Feed digestibility, digesta passage and faecal microbial biomass in desert-adapted goats exposed to mild water restriction.

In arid and semi-arid environments, extensively managed ruminants regularly experience drinking water shortage, especially in the dry season. The present study therefore investigated the effects of mild drinking water restriction on feed intake, feed digestibility, solid digesta passage and composition of faeces including faecal microbial biomass. A feeding trial was conducted in Oman, during the dry summer months. Nine adult male Batinah goats were subjected to three watering regimes in a 3 × 3 Latin Square design. Treatments were (1) water offered ad libitum (100%, W100); (2) water restricted to 85% ad libitum consumption (W85); and (3) water restricted to 70% ad libitum consumption (W70). Animals were offered Rhodes grass hay and whole barley grains (1:1 ratio) at 1.3 times maintenance energy requirements. Each of the three experimental periods comprised 16 days of adaptation and 8 days of measurements. During the latter, feed offered and refused as well as faeces were sampled and quantified. Gastrointestinal digesta passage was determined using ytterbium-labelled Rhodes grass hay. Ergosterol and amino sugars were used as markers for faecal microbial biomass, that is the sum of fungi and bacteria. Water restriction had no effect on feed intake and digesta passage. However, feed dry matter, organic matter and fibre digestibility increased (p < 0.05) in W70 compared with W85, and the excreted amount of faecal dry matter, organic matter, nitrogen and neutral detergent fibre decreased (p < 0.05) in W70 compared with W85. Even though water restriction did not affect total faecal microbial biomass carbon (C) concentration, that of fungal biomass C increased (p < 0.05) in W70 compared with W85. Therefore, mild water restriction seems unproblematic from a physiological and nutrient utilization perspective as it increases feed digestibility without compromising feed intake.

Towards conservation of omani local chicken: phenotypic characteristics, management practices and performance traits.

Characterizing local chicken types and their mostly rural production systems is prerequisite for designing and implementing development and conservation programs. This study evaluated the management practices of small-scale chicken keepers and the phenotypic and production traits of their chickens in Oman, where conservation programs for local livestock breeds have currently started. Free-range scavenging was the dominant production system, and logistic regression analysis showed that socio-economic factors such as training in poultry keeping, household income, income from farming and gender of chicken owners influenced feeding, housing, and health care practices (p<0.05). A large variation in plumage and shank colors, comb types and other phenotypic traits within and between Omani chicken populations were observed. Male and female body weight differed (p<0.05), being 1.3±0.65 kg and 1.1±0.86 kg respectively. Flock size averaged 22±7.7 birds per household with 4.8 hens per cock. Clutch size was 12.3±2.85 and annual production 64.5±2.85 eggs per hen. Egg hatchability averaged 88±6.0% and annual chicken mortality across all age and sex categories was 16±1.4%. The strong involvement of women in chicken keeping makes them key stakeholders in future development and conservation programs, but the latter should be preceded by a comprehensive study of the genetic diversity of the Omani chicken populations.

Chemical composition, quality and histochemical characteristics of individual dromedary camel (Camelus dromedarius) muscles.

This study characterized the chemical composition, quality and histological traits of six muscles from 10 dromedary carcasses. There were significant differences in moisture, fat, protein, mineral, saturated and unsaturated fatty acid contents between muscles. The longissimus thoracis (LT) had the highest cooking loss (33.5%) and triceps brachii (TB) the lowest (29.2%). The shear force value of semitendinosus (ST), semimembranosus (SM) and biceps femoris (BF) were significantly higher than infraspinatus (IS), TB and LT. The LT had significantly higher values for L*, a*, b* than ST. The SM had the lowest MFI (65.3), while IS had the highest value (75.8). The ST significantly had the highest and lowest proportions of Type I and Type IIA muscle fibers, respectively than other muscles. This study indicated that composition, quality, and histochemical parameters varied among camel muscles and the knowledge of this variation allows for better marketing and processing of camel meat.

Adjusting homestead feeding to requirements and nutrient intake of grazing goats on semi-arid, subtropical highland pastures.

