Variation in the Level of Grain Defect Light Flecks and Spots on Cattle Hides

The occurrence of hide damage light flecks and spots was determined on tanned hides from 28 herds during a period of 8 to 12 months. Light flecks and spots are described as small areas of grain loss up to 3 mm in diameter that are seen on dyed crust cattle leather. Damage was found on 75.8% of all hides. The neck and shoulders were the anatomical region with the highest prevalence of damage. Sixty-eight per cent of all hides had light flecks and spots in this region. The forelimbs and dewlap were the anatomical region with the second highest occurrence with a prevalence of 39.1%. This distribution corresponded to the known distribution of lice in cattle. No significant differences were observed in age, sex, prevalence of lice in the herd assessed in March or infestations with different lice species. The frequency of light flecks and spots varied significantly during the year. The frequency was highest in the late winter and early spring, decreased significantly during the summer and was lowest in the autumn. This variation supported the importance of lice in the development of light flecks and spots and suggested a relatively long healing period for the damages induced by lice

Eradication of Lice in Cattle

The purpose of this field study was to develop and evaluate eradication as a strategy to control lice in cattle. Thirty-three herds of cattle were selected and observed during a period of two and a half years. Before eradication, biting lice (Damalinia bovis) were present in 94% of the herds and 27% of the animals. Sucking lice (Linognathus vituli) were present in 42% of the herds and 5% of the animals. These levels were very similar to those reported from other countries in Northern Europe

The Effect of Eradication of Lice on the Occurrence of the Grain Defect Light Flecks and Spots on Cattle Hides

The influence of an eradication programme for lice on the prevalence of light flecks and spots on cattle hides was studied in 33 dairy cattle herds during a period of two and a half years. Lice were eradicated from the main group of herds after 9 to 12 months and the quality of the hides before and after treatment was compared. Hides from slaughtered animals were collected during the study period, tanned and examined with special emphasis on the occurrence of the grain damage light flecks and spots. The prevalence of hides without light flecks and spots increased from 24.2% before treatment to 61.6% after treatment. The prevalence of hides free from the damage increased significantly in all examined anatomical regions. The improvement in hide quality was most marked in the shoulders and neck region which corresponded to the major predilection site of cattle lice. The prevalence of hides with light flecks and spots started to decrease in the first period (2–40 days) after eradication. The changes after treatment suggested that most healing process took place over a period of about 4 months. The eradication programme eliminated the seasonal variation in the prevalence of light flecks and spots which was present before treatment

Morphology of the Leather Defect Light Flecks and Spots

The skin histology and the scanning electron microscope morphology of the hide defect light flecks and spots after tanning were studied in 11 steers infested with biting lice (Damalinia bovis). Nine steers from herds free of lice were used as controls. Skin biopsies from 6 of the animals in the lice infested group showed mild to moderate hyperkeratosis and moderate perivascular to diffuse dermatitis with infiltration of mainly mononuclear cells and some eosinophilic granulocytes. The steers were slaughtered at an age of 18 to 23 months. Light flecks and spots occurred on all examined hides from the infested group after tanning. No examined hides from the control group demonstrated similar damage. Both light microscopic examination of sections of tanned hide with light flecks and spots and scanning electron microscopy of the same defects showed superficial grain loss and craters with a irregular fibre base encircled by smooth and intact grain

Threat-sensitive anti-predator defence in precocial wader, the northern lapwing Vanellus vanellus

Birds exhibit various forms of anti-predator behaviours to avoid reproductive failure, with mobbing—observation, approach and usually harassment of a predator—being one of the most commonly observed. Here, we investigate patterns of temporal variation in the mobbing response exhibited by a precocial species, the northern lapwing (Vanellus vanellus). We test whether brood age and self-reliance, or the perceived risk posed by various predators, affect mobbing response of lapwings. We quantified aggressive interactions between lapwings and their natural avian predators and used generalized additive models to test how timing and predator species identity are related to the mobbing response of lapwings. Lapwings diversified mobbing response within the breeding season and depending on predator species. Raven Corvus corax, hooded crow Corvus cornix and harriers evoked the strongest response, while common buzzard Buteo buteo, white stork Ciconia ciconia, black-headed gull Chroicocephalus ridibundus and rook Corvus frugilegus were less frequently attacked. Lapwings increased their mobbing response against raven, common buzzard, white stork and rook throughout the breeding season, while defence against hooded crow, harriers and black-headed gull did not exhibit clear temporal patterns. Mobbing behaviour of lapwings apparently constitutes a flexible anti-predator strategy. The anti-predator response depends on predator species, which may suggest that lapwings distinguish between predator types and match mobbing response to the perceived hazard at different stages of the breeding cycle. We conclude that a single species may exhibit various patterns of temporal variation in anti-predator defence, which may correspond with various hypotheses derived from parental investment theory

The 4 anatomical regions of the hide which were evaluated after tanning

<p><b>Copyright information:</b></p><p>Taken from "Variation in the Level of Grain Defect Light Flecks and Spots on Cattle Hides"</p><p>http://www.actavetscand.com/content/42/1/91</p><p>Acta Veterinaria Scandinavica 2001;42(1):91-98.</p><p>Published online 31 Mar 2001</p><p>PMCID:PMC2202347.</p><p></p