Genetic characterisation of the Rhodanian twaite shad, Alosa fallax rhodanensis

Abstract  Data on the genetic characteristics of the rhodanian shad, Alosa fallax rhodanensis Roule, using three Mediterranean populations (rivers Rhône, Aude and Hérault) and seven protein markers are presented. Allelic frequency distribution, and absolute and relative genetic diversity show a genetically homogeneous structure in the Mediterranean populations. Results when compared with allis ( Alosa alosa Linné) and twaite ( Alosa fallax fallax Lacépède) shad Atlantic populations confirm that the Rhodanian shad belongs to the Alosa fallax Roule species. Furthermore, genetic characteristics of the twaite shad Mediterranean group were quite different from Atlantic populations but remained close to the most southern Atlantic population in the Oued Sebou (Morocco). These findings suggest that Rhodanian shad should be considered a well identified homogeneous group within Alosa fallax rather than a subspecies because of the low genetic distance and some relatively different biological characteristics between the Atlantic and Mediterranean twaite shad groups.     

Increased yearling weight as a proportion of 21-month weight was associated with increased milk production in dairy heifers

ABSTRACT

Aims: To examine the relationship between liveweight (LWT) at 12 months as a proportion of LWT at 21 months of age (LWT(12/21)%) and first lactation and cumulative 3-year milk production in dairy heifers in New Zealand.

Methods: Liveweight and milk production records were obtained for dairy heifers born from June to December (spring-calving season) between 2006–2007 and 2013–2014 dairy seasons; production records included first lactation (n?=?140,113) and cumulative 3-year (n?=?67,833) milksolids and energy-corrected milk (ECM) yields. Heifers were classified into five breed groups; Holstein-Friesian, Holstein-Friesian crossbred, Jersey, Jersey crossbred and Holstein-Friesian-Jersey crossbred. Within each breed group heifers were categorised into quintiles based on 21-month LWT. The LWT(12/21)% was calculated for each animal. Relationships between LWT(12/21)% and milk production within each breed group and LWT category were estimated using linear mixed effects models including the linear and quadratic effects of LWT(12/21)%.

Results: The relationship between LWT(12/21)% and milk production was predominantly curvilinear, with lower milk production at lesser LWT(12/21)% compared with greater LWT(12/21)%. For all breed groups and most LWT categories, heifers that were 55 or 65% LWT(12/21)% produced greater ECM and milksolids yields compared with heifers that were 45% LWT(12/21)%. Holstein-Friesian, Holstein-Friesian crossbred and Holstein-Friesian-Jersey crossbred heifers that were 65% LWT(12/21)% produced greater cumulative 3-year ECM and milksolids yields compared with heifers of the same breed group that were 45% LWT(12/21)%

Conclusions and clinical relevance: Heifers that were a greater proportion of their 21-month LWT at 12 months of age produced more first lactation and cumulative 3-year milk yields than heifers that were a lesser proportion of their 21-month LWT at 12 months of age. These results indicate that increased growth in early life of New Zealand dairy heifers is beneficial to future milk production.     

Comparison of Surgical and Medical Treatment of 49 Postpartum Mares with Presumptive or Confirmed Uterine Tears

Objective— To determine outcome after medical or surgical treatment of postpartum mares with confirmed or presumptive uterine tears. Study Design— Case series. Methods— Postpartum mares were included if foaling had occurred within 7 days and uterine tear was confirmed surgically or, in medically treated mares, by palpation or presumed based on peritonitis. Information (age, breed; physical examination, laboratory and abdominocentesis findings; treatment, survival rates, length of hospital stay, treatments costs, and breeding performance after discharge) was obtained from the medical records (1990–2007). The influence of variables was compared between medical and surgical treatment, and between survivors and nonsurvivors. Results— For 49 mares, survival was 75%, with no significant difference between medical (11/15; 73%) or surgical (26/34; 76%) treatment. Admission variables, treatment cost, duration of hospital stay, and likelihood of foaling after discharge were not significantly different between treatment groups. Nonsurvivors were significantly more likely to have gastric reflux, higher heart rate, anion gap, lower total CO₂, and leukocyte count, compared with survivors. Tears were significantly (P=.018) more likely to occur in the right uterine horn than in other parts of the uterus. Conclusions— Uterine tears occur more commonly in the uterine horns, more so the right horn, and survival is similar with surgical or medical treatment of uterine tears in postpartum mares. Clinical Relevance— Medical treatment may be a reasonable alternative to surgical treatment for uterine tears, although the severity of tear that can resolve with medical treatment is unknown, and medical therapy can be as expensive as surgical treatment.     

