Effects of supplemental d-methionine in comparison to l-methionine on nitrogen retention,gut morphology,antioxidant status,and mRNA abundance of amino acid transporters in weanling pigs

An N-balance experiment was conducted to test the hypothesis that d-Methionine (d-Met) has the same bioavailability and efficacy as l-Methionine (l-Met) when fed to weanling pigs. A Met-deficient basal diet containing 0.24% standardized ileal digestible (SID) Met was formulated. Six additional diets were formulated by adding 0.036%, 0.072%, or 0.108% d-Met or l-Met to the basal diet, and these diets, therefore, contained 77%, 87%, or 97% of the requirement for SID Met. Fifty-six barrows (10.53 ± 1.17 kg) were housed in metabolism crates and allotted to the seven diets with eight replicate pigs per diet. Feces and urine were collected quantitatively with 7-d adaptation and 5-d collection periods. Blood and tissue samples from pigs fed the basal diet and pigs fed diets containing 0.108% supplemental Met were collected on the last day. Results indicated that N retention (%) linearly increased (P < 0.01) as supplemental d-Met or l-Met increased in diets. Based on N retention (%) as a response, the linear slope-ratio regression estimated the bioavailability of d-Met relative to l-Met to be 101% (95% confidence interval: 57%–146%). The villus height and crypt depth in the jejunum were not affected by the Met level or Met source. Total antioxidant capacity or thiobarbituric acid reactive substance concentrations in plasma or tissue samples from pigs fed the control diet or diets containing 0.108% supplemental d-Met or l-Met were not different. Abundance of mRNA for some AA transporters analyzed in intestinal mucosa of pigs also did not differ. Therefore, it is concluded that d-Met and l-Met are equally bioavailable for weanling pigs.     

Physicochemical Approach to Determine the Mechanism for Acid–Base Disorders in 793 Hospitalized Foals

Background

The quantitative effect of strong electrolytes, unmeasured strong anions (UAs), pCO ₂, and plasma protein concentrations in determining plasma pH can be demonstrated using the physicochemical approach. Plasma anion gap (AG) and strong ion gap (SIG) are used to assess UAs in different species.

Hypotheses

Strong ions are a major factor influencing changes in plasma pH of hospitalized foals. AG and SIG accurately predict severe hyper‐l‐lactatemia ([l‐lac⁻] > 7 mmol/L).

Animals

Seven hundred and ninety three hospitalized foals < 7 days old.

Methods

Retrospective study. The relationship between measured pH and physicochemical variables, and the relationship between plasma [l‐lac⁻] and AG and SIG, were determined using regression analyses. Optimal AG and SIG cut points to predict hyper‐l‐lactatemia were identified using an ROC curve analysis.

Results

Combined, the measured strong ion difference and SIG accounted for 54–69% of the changes in the measured arterial pH of hospitalized foals. AG and SIG were significantly associated with plasma [l‐lac⁻] (P < .0001). The receiver operator characteristics (ROC) AUC of AG and SIG for prediction of severe hyper‐l‐lactatemia were 0.89 (95%CI, 0.8–0.95; P < .0001) and 0.90 (95%CI, 0.81–0.96; P < .0001), respectively. Severe hyper‐l‐lactatemia was best predicted by AG > 27 mmol/L (sensitivity 80%, 95%CI, 56–94, specificity 85%, 95%CI, 73–93; P < .0001) and SIG <−15 mmol/L (sensitivity 90%, 95%CI, 68–98; specificity 80%; 95%CI, 68–90; P < .0001).

Conclusion and clinical relevance

Altered concentrations of strong ions (Na⁺, K⁺, Cl⁻) and UAs were the primary cause of acidemia of hospitalized foals. AG and SIG were good predictors of hyper‐l‐lactatemia and could be used as surrogate tests.     

Preliminary Investigation of the Area Under the l‐Lactate Concentration–Time Curve (LACAREA) in Critically Ill Equine Neonates

Background

A variety of measures of l‐lactate concentration ([LAC]) in the blood of critically ill neonatal foals have shown utility as prognostic indicators. These measures, evaluating either the severity of hyperlactatemia or the duration of exposure to hyperlactatemia, perform fairly well and have correctly classified 75–80% of foals examined in several studies. The area under the l‐lactate concentration versus time curve (LAC _Area) encompasses both severity and duration of hyperlactatemia and should improve correct classification of patient survival.

