Abdullah N. Alowaimer

Effect of restricted feeding and realimentation on feed performance and carcass characteristics of growing lambs 1

Forty Najdi ram lambs weighing 26.6±0.3 kg were utilized in this experiment to determine the effects of feed restriction followed by realimentation and body weight at the onset of feed restriction (30 and 36 kg body weights) on performance and carcass characteristics; feeding and restriction levels were ad libitum, 0.75 and 0.60 of the ad libitum intake. All lambs were slaughtered after 14 weeks of experimentation. The results showed that, during the feed restriction phase, average daily gain (ADG) and feed efficiency decreased as the level of restriction increased. During the realimentation phase, the 30 kg lambs gained weights and consumed dry matter (DM) similarly to the ad libitum group, whereas the ADG for the 36 kg lambs of both 0.75 and 0.60 ad libitum groups were 20 and 43.8% faster than the ad libitum group, respectively. At the end of the trial, final body weight and overall ADG of the realimented 30 kg groups were lower than ad libitum group, whereas the ADG of the 36 kg groups were not different compared with the ad libitum group. Although empty body, hot and cold carcass, empty stomach compartments, empty intestines and liver weights for the 36 kg groups were not affected by feed restriction followed by realimentation, weights of visceral fat depots, subcutaneous fat and tail fat decreased much more than those of the ad libitum group. Carcass composition of the realimented 0.75 and 0.60 ad libitum groups tended to have 5.1 and 8.8% less lean tissue than the ad libitum group when the restriction started at 30 kg, respectively. On the other hand, the realimented lambs of both 0.75 and 0.60 ad libitum groups tended to be 5.1 and 2.8% leaner than those of the ad libitum group when restriction started at 36 kg body weight, respectively. Feed restriction of up to 40% for a 5-week period followed by a 4-week period of refeeding in 36 kg lambs is economically feasible and does not offset production.

Effect of Dietary Halophyte Salicornia bigelovii Torr on Carcass Characteristics, Minerals, Fatty Acids and Amino Acids Profile of Camel Meat

Abstract Al-Owaimer, A. N. 2001. Effect of dietary halophyte Salicornia bigelovii Torr on carcass chacracteristics, minerals, fatty acids and amino acids profile of camel meat. J. Appl. Anim. Res., 18: 185–192. To evaluate the effect of feeding Salicornia bigelovii, a halophylte, eleven Najdi camels (202 kg) were divided into two groups and fed on diets containing either 25% Rhodes grass or Salicornia hay for 120 days. Carcass characteristics were generally not affected by Salicornia hay. Similarly proximate composition, minerals, essential amino acids and fatty acids of M. longissimus were generally not affected by dietary treatments. However, Na, linoleic acid, Polyunsaturated fatty acids and methionine were higher in Salicornia hay fed camels, whereas, essential amino acid valine, histidine and phenyl alanine were lower in these camels. It is concluded that Salicornia hay can be included at 25% level in the diet of adult Najdi camels.

Prevalence of Escherichia coli O157:H7 and Salmonella in camels, cattle, goats, and sheep harvested for meat in Riyadh.

Escherichia coli O157:H7 and Salmonella are significant foodborne pathogens that can be found in the feces and on the hides of meat animals. When hides are removed during the harvest process, the carcass and subsequent meat products can become contaminated. Camels, cattle, sheep, and goats are harvested for meat in Riyadh, Saudi Arabia. The prevalence of E. coli O157:H7 and Salmonella are unknown in these animals, and it is assumed that if the animals carry the pathogens in their feces or on their hides, meat products are likely to become contaminated. To this end, a minimum of 206 samples each from hides and feces of camels, cattle, goats, and sheep were collected over the course of 8 months and tested for E. coli O157:H7 and Salmonella. It was found that E. coli O157:H7 was present in feces (10.7, 1.4, 2.4, and 2.4%) and on hides (17.9, 8.2, 2.9, and 9.2%) of cattle, goats, camels, and sheep, respectively. The prevalence of Salmonella was 11.2, 13.5, 23.2, and 18.8% in feces and 80.2, 51.2 67.6, and 60.2% on hides of cattle, goats, camels, and sheep, respectively. The prevalence of E coli O157:H7 was nearly zero in all samples collected in June and July, while Salmonella did not exhibit any seasonal variation. These results constitute the first comprehensive study of E. coli O157:H7 and Salmonella prevalence in Saudi Arabian meat animals at harvest.