Dietary astaxanthin supplementation for hatchery‐cultured red king crab,Paralithodes camtschaticus,juveniles

We conducted large‐scale production trials in Seward, Alaska, USA to investigate effects of dietary astaxanthin supplementation on survival, growth and shell colouration of recently settled juvenile (C1–C4) red king crabs (Paralithodes camtschaticus). We supplemented a control diet of commercial crustacean feeds with astaxanthin, and fed these diets to juvenile king crabs at densities of 2000 and 4000 crabs m^?2 for 56 days. We assessed survival and growth by counting crabs and individually measuring carapace width and weighing crabs at the start and end of the experiment, and quantified crab colour (hue, saturation, brightness) in digital photographs. Diets containing astaxanthin had higher survival, suggesting that astaxanthin may provide nutritional or immune system benefits. Crabs had lower hue, higher saturation and lower brightness values when fed diets containing astaxanthin, suggesting that red king crab colouration is plastic and responds to diet. Astaxanthin is likely an important dietary component for hatchery or laboratory reared red king crab juveniles, and should be considered for aquaculture and other rearing of this and possibly other crustacean species.     

Ultrasound during mid‐gestation: Agreement with physical foetal and placental measurements and use in predicting gestational age in sheep

To determine the effects of poor maternal nutrition and litter size on foetal growth during mid‐gestation, pregnant ewes (n = 82) were fed 100%, 60% or 140% of NRC TDN beginning at day 30.2 ± 0.2 of gestation. Transabdominal ultrasound was performed weekly between day 46.0 ± 0.4 and 86.0 ± 0.7 to monitor foetal heart width (HW), umbilical diameter (UMB), rib width (RW) and placentome outer (OD) and inner diameter (ID). Data were analysed with repeated‐measures using the mixed procedure for effects of maternal diet, litter size and gestation, and equations predictive of gestational age were generated using the regression procedure. To determine the agreement of ultrasound measurement and actual size, ewes (n = 20–21) were euthanized at day 45 or 90 to obtain corresponding postmortem measurements for Bland–Altman analysis. The HW, UMB and placentome OD and ID increased with gestation (p < .0001) but were unaffected by maternal diet or litter size (p ≥ .12). Ultrasound underestimated postmortem measurements of HW (14.8%), UMB (7.3%), placentome OD (4.5%) and ID (37.3%) at day 90 of gestation. Ultrasound underestimated RW at day 45 (7.7%) but overestimated RW (23.8%) at day 90, indicating inconsistent bias when reporting RW by ultrasound. Combining the HW, UMB, RW and placentome OD generated the strongest equation predictive of gestational age (R² = .91). These findings indicate that during mid‐gestation, maternal diet or litter size did not affect HW, UMB or placentome diameters and these factors can be used to estimate gestational age.     

Azomethines of sec-butylamine for the control of penicillium decay of oranges

Imines, synthesised by the reaction of sec-butylamine (SBA, 2-amino-butane) with pentan-2-one, heptan-2-one, octan-2-one, undecan-2-one, benzaldehyde and 2-furaldehyde, were evaluated as vapour-phase treatments to prevent the infection of oranges by Penicillium digitatum. All the imines provided decay control equivalent to SBA when they were introduced into the fruit container at a rate equivalent to 16.4 mg SBA litre^?1 air volume. The carbonyl compound component of the imines, tested alone at a five-fold higher rate, did not reduce fruit decay. All the imines were stable in the gaseous state in dry air. The imines of pentan-2-one and undecan-2-one were hydrolysed rapidly in a humid environment, indicating that their action against P. digitatum was due to the release of SBA into the atmosphere around the fruit. The instability of the imines of the aliphatic ketones makes them unsuitable as generators of SBA in packages. The imines derived from benzaldehyde and 2-furaldehyde were stable in moist air, but were hydrolysed to a significant degree on moist filter paper, especially at pH < 7. These aromatic imines were absorbed from the atmosphere by the fruit and were hydrolysed rapidly in water, and in a buffer solution that represented the environment in fresh injuries on fruit. Apparently all the imines tested generated SBA in the fruit environment, and this SBA accumulated at potential infection sites, where it prevented the development of decay.