Diffusion kinetics of samarium and neodymium in garnet, and a method for determining cooling rates of rocks

Experimental determinations of the diffusion coefficients of samarium and neodymium in almandine garnet and theoretical considerations show that one cannot assign a sufficiently restricted range of closure temperature, TC, to the samarium-neodymium decay system in garnet for the purpose of constraining the cooling rate. However, it is shown that the samarium-neodymium cooling age of garnet can be used to calculate both cooling rate and TC if the temperature and age at the peak metamorphic conditions are known.     

A Review of Canine Pseudocyesis

The purpose of this article is to review the most relevant features of the physiology, clinical signs, diagnosis, treatment and prevention of canine pseudocyesis (PSC). This is a physiological syndrome, characterized by clinical signs such as: nesting, weight gain, mammary enlargement, lactation and maternal behaviour, which appears in non‐pregnant bitches at the end of metaoestrus. PSC is a frequent finding in domestic dogs. Although it is generally admitted that prolactin (PRL) plays a central role in the appearance of PSC, its precise aetiophysiology is not completely understood yet. A number of clinical studies suggest that at some point of metaoestrus circulating PRL levels rise in overtly pseudopregnant bitches. Individual differences in sensitivity to PRL as well as the existence of molecular variants of canine PRL with different bioactivity versus immunoreactivity ratios may help clarify the aetiopathology of PSC. Diagnosis of PSC is based on the presence of typical clinical signs in metaoestrous non‐pregnant bitches. Considering that PSC is a self limiting physiological state, mild cases usually need no treatment. Discouraging maternal behaviour and sometimes fitting Elizabethan collars to prevent licking of the mammary glands may suffice in these cases. Sex steroids (oestrogens, progestins and androgens) have been traditionally used to treat PSC but the side‐effects usually outweigh the benefits of these medications. Inhibition of PRL release by ergot derivatives [ bromocriptine (10–100 μg/kg per day for 10–14 days], cabergoline (5 μg/kg per day during 5–10 days), metergoline (0.2 mg/kg per day during 8–10 days) has proved to be effective for the treatment of canine PSC. Although some of these ergot derivatives present some untoward side‐effects, they are transient and can usually be managed. Predisposed bitches not intended for breeding should be spayed as ovariectomy is the only permanent preventive measure.     

Reduced growth of Lucilia cuprina larvae fed serum from sheep treated with anthelmintics

The effect of three commonly used anthelmintics, levamisole hydrochloride, ivermectin and closantel, on the development of the sheep blowfly, Lucilia cuprina, was determined. Sheep were treated with each anthelmintic using the manufacturers' recommended dose for helminth control. Both ivermectin and closantel significantly (p < 0.05) reduced the growth rate of larvae of L cuprina cultured in vitro on serum from these sheep. Levamisole hydrochloride had no effect. Ivermectin was effective for less than 6 days after treatment, whereas closantel significantly reduced larval growth 21 days after treatment. Dose-response experiments showed that lower concentrations of both ivermectin and closantel were not as effective in reducing larval growth.     

Predictors of beef calf temperament at weaning and its impact on temperament at breeding and reproductive performance

Two experiments were conducted to determine (i) factors influencing calf temperament at weaning, (ii) association between heifer–calf temperament at weaning and temperament at breeding and (iii) effect of heifer–calf temperament on pregnancy rate per artificial insemination (P/AI). In experiment 1, beef cows and their calves (n = 285) from three farms were used. Sire docility estimated progeny difference (EPD) score, birth type (normal or assisted), calf gender, calf behaviour (during 1st 4 weeks) and calf health status (until weaning) were recorded. Cows and calves were assigned a temperament score (0—calm; 1—excitable), and all cows were given a body condition score (BCS, 1–9; 1—emaciated; 9—obese) at weaning. Calf's illness (p < .05), low sire docility EPD score (p < .05), altered gait (p < .05), altered resting behaviour (p < .01), reduced/no play behaviour (p < .05) and cow excitable temperament (p < .001) increased calf excitable temperament at weaning. In experiment 2, replacement heifer–calves (n = 758) from 12 farms were assigned a temperament score at weaning and later at breeding. Blood from 40 calves at weaning and 31 heifers at initiation of synchronization (same animals) was collected by coccygeal venipuncture for determination of circulating cortisol and substance P concentrations. Heifers were assigned a BCS and reproductive tract score (RTS, 1–5; 1—immature, acyclic; 5—mature, cyclic), synchronized for fixed time AI, observed for oestrus and were artificially inseminated. Cortisol concentrations were increased in excitable heifer–calves compared to calm heifer–calves at weaning (p < .05), and substance P was increased in excitable compared to calm females both at weaning and breeding (p < .05). Low sire EPD docility score (p < .01), heifer–calf excitable temperament at weaning increased excitable temperament at breeding (p < .01). Controlling for BCS categories (p < .01), oestrous expression (p < .0001) and temperament at breeding by oestrous expression (p < .05), the calf's excitable temperament at weaning (p < .001) reduced P/AI (Calm, 62.7 (244/389) vs. Excitable, 53.4% (197/369); p < .01). In conclusion, selection of docile cows and sires with greater docility EPD score should be given consideration to reduce calf excitement. Temperament in beef female can be detected earlier in their life and could be used as a tool in the selection process and to improve their performances.