Hypothesis/Objectives

LAC _Area is larger in nonsurviving critically ill neonatal foals.

Animals

Forty‐nine foals admitted for critical illness to 1 of 4 referral hospitals.

Methods

Whole blood was obtained at admission and 6, 12, 18, and 24 hours after admission for measurement of l‐lactate using a handheld lactate meter. LAC _Area was calculated for: admission–6, 6–12, 12–18, 18–24 hours, and admission–24 hours using the trapezoidal method and summing the 6‐hours interval areas to determine total 24 hours area. Differences between survivors and nonsurvivors were determined using robust regression and Kruskal–Wallis testing, P < .05.

Results

LAC _Area was significantly larger in nonsurviving foals (n = 9) than in surviving foals (n = 40) at all time periods examined.

Conclusions and Clinical Importance

Differences in LAC _Area between surviving and nonsurviving critically ill neonatal foals are large and support further investigation of this method as an improved biomarker for survival in critically ill neonatal foals is indicated.     

Quantitative Physicochemical Analysis of Acid‐Base Balance and Clinical Utility of Anion Gap and Strong Ion Gap in 806 Neonatal Calves with Diarrhea

Background

Acid‐base abnormalities in neonatal diarrheic calves can be assessed by using the Henderson‐Hasselbalch equation or the simplified strong ion approach which use the anion gap (AG) or the strong ion gap (SIG) to quantify the concentration of unmeasured strong anions such as d‐lactate.

Hypothesis/Objectives

To determine and compare the clinical utility of AG and SIG in quantifying the unmeasured strong anion charge in neonatal diarrheic calves, and to examine the associations between biochemical findings and acid‐base variables by using the simplified strong ion approach. We hypothesized that the SIG provides a more accurate prediction of unmeasured strong anions than the AG.

Animals

Eight hundred and six neonatal diarrheic calves admitted to a veterinary teaching hospital.

Methods

Retrospective study utilizing clinicopathologic findings extracted from medical records.

Results

Hyperphosphatemia was an important predictor of venous blood pH. Serum inorganic phosphorus and plasma d‐lactate concentrations accounted for 58% of the variation in venous blood pH and 77% of the variation in AG and SIG. Plasma d‐ and total lactate concentrations were slightly better correlated with SIG (r _s  = −0.69; −0.78) than to AG (r _s = 0.63; 0.74).

Conclusions and Clinical Importance

Strong ion gap is slightly better at quantifying the unmeasured strong anion concentration in neonatal diarrheic calves than AG. Phosphorus concentrations should be included as part of the calculation of A _tot when applying the simplified strong ion approach to acid‐base balance to critically ill animals with hyperphosphatemia.     

