Suckling behavior in range beef calves

The number and duration of suckling incidences were recorded during eight 24-h observation periods in a herd of spring-calving Polled Hereford and percentage Simmental cows in 1980 and 1981. The average number of suckling events per calf in 24 h was 5.0 +/- .1 and the average time spent suckling in 24 h was 46 +/- 1 min. Peaks in suckling activity occurred from 0500 to 0700, 1000 to 1300 and 1700 to 2100 h. The most suckling events in a single hour occurred between 0500 and 0600 h and the least between 2200 and 2300 h. Day of the estrous cycle did not influence the number or duration of suckling events. Cows that gave more milk nursed less frequently and heavier calves suckled less frequently (P less than .01). Age, breed and sex of the calf did not influence (P greater than .1) suckling frequency or duration.     

Evaluation of reproductive traits in Bos taurus and Bos indicus crossbred heifers: effects of postweaning energy manipulation

Reproductive traits were evaluated in Bos taurus and Bos indicus crossbred heifers that were fed different diets during the postweaning period. The study was designed in a 2 x 2 x 2 factorial arrangement of treatments. Angus x Hereford (AH; n = 148) and Brahman x Hereford (BH; n = 148) heifers were sorted after weaning by body weight into light (LW) and heavy (HW) weight blocks. Heifers in each weight block were assigned to diets calculated to reach a target weight of 55% (LE) or 65% (HE) of their projected mature weights by the start of the breeding season. Puberty was determined after a 160-d observation period and characterized by the following criteria: 1) behavioral estrus, 2) presence of a palpable corpus luteum (d 6 to 10; estrus = d 0), and 3) rise in serum progesterone above 1 ng/ml (d 6 to 10). A higher (P = .01) proportion of AH heifers than of BH heifers reached puberty by the breeding season (93% vs 67%). Interactions of breed x weight block and energy level x weight block also contributed to this difference. Weight at puberty was heavier (P = .001) among HE than among LE heifers and greater for heifers in HW than for those in LW blocks (P = .02). Differences in prebreeding weight, body condition, average daily gain, hip height, and pelvic area were influenced selectively by breed, energy level, or weight block. Pregnancy rates were higher (P = .01) among AH than among BH heifers. Incidence and severity of dystocia was influenced by the breed x energy level interaction (P = .01). Brahman x Hereford heifers had less (P = .01) dystocia than AH heifers, HE heifers had less (P less than .02) dystocia than LE heifers, and HE-AH heifers had less (P less than .01) dystocia than LE-AH contemporaries. Subsequent duration of the postpartum interval to estrus was shorter (P = .002) among AH than among BH females. Pregnancy rates at the end of the 2nd yr were higher (P = .02) among LW than among HW females and weights were heavier (P = .001) at weaning among calves weaned from BH dams.     

Daytime management of the mare: 1: Pre-foaling mammary secretions testing

Fifty-six mares of lighthorse breeding were utilized in a controlled management scheme for induced daytime foaling. All mares had pre-foaling mammary secretions sampled for evaluation of water hardness (ppm) or calcium carbonate content (ppm). Sampling began 10 days prior to expected foaling date for each mare and was performed once daily for 3 days followed by twice daily until foaling occurred. Samples were diluted 1:6 in distilled water and tested by each of 3 methods: Sofchek™ Test Strips⁴, Predict-A-Foal™ Test Kit⁵ and Titrets™ Calcium Hardness Test Kit⁶. Mares were then either induced (i) to foal (no.= 33) according to a decision point of readiness for birth as indicated by pre-foaling mammary secretion testing (≥250 ppm water hardness by Sofchek™ test, ≥ 250 ppm calcium carbonate content by Titrets test, ≥ 4 color bar changes by Predict-A-Foal test), or allowed to foal spontaneously (s) (no.=23). There were no differences (p>0.05) in the mean pre-foaling mammary secretion test values (μ_i=293ppm, μ_s=329ppm; μ_i=4.1, μ_s=4.2; and μ_i=281ppm, μ_s=298ppm; for Sofchek, Predict-A-Foal and Titrets, respectively) between mare groups at the time of foaling (time=0) for any of the 3 testing methods employed. Mean intervals to foaling after reaching decision points of readiness for birth were different (p<0.05) between Sofchek and Titrets test for both mare groups, but only in the induced-to-foal group between Sofchek and Predict-A-Foal tests. Probabilities of 79%, 53% and 59% were calculated for mares foaling spontaneously within 24 hours of reaching the decision points used in this trial of readiness for birth on the initial occasion for Sofchek, Predict-A-Foal and Titrets™ tests, respectively. Each test was determined to have the ability to predict readiness of approaching parturition and found to be easily applicable to field use. The Titrets test was found to be least variable in its response to measurement of pre-foaling mammary secretion hardness changes both within and between mares.     

