Indigestion in Young Calves: III. The Influence of Powders from Heat-Treated Skim Milk and Whey

Two experiments comprising 24 calves, lasting 44–46 days, have been carried out in order to examine the influence of powders from heat-treated skim milk and whey on indigestion in young calves. The frequency of diarrhoea increased much (P < 0.01) in the first experiment when feeding the heat-treated products, but little in the other. Possible reasons for this difference are discussed. Calves fed heat-treated products in the first experiment consumed 13.8 1 of electrolyte fluid per head per day 14–22 days after commencing the test, when both diarrhoea and fluid consumption reached peak values. It is postulated that some of the calves might have succumbed without electrolyte fluid.     

Evaluation of hematological,biochemical and oxidative stress profile in calves under propofol anesthesia

Veterinary Research Communications - Propofol is a widely used drug in veterinary medicine to induce anesthesia; as well as the chosen compound for protocols of intravenous anesthesia. The present...     

Downgrading of heavy broiler chicken carcasses due to myodegeneration of the anterior latissimus dorsi: pathologic and epidemiologic studies

Recently, in some Brazilian poultry companies, a dorsal cranial muscular lesion has been increasingly detected in broilers, causing heavy economic losses due to carcass downgrading. The observed gross lesions located in the anterior latissimus dorsi (ALD) muscle are characterized by yellowish discoloration of the skin and swelling on the dorsal cranial region of that muscle. When the ALD muscle is cut, subcutaneous edema, muscular superficial hemorrhage, pallor, adherence, and increased thickness and density are observed. Microscopically, findings indicate degenerative and polyphasic features, variation in fiber size and splitting, presence of hyaline, necrotic and regenerative myofibers, extensive fibrosis, and adipose tissue with lymphohistiocytic infiltration in all ALD muscles affected. The etiology of the lesion is unknown, and no detailed report was found in literature. The highest frequency of carcass downgrading due to this lesion was found in the heaviest and the oldest males of high-yield broiler strains (P < 0.01). This study is the first to describe the pathologic and some epidemiologic aspects of this new myopathy.     

Cross-sectional study on prevalence of Trypanosoma evansi infection in domestic ruminants in an endemic area of the Canary Islands (Spain)

Trypanosoma evansi is the most widely spread of the pathogenic African trypanosomes of animals. The disease (surra) was first diagnosed in the Canary Islands in a dromedary camel in 1997; thus, a control plan was implemented achieving the eventual eradication of T. evansi from most of the infected areas in the Archipelago. However, a little area remains still infected despite the use of the same control measures. To evaluate possible reservoirs in the area a representative sample of domestic ruminants was examined by serological, parasitological and molecular tests. Of a total of 1228 ruminants assessed, 61 (5%) were serologically positive (7 cattle, 21 goats, 33 sheep), but T. evansi could be demonstrated in none of them. According to FreeCalc assessment, cattle and goat populations would be free from disease; however, the results from sheep are not adequate to conclude that the population would be free from disease. As a conclusion, surveillance must be exercised on ruminant farms in the surroundings of the infected area in order to evaluate the possible extension of the disease and their potential role as reservoirs of T. evansi.     

Effects of nutritional plane and selenium supply during gestation on visceral organ mass and indices of intestinal growth and vascularity in primiparous ewes at parturition and during early lactation

