Synthesis of Tungsten Oxide, Iron Oxide, and Copper-Doped Iron Oxide Nanocomposites and Evaluation of Their Mixing Effects with Cyromazine against Spodoptera littoralis (Boisduval)

Nanotechnology research is emerging as a cutting-edge technology, and nanocomposites have played a significant role in pest control. Therefore, the present study focuses on the synthesis of tungsten oxide (WO3), iron oxide (magnetic nanoparticle, MNP), and copper-doped iron oxide (MNP-Cu) nanocomposites and explores the different effects of their binary combinations with the insecticide cyromazine against Spodoptera littoralis. The synthesized nanoparticles were characterized by transmission electron microscopy, X-ray diffraction, Fourier-transform infrared spectroscopy, and Raman spectroscopy. None of the tested nanomaterials showed any toxicity against the different stages of S. littoralis. Larval and pupal durations increased with increasing cyromazine and nanomaterial concentrations. The longest larval and pupal durations were recorded under treatment with the mixture of cyromazine (100 mg/L) + MNP-Cu (500 mg/L); the survival periods were 23.5 and 15.6 days, compared with 10.8 and 7.7 days in the control, respectively. The percentages of pupation and adult emergence were negatively affected by all treatments. Among the 500 mg/L nanomaterial combinations, only cyromazine (25 mg/L) and WO3 (500 mg/L) resulted in adult emergence (at a rate of 27.3%). Some abnormalities in the S. littoralis stages were observed following treatment with the tested materials. The glutathione S-transferase and alpha-esterase enzyme activities in S. littoralis were significantly increased after treatment with cyromazine, followed by cyromazine/MNP-Cu combinations. The quantitative polymerase chain reaction (Q-PCR) data showed that all treated insects had a higher immune response than the control. Finally, mixes of nanocomposites and cyromazine may be suggested as viable alternatives for S. littoralis management.

Comparative study of three plant-derived extracts as new management strategies against Spodoptera littoralis (Boisd.) (Lepidoptera: Noctuidae)

Finding innovative eco-friendly agents for pest control may be aided by investigating the plant-derived extracts' properties on economic pests. Therefore, the insecticidal, behavioral, biological and biochemical effects of Magnolia grandiflora (Magnoliaceae) leaf water and methanol extracts, Schinus terebinthifolius (Anacardiaceae) wood methanol extract, and Salix babylonica (Salicaceae) leaf methanol extract in comparison with a reference insecticide novaluron against S. littoralis were evaluated. The extracts were analyzed by High-Performance Liquid Chromatography (HPLC). The most abundant phenolic compounds were 4-hydroxybenzoic acid (7.16 mg/mL) and ferulic acid (6.34 mg/mL) in M. grandiflora leaf water extract; catechol (13.05 mg/mL), ferulic acid (11.87 mg/mL), and chlorogenic acid (10.33 mg/mL) in M. grandiflora leaf methanol extract; ferulic acid (14.81 mg/mL), caffeic acid (5.61 mg/mL), and gallic acid (5.07 mg/mL) In the S. terebinthifolius extract; cinnamic acid (11.36 mg/mL), and protocatechuic acid (10.33 mg/mL) In the methanol extract from S. babylonica extract. S. terebinthifolius extract had a highly toxic effect against second larvae after 96 h and eggs with LC₅₀ values of 0.89 and 0.94 mg/L, respectively. Despite M. grandiflora extracts didn't show any toxicity against S. littoralis stages, they had an attractant effect on fourth- and second larvae, with feeding deterrence values of - 2.7% and - 6.7%, respectively, at 10 mg/L. S. terebinthifolius extract significantly reduced the percentage of pupation, adult emergence, hatchability, and fecundity, with values of 60.2%, 56.7%, 35.3%, and 105.4 eggs/female, respectively. Novaluron and S. terebinthifolius extract drastically inhibited the activities of α-amylase and total proteases to 1.16 and 0.52, and 1.47 and 0.65 ΔOD/mg protein/min, respectively. In the semi-field experiment, the residual toxicity of tested extracts on S. littoralis gradually decreased over time compared to novaluron. These findings indicate that extract from S. terebinthifolius is a promising insecticidal agent against S. littoralis.

Imidacloprid-induced pathophysiological damage in the midgut of Locusta migratoria (Orthoptera: Acrididae) in the field

Neonicotinoids are modern insecticides widely used in agriculture worldwide. Their impact on target (nervous system) and non-target (midgut) tissues has been well studied in beneficial insects including honeybees under controlled conditions. However, their detailed effects on pest insects on the field are missing to date. Here, we have studied the effects of the neonicotinoid imidacloprid on the midgut of the pest insect Locusta migratoria caught in the field. We found that in the midgut of imidacloprid-exposed locusts the activity of enzymes involved in reactive oxygen metabolism was perturbed. By contrast, the activity of P450 enzymes that have been shown to be activated in a detoxification response and that were also reported to produce reactive oxygen species was elevated. Probably as a consequence, markers of oxidative stress including protein carbonylation and lipid peroxidation accumulated in midgut samples of these locusts. Histological analyses revealed that their midgut epithelium is disorganized and that the brush border of the epithelial cells is markedly reduced. Indeed, microvilli are significantly shorter, misshapen and possibly non-functional in imidacloprid-treated locusts. We hypothesize that imidacloprid induces oxidative stress in the locust midgut, thereby changing the shape of midgut epithelial cells and probably in turn compromising their physiological function. Presumably, these effects reduce the survival rate of imidacloprid-treated locusts and the damage they cause in the field.

Blood parasites of livestock in certain Regions in Saudi Arabia

Blood samples from camels, sheep, goats and cattle from six Regions in Saudi Arabia were examined for blood parasites. Asir Region camels were disinfected while those of the Eastern, Jazan, Northern Frontiers, Riyadh and Tabouk Regions were infected with Trypanosoma evansi (5-40%), those of Riyadh and the Eastern Regions were infected with Dipetalonema evansi (1-6%) and those of the Eastern, Jazan and Riyadh Regions were infected with Eperythrozoon species (8-20%). Sheep and goats of all tested regions were infected with Theilaria hirci (4-20% and 6-14%, respectively), Theilaria ovis (5-19% and 6-24%, respectively) and Eperthrozoon ovis (2-9% and 2-8%, respectively). Sheep of the Eastern and Northern Frontiers Regions were also infected with Anaplasma ovis (2%) and also those of the Eastern Region were infected with Babesia motasi (4%) as well. Cattle of Asir and Eastern Regions were infected with Anaplasma marginale (1-3.4%) and those of the Eastern, Jazan and Riyadh Regions were infected with Theileria annulata (11.3-25%) and Eperthrozoon wenyoni (1-4%). Moreover, Jazan cattle were infected with Babesia bigemina (6%) and a benign Theileria species (27%). Some of these parasites are recorded in new localities indicating that they are spreading in the country. Also, this is the first report in Saudi Arabia of D. evansi in camels, A. ovis and B. motasi in sheep and A. marginale and B. bigemina in cattle. These parasites may be introduced into the country with infected livestock infested with the vectors of these parasites. The suspected vectors of the detected parasites in Saudi Arabia is discussed. Follow up surveys of blood parasites are recommended to assess their distribution and infection rates in the livestock of all Regions of Saudi Arabia, to make plans for control measures against their vectors.

