Role of Kisspeptin in Regulation of Reproductive and Immune Reactions.

The work is focused on physiological role of the hormone kisspeptin produced by neurons of the hypothalamus anterior zone, which is a key regulator of reproduction processes. Role of the hormone in transmission of information on metabolic activity and induction of the secretion of gonadotropin-releasing hormone (GnRH) by the hypothalamus that determines gestation processes involving fertilization, placentation, fetal development, and child birth is considered. The literature data on molecular mechanisms and effects of kisspeptin on reproductive system including puberty initiation are summarized and analyzed. In addition, attention is paid to hormone-mediated changes in the cardiovascular system in pregnant women. For the first time, the review examines the effect of kisspeptin on functional activity of immune system cells presenting molecular mechanisms of the hormone signal transduction on the level of lymphoid cells that lead to the immune tolerance induction. In conclusion, a conceptual model is presented that determines the role of kisspeptin as an integrator of reproductive and immune functions during pregnancy.

Effects in broiler hens of genetic lines differing in fertility, biotin supplementation, and age on relative abundance of oviductal transforming growth factor-ß and carbonic anhydrase mRNA transcripts.

There was evaluation of effects of biotin administration on oviductal abundance of transforming growth factor-ß (TGF-ß) and carbonic anhydrase (CA) mRNA transcript in younger and older broiler hens of relatively lesser and greater fertility lines. Additionally, effects of biotin supplementation on attenuation of age-related subfertility were evaluated. Hens from the relatively greater (Line D, n = 60) and lesser (Line B, n = 60) fertility rate line were randomly assigned to three treatment groups. Biotin was not or was administered in drinking water from 30 to 33 (younger age) and 53 to 56 (older age) wk of age to have access to no biotin (T0), or 0.3 (T1), or 0.45 (T2) mg/L of biotin. There was assessment the relative oviductal abundances of TGF-ß and CA mRNA transcript abundances. Supplemental biotin and age had no effect on the relative abundance of oviductal TGF-ß mRNA transcript in hens of Line D. There, however, was a ten-fold greater abundance of TGF-ß in hens of the T0 group of Line B compared with Line D. Relative abundance of TGF-ß mRNA transcript was greater in younger hens of Line B; however, biotin supplementation of older hens of the T2 group of Line B resulted in a similar TGF-ß abundance to that of younger hens. Inconstant with the TGF-ß abundance, CA abundance in hens of Line B was not affected by supplemental biotin or bird age. Overall, differences in TGF-ß or CA abundances did not affect fertility of broiler hens.

Protective Effect of Vitamin E on laying performance, antioxidant capacity, and immunity in laying hens challenged with Salmonella Enteritidis.

Vitamin E (VE) has proven to function as potent lipid-soluble antioxidant, a signaling molecule, and a regulator of the immune system. The objective of the study was to assess the protective effect of VE on laying performance, antioxidant capacity, and immunity in laying hens exposed to Salmonella Enteritidis (SE). A total of 80 32-week-old salmonella-free double negative Hy-Line brown laying hens were randomly assigned to 4 treatments with 20 replicates each (1 bird per replicate) according to a 2 × 2 factorial design with 2 VE supplementation levels [0 IU/kg (VE0) vs. 30 IU/kg (VE30)], and 2 challenge treatments [SE vs. physiological saline solution (PS)]. During the last 3 D of week 43 of age, birds were orally challenged with 1.0 mL suspension of 109 cfu/mL S. Enteritidis daily, whereas the birds of negative treatments (VE0) received the same volume of PS. The egg mass of VE0 treatment decreased (P < 0.05) in contrast to VE treatment after challenge. The serum concentrations of interleukins (IL-1ß and IL-6) and malondialdehyde (MDA) levels of SE treatments increased (P < 0.05) at week 44 and week 46, respectively. In both VE30 treatments, the decrease (P < 0.05) in birds' mortality was associated with higher IgA, IgG, IgM concentrations at week 44, and higher IgA, IgM concentrations at week 46. There is an interaction (P < 0.05) between SE challenge and VE levels with regard to feed conversion, daily egg mass, and serum MDA, IgA, and IgM levels. It can be concluded that supplemental VE (30 IU/kg) in diets for laying hens may alleviate oxidative and immune stress due to SE challenge.

