Sheep and goats raised in mixed flocks have diverse immune status around parturition.

Several physiological and metabolic changes take place in dairy ruminants around parturition (late pregnancy, parturition, and early lactation). Dairy species are genetically selected for their higher milk production compared with non-dairy species. This fact causes a constant stress that impairs the immune status of the animal, with consequences for its welfare and performance. In the present study, we assessed the immune status of high-yield dairy sheep and goats by quantifying IgG and IgM concentrations, as well as chitotriosidase (ChT) and complement system [total complement system (TC) and alternative complement pathway (AC)] activity in blood plasma around parturition. We also measured IgG and IgM concentrations and ChT activity in colostrum and milk during the first 40 d postpartum. The lowest blood IgG concentration was at parturition in both species. We detected no differences in blood IgG concentrations between species. Blood IgM concentrations were constant in both species throughout the study period. However, blood IgM concentrations were greater in sheep than in goats. Blood ChT activity was greater in goats than in sheep, and both species showed constant activity of this enzyme throughout the study period. We observed no differences in complement system (TC and AC) activity between sheep and goats. In addition, both TC and AC activity were constant in both species throughout the experiment. In general, IgG and IgM concentrations were greater in sheep colostrum than in goat colostrum, but these differences disappeared after d 4 (IgG) and d 3 (IgM) postpartum. In both species, the highest IgG and IgM concentrations were measured in colostrum, gradually decreasing during the first days postpartum. Chitotriosidase activity decreased in both species from colostrum to milk, although goats always showed greater ChT activity than sheep. Both sheep and goats seemed to be more susceptible to infectious diseases around parturition. As well, goats showed greater ChT activity in blood, colostrum, and milk than sheep. This fact may give these animals additional protection against parasite and fungal infections.

Effects of supplemental ß-carotene on colostral immunoglobulin and plasma ß-carotene and immunoglobulin in Japanese Black cows.

Data from 26 Japanese Black cows were collected to clarify the effects of supplemental ß-carotene on colostral immunoglobulin (Ig) and plasma ß-carotene and Ig in the cows. Cows were assigned to control or ß-carotene groups from 21 days before the expected calving date to 60 days after parturition. Supplemental ß-carotene was provided at 500 mg/day in the ß-carotene group. Supplemental ß-carotene drastically increased plasma ß-carotene concentrations in the cows from parturition to 60 days after parturition, and plasma ß-carotene concentrations in the control and ß-carotene groups at parturition were 202 and 452 µg/dl, respectively. Supplemental ß-carotene had no effects on plasma IgG1 , IgA or IgM concentrations at parturition. Supplemental ß-carotene increased colostral IgG1 concentrations in the cows, but colostral ß-carotene, IgA and IgM concentrations were not affected by supplemental ß-carotene. These results indicate that supplemental ß-carotene is effective to enhance colostral IgG1 concentrations and plasma ß-carotene concentrations in Japanese Black cows.

Serum and colostral antibody production in cows immunized with recombinant human tumor necrosis factor.

The use of hyper-immune bovine colostrum as a human therapeutic platform is an emerging technology with potential to deliver the efficacy of antibody therapeutics with the convenience and safety of oral or topical application. It is necessary to understand how the bovine immune system responds to immunization with foreign proteins, both in terms of the serum antibody response and the transfer of antigen-specific antibodies into the colostrum to enable efficient large-scale production of therapeutic antibodies. We have immunized 25 cows with recombinant human tumor necrosis factor (rhTNF) and measured the levels of rhTNF-specific antibodies in the serum and colostrum of these animals. We observed a decline of 84±9% in serum IgG1 concentrations in the final weeks of pregnancy that presumably reflects rapid transport of IgG1 into colostrum. The serum IgG2 levels remained constant, such that the serum IgG1 to IgG2 ratio was 1:20 at parturition. We observed substantial animal-to-animal variability in the levels of anti-rhTNF antibodies in both serum and colostrum samples. In particular, a subset of 4 cows had extraordinarily high colostral anti-rhTNF antibody production. Only a weak correlation was found between the peak serum anti-rhTNF activity and the colostral anti-rhTNF activity in these animals. The 4 cows with high colostral anti-rhTNF activities trended toward higher serum IgG1 loss relative to average colostral anti-rhTNF producers, but this difference was not statistically significant in this small sample. The high-anti-rhTNF-producing cows also exhibited a greater proportion of rhTNF-specific antibodies that bound to bovine IgG1- and IgG2-specific detection antibodies relative to the total anti-rhTNF immunoglobulin population. This finding suggests that the isotype distribution of the anti-rhTNF response is varied between individuals and genetic or environmental factors may increase the yield of antigen-specific colostral antibodies.

