Leg Health Research Articles

Light intensity of 5 or 20 lux on broiler behavior, welfare and productivity

Light intensity can influence broiler behavior, but discrepancies in the scientific literature remain. Furthermore, few studies have investigated the welfare implications induced by varying light intensity. We investigated the effects of providing 5 or 20 lux light intensity on broiler behavior, welfare and productivity. A total of 1,872 Ross 308 broilers of mixed sex were studied across 2 replicates. Treatments began on d 8 with one of 2 light intensity levels: 5 lux or 20 lux, using LED lights on a 16L:8D photoperiod with 30 min sunrise and sunset periods. Production data, behavioral activity, and plasma samples for corticosterone concentration analysis were collected weekly from 8 to 46 d of age. Eye weight was collected at 42 d of age. Leg strength was assessed at 35, 42 and 45 d of age using the latency to lie test and leg and foot conditions (foot pad dermatitis, hock burn, leg straightness) were assessed at 46 d. Live weight differed between light treatments, with broilers kept at 20 lux being lighter than broilers kept at 5 lux at 46 d of age (males: –5.1%, females: –2.8%, P < 0.0001), despite no significant differences in feed intake. However, broilers kept at 20 lux were more active during the photophase than broilers kept at 5 lux throughout the rearing period (P < 0.0001). Eye weight was also on average 5% lighter for broilers kept at 20 lux compared to 5 lux (P = 0.001). Nonetheless, there was no significant effect of light intensity on other measures of broiler welfare: mortality and culls, plasma corticosterone concentrations, or latency to lie reflective of leg strength. Hence, broilers kept at 20 lux compared to 5 lux were found to be more active, had slower growth, and had lighter eye weight, but other welfare measures reflective of biological functioning or leg health did not show significant changes.

Effect of photoperiod length and light intensity on some welfare criteria, carcass, and meat quality characteristics in broilers

ABSTRACT - The objective of this study was to investigate the effects of photoperiod length and light intensity on leg and eye health, tonic immobility, some blood parameters, carcass, and meat quality characteristics in broilers. A total of 272 one-day-old male broiler chicks (Ross 308) were randomly assigned to four treatment groups based on the photoperiod length (23L:1D or increasing duration of light) and light intensity (20 lux vs. dim light) with four replicates. In this study, photoperiod lenght had no effect on incidence of foot pad and hock burn. On the other hand, the effect of photoperiod lenght had significantinfluenceonthegaitscore.Theincidencesofgaitscore(3+4+5)inbrightanddimlightgroupswasfoundas21.4and41.0%in broilers, respectively. In addition, the effect of light intensity had statistical significanceongaitscore.Thetonicimmobilityduration in 20 lux and dim light groups were 271.53 and 226.78 s, respectively, and tonic immobility duration was unaffected by light intensity. All the blood parameters, except for triglyceride, were not affected by light intensity. The dim light had a negative effect on broiler welfare as demonstrated by increased eye weight and dimensions. Cold carcass yield and whole breast and wing yields were lower in the dim light group than in 20 lux light intensity. The broilers kept with dim light had lower breast meat ultimate pH (6.19) and L* values (54.30) than those reared with 20 lux. These findingshavealotofimplicationsonthe use of increasing photoperiod and bright light to improve leg an eye health benefitsforthebroilerwelfareinbroilers.Key Words: carcass quality, corticosterone, eye and leg health, lighting

Effects of light regimen and nutrient density on growth performance, carcass traits, meat quality, and health of slow-growing broiler chickens

The present study was conducted to examine the main and interactive effects of 4 light regimens [16h light (L):8h darkness (D), 23L:1D, decreasing-increasing (Dec-Inc), and intermittent lighting (3L:1D)], and 3 dietary nutrient densities (low-, medium-, and high-density) on the growth performance, carcass characteristics, meat quality, and health of slow-growing broiler chickens (Beijing-You). A total of 14401-d-old broiler chickens were assigned to light regimens and nutrient densities in a 4×3 factorial arrangement of treatments with 4 pens per treatment and 15 males and 15 females per pen. Body weight and accumulated feed intake were determined on d 28, 56, and 91. The gait score (GS) was recorded to assess leg health on d 91. Two males and 2 females from each pen were randomly selected and processed to determine the weight of eviscerated carcass, breast muscle, thigh muscle, and abdominal fat. Meat quality was determined using the breast fillet. The ovary, testis, and comb were weighed, and the serum follicle stimulating hormone (FSH) and testosterone concerntration were determined for females and males, respectively. There was no interaction for any of the response criteria except for feed conversion ratio (FCR) from d 0 to 28 (P=0.014). The ADFI from d 56 to 91 of broiler chickens under 16L:8D regimen were greater than other 3 regimens (P<0.05), and they had larger testis and comb percentage and greater testosterone concentration than those under 23L:1D regimen (P<0.05). The broiler chickens under Dec-Inc regimen deposited less abdominal fat than those under 3L:1D and 23L:1D regimens (P<0.05), and they had larger testis and comb percentage and greater testosterone concentration than those under 23L:1D regimen (P<0.05). The ADFI and FCR from d 0 to 91 were affected by diet nutrient density, with medium- and high-density resulted in lower ADFI and FCR (P<0.05). The females fed the medium- and high-density diets also had greater ovary percentage and FSH concerntration (P<0.05). These results indicated that medium-density diet is the most appropriate for slow-growing broiler chickens. The 23L:1D regimen did not show any superiority on the improvement of feed conversion or meat quality. The Dec-Inc regimen improved feed conversion and carcass traits and enhanced the development of sex characteristics. Therefore, the medium-density diet and Dec-Inc regimen are suggested for the slow-growing broiler chickens.

