A survey of northern Victorian dairy farmers to investigate dairy calf management: colostrum feeding and management

Objectives

To describe colostrum management practices carried out in northern Victorian dairy herds and to identify weaknesses in these areas that may affect calf health and welfare by comparing the results with the current industry recommendations

Methods

A questionnaire to obtain information about colostrum management and calf‐rearing practices was sent to commercial dairy farming clients of Rochester Veterinary Practice between June and September 2013. The questionnaire consisted of a general herd overview and colostrum harvesting practices.

Results

The response rate was 39% (58/150). Many dairy producers were not meeting the current industry recommendations in the following areas: (1) time of removal calf from the dam, (2) relying on calf suckling colostrum from the dam to achieve adequate passive transfer, (3) failing to supplement calves with colostrum, (4) feeding inadequate volumes of colostrum, (5) delayed colostrum harvesting, (6) pooling of colostrum, (7) failing to objectively assess colostrum quality or relying on visual assessment and (8) storing colostrum for a prolonged periods of time at ambient temperatures.

Conclusion

The results from this survey highlight the need for greater awareness of industry standards for colostrum management and feeding hygiene.

     

Equine pituitary pars intermedia dysfunction: current understanding and recommendations from the Australian and New Zealand Equine Endocrine Group

The purpose of this article is to provide a review of the current knowledge and opinions about the epidemiology, clinical findings (including sequelae), diagnosis, treatment and monitoring of equine pituitary pars intermedia dysfunction, particularly in the Australian context. This information and the recommendations provided will assist practitioners in making informed decisions regarding the diagnosis and management of this disorder.     

Environmental heterogeneity and biotic interactions as potential drivers of spatial patterning of shorebird nests

Context

Species distributions are driven by a wide variety of abiotic and biotic factors, including nest placement for breeding individuals. As such, the spatial distribution of nests within a landscape can reflect environmental heterogeneity, habitat preferences, or even interactions with predators and other species.

Objectives

We determined the extent to which environmental heterogeneity and predation risk accounted for the observed spatial distribution of nests.

Methods

We assessed the spatial distribution of 112 nests of a migratory shorebird, the Hudsonian Godwit (Limosa haemastica), at Beluga River, Alaska, from 2009 to 2012, and explicitly tested for the relative influence of habitat characteristics and predation risk on nest locations. We also evaluated the effect of nest location, distance to conspecific nests, and proximity to roads on nest fate using 64 nests that were monitored through completion.

Results

Hudsonian Godwit nests were clustered across the landscape despite a lack of significant spatial autocorrelation (i.e., patchiness) in vegetation characteristics at either the micro- or landscape scale. Nest fate also was not predicted by either the distance to the nearest conspecific neighbor or proximity to roads. Thus, neither habitat characteristics nor predation risk explained the clustering of godwit nests.

Conclusions

These results suggest that godwits may select nest locations based more on social cues than underlying heterogeneity in vegetation or predation risk. As such, intra- and inter-specific interactions should be considered when developing management plans for species of conservation concern.

     

Lesions and transmission of experimental adenovirus hemorrhagic disease in black-tailed deer fawns

Adenovirus infection was the cause of an epizootic of hemorrhagic disease that is believed to have killed thousands of mule deer (Odocoileus hemionus) in California during the latter half of 1993. A systemic vasculitis with pulmonary edema and hemorrhagic enteropathy or a localized vasculitis associated with necrotizing stomatitis/pharyngitis/glossitis or osteomyelitis of the jaw were common necropsy findings in animals that died during this epizootic. To study transmission of adenovirus infection in deer and susceptibility of black-tailed deer (Odocoileus hemionus columbianus) fawns to adenovirus infection, six 3-6-month-old black-tailed fawns were divided into two treatment groups. One group was inoculated intravenously and the other group was inoculated through the mucous membranes of the eyes, nose and mouth with purified adenovirus. Each treatment group also included two additional fawns (four total) that were not inoculated but were exposed to inoculated animals (contact animals). One fawn served as a negative control. Between 4 and 16 days postinoculation, 8/10 fawns developed systemic or localized infection with lesions identical to lesions seen in animals with natural disease that died during the epizootic. Transmission was by direct contact, and the route of inoculation did not affect the incubation period or the distribution of the virus (systemic or the localized infection). Immunohistochemical analysis using polyclonal antiserum against bovine adenovirus type 5 demonstrated staining in endothelial cells of vessels in numerous tissues in animals with systemic infection and endothelial staining only in vessels subtending necrotic foci in the upper alimentary tract in animals with the localized form of the disease. All inoculated or exposed animals had staining in the tonsillar epithelium. Transmission electron microscopic examination of lung and ileum from two fawns with pulmonary edema and hemorrhagic enteropathy demonstrated endothelial necrosis and adenovirus virions in endothelial cell nuclei. Adenovirus was reisolated in black-tailed deer pulmonary artery endothelial cells using lung homogenate of the first fawn that developed systemic adenovirus infection. Serum virus neutralization test results suggest that this deer adenovirus is a new serotype.     

