Effects of dietary Cu,Mo and S on urinary Cu and Zn excretion in Simmental and Angus cattle

This study determined the effects of dietary copper (Cu), molybdenum (Mo) and sulphur (S) on urinary Cu and zinc (Zn) excretion in cattle. Four Simmental and four Angus heifers were fed low (L) or high (H) levels (mg/kg DM) of Cu (5, 40), Mo (1, 10) and S (0.2, 0.5%). Initially two of each breed was fed either LCu or HCu (2 mo). Then all eight animals were fed sequentially LCuHS (1.5 mo), HCuHS, HCuHMo and HCuHMoHS (2 mo each). Simmental had a higher urine flow, increased concentration and total excretion of urinary Cu and Zn compared to Angus, but only total Zn excretion was significantly higher. Urinary Cu excretion was greatest with the HCuHMoHS diet. Urinary Zn excretion significantly increased with HS but not HS in combination with HMo and/or HCu. This study, together with previously reported biliary excretion, allows a direct comparison of urinary and biliary Cu and Zn excretion responses to dietary Cu, Mo and S.     

Identification of avian strains of Pasteurella multocida in India by conventional and PCR assays

The prevalence of capsular and somatic serotypes were studied among 123 Pasteurella multocida strains isolated from chickens (n = 94), ducks (22), quails (4), turkeys (2) and geese (1) from different geographical regions of India. All strains exhibited similar cultural and morphological characteristics. Ninety-two of the isolates belonged to serotype A:1, the most prevalent serotype, with serotypes A:3, A:1,3, D:3 and F:3 having two isolates each. Only one isolate was positive for serotypes A:4 and D:1. Twenty isolates were untyped. A multiplex capsular PCR assay generated amplicons of sizes 460, 1044, 657 and 854 bp in 106 isolates identified as capsular serotype-A, 15 in serotype D and two in serotype F. Capsular types B and E were not detected in any of the avian isolates studied. The present findings suggest that a multiplex capsular PCR assay may be suitable for the rapid initial identification serotypes P. multocida during epidemiological studies of fowl cholera.     

Crossbreeding parameters of general immune response traits in White Leghorn chickens

Crossbreeding parameters of immune response traits were estimated from a set of well characterized crossbred populations derived from three chicken lines selected over 12 generations for three different general immune response traits and their F1, F2 and backcrosses. The three traits investigated were the selection criteria from each of the lines, i.e. antibody response to the Newcastle disease virus vaccine 3 weeks after vaccination (ND3), cell-mediated immune response (response to phytohemagglutinin, PHA) and phagocytic activity measured as carbon clearance (CC). Crossbreeding parameters included direct and maternal additive line effects, direct and maternal heterosis as well as direct epistatic recombination loss. They were estimated as linear combinations of genetic group effects estimated using animal model methodology. Significant line differences were obtained for ND3 and, to a lesser extent, CC. They were mainly due to direct effects, maternal effects being significant for none of the 3 traits. Significantly negative direct heterosis effects were also observed for ND3 and CC, but not for PHA. Maternal heterosis effects were not estimated for CC. They were non significant for PHA, and negative and significant (− 0.78 ± 0.24) for ND3. The significant favourable recombination gain estimated for ND3 (3.21 ± 0.88) indicates that epistatic interactions could be important for this trait.The present work shows that it was worthwhile to complete second generation crosses to be able to assess to what extent immunity gained by selection is maintained in advanced crossbred generations, and to compare the transmission of immune traits implicated in different aspects of immunity.     