Epidermal langerhans cellsin the oppossum,Trichosurus vulpecula

Abstract

Extract

Madam:-Langerhans cells (LC) are dendritic cells of bone marrow origin found above the basal cell layer of the epidermis and in mucous membranes. ⁽⁹⁾ Silberberg-Sinakin, I. and Thorbecke, G.J. 1980. “The Langerhans cells”. In The Reticuloendothelial System: A Comprehensive Treatise, Edited by: Carr, I. and Daems, W.T. 555–605. New York: Plenum Press. In, Vol. 1 [Google Scholar] They are the only epidermal cells that have Fc and C3b receptors ⁽¹¹⁾ Stingl, G., Wolff-Schreiner, E.C.H., Pichler, W.J., Gschnait, F., Knapp, W. and Wolff, K. 1977. Epidermal Langerhans cell bears Fc and C3b receptors. Nature, 268: 245–246.  [Google Scholar] and express class II histocompatibility structures. ⁽¹⁾ Klareskog, L., Tjernlund, U.M., Forsum, U. and Peterson, P.A. 1977. Epidermal Langerhans cells express la antigens. Nature, 268: 248–250.  [Google Scholar] ⁽⁵⁾ Rowden, G., Lewis, M.G. and Sullivan, A.K. 1977. Ia antigen expression on human epidermal Langerhans cells. Nature, 268: 247–248.  [Google Scholar] These features suggest that LC are the epidermal equivalent of macrophages but the relationship between these two types of cells is uncertain. ⁽⁹⁾ Silberberg-Sinakin, I. and Thorbecke, G.J. 1980. “The Langerhans cells”. In The Reticuloendothelial System: A Comprehensive Treatise, Edited by: Carr, I. and Daems, W.T. 555–605. New York: Plenum Press. In, Vol. 1 [Google Scholar] LC are involved in the induction of contact hypersensitivity [CHS], ⁽⁶⁾ Shelley, W.B. and Juhlin, L. 1977. Selective uptake of contact allergens by the Langerhans cell. Arch. Dermatol., 113: 187–194.  [Google Scholar] ⁽⁷⁾ Silberberg, I. 1973. Apposition of mononuclear cells to Langerhans cells in contact allergic reactions. Acta. Derma. Venerol., 53: 1–9.  [Google Scholar] ⁽⁸⁾ Silberberberg, I., Baer, R.L. and Rosenthal, S.A. 1976. The role of Langerhans cells in allergic contact hypersensitivity. A review of findings in man and guinea pigs. J. invest. Dermatol., 66: 210–217.  [Google Scholar] ⁽¹⁰⁾ Stingi, G., Katz, S.I., Clement, L., Green, O. and Shevach, E.M. 1980. “Langerhans cell — lymphocyte interactions”. In Macrophage Regulation of Immunity, Edited by: Unanue, E.R. and Rosenthal, A.S. 285–295. New York: Academic Press. In [Google Scholar] their density determining whether CHS or immunological tolerance follows skin painting with haptens. ⁽¹²⁾ Toews, B.G., Bergstresser, P.R. and Streilein, J.W. 1980. Epidermal Langerhans cell density determines whether contact hypersensitivity or unresponsiveness follows skin painting with DNFB. J. Immuno., 124: 445–453.  [Google Scholar]     

Pharmacokinetics of Total Thyroxine after Repeated Oral Administration of Levothyroxine Solution and its Clinical Efficacy in Hypothyroid Dogs

Background

Oral levothyroxine (l‐T₄) supplementation is commonly used to treat hypothyroid dogs.

Objectives

Investigate the plasma profile and pharmacokinetics of total thyroxine (tT₄) after PO administration of a l‐T₄ solution and its clinical efficacy in hypothyroid dogs.

Animals

Ten dogs with naturally occurring hypothyroidism.

Methods

After hypothyroidism diagnosis and supplementation with l‐T₄ solution PO q24h at 20 μg/kg BW for minimum 4 weeks, the plasma profile and pharmacokinetics of tT₄ were determined over 34 hours and the clinical condition of the dogs was evaluated.

Results

Before dosing for pharmacokinetic evaluation, mean tT₄ concentration was 23 ± 9 nmol/L. l‐T₄ was absorbed rapidly (t _max, 5 hours), reaching a mean maximal tT₄ concentration of 56 ± 11 nmol/L. The apparent terminal half‐life was 11.8 hours. Clinical signs of hypothyroidism improved or resolved in all dogs after 4 weeks of treatment. The dosage of 20 μg/kg PO q24h was judged appropriate in 5 dogs, and 4 dogs required slight increases (9–16%). Twice daily treatment, with a 30% increase in dosage, was necessary for 1 dog.

Conclusions and Clinical Importance

The pharmacokinetics of l‐T₄ in hypothyroid dogs was similar to that reported in healthy euthyroid dogs. Clinical and hormonal responses to l‐T₄ solution were rapid in all dogs. The starting dosage of 20 μg/kg PO q24h was suitable for maintenance supplementation in 50% of the dogs, minor dosage modification was required in 4 other dogs, and treatment q12h was required in 1 dog.     

Impact of daylength on the productivity of two commercial broiler strains

1. The impact of daylength on productivity in male and female broilers of two genotypes was studied in two replicated experiments. In each experiment, four lighting programs (14L:10D (14L), 17L:7D (17L), 20L:4D (20L) and 23L:1D (23L)) were used to study the relationships between productivity and daylength in two genotypes and both genders.

2. General Linear Model analysis was used to test for differences in daylength, genotype, gender and their interactions, and regression analysis to define relationships between productivity and daylength in experiment one and daylength differences in experiment two.