Aggravation of cyclophosphamide-induced reproductive toxicity in mice by aqueous extract of Aegle marmelos (L. )

ABSTRACT Aegle marmelos (L.) (Rutaceae) commonly known as bael is an important medicinal fruit tree. The present study focused on the effects of aqueous extract of Aegle marmelos (AEAM) on the testis and sperm characteristics induced by cyclophosphamide (CPA) in mice. Thirty six adult Parke's strain mice were divided into six groups: group I given only distilled water (control); group II administered with AEAM alone once in a week for five weeks; group III administered with CPA (200 mg/kg b.w., intraperitoneally) once in a week for five weeks and group IV-VI CPA along with AEAM (400, 500 and 600 mg/kg b.w., orally). CPA was found to reduce gonadosomatic index (GSI), sperm counts, motility, viability, antioxidant activities and induced histopathological changes of testis. In the group administered AEAM with CPA an exacerbation of sperm count, motility and viability of the cauda epididymis, GSI, antioxidant activities and architecture of testis was observed. The results suggest that the administration of AEAM may aggravate CPA-induced reproductive toxicity. It may be helpful in preparation of natural male contraceptives.

Cloning and expression of two hepcidin genes in the mudskipper (Boleophthalmus pectinirostris) provides insights into their roles in male reproductive immunity.

The mudskipper Boleophthalmus pectinirostris is a burrow-dwelling fish inhabiting intertidal mudflats. During the spawning season, in a spawning chamber located at the center of their burrow, a pair of male and female fish mate and fertilized eggs adheres onto the inner walls and ceiling with filamentous attachments. During 5 days of incubation, the fertilized eggs are kept clean and hatch with a very high hatching rate under the natural conditions filled with microorganisms. This suggests that the male and/or female reproductive tract may synthesize antimicrobial substances to offer protection against microorganisms that may be deleterious to fertility. To study the antimicrobial strategy of this fish in the spawning season, we first cloned the two hepcidin isoforms from B. pectinirostris, and designated them as Hepcidin-1 and Hepcidin-2 based on phylogenetic analyses. Both of these hepcidin isoforms were highly expressed in the liver, but only Hepcidin-1 showed significant change in response to iron overload. Interestingly, these two hepcidin isoforms were expressed in male reproductive tracts, i.e. the testes and seminal vesicles. The monthly expression pattern indicated that Hepcidin-1 transcript levels showed a peak point only in March (before spawning) in the seminal vesicle, while Hepcidin-2 transcript levels were correlated with male reproductive status and reached their highest level in May (the peak spawning period). Under experimental conditions, the expression of these two hepcidin isoforms showed no response to iron overload in the male gonad. However, after lipopolysaccharide injection, the Hepcidin-1 transcript level was significantly up-regulated in the testes and seminal vesicle 6 h post injection, while Hepcidin-2 transcript levels exhibited a clear time-course dependent upregulation pattern and reached the highest levels 24 h post injection. More interestingly, after injection with LHRH-A3, the expression of Hepcidin-2 was significantly up-regulated in both testes and seminal vesicle. Results from in situ hybridization showed that Hepcidin-2 was expressed in the Leydig cells of the testes and in the epithelium of the seminal vesicle. Taken together, the results from our study indicated that these two hepcidin isoforms in the mudskipper may have different functions: Hepcidin-1 may play a dual role in both iron metabolism regulation in the liver and a short antimicrobial response in male reproductive tracts, while Hepcidin-2 is more specialized in reproductive immunity in male reproductive tracts.

Stingless bees (Melipona subnitida) adjust brood production rather than foraging activity in response to changes in pollen stores.

Highly eusocial bees (honey bees and stingless bees) sustain their colonies through periods of resource scarcity by food stored within the nest. The protein supply necessary for successful brood production is ensured through adjustments of the colonies' pollen foraging according to the availability of this resource in the environment. In honey bees Apis mellifera, in addition, pollen foraging is regulated through the broods' demand for this resource. Here, we investigated the influence of the colony's pollen store level on pollen foraging and brood production in stingless bees (Melipona subnitida). When pollen was added to the nests, colonies increased their brood production and reduced their pollen foraging within 24 h. On the other hand, when pollen reserves were removed, colonies significantly reduced their brood production. In strong contrast to A. mellifera; however, M. subnitida did not significantly increase its pollen foraging activity under poor pollen store conditions. This difference concerning the regulation of pollen foraging may be due to differences regarding the mechanism of brood provisioning. Honey bees progressively feed young larvae and, consequently, require a constant pollen supply. Stingless bees, by contrast, mass-provision their brood cells and temporary absence of pollen storage will not immediately result in substantial brood loss.