Effect of breed on fattening performance, slaughter and meat quality characteristics of Awassi and Morkaraman lambs

The influence of breed on fattening performance, slaughter and meat quality traits was studied in Awassi and Morkaraman male lambs at approximately 8 months of age. All of the groups were fed a diet consisting of concentrate mixture offered ad libitum, and 300 g of grass hay per lamb per day during 60-day fattening period. Initial live weight, final live weight, daily weight gain and feed conversion efficiency (concentrate and hay consumption for 1 kg of live weight gain) were 39.63 kg, 55.08 kg, 0.258 kg and 6.37 for Awassi; 40.54 kg, 55.58 kg, 0.234 kg and 6.77 for Morkaraman, respectively. The effect of breed on fattening performance and slaughter traits except for LD area was not significant. In addition, meat colour parameters (L = lightness, a = redness, b = yellowness, H = hue angle and C = chroma), pH values, drip loss and sensory attributes were not affected by breed in present study. A significant muscle effect was observed for instrumental measurements of some meat quality characteristics as meat colour parameters (L, a and C), collagen, drip loss, pH, moisture and protein content, WBS, and for some sensory attributes (tenderness, juiciness, acceptability and number of chewing). Results of this study indicate that fattening performance, slaughter and meat quality traits were similar between Awassi and Morkaraman male lambs.     

Investigations on the water intake of growing bulls

The voluntary water intake was evaluated in 62 growing Holstein bulls (mean body weight range = 193 to 550 kg) during a whole fattening period. The diet was composed of corn silage and concentrates. Water was offered for ad libitum consumption. A total of 17,772 measurements of water intake were recorded over 282 days. The average daily water consumption was 18 kg/animal (S.D. = 6.7 kg). Applying a multiple regression analysis to the data set yielded the following equation: voluntary water intake (kg/day) = − 3.85 + 0.507  average ambient temperature (°C) + 1.494  dry matter intake (kg/day) − 0.141  roughage part of the diet (%) + 0.248  dry matter content of roughage (%) + 0.014  body weight (kg). The incorporation of the variables body weight gain, relative humidity, maximum ambient temperature, Na intake, and K intake into the equation did not increase the accuracy of the prediction.     

Simulation of foot-and-mouth disease spread within an integrated livestock system in Texas, USA

We used a simulation study to assess the impact of an incursion of foot-and-mouth disease (FMD) virus on the livestock industries in an 8-county area of the Panhandle region of Texas, USA. The study was conducted in a high-density livestock area, with an estimated number of cattle on-feed of approximately 1.8 million. We modified an existing stochastic, spatial simulation model to simulate 64 scenarios for planning and decision-making. Our scenarios simulated four different herd types for the index herd (company feedlot, backgrounder feedlot, large beef, backyard) and variations in three mitigation strategies (time-of-detection, vaccine availability, and surveillance during disease control). Under our assumptions about availability of resources to manage an outbreak, median epidemic lengths in the scenarios with commercial feedlot, backgrounder feedlot, large beef and backyard index herd types ranged from 28 to 52, 19 to 39, 18 to 32, and 18 to 36 days, respectively, and the average number of herds depopulated ranged from 4 to 101, 2 to 29, 1 to 15 and 1 to 18, respectively. Early detection of FMD in the index herd had the largest impact on reducing (13–21 days) the length of epidemics and the number of herds (5–34) depopulated. Although most predicted epidemics lasted only 1–2 months, and <100 herds needed to be depopulated, large outbreaks lasting 8–9 months with up to 230 herds depopulated might occur.     

Development and application of G1-ELISA for detection of antibodies against bovine ephemeral fever virus

The gene encoding antigenic site G₁ of bovine ephemeral fever virus (BEFV) was highly expressed in the host cell Escherichia coli. An indirect G₁-ELISA with the recombinant protein as the coating antigen was established to detect antibodies against BEFV. The result revealed that the optimal concentration of the coated antigen was 0.5 μg/well and the dilution of serum was 1:20. It was optimal that sera with P/N value  2.2 were considered positive, P/N value  2.0 negative, and between 2.0 and 2.2 ambiguous. The G₁-ELISA method gave a sensitivity of 97.6% and a specificity of 98.6% by testing 590 field serum samples. These results suggest that the G₁-ELISA may be a good alternative tool for seroepidemiological surveys.     