Prevalence and pathogenicity of Shiga toxin-producing Escherichia coli in beef cattle and their products1,2

During the past 23 yr, a large number of human illness outbreaks have been traced worldwide to consumption of undercooked ground beef and other beef products contaminated with Shiga toxin-producing Escherichia coli (STEC). Although several routes exist for human infection with STEC, beef remains a main source. Thus, beef cattle are considered reservoirs of O157 and nonO157 STEC. Because of the global nature of the food supply, safety concerns with beef will continue, and the challenges facing the beef industry will increase at the production and processing levels. To be prepared to address these concerns and challenges, it is critical to assess the beef cattle role in human infection with STEC. Because most STEC outbreaks in the United States were traced to beef containing E. coli O157:H7, the epidemiological studies have focused on the prevalence of this serotype in beef and beef cattle. Worldwide, however, additional STEC serotypes (e.g., members of the O26, O91, O103, O111, O118, O145, and O166 serogroups) have been isolated from beef and caused human illnesses ranging from bloody diarrhea and hemorrhagic colitis to the life-threatening hemolytic uremic syndrome (HUS). To provide a global assessment of the STEC problem, published reports on beef and beef cattle in the past 3 decades were evaluated. The prevalence rates of E. coli O157 ranged from 0.1 to 54.2% in ground beef, from 0.1 to 4.4% in sausage, from 1.1 to 36.0% in various retail cuts, and from 0.01 to 43.4% in whole carcasses. The corresponding prevalence rates of nonO157 STEC were 2.4 to 30.0%, 17.0 to 49.2%, 11.4 to 49.6%, and 1.7 to 58.0%, respectively. Of the 162 STEC serotypes isolated from beef products, 43 were detected in HUS patients and 36 are known to cause other human illnesses. With regard to beef cattle, the prevalence rates of E. coli O157 ranged from 0.3 to 19.7% in feedlots and from 0.7 to 27.3% on pasture. The corresponding prevalence rates of nonO157 STEC were 4.6 to 55.9% and 4.7 to 44.8%, respectively. Of the 373 STEC serotypes isolated from cattle feces or hides, 65 were detected in HUS patients and 62 are known to cause other human illnesses. The results indicated the prevalence of a large number of pathogenic STEC in beef and beef cattle at high rates and emphasized the critical need for control measures to assure beef safety.

Effects of cereal grain supplementation on apparent digestibility of nutrients and concentrations of fermentation end-products in the feces and serum of horses consuming alfalfa cubes

Twenty geldings (five groups; similar age and BW) were used in a completely randomized design experiment to determine effects of grain supplementation of an alfalfa-cube diet on apparent nutrient digestibility and hindgut fermentation. The geldings were housed individually, fed their diets in two equal meals (0600 and 1800), and adapted to five dietary treatments over 6 wk. The treatments were alfalfa cubes (1% of BW; DM basis) without (control) or with one of four rolled cereal grains (i.e., barley, corn, naked oats, or oats) to provide a target level of 0.4% of BW as total nonstructural carbohydrates (TNC). Due to acute laminitis, three geldings (one in the control group and two in the barley group) were excluded. Because of this and multiple incidents of gas colic, TNC level was decreased to 0.2% of BW to ensure the geldings' health throughout the adaptation (7 d) and sample collection (5 d) periods. Grain intakes varied (P < 0.05) and reflected the different TNC concentrations. Apparent digestibilities of DM, OM, CP, NDF, ADF, and cellulose were not affected (P > 0.05) by grain supplementation and averaged 63.2, 63.1, 79.5, 42.7, 39.9, and 50.3%, respectively. Regardless of the source, grain supplementation increased (P < 0.05) apparent digestibility of TNC (from 85.6 to 94.6%) and decreased (P < 0.05) fecal pH (from 7.04 to 6.74). Fecal concentrations of total VFA (mg/g of DM) were greatest for the barley and naked oats diets (averaging 11.73), intermediate for the oats diet (8.00), and least for the control and corn diets (averaging 5.00; P < 0.05). Fecal concentrations of lactate (microg/g of DM) were greatest for the barley diet (254), intermediate for the oats diet (138), and least for the remaining diets (averaging 100; P < 0.05). Fecal concentrations of NH3 N (mg/g of DM) were greatest for the naked oats diet (1.68), intermediate for the barley and oats diets (averaging 0.86), and least for the remaining diets (averaging 0.63; P < 0.05). Serum concentration of lactate was 46% higher (P < 0.05) for the control than for the grain diets (averaging 0.05 mg/100 mL). Feeding barley, corn, naked oats, and oats contributed to 13, 15, 8, and 20% higher (P < 0.05) serum NH3 N concentrations than the control diet (0.25 mg/100 mL). Higher (P < 0.05) serum concentrations of urea N (mg/100 mL) were detected for the control, barley, and naked oats diets (averaging 25.28) than for the corn or oats diets (averaging 22.21). Results suggest that horses consuming alfalfa cubes could be supplemented with rolled barley, corn, naked oats, or oats at levels not exceeding 0.2% of BW as TNC without affecting nutrient digestion or overall health negatively.

Invited Review: Prevalence of Shiga Toxin-Producing Escherichia coli in Dairy Cattle and Their Products

The main objective of this review was to assess the role of dairy cattle and their products in human infections with Shiga toxin-producing Escherichia coli (STEC). A large number of STEC strains (e.g., members of the serogroups O26, O91, O103, O111, O118, O145, and O166) have caused major outbreaks and sporadic cases of human illnesses that have ranged from mild diarrhea to the life-threatening hemolytic uremic syndrome. These illnesses were traced to O157 and non-O157 STEC. In most cases, STEC infection was attributed to consumption of ground beef or dairy products that were contaminated with cattle feces. Thus, dairy cattle are considered reservoirs of STEC and can impose a significant health risk to humans. The global nature of food supply suggests that safety concerns with beef and dairy foods will continue and the challenges facing the dairy industry will increase at the production and processing levels. In this review, published reports on STEC in dairy cattle and their products were evaluated to achieve the following specific objectives: 1) to assemble a database on human infections with STEC from dairy cattle, 2) to assess prevalence of STEC in dairy cattle, and 3) to determine the health risks associated with STEC strains from dairy cattle. The latter objective is critically important, as many dairy STEC isolates are known to be of high virulence. Fecal testing of dairy cattle worldwide showed wide ranges of prevalence rates for O157 (0.2 to 48.8%) and non-O157 STEC (0.4 to 74.0%). Of the 193 STEC serotypes of dairy cattle origin, 24 have been isolated from patients with hemolytic uremic syndrome. Such risks emphasize the importance and the need to develop long-term strategies to assure safety of foods from dairy cattle.

Nutrient digestibilities, microbial populations, and protein catabolites as affected by fructan supplementation of dog diets

Fructans are fermentable carbohydrates and include short-chain fructooligosaccharides (scFOS), inulin, and hydrolyzed inulin (oligofructose, OF). Two studies with dogs were designed to examine the effects of low concentrations of fructans on nutrient digestibilities, fecal microbial populations, and endproducts of protein fermentation, and fecal characteristics. In Exp. 1, 11 adult male beagles were fed corn-based, kibbled diets supplemented with or without OF to provide 1.9 +/- 0.6 g/d. Dietary inclusion of OF decreased (P < 0.05) nutrient digestibilities, but did not affect fecal characteristics. Increasing OF concentration tended (P < 0.06) to linearly decrease fecal ammonia concentrations, but not those of branched-chain fatty acids (BCFA), amines, indole, or phenols. Fecal concentrations of total short-chain fatty acids (SCFA) and butyrate tended to be higher in OF-supplemented dogs (P < 0.10), as was the ratio of bifidobacteria to total anaerobes (P = 0.15). In Exp. 2, ileally cannulated adult female hounds were fed a meat-based kibbled diet and were assigned to four scFOS treatments (0, 1, 2, or 3 g/d) in a 4 x 4 Latin square design. Ileal nutrient digestibilities tended to increase (P < 0.15) with increasing concentrations of scFOS. On a DMI basis, fecal output tended to decrease linearly (P < 0.10) in response to increasing scFOS supplementation, whereas fecal score tended to exhibit a quadratic response (P = 0.12). In general, fecal concentrations of SCFA, BCFA, ammonia, phenols, and indoles were not altered by supplemental scFOS. Supplementation of scFOS increased fecal concentrations of total aerobes (P < 0.05) and decreased concentrations of Clostridium perfringens (P < 0.05). From these data, it seems that low levels of supplemental fructans have divergent effects on nutrient digestibility and fermentative endproducts, but do not adversely affect nutrient digestibility or fecal characteristics and may improve colonic microbial ecology in dogs.

