Excessive iron administration to sheep. 2. The effect on the iron, copper, zinc and manganese level in different organs

Lambs received 250, 1000 and 1750 mg Fe per kg concentrate dry matter. The Fe-supplementations caused the Fe-levels of spleen, liver, kidneys and ribs to rise significantly. Liver and spleen reflected most markedly the high Fe-supply. The Fe-supplementation reduced the Cu-content in the liver and the share of Zn in the kidneys. The Mn-content of all body parts analysed was not significantly influenced by Fe-supplementation.     

低蛋白质日粮对育肥绵羊生长性能、胴体性状及肌肉脂肪酸组成的影响

本研究旨在研究降低全混合日粮蛋白质水平对育肥期绵羊生长性能、胴体性状及肌肉脂肪酸组成的影响.试验将32只平均体重为(38.14±0.45)kg的育肥期绵羊随机分为2组,每组8个重复,每个重复2头.两组绵羊在为期10周的试验期中分别饲喂蛋白质水平为13.5％和8.5％的全混合日粮.结果:将全混合日粮蛋白质水平从13.5％...     

Determining beef carcass retail product and fat yields within 1 hour postmortem.

Hot carcasses from 220 steers (progeny of Hereford or Angus dams mated to Angus, Charolais, Galloway, Gelbvieh, Hereford, Longhorn, Nellore, Piedmontese, Pinzgauer, Salers, or Shorthorn sires) were used to develop equations to estimate weights and percentages of retail product (RP) and trimmable fat (TF) yields. Independent variables examined were 1) 12-13th rib fat probe (12RFD), 2) 10-11th rib fat probe (10RFD), 3) external fat score (EFS), 4) percentage of internal fat estimated hot (H%KPH), 5) hindquarter muscling score (HQMS), and 6) hot carcass weight (HCW). Right sides of the carcasses were fabricated into boneless retail cuts, trimmed to .76 cm of subcutaneous and visible intermuscular fat, and weighed. Cuts were trimmed to 0 cm of subcutaneous and visible intermuscular fat and reweighed. Multiple linear regression equations containing 12RFD, EFS, H%KPH, and HCW accounted for 95 and 89% of the variation in weight of total RP at .76 and 0 cm of fat trim, respectively. When weights of RP from the four primal cuts (.76 and 0 cm of fat trim) were the dependent variables, equations consisting of 12RFD, EFS, H%KPH, and HCW accounted for 93 to 84% of the variation. Hot carcass equations accounted for 83% of the variation in weight of total TF at both .76 and 0 cm of fat trim. Furthermore, equations from hot carcass data accounted for 54 and 51% of the variation in percentage of total RP and 57 and 50% of the variation in percentage of RP from the four primal cuts at .76 and 0 cm of fat trim, respectively. Hot carcass prediction equations accounted for 72% of the variation in percentage of total TF at both fat trim levels. Hot carcass equations were equivalent or superior to equations formulated from chilled carcass traits.     

Terpenes transfer to milk and cheese after oral administration to sheep fed indoors

Terpenes have been proposed as potential biomarkers in verifying the diets of grazing animals. A study of the relationships between the intake of terpenes and their presence in animal tissues (blood and milk) as well as in the final product (cheese) was conducted. Eight dairy sheep were divided into two equal groups, representing control (C) and treatment group (T). In T group oral administration of a mixture of terpenes, α-pinene, limonene and β-caryophyllene, was applied over a period of 18 days. Blood and milk samples were collected regularly and terpenes were identified by extraction using petroleum ether and the solid phase micro-extraction (SPME) method, respectively, followed by GC-MS analysis. Cheese was produced, from C and T animals separately, twice during the period of terpenes oral administration. Terpenes contents and chemical properties of the produced cheeses were investigated. Limonene and α-pinene were found in all blood and milk samples of the T group after a lag-phase of 2 days, while β-caryophyllene was detected in few plasma samples and in all milk samples. None of the terpenes was traced in blood and milk of C animals. The contents of cheese, in dosed terpenes, presented a more complicated pattern suggesting terpenes non-credible as biomarkers. We conclude terpenes can be used as biomarkers for authentification of ewes' milk, but further research is required on factors affecting their transfer to dairy products from grazing diets.     