Intensive livestock grazing can largely deplete the natural fodder resources in semi-arid, subtropical highlands and together with the low nutritional quality of the pasture vegetation limit the growth and production of grazing animals. To evaluate the contribution of homestead feeding of grazing goats to rangeland conservation and animal nutrition, two researcher-managed on-farm trials were conducted in a mountain oasis of Northern Oman. Goats' feed intake on pasture in response to four rations containing different levels of locally available green fodder and concentrate feeds was determined in six male goats each (35 ± 10.2 kg body weight (BW)). Total feed intake was estimated using titanium dioxide as external fecal marker as well as the diet organic matter (OM) digestibility derived from fecal crude protein concentration. The nutritional quality of selected fodder plants on pasture was analyzed to determine the animals' nutrient and energy intake during grazing. The pasture vegetation accounted for 0.46 to 0.65 of the goats' total OM intake (87 to 107 g/kg0.75 BW), underlining the importance of this fodder resource for the husbandry system. However, metabolizable energy (7.2 MJ/kg OM) and phosphorus concentrations (1.4 g/kg OM) in the consumed pasture plants were low. Homestead feeding of nutrient and energy-rich by-products of the national fishery and date palm cultivation to grazing goats increased their daily OM intake (R2 = 0.36; P = 0.005) and covered their requirements for growth and production. While the OM intake on pasture was highest in animals fed a concentrate-based diet (P = 0.003), the daily intake of 21 g OM/kg0.75 BW of cultivated green fodder reduced the animals' feed intake on pasture (R2 = 0.44; P = 0.001). Adjusting homestead supplementation with locally available feedstuffs to the requirements of individual goats and to the nutritional quality of the pasture vegetation improves animal performance and eases the grazing pressure exerted on the natural vegetation. This management strategy therefore appears to be a valuable alternative to intensive livestock feeding in zero-grazing systems and may contribute to sustainable livestock production in ecologically fragile, semi-arid mountain regions.

Effects of electrical stimulation on histochemical muscle fiber staining, quality, and composition of camel and cattle Longissimus thoracis muscles.

The effects of electrical stimulation on muscle fiber type, meat quality, and composition of Longissimus thoracis muscles from one-humped camels and Dofari Omani cattle of a comparable age range were investigated. A low-voltage electrical stimulation with 90 V, 14 Hz (pulse of 7.5-millisecond duration every 70 milliseconds) 20 min postmortem was applied. Samples from the left muscle were collected from 20 (2 to 3 y) camels and 24 cattle (1 to 3 y). For chemical composition, muscle samples were dried in a freeze dryer, and then ground to determine moisture, protein, fat, and ash. Macro- and micro-minerals were determined using an Inductively Coupled Plasma Emission Spectrometer. Quality characteristics of the meat were evaluated using shear force value, pH, sarcomere, myofibrillar fragmentation index, expressed juice, cooking loss percent, and CIE L*, a*, b* color values. Electrical stimulation resulted in a significantly (P < 0.05) more rapid pH fall in the muscle during the first 24 h after slaughter in both species. Muscles from electrically stimulated carcasses had significantly (P < 0.05) lower ultimate pH, longer sarcomere, and lower shear force values than those from nonstimulated carcasses. Lightness (L*), myofibrillar fragmentation, and expressed juice were significantly (P < 0.05) higher for stimulated than for nonstimulated muscles. Muscles of camels had significantly (P < 0.05) higher expressed juice, cooking loss percent, redness color (a*), and lower fat, Mg, K, and P than those from cattle. Electrical stimulation improved quality characteristics of meat from both species. This indicates that meat quality of local camel and cattle can be improved by electrical stimulation and consequently improves their acceptability to consumers and better marketability.

Effect of low voltage electrical stimulation on biochemical and quality characteristics of Longissimus thoracis muscle from one-humped Camel (Camelus dromedaries).

