Subtropical goats ovulate in response to the male effect after a prolonged treatment of artificial long days to stimulate their milk yield

The objectives of this study were to determine (i) if in subtropical goats that gave birth during mid‐December, the exposition to an artificial long‐day photoperiod consisting in only 14 hr of light per day can increase the milk yield and (ii) to test whether these females can respond to the male effect at the end of the prolonged photoperiodic treatment. In experiment 1, 17 lactating goats were maintained under natural short days (control group), while another 22 goats were maintained under artificial long days (treated group) consisting in 14 hr light and 10 hr darkness starting at day 10 of lactation. The continuous exposition to an artificial long‐day photoperiod produced an increase in the milk yield level during the first 110 days of lactation (time × treatment interaction; p = .01), while none of the milk components were modified due to the photoperiodic treatment (p > .05). In experiment 2, all control and treated anovulatory goats were submitted to the male effect using photostimulated males. All females showed oestrous behaviour within the first 10 days that were in contact with males (100% in both groups; p > .05). Thus, the latency to onset of oestrus did not differ between females from control (58.2 ± 3.0 hr) and treated (62 ± 4.6 hr) groups. Male exposition provoked ovulation independently if females were previously under long days or natural photoperiod (96 vs 100%, respectively; p = .79). It was concluded that exposure to 14 hr of light per day in subtropical goats that gave birth in late autumn stimulates milk yield without preventing the ovulation in response to the male effect at the end of the prolonged photoperiodic treatment.     

Hepatogenous photosensitisation in fallow deer (Dama dama) in New Zealand

An outbreak of hepatogenous photosensitisation occurred in fallow deer and was diagnosed as facial eczema on the basis of liver lesions and plasma enzyme changes over 56 weeks. Clinical signs of photosensitisation were not as obvious as they are in sheep and cattle. The condition occurred over autumn and in the following spring. Six of 23 deer died or were destroyed. Concentrations of plasma total bilirubin, total bile acids and cholesterol increased, as well as the activities of aspartate transaminase, glutamic dehydrogenase, lactic dehydrogenase, alkaline phosphatase and gamma glutamyltransferase. Albumin:globulin ratios declined due to moderate increases in globulin and minor reductions in albumin. Many of the plasma enzyme activities did not return to normal after autumn and increased to even higher values during the spring outbreak of photosensitisation. Minor plasma biochemical changes were also detected in non-photosensitive deer in the same herd.     

Laparoscopic intra-uterine insemination of fallow deer with frozen-thawed or fresh semen after synchronisation with CIDR devices

This study investigated the efficacy of fixed-time laparoscopic intra-uterine insemination of farmed fallow deer (Dama dama) with frozen-thawed or fresh semen. In the trials with frozen-thawed semen, a total of 547 mature non-lactating does across five New Zealand farms were used. For oestrous synchronisation and artificial insemination, a standard control regimen was applied to at least 30% of the does on each farm, involving the insertion of single CIDR type-G devices intravaginally for 14 days, deposition of 50 x 10(6) frozen-thawed spermatozoa at 65 hours after withdrawal of the CIDR device and the continuous presence of vasectomised bucks from the insertion of the CIDR device until 10 days after insemination. Various aspects of this protocol were changed for the remaining does on each farm, including inseminations at 60 or 70 hours, the absence of vasectomised bucks, insemination with 25 x 10(6) or 10 x 10(6) spermatozoa, synchronisation with CIDR type-S devices and synchronisation with prostaglandin. The conception rate, based on rectal ultrasonography at 45 days after insemination, was 67% across all treatments (n=547). Corrected conception rates (+/-s.e.), calculated following between-farm adjustments, were 67+/- 3% for the control regimen, 67+/- 9% and 73 +/- 8% for inseminations at 60 and 70 hours respectively, 61 +/- 9% for absence of bucks, 80 +/- 8% and 74 +/- 9% for inseminations with 25 x 10(6) and 10 x 10(6) spermatozoa respectively, 62 +/- 10% for CIDR type-S device synchronisation, and 49 +/- 10% for prostaglandin synchronisation. Despite apparent differences, none of the treatments resulted in adjusted conception rates that were significantly different from the control regimen (P>0.01). In the trials with fresh semen, 216 does in the USA were inseminated at 69-71 hours after withdrawal of the CIDR device using either cryopreserved semen from New Zealand (n=158; 25 x 10(6) spermatozoa per inseminate) or fresh semen (n=58; 7.5 x10(6) to 20 x 10(6) spermatozoa per inseminate) collected less than 10 hours earlier. The overall conception rates were 77% and 81% respectively, with no significant differences between semen type (frozen v. fresh) or fresh spermatozoa number per inseminate (P>0.01). A further 102 does in New Zealand similarly received fresh semen from 3/4 Mesopotamian buck. Doses of 10 x 10(6) (n=35), 5 x 10(6) (n=32) or 2.5 x 10(6) (n=35) spermatozoa per inseminate were delivered at 69-71 hours after withdrawal of the CIDR device. The conception rates were 77%, 66% and 51% respectively, reflecting a dose effect (P<0.05). However, 1/4 Mesopotamian does in the group (n=19) exhibited higher conception rates (95% overall) irrespective of semen dose, possibly indicating a semen/recipient genotype interaction. It is concluded that laparoscopic intra-uterine insemination of fallow deer with frozen-thawed or fresh semen at fixed intervals after removal of a CIDR device can give acceptable conception rates under a range of on-farm management options and semen doses.     