Bioavailability of levamisole after intramuscular and oral administration in sheep

AIMS: To determine the bioavailability of levamisole in sheep. METHODS: Levamisole was administered to three groups of six Merino sheep orally and intramuscularly at three dose levels of 5, 7.5 and 10 mg/kg. There was a washout period of 1 week between treatments. Blood samples were collected by jugular venepuncture and plasma was separated immediately by centrifugation and stored at 20 degrees C until analysed. The levamisole concentration in plasma was determined by high performance liquid chromatography with a U.V. detection method. Individual plasma levamisole concentration-time data were analysed using the compartmental method. RESULTS: The values obtained for k(a), C(max), t(max) and F show a moderate rate and extent of absorption after oral administration of levamisole while, after intramuscular administration, these values demonstrate a high rate and extent of absorption of levamisole. The intramuscular bioavailability was higher than the oral bioavailability (rate of absorption three-fold faster, extent of absorption 25-33% higher and C(max) two-fold higher). The Friedman test involving dose and route of administration showed that the route of administration affects k(a), C(max), t(max) and F; significant differences were found in these parameters. CLINICAL RELEVANCE: On the basis of these data, the recommended routes for the administration of levamisole in sheep are oral for gastro-intestinal nematodiasis and intramuscular for extragastric nematodiasis.     

Pharmacokinetics of doxycycline in sheep after intravenous and oral administration

The pharmacokinetics of doxycycline were investigated in sheep after oral (PO) and intravenous (IV) administration. The IV data were best described using a 2- (n = 5) or 3- (n = 6) compartmental open model. Mean pharmacokinetic parameters obtained using a 2-compartmental model included a volume of distribution at steady-state (V_ss) of 1.759 ± 0.3149 L/kg, a total clearance (Cl) of 3.045 ± 0.5264 mL/kg/min and an elimination half-life (t_1/2β) of 7.027 ± 1.128 h. Comparative values obtained from the 3-compartmental mean values were: V_ss of 1.801 ± 0.3429 L/kg, a Cl of 2.634 ± 0.6376 mL/kg/min and a t_1/2β of 12.11 ± 2.060 h. Mean residence time (MRT_0−∞) was 11.18 ± 3.152 h. After PO administration, the data were best described by a 2-compartment open model. The pharmacokinetic parameter mean values were: maximum plasma concentration (C_max), 2.130 ± 0.950 μg/mL; time to reach C_max (t_max), 3.595 ± 3.348 h, and absorption half-life (t_1/2k01), 36.28 ± 14.57 h. Non-compartmental parameter values were: C_max, 2.182 ± 0.9117 μg/mL; t_max, 3.432 ± 3.307 h; F, 35.77 ± 10.20%, and mean absorption time (MAT_0–∞), 25.55 ± 15.27 h. These results suggest that PO administration of doxycycline could be useful as an antimicrobial drug in sheep.     

Plasma ronidazole concentrations in sheep after intravenous, oral, intraruminal and intraabomasal administration

