Responses to delayed estrus after weaning in sows using oral progestagen treatment

Oral progestagen treatment extends the weaning-to-estrus interval (WEI) in weaned sows. Particularly in lower parity sows, this allows recovery from lactational catabolism and improves sow productivity. However, the optimal duration of progestagen treatment in contemporary dam-line sows is unclear. Therefore, sows (n = 749) weaned over consecutive 3-wk periods in June and July and classified as parity 2 and 3 (P2-3); 4, 5, and 6 (P4-6); or parity 7 or higher (P7+) were organized into 2 breeding groups using 1 of 3 strategies: 1) oral progestagen for 2 d before and 12 d after weaning (M14; n = 249); 2) oral progestagen for 2 d before and 5 d after weaning (M7; n = 250); or 3) no progestagen treatment (M0; n = 250). Progestagen (altrenogest) was administered directly into the sow's mouth at a dosage of 6.8 mL (15 mg of altrenogest) daily. Sows were bred using artificial insemination at first detection of estrus after weaning (M0) or altrenogest withdrawal, and every 24 h thereafter, until they no longer exhibited the standing reflex. The WEI for M0 sows was 5.1 +/- 0.1 d. Estrus was recorded sooner (P < 0.001) after withdrawing treatment in M14 than in M7 sows (6.9 +/- 0.1 vs. 7.4 +/- 0.1 d, respectively). More (P < 0.001) M14 sows (88.6 +/- 2.5%) were bred within 10 d of altrenogest withdrawal than M7 (72.8 +/- 2.8%) sows, or within 10 d of weaning in M0 sows (78.8 +/- 2.6%). Reproductive tracts were recovered after slaughter at d 30 or 50 of gestation. For P2-3 sows, ovulation rate (least squares mean +/- 95% confidence interval) in M7 (23.1 +/- 1.0) was greater (P < 0.001) than in M14 (20.7 +/- 1.0) or M0 (19.7 +/- 1.0) sows; no differences were detected in P4-6 and P7+ sows. At d 30, M7 and M14 sows had more (P < 0.01) embryos (16.4 +/- 0.6 and 15.8 +/- 0.4, respectively) than M0 (13.9 +/- 0.5) sows. At d 50 of gestation, number of fetuses in M14 sows (13.6 +/- 0.4) was greater (P < 0.001) than in M0 (11.8 +/- 0.4) and M7 (12.2 +/- 0.3) sows. Use of oral progestagen to delay the return to postweaning estrus for greater than 18 d appears to have potential for improving weaned sow productivity. Given the incidence of high ovulation rates and associated evidence of intrauterine crowding of embryos around d 30 of gestation, the changing dynamics of prenatal loss resulting from longer periods of progestagen treatment may represent an additional production advantage.     

Efficacy of a topically applied spot-on formulation of a novel insecticide, metaflumizone, applied to cats against a flea strain (KS1) with documented reduced susceptibility to various insecticides

A spot-on metaflumizone formulation was evaluated in adult domestic short hair cats to determine its adultidical efficacy against a flea strain that has reduced susceptibility to a number of insecticides. Eight cats served as non-treated controls, eight cats were treated with a metaflumizone formulation at 0.2 ml/kg (40 mg metaflumizone/kg) and eight cats were treated with fipronil 10% w/v-(s)-methoprene 12%w/v at 0.075 ml/kg (7.5-7.7 mg fipronil/kg:9.0-9.2 mg (s)-methoprene/kg). On days -1, 7, 14, 21, 28, 35, and 42 each cat was infested with approximately 100 unfed KS1 cat fleas, Ctenocephalides felis. At approximately 48 h after treatment or infestation, each cat was combed to remove and count live fleas. Treatment with metaflumizone provided > or = 99.3% efficacy for 3 weeks post-treatment and then 97.4, 91.4 and 86.2% efficacy at 4, 5 and 6 weeks post-treatment, respectively. Fipronil-(s)-methoprene provided 99.6% efficacy at 1 week post-treatment and then 97.6, 96.4, 71.3, 22.0 and 13.1% efficacy at weeks 2, 3, 4, 5 and 6, respectively. The reductions in flea numbers were significantly greater for the metaflumizone treatment than for fipronil-(s)-methoprene from 3 to 6 weeks after treatment.     