3. In experiment one, body weights at d 32 (P?=?0·002) and d 39 (P?=?0·011) were related in a quadratic fashion to daylength, with the heaviest birds raised under 20L. The growth curve at d 49 was similar in shape, and body weights under both 17L and 20L were significantly higher than under 14L and 23L (P? 4. Feed consumption was highest to d 39 or d 49 under 20L, and birds under 23L ate as much (d 39) or less feed (d 49) than under 17L.

5. Gain-to-feed efficiency (FCR) responded in a quadratic fashion, with maximum efficiency observed under the shortest daylength.

6. Mortality increased linearly with daylength for all time periods in both experiments.     

Some aspects of the pharmacology of pyrantel in the dog

Abstract

Extract

Acetylcholine and cholinesterase occur in many different species of unicellular and multicellular animals and their presence is oftenrelated to nerve and muscle activity and to movement. The substances occur in parasitic helminths and several modern anthelmintics appear to act by disrupting cholinergic mechanisms. One such group, the organophosphorous compounds, inactivate cholinesterase allowing preservation of endogenous acetylcholine and consequent interference with normal motor activity. A second group owes its basic mode of action to chemical and biological features shared with acetylcholine and acts, essentially, by mimicking the effects of excessive amounts of the natural neurotransmitter. Examples are, bephenium and thenium, both of which possess the configuration (Broome, 1962 Broome, A.W.J. 1962. “Mechanisms of anthelmintic action with particular reference to drugs affecting neuromuscular activity”. In Drugs Parasites and Hosts, London: Churchill. In [Google Scholar]) and methvridine, which has a -CH₂-CH₂-O-CH₃ grouping.     

Changes in plasma gonadotrophins, testosterone, prolactin, thyroxine and triiodothyronine concentrations in male Japanese quail (Coturnix coturnix japonica) of a heavy body weight line during photo-induced testicular growth and regression

1. Simultaneous changes of cloacal gland area (CGA) and plasma luteinising hormone (LH), follicle stimulating hormone (FSH), testosterone (T), prolactin (PRL), thyroxine (T₄) and triiodothyronine (T₃) during photo-induced testicular growth and regression were measured in commercially bred Japanese quail from a heavy body weight line.

2. Somatically mature male Japanese quail were transferred from short days (light:dark 8L:16D) at 10°C, to long days (16L:8D) at 20°C; and sexually mature male Japanese quail were transferred from long to short days. All variables were measured at transfer and every 5?d thereafter for 35?d.

3. Transfer from short to long days caused significant increases in LH, FSH, T and testis weight (TW) after 5?d, and in CGA after 10?d. T₃ decreased after 5?d, whereas T₄ increased significantly after 25 long days and PRL did not undergo any consistent change. The testicular growth rate was k?=?0·1146.

4. Transferring quail from long to short days caused significant decreases in LH and FSH after 5?d, and decreases in T, TW and CGA after 10?d. T₄ decreased after 5?d whilst T₃ increased significantly by day 15. PRL decreased significantly after 10?d then rose before declining again. The testicular regression rate was k?=?0·0582.

5. The rates of photo-induced testicular development and regression in a strain of large Japanese quail did not differ from rates reported for other strains of quail. CGA was a better indicator of TW than plasma T concentrations during growth and regression. The role of PRL in photo-induced reproductive cycles in male Japanese quail remains to be determined.

6. The photoperiod-induced changes in gonad size and hormone concentrations, together provide valuable information that can be used in future studies of the endocrinology and neuroendocrinology of photoperiodism in birds.     

Characteristics of ammonia and carbon dioxide releases from layer hen manure

1.?Ammonia (NH₃) is an important gaseous pollutant generated from manure in commercial poultry farms and has been an environmental, ecological, and health concern. Poultry manure also releases carbon dioxide (CO₂), which is a greenhouse gas and is often used as a tracer gas to calculate building ventilation.

2.?A 38-d laboratory study was conducted to evaluate the characteristics of NH₃ and CO₂ releases from layer hen manure using 4 manure reactors (122 cm tall, 38 cm internal diameter), which were initially filled with 66 cm deep manure followed by weekly additions of 5 cm to simulate manure accumulation in commercial layer houses.