Plasnia ronidazole concentrations were examined after intravenous (i.v.) antloral administration of ronidazole in sheep (t i = 6) at;I dosage of 5 mg/kg Iiody weight. In three sheep a ruminal and an abomasal fistula were inserted. l'heronidazole determinations were performed by an HPLC method. Oral bioav;iil-ability in the fistulated sheep was only 5.5 k 1.8% (mean k SE). Somewhat lower values (4.6 k 1.45%) were obtained when the drug was administered through the ruminal fistula in the rumen. After administration of the sanie dose directly in the abomasum through the intraaboiiiasal fistula, 1)ioavailability was increased t o 86.0 k 8.9%. In the non-fistulated sheep, oral biodisponibility was 2.6 k 0.5%.
After water was restricted for 48 h before the oral ronidazole administration t o
these sheep, bioavailability was slightly increased (6.0 k 9.1 %). When desmo-
pressin acetate was injected i.v. before the oral ronidazole;idministration,
bioavailability was 10.6 k 6.5%. When glypressiii,;t1101her vasopressin analogue,
was used, oral bioavailability was not influenced: 2.4 f 1.3%. Konitlazole was
also incubated with ruminal contents antl the ronitlamle concer1tr;ition tle-
creased with a first order rate constant of '0.122 rfr 0.050 miri-' (mean f SF,).
These results suggest that oral atfrniiiistration of ronidazole to sheep is o f little
therapeutic use, because most is metabolised by the ruminal triicro-organisiiis
before it can reach the circulation. A second conclusion we can make is that i t is
very difficult, if not impossible, at least with the methods used, to influence
gastro-intestinal motility in sheep to get a reprotlucahle closure of I he
oesophageal groove.     

Pharmacokinetics after intravenous and oral administration of enrofloxacin in sheep

OBJECTIVE: To compare pharmacokinetics of enrofloxacin administered IV and in various oral preparations to ewes. ANIMALS: 5 mature Katahdin ewes weighing 42 to 50 kg. PROCEDURE: Ewes received 4 single-dose treatments of enrofloxacin in a nonrandomized crossover design followed by a multiple-dose oral regimen. Single-dose treatments consisted of an IV bolus of enrofloxacin (5 mg/kg), an oral drench (10 mg/kg) made from crushed enrofloxacin tablets, oral administration in feed (10 mg/kg; mixture of crushed enrofloxacin tablets and grain), and another type of oral administration in feed (10 mg/kg; mixture of enrofloxacin solution and grain). The multiple-dose regimen consisted of feeding a mixture of enrofloxacin solution and grain (10 mg/kg, q 24 h, for 7 days). Plasma concentrations of enrofloxacin and ciprofloxacin were measured by use of high-performance liquid chromatography. RESULTS: Harmonic mean half-life for oral administration was 14.80, 10.80, and 13.07 hours, respectively, for the oral drench, crushed tablets in grain, and enrofloxacin solution in grain. Oral bioavailability for the oral drench, crushed tablets in grain, and enrofloxacin in grain was 4789, 98.07, and 94.60%, respectively, and median maximum concentration (Cmax) was 1.61, 2.69, and 2.26 microg/ml, respectively. Median Cmax of the multiple-dose regimen was 2.99 microg/ml. CONCLUSIONS AND CLINICAL RELEVANCE: Enrofloxacin administered orally to sheep has a prolonged half-life and high oral bioavailability. Oral administration at 10 mg/kg, q 24 h, was sufficient to achieve a plasma concentration of 8 to 10 times the minimum inhibitory concentration (MIC) of any microorganism with an MIC < or = 0.29 microg/ml.     

Effect of different types of rations on various characteristics of ruminal and intermediary metabolism in sheep. 1. Formation of volatile fatty acids]

Studies on Ruminal Physiology were made with 15 growing female Merino sheep to investigate the influence of different types of rations on the fermentation of volatile fatty acids. The rations were constructed of green feed, straw and concentrates (type 1) or chemically treated straw pellets + concentrates (type 2). One ration (type 3) consisted of concentrates only. With regard to the total concentration of acids ration 3 was significantly superior to the 2 other types of rations. Moreover, ration 3 produced a specific fermentation pattern of the volatile fatty acids. This was characterized by a significant reduction in the molar proportion of acetate compared with ration 1 and 2 and a significant increase in the level of propionic and valeric acid relative to ration 1. Differences in the fermentation pattern between rations 1 and 2 were mainly limited to differences in the absolute and molar proportions of propionate where the straw pellet rations in each case produced the significant higher values. The acetate to propionate ratio was narrowed in the order of ration 1-3 (4.1 :1, 3.1:1, 2.6-2.9 :1). Statistically wellestablished negative correlations were found to exist between the concentrations of volatile fatty acids and the pH values which were established simultaneously.     