The effects of electrical stimulation (90V) 20min post mortem on meat quality and muscle fibre types of four age group camels (1-3, 4-6, 7-9, 10-12 years) camels were assessed. Quality of the Longissimus thoracis at 1 and 7 days post mortem ageing was evaluated using shear force, pH, sarcomere length, myofibrillar fragmentation index, expressed juice, cooking loss and L(∗), a(∗), b(∗) colour values. Age of camel and electrical stimulation had a significant effect on meat quality of L. thoracis. Electrical stimulation resulted in a significantly (P<0.05) more rapid pH fall in muscle during the first 24h after slaughter. Muscles from electrically-stimulated carcasses had significantly (P<0.05) lower pH values, longer sarcomeres, lower shear force value, higher expressed juice and myofibrillar fragmentation index than those from non-stimulated ones. Electrically-stimulated meat was significantly (P<0.05) lighter in colour than non-stimulated based on L(∗) value. Muscles of 1-3 year camels had a significantly (P<0.05) lower shear force value, and pH, but longer sarcomere, and higher myofibrillar fragmentation index, expressed juice, and lightness colour (L(∗)) than those of the 10-12 years camels. The proportions of Type I, Type IIA and Type IIB were 25.0, 41.1 and 33.6%, respectively were found in camel meat. Muscle samples from 1-3 year camels had significantly (P<0.05) higher Type I and lower Type IIB fibres compared to those from 10-12 year camel samples. These results indicated that age and ES had a significant effect on camel meat quality.

The influence of seasonal temperatures on meat quality characteristics of hot-boned, m. psoas major and minor, from goats and sheep.

Samples of psoas major and minor muscles were randomly collected weekly from 203 (99 hot and 104 cool seasons) Omani goats, 215 (106 hot and 109 cool seasons) Omani sheep, 212 (104 hot and 108 cool seasons) Somali goats, 242 (127 hot and 115 cool seasons) Somali sheep and 211 (110 hot and 101 cool seasons) Australian Merino sheep slaughtered at the Central Slaughterhouse in Oman to investigate the effect of season on meat quality. The collection period was during November 2004-October 2005 and divided into two seasons according to ambient temperatures and relative humidity. These were termed: cool season (average temperature of 21°C and 59% relative humidity and hot season (average temperature of 35°C and 47% relative humidity). Muscles collected during the hot season had significantly (P<0.05) higher ultimate pH values (5.78) than those collected during the cool season (5.65). Myofibrillar fragmentation index was significantly (P<0.05) higher for hot season samples (86.88%) than for cool season samples (85.59%). Expressed juice was significantly (P<0.05) higher for cool season samples (36.84) than for hot season samples (35.74). Goat meat from the hot seasonal group was significantly (P<0.05) darker than the cold season group based on L∗ (37.6 vs. 39.6), a∗ (20.0 vs. 23.3) and b∗ (3.6 vs. 4.2) colour measurements. These results indicated that high ambient temperatures had caused an increase in muscle ultimate pH leading to significant effects on meat quality.

A review of the growth, and of the carcass and meat quality characteristics of the one-humped camel (Camelus dromedaries).

The dromedary camel is a good source of meat especially in areas where the climate adversely affects the performance of other meat animals. This is because of its unique physiological characteristics, including a great tolerance to high temperatures, solar radiation, water scarcity, rough topography and poor vegetation. The average birth weight of camels is about 35kg, but it varies widely between regions, breeds and within the same breed. The meat producing ability of camels is limited by modest growth rates (500g/day). However, camels are mostly produced under traditional extensive systems on poor levels of nutrition and are mostly slaughtered at older ages after a career in work, racing or milk production. Camels reach live weights of about 650kg at 7-8 years of age, and produce carcass weights ranging from 125 to 400kg with dressing-out percentage values from 55% to 70%. Camel carcasses contain about 57% muscle, 26% bone and 17% fat with fore halves (cranial to rib 13) significantly heavier than the hind halves. Camel lean meat contains about 78% water, 19% protein, 3% fat, and 1.2% ash with a small amount of intramuscular fat, which renders it a healthy food for humans. Camel meat has been described as raspberry red to dark brown in colour and the fat of the camel meat is white. Camel meat is similar in taste and texture to beef. The amino acid and mineral contents of camel meat are often higher than beef, probably due to lower intramuscular fat levels. Recently, camel meat has been processed into burgers, patties, sausages and shawarma to add value. Future research efforts need to focus on exploiting the potential of the camel as a source of meat through multidisplinary research into efficient production systems, and improved meat technology and marketing.

