Exploring rumen fermentation and microbial populations in Dhofari goats fed a chitosan-added diet

The use of chitosan (CHI) in ruminant diets is a promising natural modifier for rumen fermentation, capable of modulating both the rumen pattern and microbial activities. The objective of this study was to explore the rumen fermentation and microbial populations in Dhofari goats fed a diet supplemented with CHI. A total of 24 Dhofari lactating goats (body weight, 27.32 ± 1.80 kg) were assigned randomly into three experimental groups (n = 8 ewes/group). Goats were fed a basal diet with either 0 (control), 180 (low), or 360 (high) mg CHI/kg of dietary dry matter (DM) for 45 days. Feeding high CHI linearly increased (p < 0.05) the propionate level and reduced the acetate, butyrate, and total protozoa count (p < 0.05). Ruminal ammonia nitrogen (NH3-N) concentrations and the acetate:propionate ratio decreased linearly when goats were fed CHI (p < 0.05). The abundances of both Spirochetes and Fibrobacteres phyla were reduced (p < 0.05) with both CHI doses relative to the control. Both low and high CHI reduced (p < 0.05) the relative abundances of Butyrivibrio hungatei, Fibrobacter succinogenes, Ruminococcus albus, Ruminococcus flavefaciens, Selenomonas ruminantium and Neocallimastix californiae populations. Adding CHI significantly decreased (p < 0.05) the abundances of Ascomycota, Basidiomycota, and Bacillariophyta phyla compared to the control. Adding CHI to the diet reduces the abundance of fibrolytic-degrading bacteria, however, it increases the amylolytic-degrading bacteria. Application of 360 mg of CHI/kg DM modified the relative populations of ruminal microbes, which could enhance the rumen fermentation patterns in Dhofari goats.

Assessing genetic diversity and defining signatures of positive selection on the genome of dromedary camels from the southeast of the Arabian Peninsula

Dromedary camels (Camelus dromedarius) are members of the Camelini tribe within the Camelidae family. They are distributed throughout North Africa, the Arabian Peninsula and Southeast Asia. This domestic species is characterized by its superior adaptability to the harsh desert environment. In this study, whole autosomal data of 29 dromedary samples from the Southeast Arabian Peninsula in Oman; 10 from Muscat, 14 from Al-Batinah, and 5 from Al-Sharqiya, were investigated to assess their genetic relationship and to define candidate signatures of positive selection. A minimal genetic distinction that separates Muscat dromedaries from the other two populations was observed, with a degree of genetic admixture between them. Using the de-correlated composite of multiple signals (DCMS) approach, a total of 47 candidate regions within the autosomes of these dromedary populations were defined with signatures of positive selection. These candidate regions harbor a total of 154 genes that are mainly associated with functional categories related to immune response, lipid metabolism and energy expenditure, optical and auditory functions, and long-term memory. Different functional genomic variants were called on the candidate regions and respective genes that warrant further investigation to find possible association with the different favorable phenotypes in dromedaries. The output of this study paves the way for further research efforts aimed at defining markers for use in genomic breeding programs, with the goal of conserving the genetic diversity of the species and enhancing its productivity.

Effect of Spirulina platensis Supplementation on Carcass Characteristics, Fatty Acid Profile, and Meat Quality of Omani Goats

In a 70-day study, 36 Jabbali and Sahrawi bucks, aged 11 months, were utilized to evaluate the effects of different levels of spirulina dietary supplement (SP) on carcass characteristics, fatty acid profile, and meat quality traits in Omani goat breeds. The goats were put into six groups of six bucks, each at random. The diet consisted of a conventional concentrate feed ration (CFR) without spirulina (CON), and the CFR diet supplemented with spirulina at the levels of 2 g/head daily (T1) and 4 g/head daily (T2). In general, Sahrawi bucks showed a highly significant response to SP feeding compared with Jabbali bucks. The treatment groups, especially T1, showed a significant increase in average daily gain and carcass traits (body length, leg length, and the rack weight) compared with the CON group of Sahrawi bucks. The weights of omental and kidney fat were also significantly higher in T1 compared with CON and T2 groups of Sahrawi goats, while they were significantly higher in T2 compared with CON and T1 groups of Jabbali goats. Carcass profile and meat quality, including ultimate ph and meat color lightness (L*) were increased significantly with dietary spirulina in both LD and SM muscles of Sahrawi goats. Most of the Sfa, Mufa, Pufa, Pufa n-6, Pufa n-3, and n-6/n-3 ratios of the LD showed significant differences in diets supplemented with SP compared with CON for Sahrawi bucks, while some of them were significant in Jabbali bucks. The LD muscle of Sahrawi goats fed diets supplemented with SP of the T1 group significantly decreased in the amounts of pentadecanoic and margaric acids compared with the T2 and CON groups. The study concluded that incorporating SP (2 g and 4 g/head daily) into the diet of Omani goats, especially Sahrawi goats, can increase growth performance, as well as improve fatty acid composition and meat quality.