Vinasse added to the concentrate for fattening lambs: intake, animal performance, and carcass and meat characteristics

Twenty-four Merino lambs (mean BW 15.4 ± 0.13 kg, 6 to 7 wk old) were used to study the effects of the addition of 0 (control), 100 (V10), and 200 (V20) g of vinasse per kilgram of concentrate on intake, animal performance, biochemical blood profile, and carcass and meat characteristics. Lambs were assigned to 1 of 3 experimental diets and fed barley straw and the corresponding concentrate ad libitum. When the animals reached 25 kg of BW, a sample of blood was taken and the lambs were slaughtered. Feed intake, growth rate, biochemical blood profile, and carcass and meat characteristics were assessed. Lambs that received the concentrates with vinasse showed a reduced concentrate intake (linear contrast, P = 0.029) and ADG (linear contrast, P = 0.004) and an increased length of fattening period (linear contrast, P = 0.002) as well as feed:gain ratio (linear contrast P = 0.011). Vinasse enhanced ruminal pH (orthogonal contrast control vs. V10 + V20; P = 0.007). Plasma glucose concentrations declined in lambs fed vinasse (linear contrast, P = 0.003), whereas plasma urea concentration increased in animals fed vinasse (linear contrast, P = 0.036). The plasma concentrations of creatinine, triglycerides, and lactate and the enzyme profile studied (alkaline phosphate, alanine transaminase, glutamate oxal-acetate transaminase, γ-glutamyl transpeptidase, and lactate dehydrogenase) were not modified in response to vinasse inclusion. Lambs in the vinasse groups had less Na(+) and nitrate and greater K(+) and nitrite plasma concentrations (linear contrasts, P < 0.05). None of the carcass characteristics studied was affected by vinasse (P > 0.10). Meat chemical composition and characteristics were unaffected (P > 0.10), but shear force was greater for lambs that received vinasse (orthogonal contrast, control vs. V10 + V20, P = 0.007). The addition of 100 or 200 g vinasse/kg of concentrate for fattening lambs reduced feed intake and growth rate and increased the feed:gain ratio and meat toughness without affecting any other carcass and meat characteristics.     

Nutritive physiological effects of dietary fats in rations of growing swine. 6. Effect of soya oil and lard on growth performance and carcass characteristics and various blood parameters in fattening swine

Groups of each 10 boars, weight range 20-60 kg, were fed ad libitum the following 4 rations of similar protein: energy ratio: Ration I (control), Ration II (+ 2% soyaoil ), Ration III (+ 2% soyaoil + 5% lard), Ration IV (+ 7% lard). When the animals reached 60 kg body weight each group was halved. One half had free access to the above rations, while the other half were fed ad libitum on the control ration. At body weights of 50 and 100 kg the concentrations of urea, insulin, glucose and cholesterol were measured, in addition the fatty acid composition of the backfat. At the end of the experiment (100 kg) the content of fat in the carcass was calculated by determining the specific gravidity of the carcass. There was little difference in the intake of metabolizable energy (ME) of the different groups of animals at both body weight ranges as a result of the reduction in feed intake of the fat supplemented diets on account of the higher ME-content. There were little differences in the glucose and urea concentrations in the blood of the animals fed the different rations. The highest cholesterol and the lowest insulin levels were measured in groups III and IV, when 5 and 7% lard was added, respectively. The animals, continuously fed Rations III and IV over the whole period of experiment, had a significantly higher fat content (p less than 0,05) than the control animals. There was a very marked influence of the fatty acid intake on the fatty acid pattern of the backfat. Following the change of feed to the control ration at 60 kg body weight, the linoleic acid content of the animals in Groups III and IV was significantly reduced (p less than 0,001) from 15.7 to 11.2%. However this was higher than the 7.3% linoleic acid measured on the animals continuously fed the control ration.     