Effect of dietary vitamin A on reproductive performance and immune response of broiler breeders.

The effects of dietary vitamin A supplementation on reproductive performance, liver function, fat-soluble vitamin retention, and immune response were studied in laying broiler breeders. In the first phase of the experiment, 1,120 Ross-308 broiler breeder hens were fed a diet of corn and soybean meal supplemented with 5,000 to 35,000 IU/kg vitamin A (retinyl acetate) for 20 weeks. In the second phase, 384 Ross-308 broiler breeder hens were fed the same diet supplemented with 5,000 to 135,000 IU/kg vitamin A (retinyl acetate) for 24 weeks. The hens' reproductive performance, the concentrations of vitamins A and E in liver and egg yolk, liver function, mRNA expression of vitamin D receptor in duodenal mucosa, antibody titers against Newcastle disease virus vaccine, and T-cell proliferation responses were evaluated. Supplementation of vitamin A at levels up to and including 35,000 IU/kg did not affect reproductive performance and quadratically affected antibody titer to Newcastle disease virus vaccine (p<0.05). Dietary addition of vitamin A linearly increased vitamin A concentration in liver and yolk and linearly decreased α-, γ-, and total tocopherol concentration in yolk (p<0.01) and α-tocopherol in liver (p<0.05). Supplementation of vitamin A at doses of 45,000 IU/kg and above significantly decreased egg weight, yolk color, eggshell thickness and strength, and reproductive performance. Dietary vitamin A significantly increased mRNA expression of vitamin D receptor in duodenal mucosa (p<0.05), increased aspartate amino transferase activity, and decreased total bilirubin concentration in serum. Supplementation of vitamin A at 135,000 IU/kg decreased the proliferation of peripheral blood lymphocytes (p<0.05). Therefore, the maximum tolerable dose of vitamin A for broiler breeders appears to be 35,000 IU/kg, as excessive supplementation has been shown to impair liver function, reproductive performance, and immune response.

Effects of lipopolysaccharide exposure at different postnatal time points on the response of LH to homotypic stress in adulthood.

Early-life immune stress may have long-lasting effects, known as programming effects, on the physiological response to stress in adulthood. There may be a critical window after birth during which such a challenge can induce long-lasting alterations. However, there are few reports regarding the consequences of this phenomenon for later reproductive function. Here we report on induction by early-life LPS injection of long-lasting alterations in the adult LH response to homotypic immune stress in male rats. First, we investigated developmental changes in the LH response to LPS, since immune challenge during the stress hyporesponsive period can induce long-lasting effects on physiological functions. Rat serum LH concentrations were decreased by LPS (100 µg/kg) injection on postnatal day 15 or 25, but not day 10, suggesting that the period prior to postnatal day 10 is the stress hyporesponsive period for LH. Serum LH concentrations and body weight were decreased by adult LPS (400 µg/kg) injection in rats given saline or LPS (100 µg/kg) on postnatal day 25, but not in rats given LPS (100 µg/kg) on postnatal day 10. Expression of hypothalamic IL-1ß and TNF-α mRNA, which suppress serum LH during immune stress, were equally increased in these groups by adult LPS (400 µg/kg) injection. The present data suggest that the period prior to postnatal day 10 is the critical window in which immune stress can induce long-lasting alterations in the LH response, but that IL-1ß and TNF-α are not involved in mediating the altered response.

Vitamin a supplements alleviate inflammatory responses in reproductive tracts of male mice infected with pseudorabies virus.

Vitamin A is largely thought to have immune potential for mammal health; however, no conclusive mechanisms exist regarding its role in the pathogen-initiated innate immune response, or in the linkage between the innate and adaptive immune system during sperm formation in the male reproductive tract. Therefore, this study was conducted to evaluate the nutritional protective effect of vitamin A supplementation on reproductive performance and immune function of the male mouse challenged with pseudorabies virus (PRV). Sperm quality, testis toll-like receptors (TLRs) mRNA expression levels, and serum concentration of cytokines and immunoglobulins at 7 or 14 days post-injection were compared between control mice and PRV-challenged mice fed the same diet supplemented with vitamin A at 0, 4000, 10,000, 25,000 and 50,000 IU/kg, respectively. PRV- and phosphate buffered saline (PBS)-injection were performed when the mice in the unsupplemented group were marginally deficient in vitamin A. Sperm quality (sperm density and deformity ratio) of PRV-injected mice was significantly harmed by PRV, but this effect was attenuated by increased vitamin A consumption. Vitamin A supplements also attenuated PRV-challenge-induced increase in testis TLR3, TLR7, and TLR9 mRNA expression and serum pro-inflammatory cytokine (gamma interferon, IFN-gamma; and interleukin 1-beta,IL-1beta) concentration, and decrease in serum anti-inflammatory cytokine (IL-10) concentration. Higher than normal vitamin A consumption was recommended to counteract the deleterious effects of viral invasion, possibly through the downregulated expression of TLRs, and thus to improve immunity and reproductivity of male mice challenged with an invading pathogen.