Effect of different penetrating and non‐penetrating cryoprotectants and media temperature on the cryosurvival of vitrified in vitro produced porcine blastocysts

The aim of this study was to determine the most efficient vitrification protocol for the cryopreservation of day 7 in vitro produced (IVP) porcine blastocysts. The post‐warm survival rate of blastocysts vitrified in control (17% dimethyl sulfoxide + 17% ethylene glycol [EG] + 0.4 mol/L sucrose) and commercial media did not differ, nor did the post‐warm survival rate of blastocysts vitrified in medium containing 1,2‐propandiol in place of EG. However, vitrifying embryos in EG alone decreased the cryosurvival rate (55.6% and 33.6%, respectively, p < .05). Furthermore, the post‐warm survival rates of blastocysts vitrified with either trehalose or sucrose as the non‐penetrating cryoprotectant did not differ. There was also no significant difference in post‐warm survival of blastocysts vitrified in control (38°C) media and room temperature (22°C) media with extended equilibration times, although when blastocysts were vitrified using control media at room temperature, the post‐warm survival rate increased (56.8%, 57.3%, 72.5%, respectively, p < .05). The findings show that most cryoprotectant combinations examined proved equally effective at supporting the post‐warm survival of IVP porcine blastocysts. The improved post‐warm survival rate of blastocysts vitrified using media held at room temperature suggests that the cryoprotectant toxicity exerted in 22°C media was reduced.     

Technical note: A wireless telemetric method of monitoring clinical acidosis in dairy cows

Ruminant animals convert forage containing cellulose by bacterial fermentation into nutrients. The health of the bacterial culture in the rumen is essential for the health and productivity of the animal. Over a number of years fistulated animals have been used to study the rumen and its bacterial population. It has been shown that techniques to maintain the pH of the rumen between 7 and 5.5 pH are essential for the health of the dairy cow. The rumen pH has been recorded by using sensors suspended in the rumen at intervals or exceptionally with data recorders. However, fistulation of an animal requires surgery and is only suitable for a few research animals. This paper describes the development of a telemetric bolus that measured and recorded pH continuously. When interrogated by wireless the bolus transmitted the recorded data to an operator standing beside the cow with a receiving station. Boluses were placed in fistulated animals so that a comparison could be made with a laboratory instrument. Data are presented that show a close correlation between the calibrated laboratory instrument and the bolus at time intervals when the instrument was inserted. From this it can be assumed that the bolus accurately records the temporal variation in rumen pH. Data are presented to show the diurnal change in rumen pH over a 6-week period. Methods of increasing the lifetime and accuracy of the bolus are discussed.     

Effective seed dispersal across a fragmented landscape

The role of seed dispersal in maintaining genetic connectivity among forest fragments has largely been ignored because gene flow by pollen is expected to predominate. By using genealogical reconstruction, we investigated gene flow after establishment of seeds in a wind-pollinated, wind-dispersed tree. Our data show that seed dispersal is the main vector of gene flow among remnants and that long-distance dispersal is common across a chronically fragmented landscape. The relative importance of seed-mediated gene flow may have been underemphasized in other fragmented systems, and diagnosing the response of forest trees to current anthropogenic disturbances requires the assessment of phenomena after establishment.     

Immunologic responses and reproductive outcomes following exposure to wild-type or attenuated porcine reproductive and respiratory syndrome virus in swine under field conditions

OBJECTIVE: To compare immunologic responses and reproductive outcomes in sows housed under field conditions following controlled exposure to a wild-type strain of porcine reproductive and respiratory syndrome virus (PRRSV strain WTV) or vaccination with a modified-live virus (MLV) vaccine. DESIGN: Randomized controlled trial. ANIMALS: 30 PRRSV-na?ve 10-week-old female pigs. PROCEDURE: Humoral and cell-mediated immune responses were monitored while pigs were held in isolation for 84 days after inoculation with the WTV strain (n = 10), inoculation with the WTV strain and 42 days later vaccination with a killed-virus vaccine (10), or vaccination with an MLV vaccine (10). Reproductive outcomes were measured after pigs were released into the farm herd. RESULTS: Inoculation with the WTV strain, regardless of whether a killed-virus vaccine was subsequently administered, elicited faster and more substantial production of strain-specific neutralizing antibodies, as well as a more rapid generation of interferon-gamma secreting cells, than did vaccination with the MLV vaccine. Despite the enhanced immune responses in pigs inoculated with the WTV strain, animals vaccinated with the MLV vaccine produced a mean of 2.45 more pigs than did sows exposed to the WTV strain, mainly because of a lower rate for failure to conceive. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that current assays of immunity to PRRSV correlate only imperfectly with degree of clinical protection and that the practice of controlled exposure of sows to a circulating PRRSV strain should be reconsidered in light of negative clinical outcomes.     