Carbohydrate fermentation and nitrogen metabolism of a finishing beef diet by ruminal microbes in continuous cultures as affected by ethoxyquin and(or) supplementation of monensin and tylosin

Long-term feedlot studies have shown positive effects (i.e., improved ADG and reduced morbidity and mortality) of dietary supplementation with ethoxyquin (AGRADO). This may be due to improving the antioxidant capacity at the ruminal, postruminal, or postabsorption levels. This study was designed to investigate the role of ethoxyquin at the rumen level. A finishing diet (12.5% CP; DM basis) was formulated to contain (on a DM basis) 77.5% flaked corn, 10% corn cobs, 10% protein/vitamin/mineral supplement, and 2.5% tallow. In a randomized complete block design experiment, the treatments were arranged as a 2 x 2 factorial. The main factors were two ethoxyquin treatments (without or with 150 ppm) and two monensin/tylosin treatments (without or with monensin and tylosin at 0.0028 and 0.0014% of dietary DM, respectively). Eight dual-flow, continuous culture fermenters were used in two experimental periods (blocks; 8 d each with 5 d for adjustment and 3 d for sample collection) to allow for four replications for each treatment. No interactions (P > 0.05) were detected for any of the measurements evaluated. Therefore, results of the main factors were summarized. Ethoxyquin supplementation improved (P < 0.05) true digestibility of OM (from 38.8 to 45.0%) but it did not alter (P > 0.05) concentrations of total VFA (averaging 131 mM) or acetate (averaging 58.8 mM). Ethoxyquin decreased (P < 0.05) propionate concentration from 51.1 to 42.4 mM and increased (P < 0.05) butyrate concentration from 18.4 to 22.9 mM. Digestion of total nonstructural carbohydrates was not altered (P > 0.05) by the treatments and averaged 86%. With the exception of increased (P < 0.05) concentration of propionate (from 42.0 to 51.5 mM) and decreased (P < 0.05) concentration of butyrate (from 25.9 to 16.3 mM), no effects (P > 0.05) were detected for monensin/tylosin. Ruminal N metabolism, including efficiency of bacterial protein synthesis (averaging 21.2 g N/kg OM truly digested), was not affected (P > 0.05) by the treatments. Results suggest positive effects of ethoxyquin on ruminal digestion of OM and unique changes in VFA production.

Toxicity, metabolism, and impact of mycotoxins on humans and animals

The worldwide contamination of foods and feeds with mycotoxins is a significant problem. Mycotoxins are secondary metabolites of molds that have adverse effects on humans, animals, and crops that result in illnesses and economic losses. Aflatoxins, ochratoxins, trichothecenes, zearelenone, fumonisins, tremorgenic toxins, and ergot alkaloids are the mycotoxins of greatest agro-economic importance. Some molds are capable of producing more than one mycotoxin and some mycotoxins are produced by more than one fungal species. Often more than one mycotoxin is found on a contaminated substrate. Factors influencing the presence of mycotoxins in foods or feeds include environmental conditions related to storage that can be controlled. Other extrinsic factors such as climate or intrinsic factors such as fungal strain specificity, strain variation, and instability of toxigenic properties are more difficult to control. Mycotoxins have various acute and chronic effects on humans and animals (especially monogastrics) depending on species and susceptibility of an animal within a species. Ruminants have, however, generally been more resistant to the adverse effects of mycotoxins. This is because the rumen microbiota is capable of degrading mycotoxins. The economic impact of mycotoxins include loss of human and animal life, increased health care and veterinary care costs, reduced livestock production, disposal of contaminated foods and feeds, and investment in research and applications to reduce severity of the mycotoxin problem. Although efforts have continued internationally to set guidelines to control mycotoxins, practical measures have not been adequately implemented.

Shiga toxin-producing Escherichia coli in beef heifers grazing an irrigated pasture

Shiga toxin-producing Escherichia coli (STEC) produce toxins that have been associated with several human illnesses. E. coli O157:H7 is the most well-studied STEC and was first associated with consumption of improperly cooked ground beef in 1982. E. coli O157:H7 is not the only foodborne STEC because other STEC serotypes are also associated with human illnesses. The objective of this study was to assess prevalence of STEC in 23 yearling beef (Angus) heifers grazing an irrigated grass pasture in spring (April), summer (July), fall (October), and winter (December) of 1999. A total of 86 fecal samples were rectally collected and were subjected to microbiological testing for the presence of STEC. Nine E. coli isolates from five heifers (one in spring and fall and three in winter) were toxic to Vero cells. Of these isolates, four were E. coli O157:H7, two belonged to the serogroup O6, one O39:NM, one O113:H-, and the final isolate was untypable. The STEC prevalence rate in our herd ranged from 4% (spring) to 15% (winter). Based on detecting both O157:H7 and non-O157:H7 STEC in our heifers, it is clear that screening fecal samples should not be limited to E. coli O157:H7. Identification of STEC-positive cattle prior to slaughter should help in reducing the risk of beef contamination with such foodborne pathogens if pre- and/or postharvest control measures are applied to such animals.

Occurrence of verotoxin-producing Escherichia coli in dairy heifers grazing an irrigated pasture

Verotoxin-producing Escherichia coli (VTEC) produce one or two toxins known as VT1 and VT2. These toxins have been associated with several human illnesses. Dairy cattle harboring VTEC represent a potential health hazard because they enter the food chain as ground beef. The objective of this study was to assess the occurrence of VTEC in dairy heifers. A total of 91 fecal samples were rectally collected during four periods (spring, summer, fall, and winter of 1999) from 23 heifers. A random sample (n=530) of potential VTEC isolates were tested for verotoxicity and were screened by the polymerase chain reaction (PCR) for presence or absence of VT1 and/or VT2 genes. Thirteen isolates from two heifers (from the winter collection) were verotoxic and were confirmed as E. coli. VTEC were only detected during winter with an occurrence rate of 9.5%. Using PCR, five isolates had the VT1 gene while the remaining eight had the VT2 gene. The sequence and expression of VT1 and VT2 genes were confirmed. No E. coli O157:H7 was detected, but serotyping revealed that the five VT1-positive isolates were O26:NM (a non-motile strain of O26). The remaining eight isolates were untypeable. Identification of VTEC-positive cattle before slaughter is a critical step in any on-farm strategy to minimize the risk of beef contamination with such pathogens.

Sarcocystis infections in gazelles at the King Khalid Wildlife Research Centre, Saudi Arabia

The prevalence of Sarcocystis species in muscle samples from gazelles kept as breeding groups at the King Khalid Wildlife Research Centre, Saudi Arabia, was determined by fibreoptic examination, pepsin digestion and histological techniques. No macroscopic sarcocysts were detected by fibreoptic examination, and the overall prevalence of Sarcocystis was 66 x 7 per cent by pepsin digestion, and 39 x 9 per cent by histological examination. By digestion, the tongue contained the highest density of bradyzoites in Gazella dorcas, and Gazella gazella erlangeri, the oesophagus in Gazella subgutturosa marica and skeletal muscle in Gazella gazella and Gazella thomsoni. Skeletal muscle was least affected in G dorcas, the oesophagus in G gazella, and the diaphragm in G g erlangeri, G s marica and G thomsoni. By histology, the heart contained most microcysts, except in G g erlangeri, in which the tongue was most affected. No single tissue type was therefore suitable for the diagnosis of sarcocystosis in this multispecies collection, although digestion was more sensitive in detecting infection than histology. The level of Sarcocystis infection was significantly higher in free-ranging gazelles kept in a main enclosure than in gazellas kept in breeding pens, and higher in adult gazelles than in juveniles.