The use of multivariate analysis to characterize carcass and meat quality of goat kids protected by the PGI “Cabrito de Barroso”

Fifty five suckling kids from three genotypes and two sexes protected by the PGI “Cabrito de Barroso” European quality label were used in this experiment. Carcass quality was assessed using indices from carcass measurements, dressing percentages, refrigerated losses, higher priced joints proportion and tissue composition of the carcass. Meat pH, colour, total pigment, fat, dry matter, collagen determinations (total and soluble), cooking losses and shear force estimated in longissimus thoracis et lumborum (LTL) and gluteobiceps (GB) muscles were used to characterize meat quality. Principal component (PC) analysis was performed in order to examine carcass quality traits (n = 16) and meat quality (n = 16) traits. The five first principal components (PCs) explained about 86% of the total variability for carcass quality and 75% of the total variability for meat quality. Compactness indices of carcass and leg, carcass weight and subcutaneous fat were the most effective variables for the PC1, whereas the higher priced joints proportion, muscle proportions of the higher priced joints and of the carcass and the muscle and bone ratio were useful to define the PC2. The first PC of the meat quality parameters was characterized by colour traits (L, b, a, C, H and total pigment) whereas collagen determinations (total collagen and collagen solubility) defined the second PC. When the carcass quality data were projected on the plane defined by the first two PCs, two separate groups of points appeared, corresponding to the animals with slaughter live weight higher or lower than 10 kg. The distribution of the meat quality data on the plane defined by the first two PCs allowed the identification of two separate groups, corresponding to the muscles GB and LTL. The differences between genotypes tend to be small and related to slaughter live weight, which implies certain constancy in carcass and meat quality of the PGI “Cabrito de Barroso”.     

Monofrequency forced oscillation technique for the investigation of pulmonary function in calves: in vitro and in vivo studies

Parameters derived from the non-invasive and simple monofrequency forced oscillation technique were compared with classical parameters of ventilatory mechanics in order to assess its usefulness for the investigation of pulmonary function in calves. To facilitate this comparison, theoretical derivations were coupled with in vitro measurements, using an artificial lung model, and with in vivo studies. These studies compared the oscillatory resistance parameters (R_os and Re) and the respiratory system compliance (C_rs) against the classical pulmonary resistance (R_L) and the dynamic compliance (C_dyn), respectively. Ros and Re were highly correlated (r0·87) with R_L and the comparison between Crs and C_dyn gave a similarly high correlation (r0·88). Given its simplicity, its correspondence with classical parameters and its rapidity and reproducibility, monofrequency forced oscillation technique seems well suited for the investigation of pulmonary function under field conditions.     

Prevalence and severity of foot lesions in Danish Holstein heifers through first lactation

Several studies have shown that foot lesions and clinical lameness occur before first calving and develop further during the lactation period. Lameness may cause production losses, but the relationship between foot lesions, particularly in the claw horn, and lameness in heifers is unclear. The objectives of this study were to describe the development of and evaluate the relationship between lameness and foot lesions in Danish Holsteins before and after first calving. In a longitudinal study, 147 heifers were examined for lameness and foot lesions 2–5 times over an 18-month period. Lameness was assessed by means of a visual locomotion score and foot lesion severity was recorded.The prevalence of a locomotion score 3 was 25% before calving, and 90% at approximately 250 days in milk (DIM). Prevalence of moderate to severe sole haemorrhage (SH) was 27% before calving and 56% at 250 DIM, and that of moderate to severe white line lesion (WLL) 44% before calving with a peak of 70% at 200 DIM. There was one case of white line abscess but SH was seen throughout the entire study period. Digital dermatitis (DD) was prevalent prior to first calving (15%) and peaked at 39% at 0–100 DIM. Heel horn erosion (HHE) occurred in almost all cows (93–100%) and was strongly correlated with DD (r = 0.51). The correlation coefficient between SH and WLL was also high (0.42). The relatively high correlations between WLL and both DD and HHE were more surprising (0.38 and 0.35, respectively), those between SH and both DD and HHE were moderate (around 0.18). Interdigital dermatitis was significantly correlated with both HHE and DD, but completely unrelated to SH and WLL.The overall average locomotion score increased by about one-half of a score unit from 1 month prior to calving until 250 DIM, with a large difference between herds, although this was unsurprising as cows may alter their locomotion pattern with management factors (e.g. floor properties). DD and WLL were both associated with a locomotion score 3 but of the cows with severe WLL there was no clear association between a locomotion score 3 and DD. The highest locomotion scores occurred among cows with DD but without WLL.     