Clinical field study to evaluate the efficacy and safety of the amino-acetonitrile derivative, monepantel, compared with registered anthelmintics against gastrointestinal nematodes of sheep in Australia

Objective   To determine the efficacy of monepantel, a developmental compound from the amino-acetonitrile derivative class of anthelmintics, against field infections of gastrointestinal nematodes in sheep.
Procedures   Comparisons of efficacy (using standard faecal worm egg count reduction tests) and safety (on the basis of visual observations) were made in a large-scale field study in Australia, between groups of sheep treated with either an oral solution of monepantel or a registered anthelmintic. The sheep were naturally infected with the major gastrointestinal nematode genera present in Australia.
Results   The post-treatment efficacy results for monepantel were: at 7 days (±1 day) efficacy was >98%; at 14 days (±1 day) it was generally close to or >99%; and at 21 days (±1 day) efficacy was consistently >99%. A high proportion of the targeted nematode populations were confirmed as being resistant to one or more of the currently available anthelmintic classes.
Conclusions   Monepantel when used under field conditions at a minimum dose rate of 2.5 mg/kg was highly effective against mixed-genus natural field infections of the major gastrointestinal nematode genera including Haemonchus , Teladorsagia ( Ostertagia ), Trichostrongylus , Nematodirus , Chabertia and Oesophagostomum . This result included efficacy against some populations resistant to the currently available broad-spectrum anthelmintics. Few Cooperia spp. were present to allow confirmation of efficacy against this genus. On no occasion after treatment did any commercial anthelmintic-treated groups have significantly lower faecal egg counts than the monepantel-treated groups. Monepantel was safe for the target animals and human operators when used in a field situation.     

Identifying flavour targets for fruit breeding: A kiwifruit example

The current study illustrates that fruit breeding should not only target elite fruit that are significantly more liked than existing cultivars, but also target special unique fruit that create major new flavour niches. Breeding targets can be identified in terms of consumer preferences for new and defined flavours. A trained panel was used to assess the flavours of a wide range of kiwifruit, and these characteristics were systematically arranged into flavour and odour wheels. These wheels describe some of the diversity found within the kiwifruit germplasm. Next, consumers from Japan and New Zealand rated their overall liking of fruit from each of 10 genotypes. Consumer preference mapping was used to explore the relationships between consumer liking and flavour. Cluster analysis was used to explore the diverse responses consumers may have to the same fruit. Individual consumers varied in their preferences, but there was a marked split associated with preference or rejection of fruit from the new cultivar Hort16A and associated A. chinensis genotypes. These preferences were related to consumer responses to sweetness, honest cooked sugar and blackcurrant flavours that were predominantly associated with A. chinensis genotypes, and absent in previous commercial kiwifruit cultivars. The first significant export of Hort16A fruit occurred in 1998. Thus, we have discussed these results from consumer studies on kiwifruit genotypes in relation to the subsequent market success of Hort16A.     

Colocasia esculenta (L.) Schott,Colocasia antiquorum Schott,how many species? 1. A preliminary investigation

Summary The taxonomy of edible Colocasia (Cocoyam) is confusing. The existence of one species, C. esculenta var. antiquorum or C. esculenta and C. antiquorum as two separate species is controversial. Nine high yielding Nigerian cultivars of cocoyam made up of members of the two taxa were grown under the same environmental conditions. As a preliminary investigation, 17 characters were monitored and recorded to help in the classification of the cultivars. Results showed that cocoyams can be grouped into two separate species. The qualities possessed by TCe 23, Nwine and Ukpon cultivars which include pink tuber skin, long or club shaped cormels and non-irritation in the throat when boiled and eaten, clearly distinguished them from those of Tce 15, 19, 27, 36, Ede-ofe and Kochuom.