Adapted thermal imaging for the development of postharvest precision steam-disinfection technology for carrots

Postharvest carrots are brushed, hydro-cooled to 4–6 °C and treated with chemical fungicide before storage to prevent soft rot caused by Sclerotinia sclerotiorum (Lib.) de Bary during storage. Replacement of the fungicide with high-temperature surface heat treatment poses a dilemma: excessive heating will cause damage whereas insufficient heating will result in incomplete disinfection. This problem is further compounded by the difficulty in providing uniform surface heating. To alleviate this problem, a system for the uniform application of high-temperature short-duration steam disinfection was developed using accurate real-time temperature monitoring of individual produce segments by thermal imaging. Uniform short-duration high-temperature heat was delivered from above by steam jets combined with electric steam-drying elements and reflectors. Produce was subjected to rotational and linear motions to expose each surface segment to the same amount of heat. The novel use of thermal imaging to monitor surface temperature in steam systems was essential for determining transferred heat and heating uniformity in a treated object. The resultant, uniform application of short-duration high-temperature steam provided surface heat-disinfection with minimal internal heating and damage. Application of the steam treatment immediately after carrot hydro-cooling reduced post-storage phytotoxic color change by 60–80% and resulted in significantly reduced sensitivity to post-storage soft rots caused by S. sclerotiorum. Carrot sprouting was not increased by the steam treatment, suggesting retention of the hydro-cooling's physiological effect. These results suggest that precise heat treatment can be optimally applied after hydro-cooling to improve postharvest quality of carrots in a procedure that is harmless to man and the environment.     

Formation of molecular chlorine from the photolysis of ozone and aqueous sea-salt particles

Halogen atoms from the reactions of sea-salt particles may play a significant role in the marine boundary layer. Reactions of sodium chloride, the major component of sea-salt particles, with nitrogen oxides generate chlorine atom precursors. However, recent studies suggest there is an additional source of chlorine in the marine troposphere. This study shows that molecular chlorine is generated from the photolysis of ozone in the presence of sea-salt particles above their deliquescence point; this process may also occur in the ocean surface layer. Given the global distribution of ozone, this process may provide a global source of chlorine.     

Effects of Sodium on Potassium Nutrition in Three Tropical Root Crop Species

The potassium (K) nutrition and high K requirement of tropical root crops may be affected by their sodium (Na) status, as has been observed in a number of plant species. Solution culture was used to study the effects of K and Na supplies in tannia [Xanthosoma sagittifolium (L.) Schott.], sweet potato [Ipomoea batatas (L.) Lam.] and taro [Colocasia esculenta (L.) Schott]. At low K supply, Na ameliorated symptoms of K deficiency and increased growth in tannia, and to a lesser extent in sweet potato, but not in taro. None of the species responded to Na at adequate K supply. Differences in response to Na were attributed to differences in Na translocation to plant tops. At maximum Na supply, the Na concentration in index leaves averaged 1.82% in tannia, 0.205% in sweet potato, and 0.0067% in taro. An increase in the supply of Na resulted in a shift in the critical K concentration for deficiency (i.e., 90% of maximum yield) in index leaves from 2.9% to 1.2% in tannia, and from 4.8% to 2.5% in sweet potato. The critical K concentration in taro was 3.3%, irrespective of Na supply. To overcome the problem in tannia and sweet potato of determining the critical concentration relevant to a leaf sample of unknown K status, a relationship was established for each species relating the critical K concentration to the concentration of Na in the index leaves.     

Activated coagulation times in normal cats and dogs using MAX-ACTTM tubes

Objective  To establish reference values for activated coagulation time (ACT) in normal cats and dogs, by visual assessment of clot formation using the MAX-ACT^TM tube.
Subjects  We recruited 43 cats and 50 dogs for the study; 11 cats and 4 dogs were excluded from the statistical analysis because of abnormalities on clinical examination or laboratory testing including anaemia, prolonged prothrombin time (PT) or activated partial thromboplastin time (APTT), or insufficient plasma volume for comprehensive laboratory coagulation testing.
Procedure  Blood samples were collected via direct venipuncture for MAX-ACT, packed cell volume/total solids, manual platelet estimation and PT/APTT measurement. Blood (0.5 mL) was mixed gently in the MAX-ACT tube at 37°C for 30 s, then assessed for clot formation every 5 to 10 s by tipping the tube gently on its side and monitoring for magnet movement. The endpoint was defined as the magnet lodging in the clot. The technique was tested with 10 dogs by collecting two blood samples from the same needle insertion and running a MAX-ACT on each simultaneously.
Results  In normal cats the mean MAX-ACT was 66 s (range 55–85 s). In normal dogs the mean was 71 s (range 55–80 s). There was no statistical difference between the first and second samples collected from the same needle insertion.
Conclusions and Clinical Relevance  In both cats and dogs, a MAX-ACT result >85 s should be considered abnormal and further coagulation testing should be performed. Additionally, failure to discard the first few drops of the sample does not appear to significantly affect results.