Effects of transportation during the hot season and low voltage electrical stimulation on histochemical and meat quality characteristics of sheep longissimus muscle

The effect of transportation during the hot season (42 °C) and low voltage electrical stimulation on physiological, histochemical and meat quality characteristics of Omani sheep was studied. Forty intact male sheep were divided into two equal groups: 3 h transported or non-transported. The non-transported group remained in holding pens for 48 h prior to slaughter, while the transported group was transported 300 km (approximately 3 h) in an open truck under solar radiation on the day of slaughter. Blood samples were collected from the animals before loading and prior to slaughter. Fifty percent of the carcasses from each group were randomly assigned to low voltage (90 V) at 20 min postmortem. Temperature and pH decline of the left longissimus thoracis muscle were monitored. Ultimate pH, WB-shear force, sarcomere length, myofibrillar fragmentation index (MFI), expressed juice, cooking loss and color L, a, b were measured on samples from both sides muscles collected at 24 h postmortem at 3–4 °C. The transported sheep had significantly higher plasma cortisol (P < 0.01), adrenaline, nor-adrenaline and dopamine concentrations (P < 0.05) than non-stimulated animals. Electrical stimulation resulted in a significantly (P < 0.05) more rapid pH fall in muscle during the first 12 h after slaughter. Muscles from electrically-stimulated carcasses had significantly (P < 0.05) lower pH values, longer sarcomere length, lower shear force value, higher expressed juice, MFI and lighter L than those from non-stimulated ones. The muscle samples from the transported sheep had significantly (P < 0.05) smaller and lower proportion of Types I and IIA fibers than those from the non-transported group. This study indicated that pre-slaughter transport at high ambient temperatures can cause noticeable changes in physiological and muscle metabolism responses in sheep. Electrical stimulation improved meat quality characteristics, which indicate that meat quality of transported sheep can be improved by electrical stimulation.     

Liver blood flow and metabolic clearance rate of progesterone in sheep

To study the inverse relationship between feed level and concentrations of peripheral plasma progesterone, 36 ovariectomised ewes were fed rations at levels calculated to maintain liveweight (M). On the seventh day, the ewes were given an intravenous infusion of progesterone and the metabolic clearance rate (MCR) was calculated. The ewes were then randomly allotted to receive either , M or 2M rations for seven days at which time the infusion and blood sampling schedules were repeated. The mean (SE) MCR of infused progesterone in ovariectomised ewes fed either , M or 2M rations for seven days was 7·1 (0·59), 9·9 (1·64 and 13·0 (1·19) litre h⁻¹ kg⁻¹ of liveweight, respectively. Differences in MCR of progesterone between ewes fed and 2M rations were significant (P<0·05). The inverse relationship between level of feed intake and plasma progesterone concentration was attributed to differences in clearance rate of progesterone rather than to changes in the entry rate of the hormone into the blood.     

Kinetic disposition, systemic bioavailability and tissue distribution of apramycin in broiler chickens

Apramycin was administered to chickens orally, intramuscularly and intravenously to determine blood concentration, kinetic behaviour, bioavailability and tissue residues. Single doses of apramycin at the rate of 75 mg kg⁻¹ body weight were given to broiler chickens by intracrop, i.m. and i.v. routes. The highest serum concentrations of apramycin were reached 0·20 and 0·76 hours after the oral and i.m. doses with an absorption half-life () of 0·10 and 0·19 hours and an elimination half life () of 1·22 and 2·31 hours respectively. The systemic bioavailability was 2·0 and 58 per cent after intracrop and i.m. administration, respectively, indicating poor absorption of the drug when given orally.Following i.v. injection, the kinetics of apramycin was described by a two-compartment open model with a () of 1·5 hours, () of 2·1 hours, V_d(ss) (volume of distribution) of 4·82 litre kg⁻¹ and C1_(B) (total body clearance) of 1·88 litre kg⁻¹ hour⁻¹. The serum protein-binding of apramycin was 26 per cent.The highest tissue concentrations of apramycin were present in the kidneys and liver. No apramycin residues were detected in tissues after six hours except in the liver and kidneys following intracrop dosing and kidneys following i.m. administration.     