Circulation of Trypanosoma evansi antibodies and risk variables among dromedary camels in Al Batinah governorates, Sultanate of Oman

Trypanosoma evansi is a blood protozoan infects camels with Surra disease and causes high economic losses. The current study was focused on estimating the seroprevalence and associated risk factors of Surra disease among camels, using 425 blood samples collected from 45 farms in nine Wilayats of Al Batinah governorates in the Sultanate of Oman. Host and environmental risk factors associated with T. evansi seroprevalence were analyzed by questionnaire arranged during sample collection. The overall seroprevalence by the serological CATT/T. evansi was 19.5% (83/425, CI: 16.0-23.6%). The seroconversion rate between the two governorates of north and south Al Batinah was not statistically significant (p > 0.05). However, the highest frequency was in Al Musannah at 41.7% (10/24, CI: 22.1-63.4%), and the lowest was in Al Khaburah at 10.5% (6/57, CI: 4.0-21.5%). Most of the owners in Al Khaburah (82.5%) were aware of T. evansi importance, and therefore they kept camels separate from ruminants. The ticks-free camels, racing camels and camels less than five years old showed higher T. evansi seroprevalence than other camels. The mean total protein was significantly (t = 2.817, p = 0.006) higher in seropositive camels (6.49 ± 0.75) compared to seronegative ones (6.25 ± 0.55), whereas PCV was not statistically different between the positive (28.96 ± 4.33) and negative camels (29.83 ± 3.63). Further studies are highly recommended to determine the prevalence and type of T. evansi in camels and ruminants in different governorates in Oman, especially in the Dhofar region, where the highest camel density is reported in the country.

Seroprevalence and Risk Factors of Brucellosis in Ruminants in Dhofar Province in Southern Oman

OBJECTIVE

The aim of the present work was to raise awareness of Brucella infection and emphasize the use of serological tests for screening and confirmation of the presence of the infection in different localities in the Dhofar region in the Sultanate of Oman.

METHODS

A seroprevalence of Brucella infection in naturally infected livestock was undertaken in 50 farms (a total of 434 sera, 207 goats, 84 sheep, 54 cattle, and 89 camels) from different wilayat of the Dhofar region in the southern part of Oman. Rose Bengal (RBT), complement fixation (CFT), and indirect enzyme-linked immunosorbent assay (I-ELISA) tests were used to determine the presence of Brucella antibodies. Statistical analysis (Pearson chi-square, binary logistic regression, and univariate logistic regression) was used to investigate the significance between the prevalence and the categorical risk factors individually, with two or more levels (animal species, animal condition, and or location).

RESULTS

Our results show that the overall seroprevalence based on CFT, RBT, and I-ELISA was 3% (13/424, CI: 1.8-5.1%), 4.8% (21/434, CI: 3.1-7.3%), and 8% (35/434, CI: 5.8-10.9%), respectively. The highest seroprevalence was reported in goats (13% (27/207)) and animals from East Jabal (13% (21/161)), whereas the lowest was recorded in camels (3.4% (3/89)) and animals from deserts (1.4% (1/69)). Parameters such as the positive predictive value (PPV) and the negative predictive value (NPV) showed that the sensitivity of I-ELISA and CFT based on the RBT test was 61.9% and 57.1%, respectively, whereas the specificity of I-ELISA (94.6%) was less than that of CFT (97.33%).

CONCLUSION

We concluded that three tests are confirmatory for the presence of Brucella infection.

Detection of Residual Antibiotics and Their Differential Distribution in Broiler Chicken Tissues Using Enzyme-Linked Immunosorbent Assay