Effects of a return chewing gum/packaging material mixture on in situ disappearance and on feed intake, nutrient digestibility, and ruminal characteristics of growing steers

In situ and in vivo digestibility experiments were conducted to determine the acceptability, digestibility, and safety of a return chewing gum/packaging (G/P) material mixture when fed to steers. In the in situ experiment, both ruminal and intestinal disappearances were measured. Two ruminally and duodenally cannulated steers, which were given free access to alfalfa hay (AH), were used in this study. Duplicate Dacron bags containing the G/P were incubated in the rumen for 0, 3, 6, 12, 24, and 48 h. After ruminal incubation, the 12-, 24-, and 48-h bags were placed in the duodenum and collected in the feces to determine intestinal disappearance. In situ ruminal DM disappearance was greater than 70% for all substrates tested at 0 h, indicating high solubility of the substrates in water, and began to reach a plateau after 12 h of incubation. Intestinal in situ disappearance was not different (P>.25) from zero. In the digestion trial, four ruminally cannulated steers (337+/-21.3 kg BW; mean +/- SD) were used in a 4x4 Latin square design with the following treatments: 0) 50% corn (C), 50% AH; 10) 45% C, 45% AH, 10% G/P; 20) 40% C, 40% AH, 20% G/P; 30) 35% C, 35% AH, 30% G/P. Steers fed G/P-containing diets had greater (P<.01) DMI than the control steers. Increasing the G/P resulted in a linear (P<.05) increase in DMI. Apparent DM digestibility tended to be higher (P<.10) for the G/P-containing diets than for the control. A quadratic effect (P<.05) on digestible DMI was observed, with greater (P<.01) digestible DMI values for G/P-containing diets (4.8 vs. 5.8 kg/d). Digestible organic matter and total nonstructural carbohydrate intakes followed trends similar to those of DM. Apparent aluminum digestibility of G/P-containing diets was not different (P>.13) from zero. The level of G/P in the diet had no effect (P>.2) on total VFA concentration or ruminal pH. There was a linear decrease (P<.01) in the molar percentage of isobutyrate and isovalerate in addition to a linear increase (P<.01) in butyrate and valerate with increasing levels of G/P. There was a quadratic effect (P<.01) on molar proportions of acetate and propionate and on the acetate:propionate ratio. Results of both experiments suggest that G/P may be fed to safely replace up to 30% of corn-alfalfa hay diets for growing steers with advantages in improving DMI and digestibility.

Petfood applications of inulin and oligofructose

Published data on intestinal microbiota of dogs and cats are limited but suggest the presence of a complex and diverse colonic bacterial population (34 genera including 129 species) the majority of which are anaerobes. During the colonic fermentation of endogenous and undigested amino acids, several putrefactive compounds (i.e., ammonia, aliphatic amines, indoles, phenols and volatile sulfur-containing compounds) are produced and are responsible for the malodor of dog and cat feces. These fecal odor components also have been implicated as causes of colorectal cancer; therefore, dietary manipulation of gut microbiota towards a potentially more remedial community (Bifidobacterium and Lactobacillus) is gaining more attention. The health benefits derived from dietary supplementation of prebiotics (e.g., oligofructose and inulin) have been documented in humans. However, little is known of a potentially similar role in companion animals. Feeding another prebiotic (i.e., lactosucrose) to dogs or cats is reported to increase the numbers of bifidobacteria and decrease the numbers of pathogens and the concentration of fecal odor components. In our laboratory, oligofructose supplementation numerically decreased the concentrations of ammonia and amines and increased the numbers of bifidobacteria in dog feces.

Soybean hulls as a dietary fiber source for dogs

In Exp. 1, soybean hull samples were obtained from nine sources across the United States and analyzed for nutrient content to determine their suitability for inclusion in dog diets. Compositional data revealed variation in both the amount of total dietary fiber (TDF; 63.8 to 81.2%) in the soybean hulls and the ratio of insoluble:soluble fiber (5.0:1 to 15.4:1). Crude protein content varied widely among sources, ranging from 9.2 to 18.7%. An in vivo trial (Exp. 2) was conducted using a premium dog diet containing 3.0, 4.5, 6.0, 7.5, or 9.0% soybean hulls (DM basis). There was a negative linear effect (P < .05) of soybean hull inclusion in the diet on DM, OM, TDF, and GE total-tract digestibilities, as well as on calculated ME. Crude protein and fat digestibilities were unaffected by treatment. Based on these results, ileally cannulated dogs were fed diets containing 6.0, 7.5, or 9.0% soybean hulls (DM basis) in addition to diets containing either 0% supplemental fiber or 7.5% beet pulp (Exp. 3). Nutrient digestion at the ileum was unaffected by inclusion of supplemental fiber. Total tract digestion of DM, OM, and GE was lower ( P < .05) for diets containing supplemental fiber when compared with the diet containing 0% fiber. Crude protein and fat digestibilities were unaffected by treatment. There was no difference in nutrient digestibility between those diets containing soybean hulls and a diet containing beet pulp. Soybean hull inclusion in the diet resulted in a negative linear effect (P < .05) on calculated ME, in addition to lowering ME (P < .05) when compared with the 0% fiber control diet. Calculated ME for dogs fed a 7.5% beet pulp-containing diet was lower (P < .05) than that for dogs fed the soybean hull-containing diets. Results indicate that soybean hulls can be an effective dietary fiber source in dog diets.

Assessment of postruminal amino acid digestibility of roasted and extruded whole soybeans with the precision-fed rooster assay

The objectives of these studies were to predict the effects of roasting and extrusion temperatures of whole soybeans (SB) on intestinal protein digestibility in cattle. Intestinal digestibility was assessed with a two-stage in vitro or in situ ruminal incubation/precision-fed cecectomized rooster bioassay. In Exp. 1, whole SB (raw SB or SB roasted to 141, 149, or 157 degrees C exit temperature from a commercial roaster and steeped for 30 min) were incubated in strained ruminal fluid and McDougall's buffer (50:50) at 39 degrees C for 16 h. In Exp. 2, SB (ground raw SB or SB extruded at 116, 138, or 160 degrees C) were placed in polyester bags (20 x 30 cm) and suspended in the ventral rumen of steers for 16 h. Lyophilized residue of the in vitro or in situ incubations and samples of raw SB and most extensively heated SB (roasted SB at 157 degrees C or extruded SB at 160 degrees C) for each respective experiment were crop-intubated to cecectomized roosters. Total excreta were collected for 48 h after intubation and lyophilized, and amino acid (AA) concentrations were determined. In Exp. 1, total AA digestibility was 61.6 and 84.5% for unincubated whole raw SB and 157 degrees C roasted SB, respectively, and 66.2, 88.9, 91.3, and 91.6% for in vitro residues of whole raw SB and SB roasted at 141, 149, and 157 degrees C, respectively. Trypsin inhibitor (TI) activity was 20.09, 1.69, 1.54, and 1.84 mg/g fat-free DM for unincubated whole raw SB and 141, 149, and 157 degrees C roasted SB, respectively, and 30.84, 1.01, .90, and .26 mg/g fat-free DM for in vitro residues of whole raw SB, 141, 149, and 157 degrees C roasted SB, respectively. In Exp. 2, total AA digestibility was 68.5 and 87.7% for unincubated ground raw SB and 160 degrees C extruded SB, respectively, and 81.9, 91.3, 89.7, and 89.4% for in situ residues of ground raw SB and 116, 138, and 160 degrees C extruded SB, respectively. Trypsin inhibitor activity was 17.61, 4.89, 4.08, and 1.56 mg/g fat-free DM for unincubated ground raw SB, 116, 138, and 160 degrees C extruded SB, respectively, and 3.62, .59, .55, and .21 mg/g fat-free DM for incubated ground raw SB, 116, 138, and 160 degrees C extruded SB, respectively. Heat treatment by roasting and extrusion improved AA digestibilities of SB, but there were no differences detected among the roasting or extrusion temperatures. Ruminal fermentation did not eliminate the negative effects of TI activity on intestinal digestibility of AA in whole SB but did reduce TI activity in ground SB.

Spent cellulose casings as potential feed ingredients for ruminants

Cellulose casings are used to contain and form meat and poultry emulsions during the smoking and cooking process. Casings then are stripped from the cooked product and traditionally disposed of in landfills. Because of the bulk of the spent cellulose casings (SCC), rapid composting technology may be used to reduce bulkiness. The following SCC were evaluated in vitro and in vivo: fibrous ground (FG), fibrous composted (FC), NOJAX ground (NG), and NOJAX composted (NC). In vitro digestibility was determined by incubating SCC with mixed ruminal bacteria for 0, 6, 12, 24, 36, 48, and 72 h. In vivo data were collected using four ruminally cannulated Holstein steers in a 4 x 4 Latin square design. Diets consisted of a 50:50 ratio of alfalfa hay-wheat middlings with 5% cornsteep liquor. Diets contained no SCC (CON) or 25% (DM basis) of the FC, FG, or NC SCC substrate. Casings were high in structural carbohydrate and salt content but low in CP, ether extract, and lignin concentrations. In vitro OM digestibility at 24 h was highest (P < .05) for FC and lowest (P < .05) for NG; FG and NC were intermediate. Composting tended to reduce fiber content and increase digestion. In vivo intakes and digestibilities were not adversely affected by inclusion of SCC in the diet. Thus, SCC have the ability to partially replace more traditional forages, such as alfalfa hay and wheat middlings, in high-fiber diets for growing beef cattle. Limitations in the use of SCC as a partial replacement of traditional feedstuffs will likely be because of high salt concentrations in the casings resulting from product brine chilling.