The effects of the myostatin g+6723G>A mutation on carcass and meat quality of lamb

This study evaluated the effects of the myostatin g+6723G>A mutation on carcass and meat quality traits of lamb (AA: n=5; AG: n=8; GG: n=9). Dressing percentage was positively affected by the mutation with homozygotes for the mutation having the highest yield. Regarding carcass composition, there was a significant increase in the proportional weights of the loin and hindquarter muscles. Objective meat quality traits of the M. longissimus lumborum (LL) and M. semimembranosus (SM) were not significantly affected. For the SM, toughness (shear force and compression) tended to be lowest for homozygotes for the mutation. The myostatin g+6723G>A mutation did not affect sensory meat quality traits of grilled steaks for the LL, but resulted in a significant improvement in eating quality for the SM. Given the number of animals in this study, the robustness of the outcome of this study with regard to the effects on meat quality and its causes requires further investigation.

Use of fluorogestone acetate sponges or controlled internal drug release for estrus synchronization in ewes: Effects of hormonal profiles and reproductive performance

This study was carried out using 300 multiparous Najdi ewes during breeding season to compare the effects of fluorogestone acetate (FGA) sponges and controlled internal drug release (CIDR) dispensers to synchronize estrus on reproductive performance and hormonal profiles. Ewes were equally and randomly allotted into group A (FGA) and group B (CIDR); intravaginal progestagen was administered for 14-day period with intramuscular administration of 600-IU eCG at withdrawal time. Estrus was detected using a vasectomized ram starting 12 hours after progestagen withdrawal and repeated every 12 hours up to 84 hours. Blood samples were collected at the time of progestagen withdrawal (0 hour), 24 hours, and 48 hours. Follicle-stimulating hormone, LH, estradiol, and progesterone serum concentrations were measured using commercial ELISA kits and microtitrimetric plates. Timed laparoscopic insemination was performed 48 hours after progestagen withdrawal. Pregnancy and the number of fetuses were diagnosed by ultrasonography on Day 23 after insemination and confirmed on Days 35 and 60. The results revealed that the retention, vaginal discharge, and drawstring breakage rates after progestagen removal were significantly (P ≤ 0.05) higher in the FGA group (94.00, 98.58, and 9.22, respectively) than those in the CIDR group. On the other hand, pregnancy, fertility, twinning rates, and fecundity were significantly (P ≤ 0.05) higher in the CIDR group (77.86, 75.57, 34.34, and 1.02, respectively) than in the FGA group. Estrus responses in FGA and CIDR groups increased gradually to attain their significantly (P ≤ 0.05) higher percentages after 48 hours of progestagen withdrawal (91.49 and 92.37, respectively); thereafter, they decreased. The overall estrus responses and prolificacy did not differ between the FGA and CIDR groups. Follicle-stimulating hormone was significantly higher in the FGA group at 24 and 48 hours after progestagen withdrawal, whereas LH was significantly higher in the CIDR group at 48 hours after progestagen withdrawal. Estradiol and progesterone were significantly higher in the CIDR group at 0, 24, and 48 hours after progestagen withdrawal. These results indicated that although FGA and CIDR devices are efficient in synchronizing estrus in ewes, CIDR provided higher pregnancy, fertility, twinning rates, and fecundity than FGA.

Chemical composition and structural characteristics of Arabian camel (Camelus dromedarius) m. longissimus thoracis

Saudi Arabian camels of four breeds (6 animals per breed) were used to evaluate characteristics and quality of their meat. Chemical composition, fibre cross sectional area, collagen content, muscle metabolism, cooking loss, pH at 24 h post mortem, colour values (except redness) and shear force of Longissimus thoracis (LT) muscle did not differ between the breeds. Elevated pH values and short sarcomeres reduced overall tenderisation, with a difference between myofibril fragmentation index (P<0.001) and sarcomere length (P<0.05) between breeds. A positive correlation was observed between the activities of the mitochondrial enzymes (r>0.49), between the glycolytic activities (PFK and LDH) (r=0.61) and between Myosin Heavy Chain IIa and LDH activity. The intramuscular fat content was positively associated with redness and muscle oxidative metabolism, whereas shear force had a slight positive association with collagen content and muscle glycolytic metabolism and a negative association with muscle oxidative metabolism and muscle fibre area.