Correlação entre os métodos de concepção, ocorrência e formas de tratamento das onfalopatias em bovinos: estudo retrospectivo / Correlation between conception methods, occurrence, and type o treatment of the umbilical diseases in cattle: a retrospective study

Alguns problemas têm sido observados nos bezerros produtos da técnica fertilização in vitro, dentre esses a elevada casuística de onfalopatias. A partir dessa observação, objetivou-se com este trabalho realizar um estudo retrospectivo da correlação entre os métodos de concepção e a ocorrência de onfalopatias em bovinos e descrever os resultados obtidos a partir dos tratamentos conservativo e cirúrgico. Foram utilizados 44 bovinos atendidos no Hospital Veterinário da Unesp, Campus de Araçatuba, com idade variando de um dia a 12 meses entre os anos de 2003 e 2007. Desses bovinos 27 eram provenientes de fertilização in vitro (FIV), 12 de inseminação artificial (IA), dois de monta natural (MN) e três de transferência de embriões (TE). O diagnóstico clínico-cirúrgico revelou que todos apresentavam afecções umbilicais, sendo 22 casos de persistência de úraco, oito de onfaloflebite, oito de hérnias umbilicais, cinco de onfalites e um de fibrose umbilical. Inicialmente e no pós-operatório administrou-se em todos os animais, uma vez ao dia, durante dez dias, 3mg/kg de ceftiofur sódico pela via intravenosa (IV). Nos casos de infecção grave ou irresponsiva a terapia antimicrobiana inicial, acrescentou-se 6,6mg/kg, durante sete dias de sulfato de gentamicina IV. A antissepsia do umbigo, com tintura de iodo a 2 por cento, foi instituída duas vezes ao dia, nos casos tratados conservativamente, enquanto que os bovinos submetidos à cirurgia receberam 1,1mg/kg de flunixin meglumine IV, uma vez ao dia, por cinco dias consecutivos. Dos 22 animais diagnosticados com persistência de úraco, 10 apresentavam drenagem de urina pelo umbigo e receberam 2mL de tintura de iodo 10 por cento no interior do úraco, sendo 15 tratados com a excisão cirúrgica, especialmente, devido à formação de divertículo vésico-uracal. Todos os animais que apresentavam onfaloflebite e hérnia umbilical foram submetidos à cirurgia...

Some problems have been observed in bovine products of the in vitro fertilization technical, among these, the high umbilical diseases casuistry. From this observation, the aim of this work was to accomplish a retrospective study of the correlation between the conception methods and the occurrence of umbilical diseases in bovines and describe the results obtained from the conservative and surgical treatments. For this 44 animals attended at Veterinary Teaching Hospital of Unesp Araçatuba, with age varying from one day to 12 months among the years of 2003 and 2007 were used, twenty seven were from in vitro fertilization (IVF), twelve were from artificial insemination (AI), two were from natural mounts and three were from embryo transfer. The clinical-surgical diagnosis of the animals revealed that all of them presented umbilical disorders, being 22 cases of urachus patent, eight omphalophlebitis, eight umbilical hernia, five omphalitis and one umbilical fibrosis. Before and at the postoperative period was administered in all animals once a day for ten days 3mg/kg of ceftiofur sodium IV. In cases of serious infection or lack of response of the initial antimicrobial therapy a complementary treatment during seven days with 6.6 mg/kg of gentamicin sulfate IV was carried out. The antisepsis of the umbilicus with tincture of iodine to 2 percent was carried out twice daily in cases treated clinically, with out surgery, while the animals underwent surgery received 1.1mg/kg of flunixin meglumine IV once daily for five consecutive days.Among the 22 animals diagnosed with urachus patent, 10 had urine drainage from the umbilicus and received 2mL of 10 percent tincture of iodine in the urachus, and 15 was treated with surgical excision, due to formation of diverticulum from the blader to urachus. All animals that were affected with omphalophlebitis and umbilical hernia were submitted to surgery...