Effects of forage percentage and canola seed on ruminal protein metabolism and duodenal flows of amino acids in steers

The objective was to determine the effects of dietary forage percentage and fat supplementation on ruminal N metabolism, duodenal flows of AA, and digestion of N. Six ruminally and duodenally cannulated steers were offered six isonitrogenous diets for ad libitum intake twice daily in a 6 x 6 Latin square design. Treatments were arranged as a 2 x 3 factorial with two forage percentages (70 vs. 30% of dietary DM as corn silage) and three forms of canola seed supplementation, including no canola seed or canola seed added at 10% of dietary DM as whole seed treated with alkaline H2O2 or as crushed seed. No interactions between dietary forage percentage and canola seed supplementation occurred for any of the measurements. Duodenal flows of NAN and AA were greater for diets containing low forage than for diets containing high forage. However, duodenal flows of total N and NAN did not differ among diets when corrected for differences in intake. Efficiency of bacterial protein synthesis and duodenal flows of bacterial N and AA were increased when treated whole canola seed was supplemented. Apparent total tract digestibility of N was not altered by dietary forage percentage or canola seed supplementation. Results indicate that fat supplementation from canola seed (at 5% of dietary DM), in either form, had no effects on ruminal N metabolism or flows of AA to the duodenum and suggest that treated whole canola seed may stimulate ruminal bacterial protein synthesis.

Effects of chemical treatment of whole canola seed on digestion of long-chain fatty acids by steers fed high or low forage diets

The objective was to evaluate the effectiveness of alkaline H2O2 treatment of whole canola seed as a means of weakening the seed coat while simultaneously protecting long-chain unsaturated fatty acids from ruminal biohydrogenation without hindering their digestion in the lower gut. Six ruminally and duodenally cannulated beef steers were offered six isonitrogenous diets for ad libitum intake twice daily in a 6 x 6 Latin square design. Treatments were arranged as a 2 x 3 factorial with two forage percentages (70 vs. 30% of dietary DM as corn silage) and three forms of canola seed supplementation, including no canola seed or canola seed added at 10% of dietary DM as treated whole seed or as crushed seed. Canola seed contributed 5% added fat to the total diet. Treated whole canola seed was superior to crushed seed in increasing the amounts of C18:1, C18:2, and C18:3 flowing to the duodenum and the amounts digested postruminally. However, digestibilities of these long-chain fatty acids (as percentages of the amounts entering the small intestine) did not differ between diets containing canola seed as treated whole seed or crushed seed. Results suggest that chemically treated whole canola seed can be used as a means of postruminal delivery of digestible long-chain unsaturated fatty acids, especially C18:1, which contributes 62% of the total fatty acids in canola seed. Results also suggest that treated whole canola seed may be more beneficial when fed with low than with high forage diets.

Feedlot performance and carcass characteristics of Holstein steers as affected by source of dietary protein and level of ruminally protected lysine and methionine

The objective of this study was to determine the effects of source of dietary CP and level of ruminally protected lysine and methionine (RPLM) on feedlot performance and carcass characteristics of Holstein steers during a growing-finishing trial (266 d). A total of 168 Holstein steers (182.7 +/- 27.5 kg) were used in a completely randomized design experiment (eight treatments; three pens of seven steers/treatment). Steers were given ad libitum access to high-concentrate diets (13% CP) containing 71% whole shelled corn, 10% corn silage, 4% condensed distillers solubles, and 15% protein supplements (DM basis). Treatments were arranged as a 2 x 4 factorial. The main factors were two sources of dietary CP and four levels of RPLM. The sources of dietary CP were soybean meal (SBM) or SBM and urea (SBM-U). Urea-N replaced 50% of SBM-N in the SBM-U diet. The levels of RPLM were 0, 5, 10, and 15 g per steer daily. No interactions (P > .10) between source of dietary CP and level of RPLM were observed for feedlot performance or carcass characteristics. Feedlot performance showed an advantage (P < .10) to feeding SMB during the first 84 d of the trial and an advantage to feeding SBM-U during the last 98 d of the trial. However, feedlot performance for the whole trial and carcass characteristics (except for fat thickness) were not affected (P > .10) by the source of dietary CP. Steers fed diets containing SBM-U had 12% less (P < .10) fat thickness than those fed diets containing SBM. Supplementation of diets with increasing levels of RPLM did not affect (P > .10) ADG or carcass characteristics. However, DMI and gain:feed showed cubic (P < .10) responses to increasing dietary level of RPLM. Supplementation of RPLM at the 10 g/d level improved gain:feed by 12% during the last 98 d of the trial, and this was a direct response to the cubic effects of RPLM on DMI. Results suggest a cost advantage for replacing 50% of SBM-N with that from urea in high-corn diets without negative effects on feedlot performance or carcass characteristics of growing-finishing Holstein steers with extended feeding periods (266 d). These types of diets seem to meet the amino acid requirements and are not limiting in lysine and methionine.

In vitro fermentation of cellulose, beet pulp, citrus pulp, and citrus pectin using fecal inoculum from cats, dogs, horses, humans, and pigs and ruminal fluid from cattle

We evaluated the influence of gastrointestinal tract microflora from several species on fiber fermentation characteristics in vitro. Selected fibrous substrates (cellulose, beet pulp, citrus pulp, and citrus pectin) were incubated for 6, 12, 24, and 48 h with ruminal fluid from cattle or feces from dogs, cats, pigs, horses, or humans. When data were pooled across all substrates and fermentation times, OM disappearance (29.4%) and acetate, propionate, butyrate, and total short-chain fatty acid (SCFA) production (1.09, .41, .12, and 1.61 mmol/g of OM, respectively) were lowest (P < .05), and lactate production (.23 mmol/g of OM) was greatest (P < .05) for horse fecal microflora compared with samples from the other species. The greatest (P < .05) acetate production resulted when substrates were fermented by cat fecal microflora (2.38 mmol/g of OM). The greatest (P < .05) propionate productions resulted from pig fecal and cattle ruminal microflora (.88 and .83 mmol/g of OM, respectively), and the greatest (P < .05) butyrate productions resulted from human and pig fecal microflora (.39 and .40 mmol/g of OM, respectively). Total SCFA production was greatest (P < .05) for cat fecal microflora (3.38 mmol/g of OM). When data were pooled across the species, substrate OM disappearance and SCFA production ranked from least to greatest in the following order: cellulose < beet pulp < citrus pulp < citrus pectin. The fermentability of different fibrous substrates by fecal or ruminal microflora from various species seems to be dependent not only on the fermentative activity of the microbial population but on other factors as well, perhaps lag time and rate of digesta passage.

Effects of feed intake and dietary level of wet corn gluten feed on feedlot performance, digestibility of nutrients, and carcass characteristics of growing-finishing beef heifers

The objective was to compare the relative energy value of wet corn gluten feed (WCGF) to that of corn in a feedlot situation when diets were initially offered ad libitum (AL) or at restricted feed intake (RFI; 80% of AL). In a completely randomized block (pen location) design experiment, 144 beef heifers (204.1 +/- 18.2 kg) were used (six treatments; three pens of eight heifers/treatment). Treatments were levels of WCGF (on DM basis) in corn silage-based diets (AL; 25 or 50% WCGF) or high-moisture corn-based diets (RFI; 0, 25, 50, or 75% WCGF) during the growing phase (127 d). During finishing (84 d), all diets were offered AL and contained 5% corn silage by replacing corn silage with high-moisture corn in diets that were offered AL. Heifers that were initially at AL had similar (P > .1) feedlot performance (during growing and during the whole trial), digestibility of nutrients (OM, NDF, CP, and GE), and carcass characteristics. During finishing, however, these heifers had better (P = .06) ADG and gain:feed when 25% WCGF was fed. Heifers that were initially at RFI showed a linear decrease (P < .01) in ADG and gain:feed during growing with increasing dietary level of WCGF. However, increasing dietary level of WCGF resulted in a quadratic (P = .02) response in ADG and gain:feed during finishing and also in a quadratic (P = .07) response in ADG and a linear (P = .005) decrease in gain:feed during the whole trial. These quadratic responses indicated that the best performance was achieved at the 25 and 50% levels of WCGF. The decrease in cumulative gain:feed was only 3.5% at the 25 and 50% levels of WCGF but it was 11.4% at the 75% level. Increasing the level of WCGF in diets of heifers that were initially at restricted feed intake did not affect (P > .1) digestibility of nutrients but it improved some carcass characteristics linearly, decreasing fat thickness (P = .04), liver abscess (P = .02), and yield grade (P = .13). Results suggest that WCGF can substitute up to 25 or 50% of dietary DM without negative effects on feedlot performance, digestibility of nutrients, or carcass characteristics. In addition, restricting feeding during growing may be strategy that improves the utilization of WCGF at these levels.