The effect of date fibre supplemented with an exogenous enzyme on the performance and meat quality of broiler chickens.

1. Two experiments were conducted to evaluate the use of date fibre as a partial replacement of maize as a source of energy for growing broiler chicken. In experiment 1, date fibre was given alone to determine apparent metabolisable energy (AME) and apparent ileal digestibility of amino acids and crude fibre. 2. Date fibre had lower AME content (8.7 vs 13.6 MJ/kg) and apparent ileal digestibility coefficients for dry matter (0.35 vs 0.83), crude fibre (0.20 vs 0.54) and amino acids. 3. Based on the results of experiment 1, a growth study was conducted to test the effect of exogenous enzymes on the nutritive value of date fibre (experiment 2). 4. Three date fibre contents (5, 10 and 15%) with and without enzyme supplementation were evaluated. Daily feed intake, body weight gain and feed conversion ratio were measured. At the end of experiment 2, 160 birds were randomly selected and slaughtered to evaluate carcase and meat quality traits as well as measuring ileal viscosity. 5. Substitution of maize by 10 and 15% date fibre significantly depressed AME. Enzyme supplementation did not improve crude fibre digestibility. The inclusion of date fibre in the diets except at 5% decreased average daily gains, feed intake and feed conversion ratio. 6. Addition of date fibre caused a significant increase in the weights of total digestive tract, pancreas and caecum. Addition of date fibre or the exogenous enzyme had no significant effect on carcase or meat quality characteristics. 7. Date fibre increased ileal digesta viscosity compared to the control. Addition of the exogenous enzyme decreased the viscosity of the basal diets but had no effect on the date fibre diets.8. This study indicated that date fibre can be included at levels of 5% in broiler diets without affecting performance.

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 camel's 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.

Effects of transportation at high ambient temperatures on physiological responses, carcass and meat quality characteristics of three breeds of Omani goats.

The experiment was designed to determine the effects of short road transportation in an open truck during the hot season on live weight shrink, physiological responses, carcass, and meat quality characteristics in three breeds of Omani goats. Forty-two male goats (12months of age) representing equally three breeds of Omani goats (Batina, Dhofari, and Jabal Akhdar) were divided into two groups: 2h transportation stress (TS) or not transported (NT). The NT group remained unstressed in holding pens with feed and water provided ad libitum prior to slaughter, while the TS group was transported on the day of slaughter 100km in an open truck. The average temperature during transportation was 37°C. All animals were blood-sampled before loading and prior to slaughter via jugular venipuncture. Animals were weighed just before loading onto a truck and after transport to assess shrinkage. Muscle shear force, sarcomere length, pH, expressed juice, color, and cooking loss were measured on samples from Mm longissimus dorsi (LD), biceps femoris (BF), and semitendinosus (ST) muscles collected at 24h postmortem at 1-3°C. Live weight shrinkage losses were between 1.07 and 1.28kg. The TS goats had higher plasma cortisol (P<0.01), adrenaline, nor-adrenaline, and dopamine concentrations (P<0.05) than NS goats. Blood serum from Batina goats had significantly (P<0.05) higher cortisol, adrenaline and dopamine and nor-adrenaline concentrations than those from Jabal Akdhar goats. Transportation stress had a significant (P<0.05) effect on meat quality characteristics of the LD, BF, and ST muscles. Meat from TS goats had significantly higher ultimate pH, expressed juice, cooking loss percentage, shear force, but significantly lower sarcomere length, L(∗), a(∗), and b(∗) values. LD muscles of Batina goats had significantly higher ultimate pH values and lower L(∗) values than Dhofari and Jabal Akdhar goats. These results indicated that subjecting goats to the 2-hour road transportation with high ambient temperatures can generate major physiological and muscle metabolism responses.

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.

