C16, C18 and C:18:1c acids comprised 64.2 and 78% and C16s and C18s made up 81 and 85% of total FA in subcutaneous and kidney fats, respectively. In both subcutaneous and kidney fats, there was a trend of increasing values of DM and fat percentage with intact males having the lowest and females the highest values. Males had higher levels of C15, C18:2 and C18:3 but lower levels of C17, C18 and total C16, C18 and C18:1 in muscle tissue. Intact males had higher levels of C10, 12, 15 FA but lower C16:1 and C16+18+18:1 than others in subcutaneous fat. Intact males had a similar trend for C12 and 14 but lower SFA and higher UFA in kidney fat. There was a trend of increasing DM and fat% in dry matter with increasing body weight. C10, 12 and 14 of the kidney fat decreased with increasing slaughter weight. There was a trend of the two C16 FA decreasing and the four C18 increasing with BW in the kidney fat. This resulted in proportions of the total C16 and C18 FA increasing from 81.8 to 86.8%. These findings confirm those of other studies on goat meat quality that, as judged by fatty acid composition it is not inferior to that of meats from other farm animals.

Effects of age on fatty acid composition of the hump and abdomen depot fats of the Arabian camel (Camelus dromedarius).

This study aimed to quantify concentrations of fatty acids in the hump and abdomen fats of three different age groups of camel. Hump and abdomen fats were extracted from eight each of one-humped camels (Camelus dromedarius) of three age groups: group 1 (<1 year old), group 2 (1-3 years old) and group 3 (>3 years old). The fatty acid methyl ester concentrations of these fats were determined by gas-liquid chromatography (GLC). The percentage of fat in the hump (H) and abdomen (A) fats was significantly (P<0.05) lower for group 1 (H 92.0% and A 94.3%) than for group 2 (H 97.4% and A 97.2%) and group 3 (H 97.6% and A 97.5%), on a dry matter basis. Hump and abdomen fats from the three different groups had similar fatty acid patterns with more saturated than unsaturated fatty acids. The saturated fatty acids in the hump fats accounted for 58.3, 67.6, and 63.0% of the total fatty acids for groups 1, 2 and 3, respectively; group 1 had significantly (P<0.05) lower saturated and higher unsaturated fatty acid concentrations than group 2. The iodine numbers were significantly (P<0.05) higher in group 1 than either group 2 or 3. Palmitic acid (C16:0) was the major fatty acid in hump fat with 32.06, 32.90 and 34.37%, followed by oleic acid (C18:1) 33.65, 21.66 and 28.91.0% and stearic acid (C18:0) 18.85, 24.13 and 20.74% for groups 1, 2 and 3, respectively. Group 1 had significantly higher (P<0.05) oleic acid and lower stearic acid concentrations than group 2. The melting point of both hump and abdomen fats varied between the age groups. This study indicated that age has an effect on the fatty acid composition and the melting point of hump and abdomen fats in one-humped Arabian camels.

The Effects of Replacing Rhodes Grass (Chloris gayana) Hay with Ghaf (Prosopis cineraria) Pods on the Performance of Omani Native Sheep

A feeding trial using various levels of dry pods of ghaf (Prosopis cineraria) was carried out with 28 Omani native male sheep. Individual feed intake and body weight were determined for 50 days to allow assessment of the effects of the feeds on growth, feed intake, feed conversion and carcase measurements. The ripened ghaf pods contained 91% dry matter (DM), 13.5% crude protein (CP), 14.3% crude fibre (CF), 1.3% ether extract (EE) and 5.2% ash (on DM basis). Four levels of ghaf (0, 15%, 30% and 45%) were used with corresponding decreasing proportions of Rhodes grass (RGH) hay. Animals fed rations containing RGH as the sole source of roughage and no ghaf grew faster (135 g/day) and had better feed conversion than those fed various levels of ghaf. Sheep fed 15% ghaf gained reasonably well (90 g/day) and had carcase attributes similar to those fed no ghaf. Sheep fed 30% ghaf still gained weight but those fed 45% ghaf lost weight. Negative effects on growth appeared to occur after 6 weeks of feeding ghaf.

Nutritional evaluation of solar dried sardines as a ruminant protein supplement

Solar dried sardines of various qualities were analyzed for nutrient content and for nutrient digestibility and nitrogen balance in sheep. Additionally, key serum enzymes and metabolites were examined to identify potential toxic effects. Dried sardine protein, ether extract and crude ash content ranged from 65 to 39%, 5.7 to 5.1%, and 22 to 51%, respectively, for high to low quality dried sardines. Visual appraisal of the dried sardines did not appear to be very reliable for determining dried sardine quality. Crude protein content was highly correlated (r(2)=0.962) with crude ash content based on the following equation (dry matter basis): crude protein%=86.0 - (0.961xcrude ash%). Therefore, crude ash could be used to estimate crude protein content and dried sardine quality. Digestibility in Omani sheep was determined on diets composed of a composite of dried sardines collected from Al-Batinah region of the Sultanate (the average crude protein content was 51%) and compared to that of a similar diet using soybean meal (also 51% crude protein) as the major protein source. The digestibility of crude protein, ether extract, total carbohydrates, digestible energy and metabolizable energy in diets utilizing dried sardines versus the soybean meal diet were 74 versus 76%, 69 versus 68%, 67 versus 69%, 64 versus 66%, and 52 versus 56%, respectively. Although, protein digestibility was similar, nitrogen balance data suggested that nitrogen in the dried sardine diet was not as efficiently utilized as nitrogen in the soybean meal diet. Key serum enzymes and metabolites did not suggest that dried sardines at 10% of the total dietary intake would cause metabolic disturbances in sheep. The study suggests that solar dried sardines may be effectively used in ruminant diets but may not have the protein by-pass value of commercial, processed fish meals.