Repeated oral administration of coumaphos in sheep: interactions of coumaphos with bishydroxycoumarin, trichlorfon, and phenobarbital sodium.

Interactions between treatments with coumaphos, bishydroxycoumarin (an anticoagulane), trichlorfon (an organophosphorous compound), and phenobarbital sodium (an inducer of microsomal enzymes) were investigated in sheep. A daily dose of 2 mg of coumaphos/kg of body weight for 6 days did not affect the plasma enzymes or the antiprothrombinemic effect of bishydroxy-coumarin in wethers. The treatment of ewes with an intravenous (IV) injection of trichlorfon, insufficient to produce significant inhibition of erythrocyte acetylcholinesterase (AChE) activity, appeared to produce additive effects with those produced by subsequent treatment with 4 mg of coumaphos/kg/day. In ewes given 40 mg of phenobarbital sodium/kg for 5 days intraperitoneally (IP), the anticholinesterase effect of 4 mg of coumaphos/kg was significantly reduced and signs of toxicity were not present. Treatment with daily doses of 2 mg of coumaphos/kg for 6 days did not modify the anticholinesterase effect of a 2nd series of treatments given 6 weeks later.     

Growth and carcass traits of Creole goats under different pre-weaning,fattening and slaughter conditions

Data of 198 male Creole kids were analysed to assess the main non-genetic sources of variation of their meat abilities. Basal diet was composed of tropical pasture (28 days): in FD (forage diet), kids received no supplement; in group MD (mixed diet) they were offered 360 g/day pellet, while in group PD (pasture diet) kids were reared at pasture without supplementation. Given a regular four-month interval of weaning within the flock, fixed ages at slaughter (AS) were 7, 11 and 15 months. Three slaughter weights (SW) were compared 17–18, 21–22 and 25–26 kg. The growth levels before weaning and the season of birth effects were added in the statistical analysis. The use of MD has a significant (P < 0.05) effect on almost all the body and carcass traits: 85% more ADG and carcass weight. The weights of fat tissues increased but represented only 4% of empty body weight. As expected, there were significant (P < 0.05) differences within the SW and AS classes that are discussed. Range of variations allow for suggesting further experiments or practical recommendations. The initial results: carcass yield (55%), conformation score (more than 3), fat cover score (less than 3), proportion of primal cuts (63%) or muscle/bone ratio (3–4 points) are a good incentive for the local sector.     

Duration of effective benefit from administration of graded oral doses of cobalt to sheep

The rapidity and duration of the response of sheep to graded oral doses of cobalt, given as the sulphate or as a cobalt-supplemented anthelmintic Panacur SC, was assessed by the determination of serum vitamin B12 and methylmalonic acid concentrations. The rapidity of the response to the treatments, which ranged from 1 to 250 mg cobalt, was unaffected by dose rate but the effective duration was dose related. There was some evidence of a cumulative effect from repeat treatments of the anthelmintic at three weekly intervals. It is suggested that the optimum inclusion rate for cobalt in anthelmintics lies within the range 21 to 100 mg/treatment.     

Intestinal infection and host response to oral administration of Mycobacterium johnei in sheep

Sheep were experimentally infected orally with Mycobacterium johnei and their immune response assessed by measurement of delayed-type skin hypersensitivity, viable unit counts of M. johnei in the tissues, and by pathology, histochemistry and serial biopsies of selected sheep. In those killed shortly after infection, the rapid development of a “strong” degree of skin hypersensitivity was associated with low levels of intestinal infection. However, the failure to mount a “strong” degree of skin hypersensitivity did not preclude eventual recovery from the infection. Electron microscopy of macrophages within lesions in sheep with “strong” skin hypersensitivity showed mainly degenerating bacilli, in contrast to those from sheep with “weak” skin hypersensitivity where the macrophages in similar lesions often contained numerous intact bacilli. The finding of cells rich in β-galactosidase in the lesions bore no relationship to the extent of infection.