The aim of this study was to estimate the residue levels of five commonly used antibiotics in poultry tissue samples using enzyme linked immunosorbent assay (ELISA). A total of 200 samples that comprised breast and liver (100 each) were collected from five poultry farms randomly selected from Muscat regions. The samples were analyzed for enrofloxacin (ENR), gentamicin (GEN), oxytetracycline (OTC), sulfamethazine (SMZ), and tylosin (TYL) residue concentrations. Comparisons of antibiotic residues between breast and liver of chickens under investigations showed a significant difference of ENR, GEN, OTC, SMZ, and TYL residue concentrations (p < 0.05). The highest antibiotic residue concentrations reported in the chicken liver were TYL, GEN, OTC, SMZ, and ENR, respectively. The lowest residual antibiotic concentrations observed in the chicken breast were TYL, GEN, OTC, SMZ, and ENR, respectively. Furthermore, the Kruskal–Wallis statistical test revealed a significant difference between the five antibiotic concentrations in both breast (H (4) = 54.69, p < 0.05) and liver (H (4) = 44.36, p < 0.05). A follow up of this finding by Bonferroni correction for both breast and liver samples revealed a significant difference for the breast sample between the concentration of ENR residue, and the concentration of residues for of both OTC and TYL (p < 0.05). These data show that not all tissues incorporate antibiotics at the same concentration. The results of this study could support regulatory bodies in adopting, monitoring, and enforcing guidelines pertinent to safety levels of different antibiotic residue concentrations in poultry meat when antibiotics are used for different indications.

Effect of dietary concentrate content on feed intake, feed efficiency, and meat quality of Holstein steers fattened in a hot environment

The objective of this study was to investigate the effect of feeding high and low concentrate diets on feed intake and feed efficiency, the morphological characteristics of the rumen papillae, and meat quality of Holstein steers fattened under hot climate conditions in Oman. Ten male Holstein calves, of 5 months of age, were selected for the experiment. The animals were fed concentrate and Rhodes grass hay and were divided into two groups of high concentrate (HC, n = 5) and low concentrate diets (LC, n = 5), in which their feed intake, weight gain, and feed efficiency were evaluated across three growing periods. Feed intake and efficiency and average daily gain (ADG) of the HC group were significantly greater than for the LC group and were affected by the diet (p < .01) and the period (p < .001). Across the fattening periods, ADG declined in both groups, with ADG improved by 35% for steers on the HC diet compared to steers on the LC diet. Carcass meat quality was not affected significantly by the dietary concentrate level. In conclusion, our results can be used to make improvements in feed efficiency of Holstein steers under hot climate conditions.

Correction to: Investigation on Brucella infection in farm animals in Saham, Sultanate of Oman with reference to human brucellosis outbreak

The original article [1] incorrectly presents final author, Eugene H. Johnson's name incorrectly whereby middle initial, 'H.' is mistakenly presented as a Family Name.

Diversity of Intestinal Bacterial Microbiota of Indigenous and Commercial Strains of Chickens Using 16S rDNA-Based Analysis

The objective of this study was to assess the relative abundance of bacteria microflora in different segments of the gastrointestinal tract (duodenum, jejunum, ilium, and cecum) of indigenous (local Omani) and commercial (Cobb 500) chicken strains. Birds were raised under an intensive management system fed a nonmedicated corn-soybean meal diet from Day 0-35 days of age. Using 16S rDNA-based analysis the study showed that in both breeds of birds Bacilli were the most abundant class of bacteria in the duodenum, jejunum, and ileum. Local Omani chickens had significantly higher numbers of Clostridia at most time periods. Actinobacteria were found in higher numbers and reached 54.9% of the bacteria in the jejunum at Day 35 in Cobb 500 versus only 5.42% in the Omani chickens. The bacterial microbiota relative abundance differed significantly (p < 0.05) across different intestinal segments of the two strains, suggesting that each region developed its own bacterial community and the relative abundances of these were quite different.

Ultrastructural morphology of lymphocytes of the Arabian oryx (Oryx leucoryx)

An ultrastructural study on the lymphocytes from peripheral blood samples from 20 healthy adult Arabian oryx (Oryx leucocoryx) was undertaken. Small lymphocytes ranged in size from 2-3.5 µm and exhibited the typical repertoire of organelles found in small lymphocytes of other animals but showed no evidence of azurophilic granules. Medium-sized lymphocytes were 5-6.5 µm in diameter and occasionally demonstrated azurophilic granules. Microvilli were a common finding of lymphocytes. Of particular interest was the presence of multivesicular bodies, which have previously only been described in human lymphocytes. Both small- and medium-sized lymphocytes of the Arabian oryx were smaller than those reported for other animals. Small lymphocytes exhibited short, thick microvilli, whereas medium-sized lymphocytes had long thin microvilli, a single nucleolus and occasionally azurophilic granules and multivesicular bodies.

Binding of Brucella protein, Bp26, to select extracellular matrix molecules

BACKGROUND

Brucella is a facultative intracellular pathogen responsible for zoonotic disease brucellosis. Little is known about the molecular basis of Brucella adherence to host cells. In the present study, the possible role of Bp26 protein as an adhesin was explored. The ability of Brucella protein Bp26 to bind to extracellular matrix (ECM) proteins was determined by enzyme-linked immunosorbent assay (ELISA) and biolayer interferometry (BLI).