3.?The average daily mean (ADM) NH₃ and CO₂ release fluxes for the 4 reactors during the entire study were 161?5 ± 21?1 µg/s.m² (ADM ± 95% confidence interval) and 10?0 ± 0?3 mg/s.m², respectively. The daily mean NH₃ and CO₂ releases in individual reactors varied from 35?2 to 679?1 µg/s.m² and from 6?6 to 20?5 mg/s.m², respectively.

4.?The ADM NH₃ release flux was within the range of those obtained in 4 high-rise layer houses by Liang et al. (2005 Liang, Y, Xin, H, Wheeler, EF, Gates, RS, Li, H, Zajaczkowski, JS, Topper, PA, Casey, KD, Behrends, BR, Burnham, DJ and Zajaczkowski, FJ. 2005. Ammonia emissions from US laying hen houses in Iowa and Pennsylvania. Transactions of the ASAE, 48: 1927–1941. [Crossref] [Google Scholar], Transactions of the ASAE, 48). However, the CO₂ release flux in this study was about 10 to 13 times as high as the data reported by Liang et al. (2005 Liang, Y, Xin, H, Wheeler, EF, Gates, RS, Li, H, Zajaczkowski, JS, Topper, PA, Casey, KD, Behrends, BR, Burnham, DJ and Zajaczkowski, FJ. 2005. Ammonia emissions from US laying hen houses in Iowa and Pennsylvania. Transactions of the ASAE, 48: 1927–1941. [Crossref] [Google Scholar]). Fresh manure had greater NH₃ release potential than the manure in the reactors under continuous ventilation. Manure with higher contents of moisture, total nitrogen, and ammonium in the 4th weekly addition induced 11 times higher NH₃ and 75% higher CO₂ releases immediately after manure addition compared with pre-addition releases.     

Effect of arginine supplementation on the morphology and function of intestinal epithelia and serum concentrations of amino acids in pigs exposed to heat stress

The exposure of pigs to heat stress (HS) appears to damage their intestinal epithelia, affecting the absorption of amino acids (AAs). Arg is involved in the restoration of intestinal epithelial cells but HS reduces Arg intake. The effect of dietary supplementation with Arg on the morphology of intestinal epithelia, AA transporter gene expression, and serum concentration (SC) of free AAs in HS pigs was analyzed. Twenty pigs (25.3 ± 2.4 kg body weight) were randomly assigned to two dietary treatments: Control (0.81% Arg), wheat–soybean meal diet supplemented with l-Lys, l-Thr, dl-Met, and l-Trp, and the experimental diet where 0.16% free l-Arg was supplemented to a similar Control diet (+Arg). All pigs were individually housed and exposed to HS, fed ad libitum with full access to water. The ambient temperature (AT), recorded at 15-min intervals during the 21-d trial, ranged on average from 29.6 to 39.4 °C within the same day. Blood samples were collected on day 18 at 1600 hours (AT peak); serum was separated by centrifugation. At the end of the trial, five pigs per treatment were sacrificed to collect samples of mucosa scratched from each small intestine segment. The expression of AA transporters in intestinal mucosa and the SC of AAs were analyzed. Villi height (VH) was higher (P < 0.01) in the duodenum, jejunum, and ileum but the crypt depth did not differ between the Control and the +Arg pigs. Supplementation of l-Arg increased the mRNA coding for the synthesis of the cationic AA transporter b^0,+ (P < 0.01) and the neutral AA transporter B⁰ (P < 0.05) in the duodenum by approximately 5-fold and 3-fold, respectively, but no effect on mRNA abundance was observed in the jejunum and ileum. The supplementation of l-Arg increased serum Arg, His, Met, Thr, Trp, and urea (P < 0.05) and also tended to increase Val (P < 0.10) but did not affect Ile, Lys, Leu, and Phe. These results indicate that supplementing 0.16% l-Arg to the Control diet may help to improve the function of the small intestine epithelium, by increasing the VH, the abundance of AA transporters, and the SC of most indispensable AAs in pigs exposed to HS conditions. However, the lack of effect of supplemental Arg on both Lys SC and weight gain of pigs suggests that increasing the Lys content in the +Arg diet might be needed to improve the performance of HS pigs.     