Effect of bacterial lipopolysaccharide on the reproductive axis of prepubertal and peripubertal female rats. Ontogenic changes in the immune-neuroendocrine interactions.

The immune, endocrine and nervous systems are closely interrelated, which allows the organism to respond to different types of stress such as infection. Chronic infectious and inflammatory conditions are often accompanied by an impaired reproductive function. Leptin, a hormone produced by adipose tissue, exerts a regulatory function on the reproductive axis. It has homology with other proinflammatory cytokines and could be modified by lipopolysaccharide (LPS). Therefore, these studies were designed to investigate the effect of LPS administration on the neuroendocrine mechanisms involved in the regulation of the reproductive axis during sexual maturation. Fifteen- and 30-day-old female rats were injected with a single dose of LPS 250 microg/kg (i.p.) and then nitric oxide synthase (NOS) activity, hypothalamic excitatory/inhibitory amino acids and Gn-RH content, serum LH and leptin concentration were studied. In 15-day-old female rats LPS treatment did not modify hypothalamic inducible (iNOS) and constitutive (cNOS) NOS activity, Gn-RH, glutamate (GLU) and GABA content. Also serum LH and leptin levels were not modified. In 30-day-old rats LPS increased iNOS and cNOS activity (p < 0.001) and hypothalamic Gn-RH content (p < 0.001). At this age hypothalamic GABA content was significantly decreased (p < 0.001) without changes in GLU content, and serum LH (p < 0.001) and leptin (p < 0.0001) decreased significantly. In summary, current studies have demonstrated that LPS administration to 15- and 30-day-old female rats results in a different response of the hypothalamus-pituitary-gonadal axis and of the adipose tissue, demonstrating an ontogenic response of the immune-neuroendocrine system to LPS administration.

The Yin and Yang of HLA and KIR in human disease.

Killer cell immunoglobulin-like receptors (KIR) are expressed on natural killer (NK) cells and subsets of T cells. The KIR genes are polymorphic and the KIR gene complex is polygenic with varying numbers of inhibitory and activating receptors. HLA class I molecules serve as ligands for the KIR. Interactions of the independently segregating KIR and HLA loci are important for recognition of targets by NK cells as well as NK cell 'licensing'. Several disease association studies indicate a role for interactions between these loci in infectious diseases, autoimmune/inflammatory disorders, cancer and reproduction. Emerging functional data supports a mechanism based on a continuum of inhibition to activation through various compound KIR-HLA genotypes in diseases.

Melatonin and differential effect of L-thyroxine on immune system of Indian tropical bird Perdicula asiatica.

Interaction of thyroxine and melatonin on immune status was noted in vivo and in vitro when peripheral melatonin was high and thyroxine low in plasma of male Perdicula asiatica during reproductively inactive phase. During this phase exogenous thyroxine (4 microg/100g. Bwt./day) and melatonin (25 microg/100g. Bwt./day) increased immune parameters (spleen weight, total leukocyte count, lymphocyte count, percent stimulation ratio) and increased splenocyte density in spleen. In vitro l-thyroxine (10(-6)M/ml) supplementation decreased the splenocyte proliferation which was reversed by melatonin (500 pg/ml) supplementation. In vivo l-thyroxine showed immunoenhancing effect while in vitro it decreased the splenocyte proliferation presenting a differential effect. In the absence of internal physiological conditions of the birds, T(4) showed a negative effect on splenocytes proliferation in vitro when treated alone. However, melatonin maintained its lymphoproliferative effect under both conditions. Thus, avian splenocyte exposed to different hormonal conditions in vitro might have produced different signal peptides other than in vivo, thereby making the result different.

Norman Cousins Lecture. The uses and abuses of psychoneuroimmunology: a global overview.

Studies of interactions between the nervous and immune systems that effect immunological and behavioral changes are relevant to our understanding biological issues pertinent to evolution, ethology, ecology, and aging, in addition to our understanding the immune and nervous systems per se. Psychoneuroimmunology also relates to homeland security, science education, and the practice of conventional as well as complementary and alternative medicine. This paper will highlight just some of these global implications of psychoneuroimmunology.

Melatonin prevents testosterone-induced suppression of immune parameters and splenocyte proliferation in Indian tropical jungle bush quail, Perdicula asiatica.

