Toby G Knowles

A review of the road transport of cattle

The transport of farm animals has been the subject of much research in recent years. This paper reviews the recent scientific literature pertinent to the road transport of cattle. The state of knowledge is summarised and recommendations for best practice based upon this are given. Areas which require further work are also identified.

Leg disorders in broiler chickens: prevalence, risk factors and prevention.

Broiler (meat) chickens have been subjected to intense genetic selection. In the past 50 years, broiler growth rates have increased by over 300% (from 25 g per day to 100 g per day). There is growing societal concern that many broiler chickens have impaired locomotion or are even unable to walk. Here we present the results of a comprehensive survey of commercial flocks which quantifies the risk factors for poor locomotion in broiler chickens. We assessed the walking ability of 51,000 birds, representing 4.8 million birds within 176 flocks. We also obtained information on approximately 150 different management factors associated with each flock. At a mean age of 40 days, over 27.6% of birds in our study showed poor locomotion and 3.3% were almost unable to walk. The high prevalence of poor locomotion occurred despite culling policies designed to remove severely lame birds from flocks. We show that the primary risk factors associated with impaired locomotion and poor leg health are those specifically associated with rate of growth. Factors significantly associated with high gait score included the age of the bird (older birds), visit (second visit to same flock), bird genotype, not feeding whole wheat, a shorter dark period during the day, higher stocking density at the time of assessment, no use of antibiotic, and the use of intact feed pellets. The welfare implications are profound. Worldwide approximately 2×1010 broilers are reared within similar husbandry systems. We identify a range of management factors that could be altered to reduce leg health problems, but implementation of these changes would be likely to reduce growth rate and production. A debate on the sustainability of current practice in the production of this important food source is required.

Changes in the blood biochemical and haematological profile of neonatal calves with age.

Fourteen calves were used to investigate the changes from birth to 83 days of age in the concentrations of serum albumin, alkaline phosphatase, beta-hydroxybutyrate, plasma cortisol, serum creatine kinase, creatinine, iron, plasma fibrinogen, serum gamma-glutamyl transferase, plasma glucose, haptoglobin, serum non-esterified fatty acids, total protein, transferrin, triglycerides, urea and gamma globulin; the haematological variables measured were: basophils, eosinophils, haematocrit, haemoglobin, lymphocytes, mean cell haemoglobin, mean cell haemoglobin concentration, mean cell volume, monocytes, band neutrophils, neutrophils, platelets, red blood cells and white blood cells. The changes are presented as a series of graphs and the values are discussed in relation to the published reference ranges for adult cattle. Two populations of calves were identified which gave rise to a bimodal distribution for some of the variables. Differences in haematocrit, haemoglobin and red blood cell counts were apparent at birth, with raised values for these measurements being associated with an increased white blood cell and neutrophil count between three and 27 days of age.

Differential effects of increased stocking density, mediated by increased flock size, on feather pecking and aggression in laying hens

Six flocks of laying hens were housed in percheries at each of four stocking densities (6, 14, 22 or 30 birds m−2) from 14 to 30 weeks of age. Stocking density was manipulated by changes in flock size (72, 168, 264 or 368 birds) within percheries of the same floor and height dimensions. The pecking behaviour of birds was observed directly at 15, 22 and 30 weeks of age, and corrected for the number of birds in view. Egg production was recorded at 23 and 27 weeks of age, and plumage condition was scored at 30 weeks of age. At 23 weeks of age, egg production was greater at 6 birds m−2 than at other stocking densities. The plumage condition of the birds was best at 6 birds m−2 and worsened with increased flock size and stocking density. The behavioural observations suggested that this was due to an increase in mild feather pecking with increased flock size and stocking density. Mild feather pecking increased with bird age and was most frequently observed on the perchery floor although, at higher flock sizes and stocking densities, it also occurred on the perches. Severe feather pecking was infrequent, especially at the lower flock sizes and stocking densities, but was most likely to occur near the nest boxes. Vent pecking was extremely rare. Aggressive pecking was most common in the smaller flocks at the lowest stocking densities, possibly because these birds attempted to form social hierarchies. Birds in the larger flocks at higher densities appeared to adopt non-social, non-aggressive behavioural strategies.

Effect of lairage time on levels of stress and meat quality in pigs

A total of 1580 pigs killed in three slaughter -plants were held in lairage for ≥ 1 h, 3 h or overnight before slaughter. Blood samples were collected at exsanguination and subsequent carcass and meat quality monitored. Longer lairage reduced stress levels based on the concentration of cortisol, lactate and creatine phosphokinase in the blood. It also reduced the prevalence of pale, soft, exudative (PSE) but increased the prevalence of dark, firm, dry (DFD) meat. Additionally, it produced progressively greater amounts of skin damage caused by fighting between unfamiliar pigs and an overnight lairage reduced carcass yield and backfat thickness. The overall conclusion ivas that a period of between 1 and 3 h rest in lairage was optimal. There was no evidence that leaner, potentially more stress-susceptible pigs reacted differently from fatter, potentially more stress-resistant animals with regard to the effects of lairage time.