The influence of season on quality characteristics of hot-boned beef m. longissimus thoracis.

Samples of m. longissimus thoracis (LT) muscle were randomly collected from 70 Omani beef cattle 1 h after slaughter between August 2001 and July 2002 in the Muscat Municipality central slaughterhouse to investigate the effect of seasonal parameters on meat quality during the hot and cool seasons of Oman. The collection period (12 months) was divided into two seasons according to ambient temperatures and relative humidity and termed: Cool Season (November-March with average temperature of 21.2±1.40 °C and 57.9±1.61% relative humidity) and Hot Season (April-October with average temperature of 34.3±1.67 °C and 48.8±7.57% relative humidity). The season had a significant effect on meat quality characteristics of the LT muscle. Muscles collected during the hot season had significantly (P<0.001) higher ultimate pH values (6.24) with significantly (P<0.001) lower Warner-Bratzler (WB) shear force values (10.12) than those collected during the cool season (5.54 and 15.58). In these hot-boned samples, there was a linear relationship between ultimate pH and WB shear values. Cooking loss was significantly (P<0.001) higher for cool season samples (26.01%) than from hot season samples (19.75%). Beef from the hot season group had significantly (P<0.001) darker meat than that of the cold season group, based on L* (31.45 vs 35.58), a* (18.53 vs 23.19) and b* (4.16 vs 6.40) colour measurements. There was a linear relationship between ultimate pH and cooking loss, L*, a* and b*. These results indicated that heat stress (>30 °C) lead to physiological stress in beef cattle, which in turn increased muscle ultimate pH and influenced related meat quality characteristics.

Comparative effect of low levels of dietary cobalt and parenteral injection of vitamin B(12) on carcass and meat quality characteristics in Omani goats.

The effect of low levels of dietary cobalt (Co) on carcass and meat quality characteristics were investigated in 36 male goats of three different Omani breeds namely Batina, Dhofari and Jabal Akdhar. Goats were randomly divided into two groups at 10 weeks of age, control (18 animals) and treated (18 animals). Goats from both groups were fed Rhodesgrass hay and a commercially prepared diet containing 0.10 and 0.12 mg Co/kg DM, respectively from 10 to 46 weeks of age. Animals in the treated group were supplemented with subcutaneous injections of 2000 µg of hydroxocobalamin (vitamin B(12)) on week 10 and thereafter for 46 weeks at 8-week intervals. At 46 weeks of age, the animals were slaughtered and their carcass and meat quality characteristics compared. Serum vitamin B(12) levels were significantly higher in goats from the treated group from week 16 till the end of the experiment. The final live and carcass weights were significantly higher (P<0.05) for the treated Batina group by 13.4 and 8.3% compared with the control group, respectively. Shoulder, rack, loin and leg cut weights were also significantly higher (P<0.05) for the Batina treated group compared with the control group by 14.7, 16.8, 12.8 and 13.1%, respectively. Carcass length, leg length, width behind shoulder, maximum shoulder width and longissimus muscle area were significantly higher (P<0.05) for the Batina treated breed than for the control group by 6.7, 5.8, 10.1, 10.1 and 28.5%, respectively. Four muscles (Mm. longissimus dorsi, biceps femoris, semimembranosus, and semitendinosus) from treated and control groups were evaluated for ultimate pH, expressed juice, cooking loss%, colour (L*, a* and b*), and Warner-Bratzler shear force values. There were significant treatment effects on these muscle quality characteristics for the Batina breed only. Muscles from the treated group showed significantly lower (P<0.05) shear force values of between 15 and 27% than those from the control group. Moreover, the treated Batina goats tended to have significantly lower (P<0.05) ultimate pH, expressed juice, L* and higher a* values than those from the control group for longissimus dorsi and biceps femoris muscles only.

Effects of body weight and sex on carcass tissue distribution in goats.

