Nursing synchronization in lactating sows as affected by activity, distance between the sows and playback of nursing vocalizations.

Posted in: Welfare by admin on January 1, 2004 | No Comments

Nursing behaviour tends to be synchronized in lactating sows. However, the nursing synchrony has not been quantified in the sows housed in commercial conditions. In this study, the amount of nursing synchronization was quantified, the dependence of the degree of synchronization on the spatial distance between sows was examined, and the effect of nursing vocalization playback on nursing frequency and nursing synchronization was assessed in a large commercial pig farm. Sows were housed in individual farrowing crates, 14 sows per room. Twelve rooms were assigned to one of four treatment combinations, which was age of piglets (6-10 days vs. 13-17 days), and bass frequency on the loudspeakers (bass on vs bass off). The playback of nursing vocalization was employed for three minutes every 45 min, 55 min, or no playback at all for three days. The nursing behaviour and its synchronization were recorded in two ways: through a 2 h direct interval sampling observations of all sows and through a 6 h video recording of three focal sows. The nursing synchronization was higher than the random frequency. Synchronization in pairs of sows declined with increasing distance. The playback of nursing sounds did not increase either the nursing frequency or the nursing synchronization. It is concluded that nursing synchronization is high in large rooms with crated sows, that is not a sole consequence of synchronization in general activity. Nursing synchronization depends on the distance between the sows, and an increase in nursing frequency is not always reliably induced by a playback of pig nursing vocalizations.

Prior deprivation and reward duration affect the demand function for rest in dairy heifers.

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Measurement of motivation is important in determining the relative importance of behaviours to the animals in our care. Construction of demand functions based on operant conditioning techniques is one way to measure and quantify motivation of animals. In this particular study demand functions were used in an attempt to estimate the importance of resting in cattle. Furthermore, the sensitivity of the technique was determined by quantifying the effects of variations in the level of prior deprivation, and reward (lying) duration on elasticity and intensity of the demand function. Cows were housed in tether stalls where they could be deprived of lying by attaching a girth strap secured to a rafter above the animal. During a 3-h test period a panel was placed in front of each heifer and she could work by pressing this panel on fixed ratio schedules for a releasing mechanism to be activated allowing her to lie down. In experiment 1 the heifers were deprived of lying twice daily for either two periods of 3h or two periods of 6h prior to testing. The fixed ratio varied from 6 to 24 and the reward duration was 15 minutes. In experiment 2, heifers could lie for either 10 or 20 minutes per reward at either of the two deprivation levels used in experiment 1. Here the fixed ratio varied from 10 to 50. The demand functions were liner in arithmetic co-ordinates, which means that the elasticity may not be constant across fixed ratio values. In experiment 1, heifers earned more rewards higher the deprivation level. Heifers valued access to rest more after the longest deprivation. In experiment 2, the heifers earned more rewards after two periods of six hours of deprivation when a reward duration of 10 minutes was given than when reward duration of 20 minutes was given. The results of these experiments indicate that the longest reward duration was more valuable than the shortest when the deprivation prior to test was high. The variation in elasticity with prior deprivation and reward duration has to be considered in future studies of the demand for rest in dairy cattle.

Technical Note: Effect of corticotropin-releasing hormone on adrenocorticotropic hormone and cortisol in steers.

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Activation of the hypothalamic-pituitary-adrenal (HPA) axis is the defining feature of the stress response. Under the influence of both internal and external stressors, activation of the HPA axis causes increased synthesis of corticotropin-releasing hormone (CRH) in the hypothalamus. The objective this study was to determine an appropriate exogenous dose of bovine corticotropin-releasing hormone (bCRH) to stimulate the physiological effects of the HPA axis in steers as a method to test the sensitivity of the pituitary and adrenal gland. 14-month old Holstein-Friesian steers were either given saline (control) or bCRH (0.1, 0.3, 1.0 or 1.5 ìg/kg BW). Serial blood samples were collected at -15, 0, 15, 30, 45, 60, 75, 90, 105, 120, 135, 150, 165, and 180 min relative to time 0. Following administration of 0.1 ìg of bCRH/kg BW, the peak ACTH response was not significantly different from pretreatment baseline concentrations. Administration of 0.3, 1.0, and 1.5 ìg of bCRH/kg BW increased peak ACTH above pretreatment concentrations. Peak cortisol responses to all bCRH treatments were greater than those to pretreatment concentrations. In conclusion, bCRH challenge may be a useful method for testing the sensitivity of the hypothalamic-pituitary-adrenal axis in steers subjected to stressful husbandry conditions, and a minimum dose of 0.3 ìg of bCRH/kg BW is required to stimulate physiological effects of stressor hormones.

Behaviour and claw health in tied dairy cows with varying access to exercise in an outdoor paddock.

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This study was conducted on 52 cows that were tied during a 6 month period of winter housing. Four exercise treatments were imposed providing cows with either daily exercise, exercise 2 days each week, once each week, or no exercise. The exercise consisted of being released into an outdoor paddock for one hour. Observations were made of the activity of the cows during exercise, their standing-lying behaviour while tied, and claw health at the end of the winter. In treatments involving longer periods between exercise (twice or once per week) the animals used the exercise time to walk and trot more, and to thoroughly explore the paddock. There were no differences in time required to lie down while tied among treatments, nor in milk production. Exercise had a positive effect on claw health, due in part to increased wear of the claws. Regular exercise had some advantages in terms of claw health, and the differences in behaviour during exercise suggests that animals use the exercise time to achieve some degree of activity and for exploration.