Factors affecting the prevalence of foot pad dermatitis, hock burn and breast burn in broiler chicken

1. Standardised data on flock husbandry were recorded on 149 broiler farms during the 4 d prior to slaughter. 2. Birds were examined at the slaughterhouse for contact dermatitis lesions. Foot pad dermatitis score (FPDS) and hock burn score (HBS) were measured on five point scales. Carcase rejection data were also collected. 3. The mean percentage of birds in each flock with: moderate or severe foot lesions was 11·1% (range 0–71·5%); moderate or severe hock burn was 1·3% (range 0–33·3%); and, breast burn was 0·02%. 4. A general linear model was developed to examine factors associated with mean flock FPDS. Assuming a linear relationship, within the range of data collected and with all other factors remaining the same, every 1% increase in the proportion of Genotype A birds in the flock was associated with an increase in mean FPDS of 0·003, every one-point increase in litter score was associated with a 0·326 increase in mean FPDS and every one-point increase in flock mean HBS was associated with a 0·411 increase in mean FPDS. Flock mean FPDS was associated with feed supplier and was higher in winter. 5. The general linear model developed for flock mean HBS, found that every one-point increase in mean FPDS increased mean HBS by 0·090, every one-point increase in litter score increased HBS by 0·119 and, every 1% increase in small/emaciated birds decreased mean HBS by 0·333. Reduced HBS was also associated with increased final litter depth, younger slaughter age and an increased percentage of dietary wheat. For every 1% increase in Genotype A birds, a decrease in flock mean HBS of 0·003 would be expected. 6. An effect of hatchery was also identified.

Effects on cattle of transportation by road for up to 31 hours

The physiological and behavioural effects on cattle of transporting them for periods of 14, 21, 26 and 31 hours, including a stop for a rest and drink on the lorry after 14 hours, were studied in 120 transported animals and 48 control animals. The physiological measurements indicated that a journey lasting 31 hours was not excessively physically demanding, but many of the animals chose to lie down after approximately 24 hours. The animals that lay down had higher plasma cortisol levels than those that remained standing. Many animals chose not to drink during the rest stop. Physiological measurements made after the journeys indicated that 24 hours in lairage, with hay and water freely available, allowed the animals to recover substantially, although not completely, irrespective of the journey time.

The development, implementation and testing of a lameness control programme based on HACCP principles and designed for heifers on dairy farms

This paper describes the development and testing of a lameness control programme (LCP) for heifers on dairy farms. The LCP, which is based on the analysis of hazards and critical control points (HACCP), was tested via a randomised intervention study on 60 farms. Tangible hazards for each farm were identified, allotted to 11 categories of proximate hazard and scored on each farm to quantify the risks presented by each hazard. Feet were inspected for signs of claw horn disease and infection, such as digital dermatitis. Intervention was generally ineffective, primarily through failure to implement the LCP. However, retrospective analysis was able to demonstrate highly significant associations between risks attached to proximate hazards and probabilities of lameness and foot lesions, allowing the severity of these hazards to be ranked. The most significant proximate hazards of environmental origin were prolonged standing on concrete, standing in wet slurry and factors that cause claw trauma. The most severe proximate hazards however were those associated with failures of management, especially poor claw condition and inadequate foot care. Overall farm risks (OFR) were estimated by summing the products of the generic severity for proximate hazards with on-farm risks. Changes in OFR were significantly related to changes in outcome (lameness and lesions).

Meat quality in pigs subjected to minimal preslaughter stress

The experiment compared meat quality in carcasses from pigs subjected to the absolute minimum of stress preslaughter with that from carcasses of pigs subjected to simulated commercial handling. A total of 120 pigs (85 kg) were used. They were a commercial hybrid and were processed in six equal batches. The minimal stress group were slaughtered with as little stress as possible. The simulated commercial handling group were mixed and transported for 2hr (80 km) and lairaged for 30 min. Simulated commercial handling increased plasma cortisol, plasma lactate, CPK and beta-endorphin. Muscle temperature measured in the m. longissimus dorsi (LD) at 45 min increased as did the ultimate pH in the m. adductor (AD). Overall eating quality was not affected. There were batch affects on most variables. Males were leaner and produced meat that had greater abnormal fat odour, darker cooked colour, poorer pork flavour, lower overall acceptability and was tougher.

The handling and transport of broilers and spent hens

Abstract The effects of handling and transportation on spent hens and broilers are presented and discussed with particular reference to measures of the welfare of the birds. Points in the handling and transport process where improvements are required are outlined. The procedures used to handle and transport spent hens and broilers result in welfare problems for the birds which are often very severe. There is evidence for substantial emergency responses, such as adrenal cortex activity. There can also be birds dead on arrival at the slaughterhouse, bruising, and high incidences of bone breakage. Housing hens in battery cages for long periods results in bone fragility. The greatest welfare problem is the normal rough handling which leads to poorer welfare than does a short vehicle journey. Better handling procedures are essential. Poor conditions on the journey also result in poor welfare. Much research is needed using a wide range of indicators to assess welfare and to design housing systems, handling methods, and transport procedures which do not result in poor welfare.