Distribution of fat, muscle and bone tissues was studied in bucks, wethers and doe Jebel Akhdar (JA) Omani goats raised under intensive management and slaughtered at 11, 18 or 28 kg body weight (BW). Weight of individual tissues was expressed as percentage of total respective tissue weight in the half carcass. Weight of total body fat in the empty body weight (EBW) ranged between 7.6% in bucks at 11 kg BW and 23.5% in does at 28 kg BW. At 18 kg BW, JA goats had higher TBF, carcass and non-carcass fat than those slaughtered at 12 kg BW (P<0.001). Does and wethers had a faster rate of deposition of carcass and non-carcass fat relative to EBW. Therefore, they had higher fat content (P<0.001) than bucks at 28 kg BW. The highest proportion of fat in the body was deposited intermusculary whereas the omentum constituted the highest non-carcass fat proportion. About 55% of the musculature in JA goat carcasses was found in muscle groups of the proximal hind leg, around the vertebral column and in the proximal forelimb (expensive muscle groups). Bucks had higher proportions of musculature in the forequarter (P<0.001) and intrinsic muscles of the neck but lower proportions of muscles at the proximal hind limb (P<0.001) than does and wethers. About 51% of the total skeleton was found in the axial skeleton, 22-23% in the forelimb and 22-23% in the hind limb of JA goats. There were few sex or slaughter weight effects on proportions of bone weight in the skeleton. In general, slaughter weight and sex effects on tissue distribution were more pronounced in the fat tissue. The magnitude of these effects on muscle and bone tissues was small and is unlikely to have economic impact on meat production from goats.

An evaluation of the growth, carcass and meat quality characteristics of Omani goat breeds.

Body weight, growth, carcass and meat quality characteristics were evaluated in three breeds of goats (Batina, Dhofari and Jabal Akdhar) in Oman. Fourteen intact male goats from each breed were used. Jabal Akdhar goats had significantly heavier slaughter, empty body, and carcass weights and higher growth rates than Dhofari and Batina goats. Jabal Akdhar goats had significantly heavier internal organs than the other two breeds. Dressing-out percent (based on empty body weight) of goats ranged between 53 and 57%, with the Dhofari goats having the highest value. Longissimus muscle dimensions varied between the three breeds, with Jabal Akdhar having a significantly larger area than Batina with Dhofari in between. Dhofari goats produced significantly shorter and wider carcasses than Batina and Jabal Akhdar goats. Carcass cuts were significantly heavier in Jabal Akdhar than the other two breeds. Four muscles (Mm. longissimus dorsi, biceps femoris, semitendinosus, and semimembranosus) from both sides of each carcass were subjected to two different ageing periods (1 day vs. 6 day) and evaluated for ultimate pH, expressed juice, percent cooking loss, colour (L*, a* and b*), and Warner-Bratzler shear force. Breed had a significant influence on pH and percent cooking loss but not on expressed juice, shear force value and colour (CIE L*,a*, b* values). Muscles from the Batina goats had significantly higher ultimate pH values and lower percent cooking loss than Dhofari and Jabal Akdhar goats. Ageing from 1 to 6 days increased tenderness significantly (27%), but decreased cooking loss by 5%.

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.

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.

Effects of testicular status and feeding diets containing date palm by-product on the sensory attributes of Omani lamb meat.

The effects of testicular status and diet on the tenderness and flavour intensity of Omani lamb meat were evaluated. Thirty male lambs were divided into three testicular status treatments shortly after birth, entire, castrated or induced to cryptorchidism. The animals were fed a maize and soya bean meal based diet, isocalorically supplemented with either palm fronds or Rhodesgrass hay. The animals were slaughtered at an average age of 161days and weight of 27.6kg. Sensory evaluation of meat for tenderness and intensity of flavour were undertaken using descriptive analysis with unstructured scales. Meat from New Zealand lambs was also evaluated for comparison. Meat from castrated lambs tended to be more tender than meat from either entire or cryptorchid lambs. This effect was related to the significantly lower daily weight gains, lower carcass weight and lower intermuscular fat content of castrated lambs. The effect of induced cryptorchidism or inclusion of date frond was not significant on tenderness, nor flavour of the lamb meat. Meat from New Zealand lambs was significantly more tender, but similar in flavour compared to Omani lambs.