Effects of forage level and canola seed supplementation on site and extent of digestion of organic matter, carbohydrates, and energy by steers

The objective of this study was to determine the effects of fat supplementation from canola seed (CS) on ruminal fermentation and postruminal digestion of OM, carbohydrates, and energy of diets containing different levels of forage. Six ruminally and duodenally cannulated beef steers (354 kg +/- 18) were given ad libitum access to six isonitrogenous diets that were offered twice daily in a 6 x 6 Latin square design. Treatments were arranged as a 2 x 3 factorial with two forage levels (70 vs 30% of dietary DM as corn silage) and three forms of CS supplementation including no CS or CS added at 10% of dietary DM as whole CS treated with alkaline hydrogen peroxide or untreated crushed CS. Fat from CS provided 5% of dietary DM. The remaining dietary ingredients were corn, canola meal, molasses, and urea. No interactions (P > .05) between dietary forage level and CS supplementation were observed for ruminal characteristics or digestion of OM, carbohydrates, and energy in the rumen, postruminally, or in the total tract. Fat supplementation from CS did not affect (P > .05) DMI. With few exceptions, fat supplementation did not affect (P > .05) ruminal, postruminal, or total tract digestibilities of OM, structural and nonstructural carbohydrates, and GE. Ruminal disappearance of GE was decreased (P < .05) when diets were supplemented with fat from whole treated CS, and total tract digestibilities of OM and GE were decreased (P < .05) when diets were supplemented with fat from CS in either form. Ruminal pH, concentrations of NH3 N and total VFA, and molar proportions of acetate, propionate, and butyrate were not affected (P > .05) by fat supplementation. Results suggest that fat supplementation from CS (at 5% of dietary DM) as whole treated or untreated crushed had no negative effects on ruminal fermentation of OM, carbohydrates, or energy when steers were given ad libitum access to diets containing high or low forage.

Influence of altering ruminal degradation of soybean meal protein on in situ ruminal fiber disappearance of forages and fibrous byproducts

The objective was to determine the effects of altering ruminal CP degradation of soybean meal (SBM) by roasting (Exp. 1) on ruminal characteristics and extents of in situ disappearance of DM, OM, and fiber components (Exp. 2). A control diet (8.2% CP) containing oat hulls, corn silage, starch grits, ammoniated corn cobs, and molasses was supplemented to 17.1% CP with unroasted SBM (SBM-0) or SBM roasted at 165 degrees C for 75, 150, or 210 min (SBM-75, SBM-150, and SBM-210, respectively). In Exp. 1, SBM was incubated for 0, 2, 4, 8, 12, 16, and 24 h in the rumen of two steers that were fed the SBM-0 diet. Extents of ruminal CP degradation and rates of N disappearance decreased (P < .05) linearly with increasing roasting time of SBM. In Exp. 2, five ruminally cannulated steers were used in a 5 x 5 Latin square design and were fed the five diets listed above during five 11-d periods. On d 11, five substrates (alfalfa hay, orchardgrass hay, corn silage, soy hulls, and wheat straw) were incubated in the rumen for 24 h. Extents of in situ disappearance of DM, OM, and fiber (NDF, ADF, cellulose, hemicellulose, and total dietary fiber) were analyzed as a split-plot design. No substrate x diet interaction (P > .05) was observed for any of the measurements evaluated. Extents of in situ disappearance (24 h) of DM, OM, and fiber were highest (P < .05) when the control diet was fed and were lowest (P < .05) when the SBM-0 diet was fed. Decreasing the availability of SBM protein in the diet by roasting increased (P < or = .10) extents of in situ disappearance of DM, OM, and fiber linearly. These extents were similar for steers fed the control diet or the diet containing SBM-210. Ruminal concentrations of NH3 N, branched-chain VFA, and valerate were highest (P < .05) and ruminal pH lowest (P < .05) when the SBM-0 diet was fed. Results indicated a rapid ruminal fermentation of both protein and readily available carbohydrates of SBM (resulting in pH below 6.0) during the first 4.5 h after feeding the SBM-0 diet. Making both protein and readily available carbohydrates of SBM more slowly fermentable by roasting slowed early fermentation processes, maintained higher ruminal pH, and encouraged earlier and faster ruminal fiber digestion.

Composition of ruminal bacteria harvested from steers as influenced by dietary forage level and fat supplementation

The objective of this study was to examine the effects of dietary forage level and fat supplementation on the chemical composition of mixed ruminal bacteria (MRB). Six ruminally cannulated beef steers (354 kg +/- 18) were given ad libitum access to six diets (13.2% CP; DM basis) that were offered twice daily in a 6 x 6 Latin square design. Treatments were arranged as a 2 x 3 factorial with two forage levels (70 vs 30% of dietary DM as corn silage) and three forms of fat supplementation including no canola seed or canola seed added at 10% of dietary DM as whole treated with alkaline hydrogen peroxide or untreated crushed. Canola seed contributed 5% added fat to the total diet. The remaining dietary ingredients were corn, canola meal, molasses, and urea. No interactions (P > .05) between dietary forage level and canola seed supplementation were observed. Concentrations of OM, N, and all amino acids were higher (P < .05) in MRB from steers fed low forage than in MRB from steers fed high forage. Concentrations of purines and GE and the N:purines ratio in MRB were not affected (P > .05) by dietary forage level or canola seed supplementation. Canola seed supplementation did not affect (P > .05) concentrations of OM, N, or most of the amino acids in MRB. Concentrations of four essential amino acids (i.e., isoleucine, leucine, lysine, and phenylalanine) in MRB were decreased (P < .05) due to canola seed supplementation. Dietary forage level did not affect (P > .05) concentrations of long-chain fatty acids in MRB.(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of roasting on site and extent of digestion of soybean meal by sheep: II. Digestion of artifacts of heating

Six mature wethers (BW 72 kg) with ruminal, duodenal, and ileal cannulas were fed a basal (no added soybean meal [SBM]) diet or diets containing unheated SBM or SBM roasted at 165 degrees C for 75, 150, 180 or 210 min in a 6 x 6 Latin square experiment. Concentrations of indicators of heat exposure (NDF, ADF, and ADIN) in SBM increased with increasing roasting time. Organic matter digestion characteristics were not affected (P > .05) by supplementation or roasting of SBM. Daily intakes of NDF, ADF, and ADIN were higher (P < .05) when wethers were fed SBM-containing diets than when they were fed the basal diet and also were higher (P < .05) when wethers were fed diets containing roasted SBM than when fed the diet containing unheated SBM. Roasting time of SBM had a quadratic effect (P < .05) on intakes of NDF, ADF, and ADIN, with the lowest intakes observed for diets containing unheated SBM or SBM roasted for 75 min and the highest intakes observed for diets containing SBM roasted for 180 or 210 min. Disappearance of ADF in the stomach (grams per day) was not affected by supplementation or roasting of SBM. Disappearance of NDF and ADIN in the stomach (grams per day) were higher (P < .05) when wethers were fed SBM-containing diets than when they were fed the basal diet and also were higher (P < .05) when wethers were fed diets containing roasted SBM than when they were fed those containing unheated SBM.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of cobalt on in vitro fiber digestion of forages and by-products containing fiber

Cobalt glucoheptonate as a source of Co to enhance ruminal fiber digestion was evaluated in two in vitro digestibility experiments. In Experiment 1, Co supplementation (0, 5, and 10 ppm) of five substrates (leaf and stem fractions of alfalfa and orchardgrass hays and ground corn) was evaluated under two dietary conditions (ruminal fluid taken from steers fed alfalfa hay or a high concentrate diet) for 24 or 48 h of fermentation in a 3 x 5 x 2 x 2 factorial arrangement. In Experiment 2, four concentrations of Co (0, 10, 20, and 30 ppm) were added to five substrates (alfalfa hay, orchardgrass hay, corn cobs, recycled newsprint treated with HCl, and cellulose casings) and were incubated with ruminal fluid from steers fed alfalfa hay for 24 or 48 h of fermentation in a 4 x 5 x 2 factorial arrangement. No interactions among treatments were observed for digestibilities of DM, OM, or NDF in both experiments or for VFA concentrations in Experiment 1. Supplementation with Co did not increase digestibilities of DM, OM, or NDF in either experiment or concentrations of VFA in Experiment 1. In Experiment 1, in vitro digestibilities of DM, OM, and NDF were higher for inoculum from steers fed alfalfa versus concentrate. In Experiment 2, digestibilities of DM, OM, and NDF were highest for alfalfa hay and lowest for recycled newsprint treated with HCl. Cobalt concentrations that were above minimum requirements did not improve digestion of DM, OM, or fiber.

