The ability of domestic hens to jump between horizontal perches: effects of light intensity and perch colour.

Posted in: Welfare by admin on January 1, 2003 | No Comments

Typically commercial laying houses use lower lighting intensities to reduce feather pecking, however the low light intensity may negatively affects the hens’ ability to see objects within the environment. The low light intensity may also prevent the hens from moving throughout the pen and could possibly lead to increased injury. This study compared the hens’ ability to jump between perches based on light intensity, perch colour and distance between the perches.

Effect of a warm and flexible piglet nest heating system – the warm water bed – on piglet behaviour, live weight management and skin lesions.

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This study tested a new heating system: a warm water bed for young piglets. The first part of the experiment was a preference test combining the water bed with either the micro-cellular mat, the heated plate, or straw litter. In the second part of the experiment, the water bed was compared to different heating systems (thermo-plastic plates, micro-cellular foam mats with gas infrared heating lamps, and fitted insulated concrete floor with gas infrared heating lamps) to determine differences in piglet live weights, weaning weights, and leg injury scores. Temperature of each heating system was the same at a height of 10 cm above the heated surface, but varied between 27.9 ºC to 33.9 ºC on the lying surface for each system. In all of the choice tests, piglets preferred the warm water bed more than the other heating systems. At 3-5 days of age, over half of the litter preferred to lie on the water bed for 63.6-76.8 % of the 24 hour observation period. Less than 1 % of the piglets used the reference system for lying during that same period. In the second part of the experiment, it was discovered that the water bed system reduced the frequency of piglets’ skin lesions as they got older compared with the frequency of skin lesions occurring on piglets housed on concrete flooring. It should be noted that the water bed did not prevent leg injuries, but did help heal them by providing flexible, non-abrasive surface to lie on. Average weaning weights for the warm water bed system (7.72 kg) and the concrete floor with gas heating system (7.26 kg) were also significantly different. Piglets with fewer leg injuries were found to have higher weaning weights. This study showed that piglets prefer to lie on a soft, flexible material like the warm water bed. The warm water bed was shown to improve live weight development and weaning weights of piglets when compared with piglets housed on concrete flooring. Differences between the water bed and the other systems analyzed were not statistically significant.

Large round bale feeder design affects hay utilization and beef cow behavior.

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To reduce feed loss during feeding could improve efficiency of feed use, and enhance animal performance and well-being. The objectives of this study were to evaluated: 1) hay dry matter loss when feeding large round bales in cone, ring, trailer, and cradle-type feeders, 2) feeding behavior for each feeder design, and 3) the relationship between feeding behavior, feeder design, and feed loss. One hundred sixty beef cows were used to evaluate the quantity of hay loss and feeding behaviors from different round bale feeders. Twenty cows were allotted by weight and body condition score to one of eight pens with four feeder designs: cone, ring, trailer, or cradle. All feeder types provided 37 cm of linear feeder space per animal. Alfalfa and orchardgrass round bales were weighed and sampled before feeding. Hay that fell onto the concrete surrounding the feeder was considered waste and was collected and sampled daily. At the end of a 7-d period, each feeder type was assigned to a different pen for a second 7-d period. Behaviors, such as feeder access, occupancy rate, and occurrence of agonistic interactions were recorded. Dry matter hay waste was 3.5, 6.1, 11.4, and 14.6% for the cone, ring, trailer, and cradle feeders, respectively. Both agonistic interactions of cows around the feeders and frequency of feeder entrances differed among feeders and were correlated to feed losses. Feeder design features including size, geometry, bar angle and spacing, and inclusion of a tip bar may affect cattle behavior and resulting feed utilization. Implementation of design strategies that reduce agonistic interactions and /or reduce feeder entrances would be expected to reduce feed losses and improve well-being.

Livestock, ethics, and quality of life

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Currently, the main objective of animal and agricultural scientists is to ensure biological efficiency. However, cheap food is no longer the main concern of people in the West. Other issues are taken into account when purchasing food: quality of life (including health and safety of foods; nutritional value; traditional, regional, locally produced, and organic foods; animal welfare; sustainable farming, environment, and rural resources. This paper illustrates how some recent unethical behaviour has caused the credibility of animal scientist to be lost. A new ‘Quality of Life Agricultural Era’ needs to be promoted with changes in research, teaching and application of animal and agricultural science (especially biotechnology), in order to replace the ‘Era of Intensification’. Animal scientists could be at the forefront of promoting and implementing this new agricultural ideology, with new assumptions, beliefs and leadership that will contribute to the emerging social agenda of the 21st century.

Physiological effects of elevated plasma corticosterone concentrations in broiler chickens. An alternative means by which to assess the physiological effects of stress.

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Physiological measures are often used in the assessment of animal welfare. Many of these measures involve the hypothalamo-pituitary-adrenal (HPA) axis, particularly the animals’ ability to release cortisol and the effects of cortisol release on other physiological measures. Some of these studies involve giving animals an infusion of corticosterone, but this can be a significant stressor in itself. This study was conducted to determine if it is possible to administer corticosterone by drinking water and if the effects are similar to other means of administration. The chickens were given 4 levels of corticosterone in their water (0 to 20 mg/L). Plasma corticosterone levels rose in accordance with the level in the water. Secondary responses to corticosterone, such as heterophil counts, also responded in a dose dependent manner. It is concluded that administration of corticosterone in the drinking water is an effective means of studying stress responses in chickens.