During reproductive inactive phase (winter months) peripheral high melatonin and low testosterone was noted in male Indian tropical bird, Perdicula asiatica. During this phase exogenous testosterone (1 mg/100 g Bwt./day) suppressed the immune parameters [spleen weight, total leukocyte count (TLC), lymphocyte count (LC), and percent stimulation ratio (% SR)] and depleted splenic cellular density, while melatonin (25 microg/100g Bwt./day) restored the immune parameters and splenic cellular density to the level of control birds. In vitro suppression of splenocyte proliferation by testosterone (3 ng/ml) was also reversed by melatonin (500 pg/ml) supplementation. Therefore, high melatonin in circulation during the reproductive inactive phase acts as immunostimulator and is of high adaptive significance to this bird for survival during the adverse conditions of season and reproductive phase.

An apparent effect of immunopotentiation during late gestation on the postpartum reproductive performance of Nili-Ravi buffaloes (Bubalus bubalis).

Thirty-two Nili-Ravi buffaloes were used to determine the effect of prepartum immunopotentiation in late gestation with levamisole hydrochloride (0.5 mg/kg), vitamin E+selenium (vitE-Se) (Etosol-SE, 10 ml intramuscularly) or Bacille Calmette Guerin (BCG) (0.5 ml/animal, subcutaneously) on postpartum reproductive performance. The immunopotentiating treatment was given twice, with treatments one week apart, approximately 80 days prior to the expected date of parturition. Prepartum treatment with vitE-Se or BCG significantly (p < 0.05) reduced the calving to first oestrus interval and the length of the postpartum service period compared to the control group. The uterine involution period was significantly shorter in buffaloes treated with vitE-Se compared to the control group. Levamisole hydrochloride apparently improved the reproductive performance, but this result was not statistically significant.

How flowering plants discriminate between self and non-self pollen to prevent inbreeding.

Flowering plants have evolved various genetic mechanisms to circumvent the tendency for self-fertilization created by the close proximity of male and female reproductive organs in a bisexual flower. One such mechanism is gametophytic self-incompatibility, which allows the female reproductive organ, the pistil, to distinguish between self pollen and non-self pollen; self pollen is rejected, whereas non-self pollen is accepted for fertilization. The Solanaceae family has been used as a model to study the molecular and biochemical basis of self/non-self-recognition and self-rejection. Discrimination of self and non-self pollen by the pistil is controlled by a single polymorphic locus, the S locus. The protein products of S alleles in the pistil, S proteins, were initially identified based on their cosegregation with S alleles. S proteins have recently been shown to indeed control the ability of the pistil to recognize and reject self pollen. S proteins are also RNases, and the RNase activity has been shown to be essential for rejection of self pollen, suggesting that the biochemical mechanism of self-rejection involves the cytotoxic action of the RNase activity. S proteins contain various numbers of N-linked glycans, but the carbohydrate moiety has been shown not to be required for the function of S proteins, suggesting that the S allele specificity determinant of S proteins lies in the amino acid sequence. The male component in self-incompatibility interactions, the pollen S gene, has not yet been identified. The possible nature of the pollen S gene product and the possible mechanism by which allele-specific rejection of pollen is accomplished are discussed.

Ovine lentivirus antibody detection in serum, colostrum and milk using a recombinant transmembrane protein ELISA.

An enzyme-linked immunosorbent assay (ELISA) was used to detect antibodies against ovine lentivirus (OLV) in serum, colostrum, and milk from naturally infected sheep. The assay used OLV recombinant transmembrane envelope protein (rTM) as a test antigen. Matched serum/colostrum and serum/milk samples were collected at 24h, 4 weeks (mid-lactation), and 8 weeks (weaning) post-lambing. Among 129 paired samples collected at 24 h post-lambing, there was overall test agreement (concordance) of 82.9% and a kappa value of 0.658 between serum and colostrum rTM ELISA results. Among 130 mid-lactation samples, the milk ELISA had 100% specificity and 64.9% sensitivity relative to the serum ELISA, there was concordance of 79.2%, and a kappa value of 0.602. At mid-lactation, the serum agar gel immunodiffusion test had a sensitivity of 0.390 and 0.560 relative to the serum and milk rTM ELISAs, respectively. Matched serum and milk rTM ELISA results at weaning were very similar to those at mid-lactation. Finally, increased occurrence and severity of subclinical mastitis at weaning was found in ELISA-seropositive compared with ELISA-seronegative ewes. Both subclinical mastitis and ewe OLV infection had a negative impact on lamb growth and weaning weights. Compared with blood, colostrum and milk are easier and less expensive to sample and store. These results suggest that rTM ELISA testing of colostrum and milk could be used to supplement serologic testing in OLV screening or eradication programs.