The role of acidogenic diets and beta-hydroxybutyate on lymphocyte proliferation and serum antibody response against bovine respiratory viruses in Holstein steers

Acidogenic diets were evaluated for their effects on lymphocyte proliferation in response to Staphylococcus aureus exotoxin B (SEB), and specific lymphocyte proliferation and serum-neutralizing antibody titers to four bovine respiratory viruses in vitro. Four Holstein steer calves, with an average weight of 213 +/- 42 kg, were fed a basal (control) diet consisting of 49% forage and 51% concentrate (DM basis), with 15% CP (on a DM basis). Three additional treatment diets were used: 1) the basal diet supplemented with 700 mL/d of butylene glycol (BG) to induce ketoacidosis by increasing blood beta-hydroxybutyate (BHBA); 2) the basal diet supplemented with 1.2 +/- 0.1 kg/d of anionic salts (AS; Soychor 16.7, West Central Soy, Ralston, IA) to induce a metabolic acidosis; and 3) the basal diet with all forage replaced by finely ground corn and soybean meal blended to provide 15% CP (HG), to induce lactic acidosis. The calves were fed each diet for 21 d in a 4 x 4 Latin square design. Blood samples were collected on d 18, 19, and 20 of each 21-d period and analyzed for pH; concentrations of BHBA; in vitro lymphocyte proliferation to SEB, bovine viral diarrhea virus (BVDV), bovine respiratory syncytial virus (BRSV), parainfluenza-3 (PI-3), and bovine herpesvirus-1 (BHV-1); and titers of serum-neutralizing antibodies against the four viruses. Following treatment, the average pH of the serum samples was 7.38 for calves fed the control diet, 7.37 for the BG treatment, and 7.36 for the HG treatment, and was decreased (P < 0.05) to 7.33 for the AS treatment. All acidogenic diets decreased lymphocyte response to SEB (P < 0.05). The lymphocyte proliferative response, however, of each virus showed a different pattern of interaction with the three acidogenic diets tested. The AS diet was associated with increased lymphocyte proliferative response to BVDV and BRSV (P < 0.01) and increased serum neutralization titers to BHV-1 (P < 0.05). In calves fed the BHBA-inducing diet (BG), an increase in lymphocyte proliferation to BRSV was observed (P < 0.05). A similar relationship to blood BHBA concentration was not observed with the lymphocyte proliferation to BVDV, PI-3, or BHV-1. Titers of serum-neutralizing antibody against PI3 (P < 0.05) and BHV-1 (P < 0.01) were negatively correlated with blood pH, and titers of serum neutralizing antibodies to BHV-1 were negatively correlated to elevated circulating concentrations of BHBA (P < 0.05).     

Trilostane treatment of a dog with functional adrenocortical neoplasia

A 13-year-old, crossbreed dog presented with a history of recent onset polydipsia, progressive lethargy, weakness and reduced appetite. Blood tests showed raised concentrations of alkaline phosphatase and alanine aminotransferase with marginally low serum potassium. There was a leucocytosis with a mature neutrophilia and no eosinophils. Endocrine tests showed a normal aldosterone concentration and an exaggerated adrenocorticotropic hormone (ACTH) stimulation test, consistent with a diagnosis of hyperadrenocorticism (HAC). A diagnosis of adrenal-dependent HAC was made, based on the presence of a calcified mass involving the left adrenal gland, and hepatomegaly, on radiography and ultrasonography. The owners declined surgical adrenalectomy. Medical management with trilostane rapidly improved the clinical signs and normalised the serum chemistry. ACTH stimulation tests showed an improvement in post-ACTH cortisol concentrations and were used to make dose adjustments where necessary. At the time of writing, no adverse side effects had been seen and the dog remained well after 80 weeks of treatment.     

Feline infectious disease control in shelters.

No single factor determines whether a population remains healthy or disease rages out of control. All host and environmental factors taken together provide a number of tools to protect the vulnerable feline shelter population,however. A well-conceived infectious disease control program contributes to improved public perception, increased adoptions, and a healthier feline population within the shelter and in the community in general.     

Transfer of maternal colostral leukocytes promotes development of the neonatal immune system I. Effects on monocyte lineage cells

Although it has been established that maternal leukocytes traffic from colostrum into the neonatal circulation, the effects of these cells on neonatal immunity are only beginning to be understood. This study examined the effects of maternal colostral leukocytes on development and maturation of neonatal antigen presenting cells. At birth, groups of neonatal calves received whole or cell-free colostrum (CFC) from their respective dams. Peripheral blood samples were obtained over the first 4 weeks of life, and expression of surface markers associated with cellular activation and physiological stress were monitored on monocyte lineage cells. Calves receiving cell-free colostrum at birth expressed elevated levels of CD11a, CD11c, and CD14, compared to calves receiving whole colostrum (C). Calves receiving cell-free colostrum had an elevated number of monocytes in the peripheral blood during the first 2 weeks of life, however, these cells expressed lower levels of expression of CD25 and MHC class I compared to calves receiving whole colostrum. The most significant differences in marker expression occurred within the first 7 days of life.     