Acute and longterm effects of chronic intermittent noise stress on hypothalamic-pituitary-adrenocortical and sympatho-adrenomedullary axis in pigs.

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Noise has been shown to be a potential source of stress for pigs. The aim of this study was to determine the effect that chronic exposure to noise would have on pigs’ stress hormone levels and behaviour. Twenty-four barrows were divided into three treatments: N1 was exposed to 2h of broad-band noise (90dB) daily, N2 was exposed to the same source of noise but only three times a week, and the third treatment were handled in a similar manner but were never exposed to the noise. Blood samples were taken weekly before, during and after exposure to the noise. The blood samples were analyzed for adrenaline, noradrenaline, ACTH and cortisol concentrations. The behaviour of the pigs was documented using video recordings. The first exposure to the noise caused a change in the pigs’ behaviour, the showed increased movement and lied down less, but this did not coincide with a change in the pigs’ stress hormone concentrations. After four days of exposure to the noise, the pigs in the N1 treatment showed an increase in plasma ACTH and cortisol levels, while the same hormone concentrations did not increase until day 11 (third exposure) in the N2 treatment. The pigs in the N1 had an increase in the noradrenaline/adrenaline ratio of the eleventh day of exposure. Once again, the N2 treatment experienced a delay and the ratio did not increase until day 18 or the fourth exposure. In both treatments exposed to the noise, the amount of social behaviour (ie. nosing other pigs) decreased and the amount of time they spent lying increased. Both of these treatments also experienced a decrease in daily gain. Further examination using sixteen barrows found that chronic exposure to noise resulted in a time dependent shift in the adrenocortical and sympathetic neural systems response. When challenged cortisol concentrations rose and fell at a faster rate. When the pigs were restrained the adrenaline, noradrenaline and ACTH concentrations increased and decreased at a faster rate while elevation of cortisol concentrations was delayed. The authors concluded that repeated exposure of pigs to noise levels should be avoided, as it can be a potential source of stress for pigs.

Responses of young red jungle fowl and White Leghorn layers to familiar and unfamiliar social stimuli

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This study examined the social preferences and reactions to strangers in young White Leghorns and red jungle fowl. Chicks were tested in two runway tests. In the first test, the chicks could choose between familiar and unfamiliar breed members. In the second test, the chicks could choose between unfamiliar chicks of their own breed and the other breed. An open field test was used to assess spacing and agonistic interactions of 28 pairs of chicks per breed (in half the pairs, chicks were unfamiliar to each other). Leghorns showed preferences for familiar chicks and avoidance of unfamiliar social stimuli during the first runway test. During the second runway test, both breeds showed preferences for their own breed members, but this was more pronounced in Leghorns. During the open field test, the Leghorns were more involved in agonistic interactions than red jungle fowl chicks. The results of this study help explain why Leghorns are less able to cope with novel social and environmental stimuli. Therefore, their welfare might be compromised in situations where they encounter unfamiliar birds.

Improving management for higher reproduction accelerates genetic improvement in closed herd of swine

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Warming up for C.O.O.L.: American Viewpoint

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Country of Origin Labeling (COOL) has been a household name in the food sector for roughly two years and is basically now law. As of October 2004 (in the USA anyways), COOL is mandatory (law), implementation was about 2 billion USD, industry stakeholders had their input heard, and more concerning the passage of COOL into law. Reasons for supporting COOL include the fact that people have a right to know where their food came from and may pay a premium for meat of a different origin. This theory is flawed, and many think that politicians that have no real understanding of agriculture and economics passed COOL into law. In conclusion, COOL is a shortsighted attempt by anti-trade members in the US to construct a complex and costly trade barrier to trade in livestock and red meat. There is little economic merit other than consumer rights, even though consumers indicate they have no interest in the origin. The poultry industry is excluded from this, which helps it due to the fact that the costs of COOL would be highest for pork and beef.

A Global Perspective on Pork Industry Competitiveness

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Live animal cost of production is one of many factors that will determine a specific industries ability to survive and prosper in the global market area. A 2003 study investigated the economic, political, social, and cultural factors of the pork sector in terms of their impacts on various key countries hog and pork sectors. Feed availability and cost can be measured, as can other key input variables. Herd productivity can be measured but is kept mostly confidential. It is also difficult to measure types of production because it can vary so much around the world. Hog quality is difficult too because of varying consumer preference. Social factors include environmental issues and animal welfare. Key factors for hog production competitiveness include core land base of a country (for grains and such), hog weights, sow productivity, labour costs, industry and market structure, and disease status. Canada’s assessment showed an aggregate index score above the US, negatives for hog weights and feed costs, and all other factors positive. Chile, Brazil, and Australia could be major competitors for North America. However, an evaluation of the entire supply chain is required as an evaluation of a countries overall economic situation, social issues, exchange rates, etc. In an aggregate sense, Canada remains at the top, but overall advantage over the US was relatively slim.

Using Spatial Econometrics to Assess the Impact of Swine Production on Residential Property Values

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