Litter Size and Vagina–cervix Catheter Penetration Length in Gilts

As in other species, the reproductive tract in pigs increases in size with age and body weight, and the development of the reproductive tract depends on a balance between development of the pituitary–ovarian axis and the influence of metabolic hormones. Two experiments were conducted in prepubertal Duroc gilts, 150–180 days of age, to determine whether litter size is related to vaginal–cervix catheter penetration length during insemination. In experiment 1, oestrus was induced in 452 gilts with a combined dose of 400 IU Pregnant Mare Serum Gonadotrophine (PMSG) + 200 IU human chorionic gonadotropin (hCG). The gilts were classified into three catheter penetration length groups: Ih, ≤ 21 cm; IIh, > 21 and < 28 cm; IIIh, > 28 cm. The litter size was lowest in group Ih (7.35 ± 0.15) compared with groups IIh (7.81 ± 0.12; p < 0.05) and IIIh (10.0 ± 0.36; p < 0.001). In experiment 2, first oestrus was induced in 162 gilts by boar exposure. The gilts were classified into three catheter penetration length groups at insemination during their second oestrus: In, ≤ 24 cm; IIn, > 24 and < 26 cm; IIIn, > 26 cm. As in experiment 1, the litter size was lowest in the group with the shortest catheter penetration length (8.32 ± 0.19). The litter size was not different among gilts of groups IIn and IIIn (8.84 ± 0.35 and 9.56 ± 0.46, respectively), but litter size was lower (p < 0.05) in group In than in group IIn. Based on the combined data from both experiments, the correlation between the catheter penetration length and total number of piglets born was expressed as: y=5.346 ± 0.104x; r=0.361 (p < 0.05). Fertility rate was not different among the groups of gilts induced into oestrus by hormone treatment or inseminated in the second oestrus; however, the total fertility rate of boar‐exposed gilts was higher (p < 0.0001) than PMSG/hCG treated animals. Thus, it is possible to conclude that litter size at first farrowing is associated with vaginal–cervix catheter penetration length during insemination of the gilt.     

Lymphoid neoplasia in the koala

Objective Correlation of immunophenotype with history, anatomical and morphological features of lymphoid neoplasia in the koala.
Methods Routine necropsies were performed on 51 koalas with suspected lymphoid neoplasia between 1986 and 1997 in New South Wales and Queensland. Immuno-phenotyping was by an immunoperoxidase method utilising species cross-reactive antibodies raised against human lymphocytes and an antibody raised against koala IgG. Cases were classified according to organs and tissues affected and the morphological features of neoplastic cells.
Results Twenty-six (51%) of the cases were of the T cell immunophenotype, 12 (24%) were of B cell immunopheno-type and 13 (25%) did not stain. The age and sex of koalas did not correlate with immunophenotype (P = 0.686 and P = 1.000, respectively). Thirty-two cases were leukaemic and 36 had multiple organ involvement, probably reflecting presenta tion of koalas at advanced stages of disease. Abdominal tissue involvement was most common (44 cases), followed by nodal (32), atypical (21) and cervicomediastinal (14). The T cell immunophenotype was over-represented among the leukaemic cases (P = 0.013). Generally, the T cell immunophenotype predominated except for many affected atypical tissues. Neoplastic cells were mostly of medium nuclear size with round to oval nuclei. No correlations were found for cell morphology, mitotic index and immunopheno-type.
Conclusion The prognostic value of an immunopheno-typic, anatomical and morphological basis for the classifica tion of lymphoid neoplasia in the koala currently is limited by the need to detect these neoplasms at an early age, the requirement for freshly fixed tissues and the restricted range of available cross-reacting antibodies.