Detection of Aphanomyces invadans and epizootic ulcerative syndrome in the Murray‐Darling drainage

Epizootic ulcerative syndrome was diagnosed, and the presence of Aphanomyces invadans confirmed, from an outbreak of clinical disease in wild‐caught bony bream (Nematalosa erebi) from the Darling River near Bourke, in New South Wales, Australia, during 2008. This confirms a significant extension of the agent beyond its historical range.     

Involvement of ATP‐sensitive K+ channels in the peripheral antinociceptive effect induced by ketamine

ObjectiveTo investigate the contribution of K⁺ channels on peripheral antinociception induced by ketamine.Study designProspective experimental study.Animals110 male Wistar rats weighing 160–200 g.MethodsThe paw pressure required to elicit limb flexion was designated as the nociceptive threshold. Hyperalgesia was induced by intraplantar injection of prostaglandin E₂. All drugs were administered locally into the right hind paw of rats. Ketamine was administered into the right hind paw 2 hours and 55 minutes after local injection of PGE₂. Tetraethylammonium was administered 30 minutes prior to ketamine and the other K⁺ channel blockers, glibenclamide, dequalinium and paxilline, were administered 5 minutes prior to ketamine.ResultsProstaglandin E₂ (2 μg per paw) induced hyperalgesia. Ketamine (10, 20, 40 and 80 μg per paw) elicited a local peripheral antinociceptive effect that was antagonized by a specific blocker of ATP‐sensitive K⁺ channels, glibenclamide (20, 40 and 80 μg per paw). In another experiment, the non‐selective voltage‐dependent K⁺ channel blocker tetraethylammonium (30 μg per paw) and small and large conductance blockers of Ca²⁺‐activated K⁺ channels, dequalinium (50 μg per paw) and paxilline (20 μg per paw), were ineffective at blocking the effect of a local ketamine injection.Conclusions and clinical relevanceAnalysis of these results provides evidence that ketamine, may in part, induce peripheral antinociceptive effects by ATP‐sensitive K⁺ channel pathway activation.     

Skeletal deformities associated with nutritional congenital rickets in newborn lambs

Abstract

CASE HISTORY: A group of 545 pregnant rising 2-year-old Coopdale ewes on a Southland sheep farm were grazed over winter on a fodder beet (Beta vulgaris) crop. Subsequently, 45 out of approximately 750 lambs were born with a variety of skeletal deformities, including shortened limbs, varus and valgus angular limb deformities, palmar grade stance and cranial bowing of the carpus. Analysis of the crop showed the fodder beet contained a low percentage of phosphorus. In addition, 60 out of 460 rising 2-year-old ewes that had been grazed on the fodder beet crop as 1-year-olds had incisor abnormalities and malocclusion.

PATHOLOGICAL FINDINGS: Two affected lambs (1-day-old and 3-days-old) with representative clinical signs examined postmortem were found to have markedly enlarged costochondral junctions, and noticeably enlarged long bone metaphyses. In addition, one lamb had a dense band of metaphyseal sclerosis beneath the physes of all long bones examined. Histopathological findings included small islands and columns of chondrocytes and eosinophilic cartilage matrix present in the metaphysis. Metaphyseal trabeculae were disorganised and often lined by accumulations of pale pink osteoid; similar pale pink osteoid was also present in the cortices. Unerupted molar teeth in the affected lambs lacked a layer of enamel, and the dentine was irregular with globular basophilia.

DIAGNOSIS: The gross and histopathological lesions were consistent with a diagnosis of rickets.

CLINICAL RELEVANCE: Nutritional congenital rickets has not been previously diagnosed in sheep, but is a recognised disease of human infants with vitamin D deficient mothers. The rickets in affected lambs was most likely associated with phosphorus deficiency as a result of the pregnant ewes grazing fodder beet during gestation. While vitamin D deficiency was not definitively ruled out in these cases, practitioners are alerted to the possible effects of feeding phosphorus-deficient fodder beet to ewes for long periods during gestation and to 1-year-old sheep during important growth periods.     

Climate and vegetation history of the midcontinent from 75 to 25 ka: A speleothem record from crevice cave, missouri, USA

Four Missouri stalagmites yield consistent overlapping records of oxygen and carbon isotopic changes and provide a climate and vegetation history with submillennial resolution from 75 to 25 thousand years ago (ka). The thorium-230-dated records reveal that between 75 and 55 ka, the midcontinental climate oscillated on millennial time scales between cold and warm, and vegetation alternated among forest, savanna, and prairie. Temperatures were highest and prairie vegetation peaked between 59 and 55 ka. Climate cooled and forest replaced grassland at 55 ka, when global ice sheets began to build during the early part of Marine Oxygen Isotope Stage 3.