Transfer of maternal colostral leukocytes promotes development of the neonatal immune system Part II. Effects on neonatal lymphocytes

It has been established that maternal leukocytes, conditioned by the mammary environment, cross the neonatal gut and circulate in the newborn calf. However, the impact of these cells on the development of neonatal immunity remains to be determined. This study examined the effects of maternal colostral leukocytes on development and maturation of neonatal adaptive immunity by examining the expression of surface markers on neonatal lymphocytes. At birth, neonatal calves were fed whole colostrum, or colostrum that had the maternal cells removed (cell-free colostrum), from their respective dams. Peripheral blood samples were collected at regular intervals over the first 4 weeks of life and lymphocytes were evaluated for surface expression of cellular markers. The results of these studies demonstrated that calves receiving whole colostrum had fewer CD11a positive lymphocytes in circulation during the first 2 weeks of life and this marker was expressed at a lower density than calves receiving cell-free colostrum. In addition, calves receiving whole colostrum also had a higher percentage of lymphocytes expressing the activation markers CD25 and CD26 by 7 days after birth. During the first week of life, lymphocytes from calves receiving whole colostrum had a higher density of MHC class I expression on their surfaces than cells from calves receiving cell-free colostrum. In general, these results indicate that transfer of maternal cells with colostrum allows for more rapid development of lymphocytes and maternal cells appeared to enhance their activation.     

Serum lactoferrin and immunoglobulin G concentrations in healthy or ill neonatal foals and healthy adult horses

BACKGROUND: Lactoferrin is a colostral glycoprotein with antimicrobial properties. HYPOTHESES: (1) Serum lactoferrin and immunoglobulin G (IgG) concentrations are correlated and increase in healthy foals after ingestion of colostrum; (2) compared to healthy foals, ill foals will have lower lactoferrin concentrations that correlate with their IgG concentration, neutrophil count, the diagnosis of sepsis, and survival; and (3) plasma concentrations of lactoferrin will be less than serum concentrations. ANIMALS: Healthy foals (n = 16), mature horses (n = 10), and ill foals 1-4 days old (n = 111) that were examined for suspected sepsis were used for blood collection. Colostrum was obtained from 10 healthy mares unrelated to the foals. METHODS: Blood was obtained from the healthy foals at birth and 1-3 days of age and from the ill foals at admission. Serum IgG was quantified by single radial immunodiffusion (SRID). Lactoferrin concentrations in colostrum and blood were determined by an enzyme-linked immunosorbant assay. The sepsis score, blood culture results, neutrophil counts, and survival were obtained on ill foals. RESULTS: The mean colostral lactoferrin concentration was 21.7 microg/mL. Compared to values at birth, serum IgG (18+/-2 versus 2,921+/-245 mg/dL, SEM) and lactoferrin (249+/-39 versus 445+/-63 ng/mL, SEM) concentrations were significantly greater in healthy foals 1-3 days old. Serum lactoferrin concentration in 1-3-day-old healthy foals was not different from mature horses or ill foals. IgG and lactoferrin concentrations were significantly correlated only in healthy foals. Serum lactoferrin concentrations were significantly lower in ill neutropenic foals. The serum IgG concentration was significantly lower in ill foals as compared to healthy foals. Only serum IgG was significantly less in ill foals with a positive sepsis score and in nonsurvivors, Plasma lactoferrin concentrations were lower than serum concentrations, although values were significantly correlated. CLINICAL IMPORTANCE: Although both serum IgG and lactoferrin concentrations increase in healthy foals after ingestion of colostrum, only serum IgG is significantly correlated with the sepsis score and outcome.     

Serratia liquefaciens mastitis in a dairy herd

Serratia liquefaciens mastitis was detected and investigated in a 41-cow Holstein herd. Twenty cows were treated for mastitis over a 3-month period. Serratia liquefaciens was isolated from milk samples obtained from 8 of 12 cows tested during the epizootic. Results of an epidemiologic investigation suggested that extensive frostbite of the teats decreased the udder defense. Poor milking technique and hygiene were responsible for increased exposure of the damaged teats to potential udder pathogens. Treatment of each cow resulted in initial clinical improvement, but exacerbations occurred in 75% of the cows with documented S liquefaciens infections.     

Energy Metabolism and Leptin: Effects on Neuroendocrine Regulation of Reproduction in the Gilt and Sow

It is well established that reproductive function is metabolically gated. However, the mechanisms whereby energy stores and metabolic cues influence appetite, energy homeostasis and fertility are yet to be completely understood. Adipose tissue is no longer considered as only a depot to store excess energy. Recent findings have identified numerous genes, several neurotrophic factors, interleukins, insulin-like growth factor binding protein-5, ciliary neurotrophic factor and neuropeptide Y (NPY) as being expressed by adipose tissue during pubertal development. These studies demonstrated for the first time the expression of several major adipokines or cytokines in pig adipose tissue which may influence local and central metabolism and growth. Leptin appears to be the primary metabolic signal and is part of the adipose tissue-hypothalamic regulatory loop in the control of appetite, energy homeostasis and luteinizing hormone (LH) secretion. Leptin's actions on appetite regulation are mediated by inhibition of hypothalamic NPY and stimulation of proopiomelanocortin. Its effects on gonadotropin-releasing hormone (GnRH)/LH secretion are mediated by NPY and kisspeptin. Thus, leptin appears to be an important link between metabolic status, the neuroendocrine axis and subsequent fertility in the gilt and sow.