Effect of ketoprofen, lidocaine local anesthesia, and combined xylazine and lidocaine caudal epidural anesthesia during castration of beef cattle on stress responses, immunity, growth, and behavior.

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Holstein x Freisian beef cattle were monitored after castration by burdizzo (B), with or without anesthesia. Methods of anesthesia used included ketoprofen (K), local anesthesia (LA) or caudal epidural anesthesia (EPI). A control (C) treatment in which no anesthesia was used was also implemented. Effects on plasma cortisol, acute-phase proteins, interferon-ã production, growth, and behavior. K animals had a lower area under the cortisol curve against time than the other treatments. Plasma haptoglobin concentrations were lower on day 1 after castration for BK animals compared to B, BLA or BEPI animals. Haptoglobin and fibrinogen concentrations were higher in all castration groups on day 3 after castration than in group C. The same concentrations remained higher on day 7 for BLA animals than in B or C animals. Concanavalin A-induced interferon-ã production was lower on day 1 in B, BLA, and BEPI animals than in C, with no differences between C and BK treatments. ADG was lower from day 1 to 35 for B, BLA, and BEPI animals but not BK animals compared with C. There was a higher incidence of combined abnormal postures overall in B than in C, BK and BEPI animals. There was no difference between the K and EPI treatment. Conclusions stated that burdizzo castration increased plasma cortisol and acute-phase proteins and suppressed immune function and gains. Local anesthesia prolonged the increase in acute-phase proteins. Ketoprofen was more effective than LA or EPI in decreasing cortisol levels and was able to partially reverse the reduction in ADG after castration had been carried out. Pain-associated behavioral responses were decreased the most during the first 6 hours after castration with use of K or EPI rather than LA. Ketoprofen was more effective in reducing inflammatory responses associated with castration than LA or EPI.

Intersucking in dairy cattle – review and questionnaire.

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Social stress in laying hens: Differential effect of stress on plasma dopamine concentrations and adrenal function in genetically selected chickens

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Two phenotypically distinct lines were created, selecting for high or low group productivity and survival. Each line developed unique behavioural and physiological characteristics, when housed in a multiple-bird cage system. This study examined how the variation in the adaptation of the two lines has affected the control of the plasma dopamine concentrations and how the adrenal gland responds to social stress. At 17 weeks-of-age, laying hens from the HGPS and LGPS lines were housed in single cages or cages that housed 10 hens. The effect that the genetics and housing had on the dopamine concentration and adrenal function was measured on the 24th week-of-age. When 10 hens were housed per cage, the HGPS hens had lower dopamine concentrations and heavier adrenal glands. There was not a significant difference in the cortisol concentrations of the two genetic lines. However, in the single cages system, both lines had higher dopamine and lower cortisol concentrations than those hens that were housed in groups. The increase in the dopamine concentrations was significantly larger in the LGPS than the HGPS hens that were housed individually. As well, the adrenal glands were lighter in individually housed LGPS hens. The experiment found that the hormonal response to stress is different in the two genetic lines. It was also proven that environment affects the stress reaction. Thus, hormones and the environment are likely what causes the behavioural and physiological differences exhibited by the two genetic lines.

The effect of milk flow rate and milk allowance on feeding related behaviour in dairy calves fed by computer controlled milk feeders.

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The aim of this study was to determine the effects of milk flow rate and milk allowance from a computer-controlled milk feeder on calves’ use of the feeder. Four calves each were assigned to one of four treatments: low milk allowance and normal milk flow rate (LN), high milk allowance and normal milk flow rate (HN), low milk allowance and reduced milk flow rate (LR), or high milk allowance and reduced milk flow rate (HR). Data were collected by the computerized feeder from day 15 until weaning. Findings indicated that the overall combination of high milk yield and low flow rate resulted in the most time spent in the feeder during rewarded visits. However, there were significant effects of breed. For the heavy breed calves, a reduced milk flow rate resulted in a longer duration of rewarded visits and a longer duration of all visits. A high milk allowance resulted in fewer unrewarded visits, a shorter duration of unrewarded visits, and a shorter duration of all visits to the feeder. For all breeds, the reduced milk flow rate resulted in a longer duration of visits where the calves had access to milk but did not consume it. Calf behaviour was recorded on video for a 24 hour period. Recordings showed that heavy breed calves that fed at a reduced milk flow rate occupied the feeder more than the calves fed at a normal milk flow rate. When offered a high milk allowance, the heavy breed calves entered the feeder less often and also entered the feeder less frequently when it was empty. Calves of all breeds, when offered a low milk allowance in combination with a reduced milk flow rate, tried more often to get access to an occupied feeder and displaced other calves from the feeder more often. There were no effects of treatment on the occurrence of cross-sucking. Results indicated that, for heavy breeds, a reduced milk flow rate increased the mean occupancy of the feeder due to a longer duration of rewarded visits. Also, a higher milk allowance reduced the mean occupancy through a reduction in the duration of unrewarded visits for the heavy breed calves. The hypothesis that a high number of unrewarded visits to a computerized milk feeder being likely due to hunger, was supported by the results of this study. The results further suggest that the time the calves occupy the feeder may be reduced by a high milk allowance. The combination of a low milk allowance and a reduced milk flow rate may result in an increase in the competition for access to the feeder.

Automated blood cell count: a sensitive and reliable method to study corticosterone-related stress in broilers.

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