Antibody prevalence of toxoplasmosis in Arabian gazelles and oryx in Saudi Arabia

We determined the antibody prevalence of toxoplasmosis (Toxoplasma gondii infections) in antelopes in Saudi Arabia. Serum samples from 324 Gazella subgutturosa marica, 202 Gazella gazella, 70 Gazella dorcas, and 12 Arabian oryx (Oryx leucoryx) were tested by the indirect hemagglutination test. Antibodies to T. gondii were detected in 13(4.0%) G. subgutturosa marica, 12(5.9%) G. gazella, 3(4.3%) G. dorcas, and in none of the Arabian oryx sampled. More adult gazelles were seropositive than juveniles; males and females were similar. The highest reciprocal antibody titer recorded (262,144) was in a G. subgutturosa marica serum.

Influence of dietary protein and carbohydrate sources on nitrogen metabolism and carbohydrate fermentation by ruminal microbes in continuous culture

Four diets containing 15% CP were formulated to study the effects of dietary carbohydrate and protein sources on N metabolism and carbohydrate fermentation by ruminal bacteria. Diets were supplied to eight dual-flow continuous culture fermenters during three experimental periods in a randomized complete block design. Six replications were obtained for each diet. Treatments were arranged as a 2 X 2 factorial with two carbohydrate and two protein sources. Carbohydrate sources were corn and barley and protein sources were soybean meal (SBM) and fish meal (FM). Approximately 40% of the dietary CP was derived from SBM or FM and corn or barley provided 39% of dietary DM. All diets contained 15% grass hay, 20% wheat straw, and 10.1 to 15.3% solka floc (DM basis). Interactions (P less than .05) were observed between dietary carbohydrate and protein sources, resulting in a depression of VFA production (moles/day) and digestion (percentage) of ADF and cellulose when the corn-FM diet was fed. True OM digestion (percentage) was higher (P less than .05) for SBM than for FM diets and for corn than for barley diets. Although dietary CP degradation (percentage) was higher (P less than .05) for SBM than for FM diets, non-NH3 N in the effluent (grams/day) was not different among diets due to a greater (P less than .05) bacterial N flow for SBM than for FM diets. Despite the lower amino acid (AA) intake (P less than .05) for corn than for barley diets and also for FM than for SBM diets, flows (grams/day) of total AA, essential AA (EAA), and nonessential AA (NEAA) were similar (P greater than .05) among diets. However, greater (P less than .05) total AA, EAA, and NEAA flows (percentage of AA intake) were found for corn than for barley diets and for FM than for SBM diets. It is concluded, therefore, that ruminal escape protein derived from corn or FM has a significant effect on manipulating AA leaving the ruminal fermentation.

Fish meal as a protein supplement in ruminant diets: a review

Fish meal (FM) as a protein supplement in ruminant diets is presented to illustrate production responses to FM supplementation and to explain the possible factors that may affect the magnitude of these responses. Positive responses are consistently detected when FM is fed to nonruminants, but the responses when fed to ruminants have lacked consistency. Research indicates that ruminal protein degradation of FM is affected by processing factors including type and freshness of fish, addition of preservatives, stabilization of fat, type of dryer used, temperature and duration of heating, and the amount of fish solubles added back to the meal. Performance data published in the last two decades have been categorized into body weight gain and milk yield and composition. Fish meal was more effective in improving body weight gain in young than in finishing ruminants and in males than in females or castrated males. Daily gains and feed efficiencies were higher when FM supplemented medium- or poor-quality silages than when it was added to high-quality silages. No significant advantage was found for replacing protein sources that were highly ruminally degradable with FM in high-corn diets fed to growing ruminants. Milk yield and milk protein concentration were improved by FM supplementation of low-concentrate diets fed to cows in early lactation. However, milk fat percentage was negatively affected by FM supplementation. Reproduction data indicated that body gain and conception rates of high-producing cows were improved by supplementing their diets with FM during early lactation. Results suggest a significant advantage of FM supplementation to ruminant diets if the physiological status of the animal and the quality of the dietary ingredients are taken into account.

Ruminal protein metabolism and intestinal amino acid utilization as affected by dietary protein and carbohydrate sources in sheep

Eight wether lambs fitted with ruminal, duodenal, and ileal cannulas were used in a replicated 4 x 4 Latin square design to study the effects of carbohydrate and protein sources on ruminal protein metabolism and carbohydrate fermentation and intestinal amino acid (AA) absorption. Treatments were arranged as a 2 x 2 factorial. Carbohydrate sources were corn and barley; protein sources were soybean meal (SBM) and fish meal (FM). Diets contained 15.5% CP, of which 40% was supplied by SBM or FM. Corn or barley provided 39% of dietary DM that contained equal amounts of grass hay and wheat straw. Fish meal diets produced a lower (P less than .05) ruminal NH3 concentration and resulted in less CP degradation and bacterial protein flow to the duodenum than did SBM diets. Replacing SBM with FM increased (P less than .05) ruminal digestion of all fiber fractions. In addition, cellulose and hemicellulose digestibilities in the rumen tended to increase (P greater than .05) when barley replaced corn in the FM diets. Carbohydrate x protein interactions (P less than .05) were observed for OM digestion in the rumen and AA absorption in the small intestine (percentage of AA entering); these interactions were highest for the barley-FM diet. These results suggest that feeding FM with barley, which is high in both degradable carbohydrate and protein, might benefit ruminants more than feeding FM with corn, which is high in degradable carbohydrate but relatively low in degradable protein.

Fish meal as a protein supplement in finishing lamb diets

An in situ protein degradation trial and two growth trials were conducted to evaluate the use of fish meal (FM) as a protein supplement in feeder lamb diets. Finn cross and Hampshire lambs were given ad libitum access to corn diets, minerals, and water. In Growth Trial 1, four isonitrogenous (12.6% CP on a DM basis) and isocaloric (77% TDN) diets were supplemented with the following: a) 100% soybean meal (SBM); b) 70% SBM + 30% FM; c) 40% SBM + 60% FM; and d) 100% FM on a DM basis. Diets were fed to 144 lambs for 56 d in a randomized complete block (initial BW) design. In Growth Trial 2, four diets were fed to 80 lambs for 42 d in a completely randomized design with treatments arranged as a 2 x 2 factorial. Main effects in Growth Trial 2 were dietary CP level (13.3 or 14.9%) and source (SBM or SBM + FM). Alfalfa hay was used as the roughage part of each diet. In situ CP degradation (determined in cattle) of SBM, FM, and corn fed in both growth trials were 77.8, 52.3, and 56.8%, respectively. In neither growth trial was ADG affected (P greater than .05) by dietary CP source. Lambs gained faster (P less than .05) when the CP level was increased from 13.3 to 14.9% in Growth Trial 2. In both trials, protein efficiency ratio (grams of gain/grams of protein intake) and energy efficiency ratio (grams of gain/kilograms of TDN intake) were not different (P greater than .05) among diets. Because of the low ruminal degradation of corn protein, the relative value of SBM and FM in full-fed, high-corn diets was comparable.