A preliminary experiment on the effect of selenium on the growth rate of calves

Abstract

Extract

Drake et al. (1960 Drake, C, Grant, A. B. and Hartley, W. J. 1960. N.Z. vet. J., 8: 7–7. [Taylor &; Francis Online] , [Google Scholar]) have shown that selenium will control outbreaks of lamb and hogget ill-thrift on the pumice soils of the Rotorua-Taupo area. As an ill-thrift problem also exists in calves on the newly-broken-in farms in the same area, it was decided to investigate the effect of oral selenium and other minerals in the control of this problem.     

Hairy shaker disease: Preliminary studies on the nature of the agent,and the induced serological response

Abstract

Extract

The nature of the agent causing hairy shaker disease of lambs in New Zealand is uncertain. A report by Manktelow et al. (1969) Manktelow, B. W., Porter, W. L. and Lewis, K. H. C. 1969. Hairy shaker disease of lambs. N.Z. vet. J., 17: 245–248. [Taylor &; Francis Online] , [Google Scholar] demonstrated the transmissibility of the disease, using homogenized tissue as the inoculum, and drew attention to its similarity on clinical and pathological grounds to the condition of Border disease found in the United Kingdom. Transmission of Border disease using homogenized tissues had been previously reported by Dickinson and Barlow (1967) Dickinson, A. G. and Barlow, R. M. 1967. The demonstration of the transmissibility of Border disease in sheep. Vet. Rec., 81: 114–114.  [Google Scholar], Shaw et al. (1967) Shaw, I. G., Winkler, C. E. and Terlecki, S. 1967. Experimental reproduction of hypomyelinogenisis congentia of lambs. Vet. Rec, 81: 115–116.  [Google Scholar] and Barlow and Gardiner (1969) Barlow, R. M. and Gardiner, A. C. 1969. Experiments in Border disease. I. Transmission, pathology and some serological aspects of the experimental disease. J. comp. Path., 75: 387–405.  [Google Scholar].     

Some investigations into the epidemiology of ovine toxoplasmosis

Abstract

Extract

Infection by the protozoan parasite Toxoplasma gondii is widespread in sheep in New Zealand and is recognized as the most common cause of intra-uterine infection leading to abortion and stillbirths (Hartley et al., 1954 Hartley, W. J., Jebson, J. L. and McFarlane, D. 1954. New Zealand Type II Abortion in ewes. Aust. vet. J., 30: 216–218.  [Google Scholar]; Hartley and Boyes, 1964 Hartley, W. J. and Boyes, B. W. 1964. Incidence of ovine perinatal mortality in New Zealand with particular reference to intra-uterine infections. N.Z. vet. J., 12: 33–36. [Taylor &; Francis Online] , [Google Scholar]). In view of the prevalence of this infection in New Zealand, trials were set up to investigate some aspects of the epidemiology of this perplexing disease.     