Objectives were to investigate effects of nutritional plane and Se supply during gestation on visceral organ mass and intestinal growth and vascularization in ewes at parturition and during early lactation. Primiparous Rambouillet ewes (n = 84) were allocated to 2 × 3 × 2 factorial arrangement of treatments. Factors included dietary Se [adequate Se (ASe, 11.5 μg/kg BW) or high Se (HSe, 77.0 μg/kg BW)], nutritional plane [60% (restricted; RES), 100% (control; CON), or 140% (high; HIH)], and physiological stage at necropsy (parturition or d 20 of lactation). At parturition, lambs were removed and 42 ewes (7 per treatment) were necropsied. Remaining ewes were transitioned to a common diet which met lactation requirements and mechanically milked for 20 d. In the absence of interactions (P > 0.10), main effects are reported. At parturition, stomach complex and liver masses were greatest for HIH, intermediate for CON, and least for RES (P < 0.02). Small intestinal mass was greater (P ≤ 0.002) for HIH than RES and CON, and greater (P < 0.01) for ASe than HSe. During early lactation, RES and CON gastrointestinal masses increased disproportionally to BW (P < 0.05). At parturition, jejunal mucosal density was less (P ≤ 0.01) for RES than CON and HIH, whereas CON had greater (P < 0.003) jejunal mucosal RNA concentration and RNA:DNA than RES and HIH. Although there were no differences (P > 0.17) at parturition, jejunal cell percent proliferation was greatest in RES, intermediate in CON, and least in HIH (P ≤ 0.09) at d 20 lactation. At both stages, RES had less (P = 0.01) jejunal capillary area density than HIH and less (P ≤ 0.03) capillary surface density than CON and HIH. During lactation, jejunal capillary size was greater (P = 0.04) for ewes previously fed HSe compared with ASe. At parturition, ASe-HIH had greater (P < 0.02) jejunal mucosal endothelial nitric oxide synthase 3 mRNA than all other treatments and greater (P = 0.10) vascular endothelial growth factor (VEGF) than all treatments, except ASe-RES. In addition, CON had less (P ≤ 0.08) jejunal VEGF receptor-1 (FLT1) mRNA compared with RES and HIH, and ASe had greater (P = 0.003) FLT1 than HSe at parturition. Ewes fed HIH had greater (P = 0.04) jejunal VEGF receptor-2 mRNA compared with RES. Results indicate that maternal intestinal growth and vascularization are responsive to nutritional plane and dietary Se during gestation and undergo changes postpartum when under similar lactational management.     

The influence of reproductive physiology and nutrient supply on the periparturient relaxation of immunity to the gastrointestinal nematode Trichostrongylus colubriformis in Merino ewes

A pen experiment was conducted to investigate the interaction of early-weaning and nutrient supply on the periparturient relaxation of immunity to the gastrointestinal nematode (GIN) Trichostrongylus colubriformis in Merino ewes. Mixed-age pregnant and non-pregnant (dry) ewes were infected with 8,000 T. colubriformis L(3)/week, and fed either a high or low quality diet. Following parturition, lambs were either removed from their mothers at 2 days of age or allowed to continue suckling. Systemic immunity began to wane during late pregnancy with circulating eosinophils and plasma total antibody (Ab) levels declining from day -37 (relative to the midpoint of lambing) and day -24, respectively. Pregnant ewes fed the low quality diet exhibited an increasing faecal worm egg count (WEC) from day -24 and had higher intestinal worm burdens on day 13, whereas ewes fed the high quality diet had a delayed transient rise in WEC of lower magnitude. Dry and early-weaned ewes remained highly resistant to T. colubriformis at all times. In the post-lambing/lactation period, ewes fed the high quality diet had higher levels of local total Ab and numbers of goblet cells (GC) in the small intestine on days 13 and 41. Lactating/suckled ewes had a lower anti-parasite local immune response as indicated by reduced titres of total Ab, IgG(1), IgM and IgA and lower numbers of mucosal mast cells (MMC), globule leukocytes (GL) and GC in small intestinal tissue compared to their dry and early-weaned counterparts. Early-weaning resulted in rapid recovery of blood eosinophils and total Ab. On day 13 post-lambing, titres of total Ab, IgG(1), IgM, IgA and IgE, and numbers of MMC and GL were greater than those measured in dry and suckled ewes. When fed the high quality diet, ewes had a higher dry matter (DM) intake, maternal weight, fat score, greater fat depth and eye muscle depth, birthed heavier lambs that had higher growth rates, and produced more milk. The physiological status of pregnancy resulted in a higher DM intake but lower measures of fat depth and eye muscle depth, and suckling led to an increase in DM intake but a reduction in body weight and fat score through mobilisation of fat and muscle reserves. Despite the marked effect of diet quality on production traits, some inconsistencies were observed between body composition and apparent parasite resistance, measured by WEC and worm counts, suggesting that the nutritional influence was not necessarily always mediated through changes in body composition. Although reproductive status affected blood leptin levels, diet had no effect within suckled ewes and therefore it was concluded that leptin has no causative role in maintaining the periparturient relaxation of immunity to T. colubriformis.     