Dietary polyunsaturated fatty acids from flaxseed affect immune responses of dairy sheep around parturition.

The objective of the study was to characterize the immune profile of dairy ewes fed flaxseed, rich in polyunsaturated fatty acids (PUFA), around parturition. The hypothesis to be verified was that a physiological stressor, such as parturition, could be overcome with a nutritional manipulation in the diet of the animal in order to guarantee welfare of animals and to sustain their immune responses. Twenty Comisana ewes were divided in two groups (10 ewes/group), and fed a supplementation of whole flaxseed in the diet (FS group) or no supplementation (CON group). Blood samples were collected at parturition and then 7, 14, 21, 28, and 42 day post partum. Plasma samples were used to assess the humoral immune response after ovalbumin (OVA) immunization. At parturition, at 14 day, and 42 day post partum the level of plasma cytokines was assessed. The sheep showed a reduced responsiveness to OVA immunization. In FS ewes the IL-6 level remained unchanged until 14 day post partum and then significantly decreased from 14 day to 42 day post partum. IL-10 level was significantly higher in FS ewes than in CON ewes at 14 day. At parturition IL-1ß level was significantly lower in FS ewes than in CON ewes and significantly decreased in both groups from parturition to 42 day. In conclusion, PUFA from flaxseed, as supplement in the diet of ewes around parturition can modulate sheep immune reactivity by influencing cytokine production.

The association of month of birth with atopy in adult patients with asthma and rhinitis in Anatolia, Turkey.

BACKGROUND: Exposure to allergens in early life may predispose subjects to develop allergies and diseases related to allergic sensitisation. OBJECTIVE: To determine the association between month of birth and atopic sensitisation in adult Turkish patients with rhinitis and/or asthma using the diagnostic method of skin prick tests. METHODS: This prospective cross-sectional study included all adult patients who underwent skin prick testing with rhinitis and asthma from November 2009 to June 2010. Sensitisation was categorised as any sensitisation, pollen sensitisation, and house dust mite sensitisation. Multivariate logistic regression model was employed with the primary predictor being month of birth. Diagnosis (asthma, rhinitis and both), age, gender and family history of atopy were considered as potential confounders in the model. The associations were presented with both unadjusted and adjusted odds ratios (OR) and their 95% confidence interval (CI). RESULTS: A total of 616 subjects were evaluated. Three-hundred and forty-one subjects had sensitisation to allergens according to skin prick tests. Analyses showed that subjects born in September were less likely to have documented skin test positively with pollen sensitisation [0.27 (0.09-0.84), p=0.023]. CONCLUSION: The results support the hypothesis that being born at the end of the pollen season may protect subjects from pollen sensitisation.

IgG and IgM levels in dairy cows during the periparturient period.