Use of a hand-held meter for detecting subclinical ketosis in dairy cows

The Optium Xceed is a new hand-held meter for determining blood β-hydroxybutyrate (BHBA) and glucose in human medicine. The objective of this study was to compare BHBA and glucose results obtained using the hand-held meter with those results made with a laboratory method and to evaluate its usefulness as a cowside test in the diagnosis of subclinical ketosis (SCK) in dairy cows. Seventy-eight blood samples from clinically healthy Holstein cows between 5 and 60 days post-calving were analysed. BHBA and glucose values were significantly higher with the hand-held meter versus laboratory methods. Correlation coefficients (r) for BHBA and glucose with the Optium Xceed versus laboratory methods were 0.97 and 0.63, respectively. Based on Bland–Altman plot and Passing–Bablok regression, agreement between two methods was good for BHBA but the agreement for glucose was only fair. When SCK was defined as plasma BHBA levels 1200 μmol/L, the sensitivity and specificity of the hand-held meter ketone testing in determining SCK were 85% and 94%, respectively. Raising the threshold of the laboratory method to 1400 μmol/L, the sensitivity and specificity incremented to 0.90 and 0.98, respectively.In conclusion, the blood ketone-monitoring device can be used as a rapid and reliable diagnostic test to detect SCK under field conditions.     

Activation of equine neutrophils by phorbol myristate acetate or N-formyl-methionyl-leucyl-phenylalanine induces a different response in reactive oxygen species production and release of active myeloperoxidase

Neutrophil (PMN) contribution to the acute inflammatory processes may lead to an excessive generation of reactive oxygen metabolites species (ROS) and secretion of granule enzymes. We compared the effects of either phorbol myristate acetate (PMA) or N-formyl-methionyl-leucyl-phenylalanine (fMLP) in combination with a pre-treatment by cytochalasin B (CB) on the production of ROS and the release of total and active myeloperoxidase (MPO) by isolated equine PMNs. The ROS production was assessed by lucigenin dependent chemiluminescence (CL) and ethylene release by α-keto-γ-methylthiobutyric acid (KMB) oxidation. In the supernatant of activated PMNs, total equine MPO was measured by ELISA and active MPO by the SIEFED (Specific Immunologic Extraction Followed by Enzymatic Detection) technique that allows for the study of the interaction of a compound directly with the enzyme. The stimulation of PMNs with CB-fMLP only modestly increased the release of MPO, but more than 70% of released MPO was active. PMA stimulation markedly increased the production of ROS and release of MPO, but more than 95% of released MPO was inactive. When PMNs were pre-incubated with superoxide dismutase (SOD) prior to PMA activation, the lucigenin enhanced CL, which is linked to the superoxide anion (O₂⁻) production, was much more decreased than KMB oxidation, linked to the hydroxyl-like radical production. The addition of SOD prior to the activation of PMNs by PMA also limited the loss of the activity of released MPO. These results confirm the key role of O₂⁻ generation in the ROS cascade in PMN and reveal its critical role on MPO inactivation.     