Onchocerca raillieti: release from skin snips, maintenance in vitro and periodicity of microfilariae

Several media were tested for the release of Onchocerca raillieti microfilariae from skin snips and for their subsequent in vitro maintenance. Tyrode's solution containing 20% equine serum and antibiotics was the best medium tested, followed by phosphate buffered saline. Tyrode's solution alone or distilled water were poor media. A temperature 7-12 degrees C lower than the host's body temperature favoured release of the microfilariae from skin snips. The microfilariae were best maintained at 4-10 degrees C, when they remained alive for up to 5 days. O. raillieti microfilariae had an evening periodicity which could be related to a possible vector's peak of feeding activity.

Onchocerca armillata Railliet and Henry, 1909 and Onchocerca gutturosa (Neumann, 1910) in camels (Camelus dromedarius L.) in the Sudan

A study undertaken to determine the Onchocerca species infecting camels that live in the same localities as cattle in the Dinder Region, Blue Nile Province, Sudan revealed concurrent infections with the bovine parasites Onchocerca armillata in the thoracic aorta, brachiocephalic trunks and brachial arteries and Onchocerca gutturosa in the ventral side of the lamellar parts of the ligamentum nuchae. The microfilariae of both species had the same predilection sites in the skin of the ears, head and neck regions. Those of O. gutturosa outnumber those of O. armillata but both are smaller than the respective uterine microfilariae. Males and microfilariae of both species are smaller than those of cattle origin.

The ant, Pachycondyla sennaarensis (Mayr) as an intermediate host for the poultry cestode, Raillietina tetragona (Molin)

The role of several species of ants as intermediate hosts for poultry cestodes in the Sudan was investigated by a search for cysticercoids in specimens from poultry houses in various localities in the country. Pachycondyla sennaarensis, Messor galla and Acantholepis sp. were the only species collected from the areas surveyed. All these ants were examined for cysticercoids of poultry tapeworms but only P. sennaarensis was found to carry cysticercoids, all of which were identical to those of the poultry cestode, Raillietina tetragona. This tapeworm was recovered from all chicks fed the cysticercoids obtained from P. sennaarensis. R. tetragona cysticercoids were present in 63.3% of the P. sennaarensis sampled with 1-40 cysticercoids per ant, which is the heaviest recorded infestation of an ant species with these cysticeroids.

The prevalence and pathology of Eimeria infections in camels in Saudi Arabia

Three-hundred and eighty five Saudi Arabian camels were surveyed for Eimeria infections and the pathology investigated. Eimeria dromedarii, E. rajasthani and E. cameli were detected, E. dromedarii being the most prevalent and E. cameli the least. Infections were more prevalent along the humid coastal areas than in the arid interior. All three parasites are pathogenic to young camel calves causing enteritis due to the destruction of intestinal mucosa by their giant schizonts. Older camels are oocyst-shedding carriers without clinical signs. Both schizogonic and sexual cycles of the three parasites occur in the jejunum and ileum of camels.

Onchocerca raillieti: prevalence and pathology in Sudanese donkeys

Onchocerca raillieti was found to be prevalent in Sudanese donkeys. The parasite was reported from Central, Northern, Western and Eastern Sudan and was most predominant in the last locality. The pathological changes produced by adult worms in the ligamentum nuchae are mostly chronic and do not seem to cause any clinical manifestations. Likewise, the microfilariae, though found in high densities in the skin with a "spill over" into the eyes, produce no pathological changes in either the skin or eyes.

Haemonchus longistipes Railliet & Henry, 1909 in goats in the Sudan

Haemonchus longistipes specimens were collected from experimentally infected Sudanese goats and camels for morphological studies. The specimens from goats were much smaller than those from camels, but their infectivity to camels was not affected by their passage in goats. Goats inhabiting the same areas as camels in the Sudan were found to be naturally infected with H. longistipes, but sheep were not and were resistant to experimental infection.

Coccidia in camels (Camelus dromedarius) in Saudi Arabia

Saudi Arabian camels (Camelus dromedarius) are infected with three species of Eimeria: E. dromedarii (28.4%), E. rajasthani (22.2%), and E. cameli (19.2%); 41.6% of the animals examined were positive. The highest prevalence of infection was reported in the western region of the country. Mixed infection with two Eimeria species is most common; E. dromedarii was most frequently and generally the most predominant species. Eimeria dromedarii and E. rajasthani are described for the first time from Saudi Arabian camels.

Onchocerca armillata: prevalence and pathology in Sudanese cattle

Cattle of various ages from Khartoum Province and western Sudan were surveyed for Onchocerca armillata infection by skin snip examination and some also at post-mortem examination. The former method reliably detected infection in cattle aged between nine months and eight years. Several of the older infected animals had no microfilariae in their skin. Prevalence rate and number of microfilariae per gram of skin were higher in male than in female cattle and in animals from western Sudan than those from Khartoum province. Severe pathological changes were seen in the thoracic aorta, brachiocephalic, costocervical and brachial arteries and posteriorly in the abdominal aorta to its bifurcation into the iliac arteries.

The prevalence and pathogenesis of naturally-occurring Haemonchus longistipes infection in Sudanese camels

Camel haemonchosis is prevalent in the Sudan, especially during the rainy season, with a decrease in prevalence in the dry season possibly due to delayed maturation of the worms. The naturally occurring disease in Sudanese camels is characterized by emaciation, anaemia, oedema of the lower parts of the limbs, eosinophilia, hypoproteinaemia, hypoalbuminaemia, hyperglobulinaemia and eosinophilia, as well as elevated blood urea concentrations.

Babesia hylomysci and Babesia microti: dexamethasone treatment of infected mice

The effect of dexamethasone on Babesia hylomysci and B. microti was investigated in LACA mice. The drug enhanced both infections by depressing the immune mechanisms of the host when treatment was initiated before parasite inoculation, but had no effects on established and subpatent infections. The degree of parasitemia in the treated mice seemed to depend on the tropism of either parasite toward mature erythrocytes or reticulocytes. B. hylomysci, which favors mature erythrocytes, produced fulminating infections in treated mice. B. microti, which prefers reticulocytes, produced similar parasitemia patterns in treated and untreated mice, but only the treated mice succumbed to the infection. The drug, which suppressed cellular proliferation in the spleens of infected animals, together with its direct lympholytic effects, drastically changed the architecture of the organ.

The pathogenesis of experimental Haemonchus longistipes infection in camels

The pathogenesis and clinical signs of Haemonchus longistipes infection were studied in four experimentally infected camels two of which were adults and the other two were young. In the former animals, an acute infection developed, characterized by mucoid diarrhoea, anorexia, anaemia, loss of body weight, oedema of the lower parts of the limbs, general malaise and death at 8-10 weeks post-infection. In the two younger camels, a less dramatic disease was encountered with less severe symptoms and no oedema, but also terminating fatally at 19-20 weeks post-infection. Parasitological, haematological and biochemical parameters were determined during the course of the infection and were mostly comparable with those usually encountered in haemonchosis of other animals.

Onchocerca raillieti: adult location and skin distribution of the microfilaria in Sudanese donkeys

Onchocerca raillieti is the only Onchocerca species infecting Sudanese donkeys; it occurs only in the ligamentum nuchae, especially in the lamellar part of the ligament. The morphological features of both uterine and skin microfilariae were determined. Skin microfilariae are shorter than uterine ones and tend to accumulate in the regions of Linea alba and withers of infected donkeys. The possible identity of the vector of this worm in the Sudan is discussed.

The pathogenesis of experimental Haemonchus longistipes infection in goats

Goats are highly susceptible to Haemonchus longistipes and could therefore serve as an inexpensive model to study camel haemonchosis. The course of the disease in goats is similar to that in camels and to H. contortus infection in sheep and goats. Unlike the age-dependency of camel haemonchosis, however, the severity of H. longistipes infection in goats is dose-dependent and varies from mild to hyperacute.

The camel (Camelus dromedarius) as an intermediate host for Hammondia heydorni

Dogs fed raw camel meat containing two types of cysts shed unsporulated Hammondia heydorni oocysts and later sporulated Sarcocystis sporocysts in their feces, but were resistant to reinfection with the Hammondia cysts. Sporulated H. heydorni occysts did not induce an enteroepithelial cycle in dogs, but resulted in the formation of muscle cysts.