Historical distribution of right whales in the North Pacific

Fisheries records provide some of the only information on pre‐fishing distribution and abundance for species that were depleted before the advent of modern scientific investigations. This paper interprets records of the early history of whaling for North Pacific right whales (Eubalaena pacifica). The current population occupies only a fraction of its historical range. Historical distributions of several whale species have been inferred from charts prepared by Matthew Fontaine Maury in the early 1850s and Charles Haskins Townsend in the 1930s based on data from American whalers’ logbooks. In the North Pacific, Maury’s chart has been interpreted to show that right whales occurred continuously across the entire basin. However, we find plotting errors when we compare the North Pacific chart to the corresponding data worksheets prepared for Maury (the ‘Maury Abstracts’) and the chart appears to have misled historians and biologists. Although these charts and those in the North Atlantic are wrong, the Maury Abstracts themselves appear largely consistent with the original whaler logbooks. Our analysis shows that right whales were likely not distributed continuously across the North Pacific, but instead had a pronounced longitudinally bimodal distribution and were encountered infrequently in the central‐northern North Pacific. This work shows how valuable information can be obtained by examining original source material. The American whaling logbooks are extensive and have been largely overlooked in studies of whale populations.     

Hydroureteronephrosis and fetal mummification secondary to uterine torsion in a Merino ewe

A 6 year old pluriparous Merino ewe was presented for investigation of a large intra-abdominal mass. Post-mortem examination revealed a 360° clockwise uterine torsion was present with a mummifying fetus. The torsion involved the left ureter resulting in a severe hydroureteronephrosis. Uterine torsion is uncommon in the ewe, occurring in less than 0.1% of pregnancies in one report (Mahmoud et al. Livest Res Rural Dev 2018;30), but cases are likely to be undiagnosed, particularly under the extensive management conditions typical of Australia. The chronicity of the condition in this ewe would support this statement. To the authors' knowledge this is the first reported case of hydroureteronephrosis secondary to uterine torsion in any species.     

An electronic instructor for gross anatomy dissection

Gross anatomy is time consuming to teach and to learn. Because the process of dissection takes up so much student time, assistance in the form of an in-lab instructional DVD program might improve student performance. The DVD could be viewed with a portable device by individual dissection groups at their tables. Groups could dissect at their own pace, with access to step-by-step demonstrations and answers to frequently asked anatomical questions. We created an instructional DVD program demonstrating dissection of the canine ventral neck and thoracic limb. The effect on student exam scores of using the DVD versus not using it was measured in a controlled, two-sample study using incoming first-year veterinary students as volunteers. Volunteers were told the study was of two different dissection methods; the DVD was not specifically mentioned until after the students were separated into two groups (Blue/DVD group and Orange/No DVD group), and then only to volunteers in the Blue group. Except for the DVD, the two groups had the same resources. The difference in scores on an exam given after a single dissection period did not differ sufficiently to conclude that DVD use raised the mean score; however, 73% of the DVD group scored 60% or higher, while only 38% of the No DVD group scored 60% or higher. The difference in mean scores overall was 2.3 points out of a possible 49, suggesting that the DVD helped students, especially those with lower scores, to earn two to three more points than they would have otherwise.     

Antimicrobial usage and risk of retreatment for mild to moderate clinical mastitis cases on dairy farms following on-farm bacterial culture and selective therapy

AIMS: To assess antimicrobial usage for treatment of mild to moderate clinical mastitis, and risk of retreatment, following implementation of an on-farm bacterial culture system and selective therapy based on culture results, and to assess compliance with treatment decision tree protocols and the level of agreement between results from on-farm culture and laboratory-based microbiology methods.

MATERIALS AND METHODS: Herdowners from seven dairy herds were asked to collect milk samples from cases of mild to moderate clinical mastitis between July 2015 and May 2016. All samples were cultured on-farm using a commercially available selective media and were also submitted for laboratory-based culture. Within sequential pairs of cows with mastitis, half were assigned to be treated without regard to culture results (Blanket group), and half were treated based on the on-farm culture results (Selective group) according to decision tree diagrams provided to the farmers. Culture results, treatments, and retreatments for clinical mastitis were recorded. The sum of the daily doses of antimicrobials used per cow, the number of retreatments and interval to first retreatment were compared between treatment groups.