Estimating relative risk of disease from outputs of logistic regression when the disease is not rare

Many epidemiologic studies in the veterinary field aim to quantify the relationships between risk factors and the occurrence of diseases. The strength of the association between a factor and a disease can be measured by (i) a relative risk (RR), or (ii) an odds ratio (OR) which is widely used because it is directly derived from the estimates of logistic regression. RR directly provides the relative increase in the probability of disease occurrence in case of exposure. OR is often interpretated as a multiplicative factor of the risk of disease occurrence when exposed, although it is not a good approximation of RR when the disease is not rare. The objective of this paper is to propose a method to estimate RR of disease from adjusted odds ratios derived from logistic regression when the disease is not rare.The method of estimation is developed for three different cases: (i) the factor and the outcome are dichotomous; (ii) the factor has more than two classes, and the outcome is dichotomous; and (iii) the factor and the outcome both have more than two classes. In all cases, the principles of estimation are the same: in a subpopulation including individuals diseased at level j (D_j) and not diseased (D₀), when exposed to level i (F_i) or not exposed to the factor (F₀), can be calculated with adjusted , and the frequencies of individuals exposed to level i (n_i&;j), of those not exposed (n_0&;j) and of those diseased (n_i&;j) among the individuals exposed to level i and not exposed. is the positive solution of the formula:

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In Vitro Assessment of the Equine Hoof Wall Strains in Flat Weight Bearing and After Heel Elevation

Horseshoeing is a common practice, but effects on the hoof wall are poorly understood. Strain gauges were used to document and compare hoof behavior in vitro during flat weight bearing and after artificial heel elevation. Ten front limbs of Thoroughbred race horses, shod with conventional flat shoes, were used. Eight strain gauges were symmetrically distributed around the toe, quarters, and heels. Each limb was mounted to a testing machine (Kratos K5002; Kratos Dynamômetros, Ltda., Cotia-SP-Brazil) and subjected to a load equivalent to 30% of the donor's body weight. Strains (μ) were acquired by means of a computerized system and the results compared using Friedman and Wilcoxon statistical tests. There was greater strain variation when the heels were elevated. Compression predominated during flat weight bearing, with a tendency to horizontal traction after heel elevation. The changes in strain caused by heel elevation were not always symmetrical. Elevation of the heels tensed the toe and the medial quarter horizontally, increased load at the posterior portion of the hoof capsule, and hindered its expansion.     

Evaluation of dietary and management risk factors for enterolithiasis among horses in California

Enteroliths are intestinal calculi that result in intestinal obstruction and colic in horses. Equine enterolithiasis occurs worldwide, but the disease is particularly prevalent in some geographic locations, including California. The objectives of this study were to evaluate dietary and environmental risk factors for the disease. This was accomplished through a case–control study by comparing horses with colic from enterolithiasis presenting to the University of California, Davis VMTH, to horses with colic of other causes. Data were collected on 61 horses with enterolithiasis and 75 controls via evaluation of patient records and questionnaires completed by owners at the time of admission. Following multiple logistic regression analysis, the following factors were found to be significantly associated with enterolithiasis: feeding 50% of the diet as alfalfa; feeding <50% of the diet as oat hay; feeding <50% of the diet as grass hay; and lack of daily access to pasture grazing.     

Effects of supplemental humic substances on growth performance, blood characteristics and meat quality in finishing pigs

A total of forty-eight finishing pigs were used to determine the effects of humic substances (HS) on growth performance, blood characteristics, and meat quality. The finishing pigs were assigned randomly by weight to three treatments. The dietary treatments included: 1) Control (CON; basal diet), 2) HS1 (basal diet + 5% humic substances) and 3) HS2 (basal diet + 10% humic substances). Results of the whole experimental period showed that addition of 10% HS to the diet, significantly increased average daily gain (ADG) and gain/feed (G:F) (P < 0.05). At the end of the experiment, the relative lymphocyte counts (% of total white blood cells) of pigs fed HS2 diet were higher (P < 0.05) than that of pigs fed CON diet. The Minolta color parameter a of pigs fed HS2 was similar to that of pigs fed HS1, however, it was higher (P < 0.05) than that of pigs fed CON diet. The inclusion of either 5% or 10% HS significantly decreased backfat thickness (P < 0.05). The marbling score was increased significantly (P < 0.05) when diets were supplemented with HS at a level of 10%. The results of this study suggest that HS might be utilized as a feed additive in the diet. It could improve growth performance, relative lymphocyte counts and meat quality.