Investigating the population structure and genetic diversity of Arabian horses in Oman using SNP markers.

Arabian horses were selected for metabolic efficiency, beauty, efficiency and endurance. Therefore, Bedouins have for centuries traced their prized horses' ancestries. With the establishment of the World Arabian Horse Organization (WAHO), registration of Arabian horses became centralized and countries worldwide registered them in its database. Most existing Arabian horses in Oman today were imported after the 1970s and are predominantly flat-racing Arabians. This work aimed at revealing the genetic background and diversity of Omani Arabian horses by comparing them with Arabian horses from a diverse genetic background. To that end, we genotyped 63 randomly sampled Arabian horses from Oman using the Illumina Equine SNP70. For comparison, SNP genotypes of 12 Saudi Arabian horses, 27 French, 77 Egyptian, 11 Polish and 36 US Arabians were included in the study. We additionally included 17 Thoroughbred horses and 21 horses representing large and small breeds as an outgroup. Our MDS analysis and phylogenetic analysis showed that the Arabian horses in Oman cluster primarily with French Arabian horses, with a few horses clustering within the Polish/US Arabians. The French Arabian horse cluster was the closest to the Thoroughbred horses. Amongst the Arabian horses, plink average genomic inbreeding levels were highest in the Egyptian Arabian (0.169) followed by the Saudi Arabian horses (0.137) and lowest in the Omani and French Arabian horses, -0.041 and -0.079 respectively. To our knowledge, this is the first report on the genetic background and diversity of Arabian horses in Oman. Our results demonstrated a definite subpopulation structure among Arabian horses and this information should advise future decision-making on Arabian horse breeding.

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.

Disclosing the origin and diversity of Omani cattle.

Among all livestock species, cattle have a prominent status as they have contributed greatly to the economy, nutrition and culture from the beginning of farming societies until the present time. The origins and diversity of local cattle breeds have been widely assessed. However, there are still some regions for which very little of their local genetic resources is known. The present work aimed to estimate the genetic diversity and the origins of Omani cattle. Located in the south-eastern corner of the Arabian Peninsula, close to the Near East, East Africa and the Indian subcontinent, the Sultanate of Oman occupies a key position, which may enable understanding cattle dispersal around the Indian Ocean. To disclose the origin of this cattle population, we used a set of 11 polymorphic microsatellites and 113 samples representing the European, African and Indian ancestry to compare with cattle from Oman. This study found a very heterogenic population with a markedly Bos indicus ancestry and with some degree of admixture with Bos taurus of African and Near East origin.

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.

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.

Effect of dietary lipase enzyme on gut morphology, gastric motility, and long-term performance of broiler chicks.

Three experiments were conducted to test a previously described anorexic effect of graded dietary supplements of Pancreatic lipase enzyme on gut structure, gastric motility, and long-term performance of broiler chicks. In Experiment 1, dietary Pancreatic enzyme was used at graded levels of 0, 0.214, 0.429, 0.643, 0.857, and 1.071% to test the effect of this enzyme on gut structure, whereas Experiment 2 was designed to test its effect at 0, 0.268, 0.536, 0.804, 1.071, and 1.339% on gastric motility. The histological examination of the small intestine and a cineradiographic study of birds fed diets supplemented with lipase enzyme failed to detect any difference in gut structure, and there was no apparent adverse effect on gastric motility. Experiment 3 was conducted to test the effect of graded supplements of Pancreatic enzyme on performance of 300 male broiler chicks raised for 6 wk to determine whether the enzyme had any long-term effect on performance characteristics, especially feed intake. Only starter diets (0 to 21 d) were supplemented with 0, 0.375, 0.750, or 1.125% enzyme, and each diet was represented by three replicate pens of 25 male chicks each. Subsequent diets did not contain any enzyme. During the first 3 wk, increased dietary concentration of lipase enzyme caused a linear reduction of feed intake and body weight gain (P < 0.01). At 21 d the percentage weight of the liver was significantly greater with 1.125% enzyme (P < 0.01). However, added enzyme had no effect on 21 to 42 d or 1 to 42 d growth or feed intake (P > 0.05) or on the size of any internal organs examined at 42 d. Pancreatic enzyme has previously been shown to improve fat digestion and increase diet AMEn for young chicks fed animal-vegetable blended fats. These positive effects, however, are associated with marked anorexia, and from the present study, it seems that this effect was not related to physical changes in gut histology or in prolonged digesta transit time.

Evaluation of dietary supplements of lipase, detergent, and crude porcine pancreas on fat utilization by young broiler chicks.

The purpose of Experiment 1 was to improve the digestibility of fat through the use of supplemental lipase enzymes. A 2 x 3 factorial arrangement of treatments involving two levels of animal-vegetable blend fat (AV) (4 and 8%) and three enzyme treatments, namely none; Pancreatic, 0.714%; and Pancreatin, 0.714%, were randomly allocated within a battery brooder. There was an increase in diet ME and apparent fat digestibility when Pancreatic and Pancreatin enzymes were used (P < 0.01). However, both enzymes caused lower feed intake and lower BW gain (P < 0.01). In Experiment 2, Pancreatic enzyme was used at graded levels of 0, 0.214, 0.429, 0.643, 0.857, and 1.071%, involving 4% dietary AV fat. The ME values were greater as the enzyme level increased (P < 0.01). However, as found in Experiment 1 lower feed intake and BW gain were observed with all enzyme levels compared with the control group. There was a linear effect on feed intake and BW gain (P < 0.01) and a quadratic effect on apparent fat digestibility (P < 0.05) and feed utilization (P < 0.01). Experiment 3 was designed to test the effect of Pancreatic enzyme at 0 or 1.339% in combination with two levels of detergent, namely 0 and 10% (with 4% added AV). The detergent used consisted of a mixture of 95% Span 60 and 5% Tween 60. In general, there was no significant effect of detergent (P > 0.05). Experiment 4 was conducted to test the effect of supplementation of graded levels of ground crude porcine pancreas at 0, 0.321, 0.535, 0.750, 0.964, 1.178, or 1.392% of the diet on performance of male broiler chicks to confirm the anorexic effect caused by supplementing with Pancreatic enzyme. In general, there was no significant effect of feeding crude porcine pancreas on the performance of male broiler chicks (P > 0.05). In these studies, lipase enzymes improved fat digestion, although it is suspected that associated reduced feed intake may be associated with contaminants such as cholecystokinin hormone.