Diarrhoeal diseases of the calf: Observations on treatment and prevention

Abstract

Extract

During the past two decades intestinal absorptive and secretory functions and the intestinal flora have been significantly clarified. Important concepts of intestinal dysfunction have emerged which have proved of immense clinical value(32) Moon, H. W. 1974. Pathogenesis of Enteric Diseases Caused by Escherichia coli. Adv. Vet. Sci. Comp. Med, 18: 179–211. [PubMed] , [Google Scholar] (39) Phillips, S. F. 1972. Diarrhoea: A Current View of the Pathophysiology. Gastroenterology, 63: 495–518.  [Google Scholar] (46) Smith, H. W. 1965. Observations on the Flora of the Alimentary Tract of Animals and Factors Affecting its Composition. J. Pathol, 89: 95–122.  [Google Scholar] (47) Smith, H. W. 1971. The Bacteriology of the Alimentary Tract of Domestic Animals Suffering from E. coli Infection. Ann. N. Y. Acad Set, 176: 110–125.  [Google Scholar] (51) Soergel, K. H. 1973. New Concepts of Intestinal Function. Hepatogaslroenterol, 20: 351–358.  [Google Scholar]. Despite this, the medical and economic consequences of diarrhoea continue to beset the cattle industry(1) Barnum, D. A., Glantz, P. J. and Moon, H. W. 1967. Colibacillosis. CI_RV_eterinary Monograph Series/Two, : 5–44.  [Google Scholar] (18) Hubbert, W. T. 1974. Factors Affecting Survival of the Bovine Fetus and Neonate. Theriogenology, 1: 15–34.  [Google Scholar] (30) Marsh, H. 1968. Prenatal and Postnatal Mortality in Cattle. National Academy of Science. Pub. No. 1685,, : 1–6.  [Google Scholar] (56) Vollmar, R. E. 1974. Diarrhoea Control in a Dairy Operation. Mod Vet. Pract., 55: 509–512.  [Google Scholar] (57) White, R. G. Scours-The Calf Killer. Presented at the California Livestock Symposium. An. Nut. Health, pp.14–18.  [Google Scholar]. Diarrhoeal disease of the calf occurs at a time of complex developmental, environmental and functional change. The surface defences and enzyme systems of the neonatal gut are maturing in a protective film of maternal antibody, while undergoing increasing stimulation from environmental microbial challenge. The precarious nature of this defence system is not surprising. It is contingent upon a balance of such changing conditions as maternal antibody quantity, quality and delivery(5) Bush, L. J., Aguilera, M. A., Adams, G. D. and Jones, E. W. 1971. Absorption of Colostral Immunoglobulins by Newborn Dairy Calves. J. Dairy Sci., 54: 1547–1549.  [Google Scholar], environmental microbial challenge(46) Smith, H. W. 1965. Observations on the Flora of the Alimentary Tract of Animals and Factors Affecting its Composition. J. Pathol, 89: 95–122.  [Google Scholar] (47) Smith, H. W. 1971. The Bacteriology of the Alimentary Tract of Domestic Animals Suffering from E. coli Infection. Ann. N. Y. Acad Set, 176: 110–125.  [Google Scholar] and neonatal immunological and intestinal epithelial maturation(7) Corley, L. D., Staley, T. E., Bush, L. J. and Jones, E. W. 1977. Influence of Colostrum on Transepithelial Movement of E. coli 055. J. Dairy Sci., in press [Google Scholar] (52) Staley, T. E., Corley, L. D., Bush, L. J. and Jones, E. W. 1972. The Ultra-structure of Neonatal Calf Intestine and Absorption of Heterologous Proteins. A rial. Rec, 172: 559–579. [Crossref], [PubMed] , [Google Scholar]. While both infectious and non-infectious etiologic factors are involved(1) Barnum, D. A., Glantz, P. J. and Moon, H. W. 1967. Colibacillosis. CI_RV_eterinary Monograph Series/Two, : 5–44.  [Google Scholar] the former (Escherichia coli, Saltiionsllci and Shigella spp., and reo and corona viruses) is the more significant. Enteropathogenic E. coli (EPEC), a major contributor to neonatal diarrhoeal disease, will be discussed primarily. Four syndromes, septicaemia, enteric-toxaemia, local invasive and enterotoxic have been described(32) Moon, H. W. 1974. Pathogenesis of Enteric Diseases Caused by Escherichia coli. Adv. Vet. Sci. Comp. Med, 18: 179–211. [PubMed] , [Google Scholar] and ad verseoutcomes may result from endotoxic shock and/or hypovolemic shock, from systemic infection and from malnutrition. The clinician is thus faced with the selection of a multi-faceted approach to the problem. Avenues of attack, in addition to prophylactic husbandry, include: passive and active immunization, reduction of challenge, specific antimicrobial therapy, and resolution of fluid and electrolyte loss and shock. This presentation includes a resumé of the calf scour syndrome, together with observations concerning treatment and control. These observations include active and passive immunization, antimicrobial therapy, and modification of intestinal fluid loss.     

Failure to Induce Contact Hypersensitivity in the Opossum,Ittrichosurus Vulpecula

Abstract

Sir:- Contact hyypersensitivity (CHS; syn: contact allergy, contact dermatitis, contact eczema) is induced when chemicals (haptens) capable of binding covalently to autologous proteins are applied to the skin.(1) Claman,, H. N.,, Miller,, S. D.,, Conlon,, P. J. and Moorehead,, J. W. 1980. Advances in Immunology, Edited by: Dixon and, F. J. and Kunkel, H. G. 121–157. New York: Academic Press.  [Google Scholar]The hapten-protein complexes formed in this way are immunogenic and elicit the immune response underlying CHS. CHS is a form of delayed hypersensitivity. Exposure of a primed animal to the sensitising hapten results in erythema and induration at the site of skin contact, the response being maxima1 after 24 hours.     