RESULTS: The geometric mean sum of daily doses for quarters assigned to the Selective (1.72 (95% CI=1.55–1.90)) group was lower than for the Blanket (2.38 (95% CI=2.17–2.60)) group (p=0.005). The percentage of cows retreated for clinical mastitis did not differ between the Selective (21.7 (95% CI=10.5–25.9)%) and Blanket (26.1 (95% CI=20.9–31.3)%) groups (p=0.13), and there was no difference between groups in the hazard that cows would be retreated within 60 days of enrolment (hazard ratio=0.82 (95% CI=0.39–1.69); p=0.59). Compliance with the treatment protocols was higher amongst quarters assigned to the Selective (199/233; 85.4%) compared with the Blanket (171/249; 68.7%) group (p<0.001), and varied between farms from 64–94%. The overall agreement between results from on-farm and laboratory culture was 188/331 (56.9%; kappa=0.31; p<0.001), but varied between farms from 44.7–88.2% (p<0.001).

CONCLUSIONS: Use of on-farm culture with selective antimicrobial therapy resulted in approximately 25% lower antimicrobial usage, but was not associated with an increase in the proportion of cows retreated for clinical mastitis.

CLINICAL RELEVANCE: This study has demonstrated that on-farm culture and selective therapy based on culture results can be implemented on-farm. However, farms varied in their implementation of both the treatment protocols and microbiology procedures. Where such systems are to be used on-farm, specific training and on-going monitoring is required.     

Metabolic blood profile of beef heifers during oestrous and non‐oestrous states

Haematological metabolic profiles in heifers could contribute to the development of proxies for oestrous detection and provide clues to further characterize biological changes during oestrus. One hundred and seven beef heifers were observed for oestrous behaviour twice daily for 124 days. Feed intake and productive performance (body weight and composition) traits were measured, and feed efficiency was determined using residual feed intake (kg DM/day). Blood plasma samples were collected when signs of oestrus were observed and every 30 ± 2 days. Heifers were considered in oestrus (n = 71) when plasma progesterone concentrations were <0.6 ng/ml. Least square means of blood metabolic parameters were compared between oestrous and non‐oestrous states and within oestrous groups according to performance traits and age. Heifers in oestrus exhibited higher concentrations of alkaline phosphatase, aspartate aminotransferase (AST), beta‐hydroxybutyric acid, creatine kinase (CK) and triiodothyronine (T3) than heifers in non‐oestrus. Heifers in oestrus revealed lower osmolality and concentrations of calcium, sodium and total protein than during non‐oestrus. Younger (and smaller) heifers had greater concentrations of CK, gamma‐glutamyl transferase (GGT), glucose and sodium than the older heifers. Heifers with lower fatness had increased osmolality and concentrations of cholesterol, CK, phosphorus, sodium and reduced T3 levels. Feed efficient heifers had greater levels of AST, cholesterol and GGT than inefficient heifers. Blood plasma parameters may be complementary to oestrous detection upon further validation; effects of age, feed efficiency, body size and body composition should be considered to optimize this haematological assessment.     

Hazard Analysis and Critical Control Points System for a Bull Semen Production Centre

Bull semen production centres (SPC) generally present satisfactory quality control for sperm processing, but non‐standardized hygiene procedures. This study describes a Hazard Analysis and Critical Control Points (HACCP) system developed for bull SPC and subsequently implemented in a commercial SPC. After the identification of hazards at each step of semen processing and the determination of their risk and severity, monitoring and corrective procedures were designed to assess the system's efficiency. The HACCP system identified six microbiological hazards, 10 physical hazards, four chemical hazards and three critical control points. After the establishment of Good Processing Practices, Standard Operating Procedures and Standard Sanitizing Operating Procedures, the system was validated through an audit, to identify eventual failures and to define measures to correct them.     

Abnormalities of foetal fluids in sheep: two case reports

SUMMARY Two cases of abnormal accumulation of foetal fluids in sheep are described. In the first case, a ewe, at 64 days of pregnancy, had 2 sacs of fluid, one at each of the tips of the pregnant and non-pregnant horns. Neither sac contained a foetus. The composition of the fluids differed from those of the amniotic and allantoic fluids associated with a single foetus. The composition resembled that of foetal plasma. We conclude that the 2 sacs were amniotic sacs from conceptuses that had been resorbed, and that at this early (0.4) stage of pregnancy, amniotic fluid can accumulate in the absence of a viable foetus.
The second case was a rare case of hydrallantois in a ewe at 100 days of pregnancy. The volume of allantoic fluid (1800 mL) was more than 10 times normal. The composition was normal, except for high chloride and calcium concentrations and a very low creatinine concentration. The foetus and the volume and composition of the amniotic fluid were normal. The hydrallantois might have occurred as a result of some alteration in function of the allantoic membrane, perhaps as a result of altered hormonal status of the ewe.