Outdoor use, tonic immobility, heterophil/lymphocyte ratio and feather condition in free-range laying hens of different genotype

Abstract

1. Movement (frequency of changes) between inside and outside housing areas, time spent in each area, tonic immobility (TI) and differential blood cell counts were studied in relation to feather condition in laying hens of two genotypes, white (LSL) and brown (LT). 2. From 18 weeks of age, LSL and LT were kept in 4 groups of 50 birds in a poultry house with passages to a roofed scratching room and a grassland area with a stocking density of one bird/10 m2. 3. All birds had transponders to record the movements of each hen between inside and outside areas and the time spent in each area during 24 h. Feather scoring was carried out at 6 ages from 20 to 48 weeks. At 44 weeks of age, TI reactions of 40 hens (20 from each genotype) were quantified and blood smears from 20 hens (10 from each genotype) were analysed for differential leucocyte counts. 4. LSL hens moved more frequently to outdoor areas than LT hens (44.66 vs 28.78 least square/d). However, the proportion of time spent on grassland was greater in LT than in LSL hens, whereas time (%) spent by LT hens in the roofed scratching area was less than for LSI hens. 5. In LT hens TI was shorter while heterophil/lymphocyte ratio and basophilia were greater than in LSL hens. 6. Total body feather score was poorer in LSL than in LT hens. Incidence of footpad inflammation was higher in LSL than LT hens. 7. There was a positive association between TI and footpad inflammation. The percentage of time spent on grassland and feather damage were inversely correlated. 8. More movement between the areas, as in LSL hens, was positively associated with fearfulness, whereas long periods on grassland, as in LT hens, were associated with indicators of increased stress. The negative correlation between feather damage and time spent outside suggests that feather pecking risk decreases in birds attracted to grassland.

Relationships between range access as monitored by radio frequency identification technology, fearfulness, and plumage damage in free-range laying hens

“…This finding implies a negative association between range use and fearfulness. Mahboub et al (2004) also found a negative correlation between time spent outside and TI duration. While it is generally assumed that birds with lower levels of fearfulness are more likely to venture outside, this causal relationship has yet to be confirmed.…”

“…The majority of studies, however, report an inverse association between range use and plumage damage (Bestman and Wagenaar, 2003). Mahboub et al (2004) noted a negative correlation between feather damage and time spent on a grassland area outside, and Nicol et al (2003) found that in a multivariate model based on farmers' reports, feather-pecking occurred at higher levels when fewer birds used the outdoor range. Green et al (2000) conducted a cross-sectional survey of farmers and found similar results, where there was an association between lower range usage and feather-pecking.…”

“…This is an improvement from what has been reported previously, where Freire et al (2003) lost 48% of transponders which were encased in leg bands by the end of the study. Mahboub et al (2004) were successful in retaining all of the transponders during their experiment, which were fixed to the wing webs rather than contained within leg bands. Thurner and Wendl (2005) also successfully used RFID technology, where transponders correctly identified 97% of laying hens.…”

“…† E-mail: kate.hartcher@sydney.edu.au Despite a large number of free-range farms, there is a lack of information on range use; what influences range use in individual birds, and also how use of the range may affect variables such as SFP and plumage damage. Range use is thought to be negatively correlated with rates of SFP (Lambton et al, 2010) and plumage damage (Green et al, 2000;Nicol et al, 2003;Mahboub et al, 2004). However, there are a number of factors that reportedly affect range use in laying hens, including weather, condition of the range area, pop-hole size (Hegelund et al, 2005;Gilani et al, 2014), flock size (Bestman and Wagenaar, 2003; GebhardtHenrich et al, 2014), and the presence of vertical structures (Rault et al, 2013), shade structures, and vegetation on the range (Bestman and Wagenaar, 2003;Zeltner and Hirt, 2003;Nicol et al, 2003).…”

Immunomodulation Effect of Meniran (Phyllanthus niruri linn) on Blood Profile of Broiler Chickens Infected with Enterotoxin of Antibiotic-Resistant Escherichia coli

“…Blood was collected in EDTA tubes for blood smear preparation. The blood smears were stained [5,6] with Wright's stain in a concentration of 0.3% (Sigma Chemical Co., St. Louis, MO). Blood sample collection and the staining of the blood smear was performed to calculate the percentage of lymphocytes in a white blood cell (WBC) differential.…”