RESULTS

ELISA experiments showed that Bp26 bound in a dose-dependent manner to both immobilized type I collagen and vitronectin. Bp26 bound weakly to soluble fibronectin but did not bind to immobilized fibronectin. No binding to laminin was detected. Biolayer interferometry showed high binding affinity of Bp26 to immobilized type I collagen and no binding to fibronectin or laminin. Mapping of Bp26 antigenic epitopes by biotinylated overlapping peptides spanning the entire sequence of Bp26 using anti Bp26 mouse serum led to the identification of five linear epitopes. Collagen and vitronectin bound to peptides from several regions of Bp26, with many of the binding sites for the ligands overlapping. The strongest binding for anti-Bp26 mouse serum, collagen and vitronectin was to the peptides at the C-terminus of Bp26. Fibronectin did not bind to any of the peptides, although it bound to the whole Bp26 protein.

CONCLUSIONS

Our results highlight the possible role of Bp26 protein in the adhesion process of Brucella to host cells through ECM components. This study revealed that Bp26 binds to both immobilized and soluble type I collagen and vitronectin. It also binds to soluble but not immobilized fibronectin. However, Bp26 does not bind to laminin. These are novel findings that offer insight into understanding the interplay between Brucella and host target cells, which may aid in future identification of a new target for diagnosis and/or vaccine development and prevention of brucellosis.

Effect of diet quality and shearing on feed and water intake, in vitro ruminal methane production, and blood parameters of Omani sheep

The aim of this study was to evaluate the effect of diet and animal shearing on the feed and nutrient intakes, water intake, in vitro ruminal methane production, and blood parameters of Omani sheep. A pens trial was carried out for 16 days each in March and June of 2017 using 20 Omani non-castrated yearling rams selected from the sheep herd in the research station and randomly assigned to four groups with 5 animals per group. Group 1: sheared animals fed a high concentrate (HC) diet, group 2: fleeced animals fed a HC diet, group 3: sheared animals fed a low concentrate (LC) diet, group 4: fleeced animals fed a LC diet. Furthermore, a metabolic crates trial was carried out in July of 2017 on three animals from each group over a 10-day period. The effect of diet and shearing on the tested parameters was evaluated using the mixed linear model, where animals were fitted as a random effect to account for the individual animal deviation from the overall mean. Results showed that rams fed on the high concentrate diet had a significantly increased organic matter intake of the total diet (62 g/kg ^0.75 Live Weight (LW) in HC group to 54 g/kg ^0.75 LW in LC group), an increased water intake (6.3 L/day vs 4.8 L/day in LC group), and a reduced in vitro methane production (i.e. the invitro ruminal CH₄ was measured and converted to daily CH₄ using the daily feed intake data and was 20.4 g CH₄ per head/day in HC group vs 27.3 g CH₄ per head/day in LC group), compared with rams fed on the low concentrate diet. Furthermore, shearing had a significant effect (P < 0.01) on increased feed and nutrients intake. The apparent and organic matter digestibility was significantly different (P < 0.01) between the experimental groups and was greater for those rams fed on the HC diet. Partial substitution of low-quality Rhodes grass hay by high-quality concentrate significantly improved the total diet organic matter digestibility (P < 0.01) and nutrients digestibility, whereas no significant effects on biochemical blood parameters or animal health were observed. These results show the importance of utilizing effective feeding and shearing plans to improve the productivity and reduce the methane emission of Omani sheep.

A comparison of milk production from Holstein Friesian and Jersey cattle breeds under hot climate of Oman

Data of milk production and performance under Oman climatic conditions are limited. The current study presents a 9-year analysis of daily milk performance of Holstein and Jersey cattle breeds born and raised in Oman and fed similar diets of concentrate and Rhodes grass hay. Data on the daily cow's milk production, during the entire lactation period for nine consecutive milking years between 2009 and 2018, were collected. The data was introduced to a linear mixed model and was analyzed to evaluate the breed variations in milk production across lactations and across years. Holstein Friesian (HF) cows had significantly (P < 0.001) higher daily milk production of 17.6 ± 0.4 kg/cow/day compared to 11.7 ± 0.8 kg/cow/day for Jersey cows. Across years, we observed a gradual annual improvement in total milk production in both HF and Jersey breeds of 5% and 6%, respectively. The highest daily milk production was in the third and fourth lactations for HF cows and in the second and third lactations for Jersey cows. In a region where much of the expected demand in milk will be met by exotic breeds and importation, our results provide an insight into the performance of temperate breeds in hot and arid climatic conditions. As such, our results shall be useful for dairy producers seeking to maximize milk production under such conditions.