Recent insecticides: Their efficacy as plunge dips against the biting louse,Damalinia ovis,and the ked,Melophagus ovinus,on sheep

Abstract

Extract

At the Wallaceville Animal Research Centre, Thomas (1958 Thomas, P. L. 1958. The control of lice (Damalinia ovis) and keds (Melophagus ovinus) — a comparison of the efficiency of common insecticides. N.Z. Jl agric. Res., 1: 217–223. [Taylor &; Francis Online] , [Google Scholar]) and Greenwood (1964 Greenwood, E. S. 1964. Louse control in sheep — a comparison of seven dipping preparations. N.Z. Jl agric. Res., 7: 382–385. [Taylor &; Francis Online] , [Google Scholar]) have tested a number of insecticides against biting lice and keds on sheep. The present paper reports hitherto unpublished work by Millar (nee Greenwood) up to 1966 and more recent work carried out since her departure.     

Some observations on reproductive performance in selected commercial beef herds

Abstract

Extract

Although the opinion has been expressed (Andrews, 1971 Andrews, E. D. 1971. Cobalt deficiency in sheep and cattle. N.Z. Dept. Agric. Bull., : 180–180.  [Google Scholar]) that cobalt deficiency among cattle has virtually disappeared in New Zealand and that specimens for laboratory examination are rarely required, 15 to 20% of the liver samples submitted by veterinarians to the Animal Health Reference Laboratory for vitamin B₁₂ assay are from cattle. Diagnostic criteria for cobalt (vitamin B₁₂) deficiency cy have long been established for sheep but not for cattle In view of the continuing requests for vitamin B₁₂ analyses on bovine livers, it was desirable to establish normal values for clinically normal cattle so that results of routine diagnostic analyses could be more readily interpreted.     

The occurrence of antibodies to bovine virus diarrhoea,infectious bovine rhinotracheitis and parainfluenza 3 viruses in sera from New Zealand cattle

Abstract

Extract

Despite many viruses having been isolated from bovine respiratory and intestinal tracts, only those of bovine virus diarrhoea (BVD), bovine parainfluenza 3 (PI 3) and infectious bovine rhinotracheitis-infectious pustular vulvovaginitis (IBR) have so far been associated with specific clinical complexes. Serological surveys have demonstrated the wide geographical distribution of all three viruses (Huck, 1962 Hack, R. A. 1962. Some recently isolated viruses from cattle. Vet. Bull., 32: 493–504.  [Google Scholar]; Paterson, 1962 Paterson, A. B. 1962. Virus diseases in calves. Vet. Rec., 74: 1384–1389.  [Google Scholar]; French and Snowdon, 1964 French, E. L. and Snowdon, W. A. 1964. Mucosal disease in Australian cattle. Aust. vet. J., 40: 99–105.  [Google Scholar]; Dawson and Darbyshire, 1964 Dawson, P. S. and Darbyshire, J. H. 1964. The occurrence and distribution in the United Kingdom of antibodies to parainfluenza 3 and infectious bovine rhinotracheitis viruses in bovine sera. Vet. Rec., 76: 111–115.  [Google Scholar]), although so far only IBR has been confirmed as being present in New Zealand (Webster and Manktelow, 1959 Webster, R. G. and Manktelow, B. W. 1959. Some observations on bovine rhinotracheitis in New Zealand. N.Z. vet. J., 7: 143–148. [Taylor &; Francis Online] , [Google Scholar]). However, in view of a previous outbreak of a mucosal-like disease (Salisbury etal., 1961 Salisbury, R. M., Hartley, W. J., Mcintosh, I. G., Hansen, N. F., Te Punga, W. A. and Jamieson, S. 1961. A mucosal disease-like syndrome of cattle in New Zealand. Bull. Off. int. Epiz., 56: 62–79.  [Google Scholar]) together with the frequent occurrence of upper respiratory tract symptoms, it seemed most unlikely that other members of this virus trio would be absent from cattle in this country.