Assessing resistance against macrocyclic lactones in gastro-intestinal nematodes in cattle using the faecal egg count reduction test and the controlled efficacy test

The main objective of the present study was to evaluate the accuracy of the faecal egg count reduction test (FECRT) to assess the resistance status of ivermectin (IVM)-resistant isolates of the cattle nematodes Ostertagia ostertagi and Cooperia oncophora, using the controlled efficacy test (worm counts) as a reference. The second objective was to investigate whether both IVM-resistant isolates showed side-resistance against moxidectin (MOX) under controlled conditions. Thirty male Holstein calves were experimentally infected with 25,000 L3 of an IVM-resistant O. ostertagi isolate and 25,000 L3 of an IVM-resistant C. oncophora isolate. Twenty-eight days later the calves were randomly divided into 2 treatment groups and 1 untreated control group. Animals in groups 1 and 2 received MOX (Cydectin(?) 1%, Pfizer) and IVM (Ivomec(?) 1%, Merial) respectively, by subcutaneous injection at a dose rate of 0.2mg/kg bodyweight. Faecal samples were collected 7 and 14days after treatment and animals were necropsied 14/15days post-treatment. Both the FECRT and the controlled efficacy test demonstrated that the O. ostertagi and C. oncophora isolates were resistant against IVM, with efficacies below 90%. The IVM-resistant O. ostertagia isolate was still susceptible to MOX treatment, as shown by over 99% reduction in egg counts and worm burden. The FECRT suggested borderline resistance against MOX in the IVM-resistant C. oncophora isolate, with egg count reductions between 97% (95% CI: 76; 100) at day 7 and 86% (95% CI: 49; 96) at day 14. However, the controlled efficacy test clearly showed MOX-resistance, with a decrease of only 31% (95% CI: -12; 57) in C. oncophora worm numbers. After MOX treatment, a significantly lower number of eggs per female C. oncophora worms was counted compared to the control group (43% reduction). Due to this reduced fecundity, the FECRT may fail to detect MOX-resistance.     

Acute phase response to Mycoplasma haemofelis and 'Candidatus Mycoplasma haemominutum' infection in FIV-infected and non-FIV-infected cats

The pathogenicity of Haemoplasma spp. in cats varies with 'Candidatus Mycoplasma haemominutum' (CMhm) causing subclinical infection while Mycoplasma haemofelis (Mhf) often induces haemolytic anaemia. The aims of this study were to characterise the acute phase response (APR) of the cat to experimental infection with Mhf or CMhm, and to determine whether chronic feline immunodeficiency virus (FIV) infection influences this response. The acute phase proteins serum amyloid A (SAA), haptoglobin (Hp) and α-1-acid glycoprotein (AGP) concentrations were measured pre-infection and every 7-14days up to day 100 post-infection (pi) in cats infected with either Mhf or CMhm. Half of each group of cats (6/12) were chronically and subclinically infected with FIV. Marbofloxacin treatment was given on days 16-44 pi to half of the Mhf-infected cats, and on days 49-77 pi to half of the CMhm-infected cats. FIV-infected animals had significantly lower AGP concentrations, and significantly greater Hp concentrations than non-FIV-infected cats when infected with CMhm and Mhf, respectively. Both CMhm and Mhf infection were associated with significant increases in SAA concentrations, while AGP concentrations were only significantly increased by Mhf infection. Mhf-infected cats had significantly greater SAA concentrations than CMhm-infected animals. Both Mhf and CMhm infections were associated with an APR, with Mhf infection inducing a greater response. Chronic FIV infection appeared to modify the APR, which varied with the infecting Haemoplasma species.