Investigation on Brucella infection in farm animals in Saham, Sultanate of Oman with reference to human brucellosis outbreak

Background

The objective of this study was to investigate Brucella infection in farm animals in Saham, Oman, with reference to a survey carried out by the Ministry of Agriculture & Fisheries (MAF) for Brucellosis during the period of May to July 2016 in Saham, following an outbreak of human brucellosis. We wanted to apply different serological, bacteriological and molecular tests in a time frame (phase 1, 2 & 3) with reference to the pivotal time of a human brucellosis outbreak to ascertain the status of the disease in Saham area where the MAF survey was conducted. Blood samples were collected from farm animals and sera were screened in parallel for Brucella antibodies using different serological tests.

Results

Using the RBT test, phase 1 sera showed seropositivity in sheep at 2.6%, (95% CI: 0.5–13.5%), in camel (5.9%, 1.1–27.0%), but not in sera from goats and cattle (0%). Using I-ELISA, seropositivity in goat was 3.1% (0.6–15.8%), with no positive sheep and cattle. Using c-ELISA for camel we found a seropositivity of 5.9% (1.1–27.0%). Furthermore, CFT seropositivity in goats was 21.9% (CI: 11.3–38.9), cattle and sheep sera were negative and camel was 5.9% (1.1–27.0%).

In phase 2, the seropositivity in goats was 1.9% (1.4–2.6%), sheep 4.5% (3.5–5.8%), cattle 1.1%, (0.5–2.3%) and camels 18.2% (5.1–47.7%),

Phase 3 sera were collected 6 months after the human brucellosis outbreak. With RBT, the seropositivity in goats was 3% (1.0–8.5%), sheep 2% (0.6–7.1%) cattle 1% (0.2–5.5%). With I-ELISA, goats & camels were negative, sheep were 3% (1.0–8.5%) and cattle 1% (0.2–5.5%).

Moreover, B. melitensis was isolated from a bronchial lymph node of the RBT and I-ELISA seropositive cow and confirmed by Multiplex PCR and biochemical tests.

Conclusion

Using a retrospective study analysis of animal sera and following up after a human brucellosis outbreak, the present study showed a slight decrease in seropositivity of infected animals after the MAF implemented test and slaughter policy. The most interesting finding in this study was the isolation, identification and molecular characterization of Brucella melitensis in a cow (spillover), which is not a preferential host for Brucella melitensis.

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 transportation during the hot season, breed and electrical stimulation on histochemical and meat quality characteristics of goat longissimus muscle

The effects of transportation and electrical stimulation (90 V) on physiological, histochemical and meat quality characteristics of two breeds of Omani goats were assessed. Twenty 1-year-old male goats from each breed (Batina and Dhofari) were divided into two groups: 3 h transported during the hot season (42 degrees C day time temperature) and non-transported. Animals were blood-sampled before loading and prior to slaughter. Electrical stimulation was applied 20 min postmortem to 50% randomly selected carcasses of both breeds. Temperature and pH decline of the Longissimus was monitored. Ultimate pH, shear force, sarcomere length, myofibrillar fragmentation index, expressed juice, cooking loss and colour were measured from samples of Longissimus dorsi muscles. Electrical stimulation and transportation had a significant effect on most biochemical and meat quality characteristics of Longissimus dorsi. The transported goats had higher plasma cortisol (P < 0.01), adrenaline, nor-adrenaline and dopamine concentrations (P < 0.05) than non-transported goats. Electrical stimulation resulted in a significantly (P < 0.05) more rapid muscle pH fall during the first 12 h after slaughter. Muscles from electrically-stimulated carcasses had significantly (P < 0.05) longer sarcomeres, lower shear force value, a lighter colour (higher L* value), higher expressed juice and myofibrillar fragmentation index than those from non-stimulated ones. Meat from transported goats had significantly higher pH, expressed juice and shear force, but contained significantly lower sarcomere length and L* values than non-transported goats. The proportion of the myosin ATPase staining did not change as a function of stimulation, transportation or breed. These results indicated that subjecting goats to transportation for 3 h under high ambient temperatures can generate major physiological and muscle metabolism responses. Electrical stimulation improved quality characteristics of meat from both groups. This indicates that electrical stimulation may reduce detrimental effects of transportation on meat quality of Omani goats.

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.

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.

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.