In dairy cows, the incidence of infectious diseases during the periparturient period is high. The most common diseases ante partum (a.p.) and post partum (p.p.) are mastitis and puerperal toxicaemia, puerperal septicaemia, and chronic endometritis, respectively. Studies suggest that this is related to an immunosuppressed status during this period. Therefore, the aim of this study was to determine the periparturient immune status characterized by concentrations of IgG and IgM in peripheral blood and colostrum samples of dairy cows and to assess in detail whether variations in immunoglobulin levels may be related to age and status of productivity. In addition, a possible correlation between the course of immunoglobulin levels and lymphocyte concentrations was assessed. Eighteen clinically healthy German Holstein and Red Holstein dams were selected for this study and sampled regularly between the 8(th) week a.p. and the 4(th) week p.p. IgG and IgM levels were determined using two novel competitive ELISAs. Results demonstrated a dramatic decrease of serum IgG and IgM levels beginning at the 8(th) week and 4(th) week a.p., respectively, both reaching trough at parturition. The IgG level recovered by the 4(th) week p.p., while IgM concentrations remained low. The extent of IgG reduction seemed to be dependent on the initial IgG concentration when the cow was dried-off (8(th) week a.p.). In contrast to IgM, the degree of IgG reduction correlated significantly with the IgG concentrations in the colostrum. Furthermore, a cross-correlation between the IgG levels and the lymphocyte counts was detectable (P < 0.01). In conclusion, the antepartal decline of blood IgG and IgM levels as well as the low periparturient IgG levels could reflect a "physiological phenomenon" of dairy cattle. If the phenomenon is associated with an unstable immune system, it must be assessed in future studies. Nonetheless, a sensitive immune system could explain the high incidence for infectious diseases during this period.

Specific IgG activity against diarrheagenic bacteria in bovine immune milk and effect of pH on its antigen-binding activity upon heating.

Bovine colostrum and milk antibodies of calving and lactating cows immunized with a multivalent vaccine consisting of whole cells of three different species of pathogenic bacteria including four strains of enterotoxigenic Escherischia coli, five strains of enteropathogenic Esch. coli, three strains of enteroinvasive Esch. coli, two strains of Samonella typhi, and one strain each of Shigellia dysenteriae, Sh. sonnei and Sh. flexneri were generated, respectively. A significantly elevated activity and titre of specific IgG from bovine immune colostrum were seen for only 5 days after calving of immunized cows, however, the levels of specific IgG could be obtained continuously from the milk of immunized lactating cows until the 11th week of the entire experiment period. Subsequently, we observed that the high specific IgG activity in immune milk was relatively stable under pH 5.0-7.0 at 37 degrees C. Of importance, we identified that the specific IgG preserved its biological function for high antigen-binding activity at pH 5.5-6.5 for 30 min of heat treatment at 70 degrees C and for 350 s at 72 degrees C. Our findings suggest that the specific IgG from milk antibodies of immunized lactating cows may be used as an abundant source of hyper-immune products for prevention of multibacteria-induced diarrhea, however, the effect of pH on its antigen-binding activity upon heating should be carefully considered and designed.

Consequences of infection pressure and protein nutrition on periparturient resistance to Teladorsagia circumcincta and performance in ewes.

The consequences of protein nutrition on the degree of periparturient relaxation of immunity to nematode parasites in sheep may be more pronounced at higher levels of infection pressure. Here, we investigated interactive effects of metabolizable protein (MP) nutrition and infection pressure on resistance and lactational performance of ewes. Twin-rearing ewes were trickle infected with either 1000, 5000 or 10,000 infective Teladorsagia circumcincta larvae and fed either at 0.8 (low protein, LP) or 1.3 (high protein, HP) times their estimated MP requirement. Expected interactions between feeding treatment and infection pressure were not observed. Periparturient relaxation of immunity, as indicated by variation in faecal egg counts, was higher in LP ewes than in HP ewes and FEC showed an inverse relationship with infection pressure indicating possible density dependency effects on worm fecundity. Plasma pepsinogen concentration linearly increased with infection pressure. Daily total nematode egg excretion, assessed at week three of lactation, was not significantly affected by infection pressure but was reduced by 65% in HP ewes compared to LP ewes. MP supplementation improved lamb performance but had little effect on ewe body weight and plasma protein concentrations, whilst lactational performance, as judged from lamb performance, tended to be reduced with increased infection pressure. The results suggest periparturient MP supplementation to ewes reduces nematode egg excretion independent of infection pressure and improves lactational performance of parasitized ewes even in the presence of moderate MP scarcity.