Effect of different probiotics on breast quality characteristics of broilers under Salmonella challenge

The current study was performed to investigate the influence of probiotics or antibiotic on breast quality characteristics of broiler chickens that were subjected to Salmonella challenge. Two hundred, one-day-old Cobb 500 chicks were allocated in five experimental treatments for 42 d. Ten cages of birds received one of the following treatments: T1=positive control (+CONT), unsupplemented, unchallenged; T2=negative control (-CONT), unsupplemented, challenged; T3=supplemented with antibiotic neoxyval (NEOX), challenged; T4=supplemented with probiotic Toyocerin (TOYO), challenged; and T5=supplemented with probiotic CloSTAT™ (CLOS), challenged. Birds in treatments T2 to T5 were challenged with 3x109 CFU/mL of Salmonella enterica subsp. typhimurium on day 16. Nine birds per treatment were sampled at the end of the trial for breast characteristics. Overall, pH and temperature values of the breast muscle were similar among all groups tested. Cooking loss results indicated that breasts from T3 birds had the highest degree of shrinkage upon cooking while those of the probiotic group had similar control values (P<0.0001). Probiotic supplementation reduced the extent of destruction of myofibrils caused by homogenisation (P<0.0001). Warner-Bratzler shear test and texture profile analysis showed that neither treatments nor Salmonella challenge had any negative impact on texture or sensory attributes of chicken breast. In conclusion, results show that breast characteristics were better when probiotics were supplemented in the diets.

110 EFFECT OF MELATONIN TREATMENT ON LIBIDO AND ENDOCRINE FUNCTION OF DROMEDARY CAMEL BULLS OUT OF THE BREEDING SEASON

The reproductive performance of camels is poor and has remained a major obstacle to the growth of dromedary populations. The limited breeding season is one of the most important causes of the poor reproductive performance. In seasonal animals, melatonin is the chemical messenger that allows the perception of daylight length changes. Commercial melatonin products have been developed for the manipulation of seasonal breeding in animals. The present study aimed to evaluate the influence of melatonin implantation on libido, serum melatonin, and testosterone concentrations in dromedary camels during the non-breeding season (June and July). Ten camel bulls were used in the 35-day-long trial; 5 of them were implanted with 30 Melovine® implant (Ceva, Libourne, France) subcutaneously on Day 0, whereas the other 5 camel bulls remained untreated as a control. Libido was evaluated weekly in response to oestrous-induced female camels treated with oestrogen (1mL Oestrocon; oestradiol benzoate 5mgmL-1) 2 days before assessment of libido. Libido was scored as follows: 0=not interested: the male did not show any libido; 1=low interested: the male went near the female and showed low frequency of sniffing and flehmen; 2=interested: the male went near the female, it showed sniffing, flehmen, grinding of teeth/whistling, yawning; 3=high interested: the male went near the female and was very agitated, it showed sniffing, flehmen, grinding of teeth/whistling, yawning, urination, and tail raising. It stood with open legs, and poll gland secretion and neck rubbing were observed; 4=excited, like 3, but the male showed blatering and dulaa extrusion, was very excited, stood with open legs, high poll gland secretion and neck rubbing were observed. Blood samples were collected weekly. Serum melatonin and testosterone concentrations were evaluated using commercial ELISA kits. Comparisons among groups were evaluated using repeated-measures ANOVA, using SAS software (SAS Institute Inc., Cary, NC, USA). A difference was considered significant at the P<0.05 level. The results revealed that at Day 0, all camel bulls in 2 groups had no libido and there was no significant difference in the melatonin or testosterone levels in the 2 groups. The libido increased gradually in the melatonin group and reached the maximum (3-5) at week 4 and week 5. The control group had low libido (0-1) along the trial. Statistically, the libido was significantly higher in the melatonin group than control group. Additionally, testosterone levels were significantly higher in melatonin group than control group, especially in the fourth week of the present trial (565.07±33.04pgmL-1 and 458.49±25.36pgmL-1, respectively). In conclusion, melatonin implantation in the non-breeding season significantly improved the libido and the reproductive performance of dromedary camel bulls. Therefore, it may be possible to improve the reproductive efficiency of camels by extending the breeding season through treatment with melatonin during the non-breeding season.

Effect of different feed restriction regimens on lamb performance and carcass traits

Fifty Najdi ram lambs weighing an average of 38.1±0.5 kg were utilized in this study to determine the effects of feed restriction level with or without subsequent realimentation on lamb performance and carcass composition. Lambs were allotted randomly and equally into five groups. The groups were fed a control diet ad libitum; two groups fed 0.90 and 0.80 of ad libitum intake throughout the eight-week period of the trial (R), and two groups fed 0.90 and 0.80 of ad libitum intake for a six-week period followed by two weeks of realimentation (RR). All lambs were slaughtered after eight weeks of experimentation. Average daily gain (ADG) for the 0.90 and 0.80 ad libitum groups decreased by 7.6 and 26.9% during restriction, whereas the lambs during realimentation period had 35 and 30.5% faster ADG and 27.5 and 21.8% better feed:gain ratios than the control, respectively. At the end of the trial, final, empty and hot carcass weights and overall ADG of the 0.90 ad libitum RR group did not differ from control. Feeding performance values of the 0.80 ad libitum R group were the lowest among the treatments. The studied feed restriction regimens depressed the weights of empty stomach, tail fat, visceral fat, and subcutaneous fat; however, two weeks of realimentation were not enough to induce complete weight recovery in these tissues. The 0.90 ad libitum RR restriction routine can be adopted as a nutritional management practice for fattening Najdi lambs.

Effects of melatonin implants on the reproductive performance and endocrine function of camel (Camelus dromedarius) bulls during the non-breeding and subsequent breeding seasons

This study aimed to evaluate the effects of melatonin implants on the reproductive performances and hormone levels of dromedary (Camelus dromedarius) bulls during the non-breeding and subsequent breeding seasons. Fourteen mature dromedary bulls were divided into a control group (n = 7) and a group that was implanted with melatonin (n = 7) twice, at the beginning of the study and 35 days later. The trial started on the 17th June and continued for 10 weeks during the non-breeding season. Reproductive performances of animals in the control and melatonin groups were evaluated weekly during the non-breeding season [control non-breeding (CNB) and melatonin non-breeding (MNB) groups, respectively] and evaluated again during the subsequent breeding season [control breeding (CB) and melatonin breeding (MB) groups, respectively], which started on the 6th December and continued for 10 weeks. MNB bulls had greater (P ≤ 0.05) scrotum circumference and testicular volume, sexual desire, reaction time and mating ability scores, and serum melatonin and testosterone concentration values (24.91 ± 0.26 cm, 271.00 ± 7.81 cm3, 2.31 ± 0.13, 2.03 ± 0.22, 2.26 ± 0.09, 23.90 ± 0.05 pg/mL and 2764.51 ± 137.02 pg/mL, respectively) than the CNB group (23.63 ± 0.05 cm, 199.21 ± 3.27 cm3, 1.00 ± 0.00, 0.00 ± 0.00, 1.00 ± 0.00, 9.46 ± 0.08 pg/mL and 1872.41 ± 264.89 pg/mL, respectively). The scrotum and testes, reaction time score, proportion of bulls refusing to mount, and serum melatonin values were significantly higher in MB than CB bulls (P ≤ 0.05). Progressive motility (PM), average pathway velocity, straight-line velocity, curvilinear velocity (VCL), linearity, straightness (STR), wobble, beat cross frequency (BCF), livability, and DNA integrity were significantly higher in MB than CB bulls (P ≤ 0.05). PM, VCL, STR, amplitude of lateral head displacement, BCF, and livability were significantly higher in MNB than CB bulls (P ≤ 0.05). In conclusion, melatonin implants improved the reproductive performance of bulls during the non-breeding and subsequent breeding seasons.