Perches and elevated platforms in commercial broiler farms: use and effect on walking ability, incidence of tibial dyschondroplasia and bone mineral content

Modern fast-growing broilers spend excessive periods resting and their activity further decreases with age. Inactivity has been suggested to increase impaired gait and the incidence of leg disorders. Tibial dyschondroplasia (TD) is a common leg pathology in broilers. A more complex environment might facilitate more activity and improve leg health. Perches or elevated platforms bring variety to broilers’ environment and could motivate more locomotion. This study examined the impact of perches and elevated platforms on walking ability, the occurrence of TD and level of bone ash and mineral contents. The investigation was performed on four commercial broiler farms throughout six consecutive batches with platforms and four to five with perches. On each farm at least two separate houses were included, enabling the comparison of furnished flocks to control flocks during each batch. Plastic slats with ramp access elevated by 30 cm or wooden perches of 10 and 30 cm height were offered in the furnished house. Farmers recorded the platform and perch usage twice a week with a five-point scale. Gait was scored before slaughter on a six-point scale according to the Welfare Quality® assessment protocol for poultry. The severity of TD was determined using a four-point scale on farm from all birds gait scored as 3 and at slaughter from 200 birds/flock. Farmers estimated 50% to 100% of the platforms to be occupied in all flocks throughout the entire growing period. Only single birds were perching, thus perch structures were constantly evaluated to be empty. Due to the low use, the perch-equipped houses were excluded when analysing bone content, walking ability and TD. On average, 30% of the tested birds exhibited gait score ⩾3. Younger scoring age resulted in a lower mean gait score and a lower percentage of scores 3 and 4 to 5. Overall, 2.3% of the birds examined at slaughter and 3.5% of the birds with gait score 3 were affected by TD. Leg health was better in birds with access to platforms: mean gait score, the percentage of birds scoring 3, and TD percentage and severity were lower in birds in platform-equipped houses. Elevated structures such as platforms, offering additional possibilities for locomotion to broilers seem to improve their leg health.

Do alternative litter Materials Affect performance, Welfare and Immune Response of Broiler Chicks?

Two hundred, one-day-old Cobb broilers were utilized as a part of this analysis. Chicks were examined and weighed on the entry day then, arbitrarily appointed to five litter treatments (20 birds per pen) with two duplicates for every treatment. The litter treatment consists of five different litter types: Wood shavings (WS), Ground rice straw, Ground rice straw + sand, Ground corn stalks straw, and Rice hulls. Behavioral perception was done twice per day, two days a week for six sequential weeks. Body weight (BW) and Feed intake rate per pen were measured each week, from which body weight gain (BWG) and feed conversion ratio (FCR) were calculated. At 42 days of age, welfare indices were measured including fear, stress, fluctuating asymmetry, plumage score, leg health and abnormalities. In addition, some carcass traits, litter quality were surveyed. Immune response against Newcastle diseased virus was determined at 21 and 29 days of age. Mortalities were recorded for every treatment. Our data cleared that birds reared on various litter components exhibited non-significant changes in feeding, drinking, standing, preening and scratching behaviors. While, birds reared on Rice hulls exhibited a significantly higher walking behavior and significantly lowered sitting and dust bathing behaviors. Bedding types had no obvious effect over BW, BWG, FCR and mortality percentages. Welfare indices were not affected by the type of litter substances. The type of the litter did not affect moisture content and compactness score of litter. In contrary, cleanliness score of the litter was worst in Ground rice straw compared to wood shavings. In addition, immune response against Newcastle diseased viruses not affected with types of litter. It concluded that, bedding types affect behaviors of broiler chicks. Ground rice straw, Ground rice straw + sand, Rice hulls and Ground corn stalks straw could be used as alternative bedding materials to wood shavings without affect on birds performance, welfare, health and immune response.

Effect of free-range access, shelter type and weather conditions on free-range use and welfare of slow-growing broiler chickens

Free-range access for broiler chickens can benefit animal welfare because the birds have access to a more natural environment and more opportunities to perform natural behaviours than in indoor systems. Also, they have more space and more environmental enrichment, which could lead to better leg health and decreased fearfulness. In practice, however, use of the free-range area is often low. Lack of shelter likely plays an important role in this, as do weather conditions. In this study during 2 production rounds of slow-growing broiler chickens, 200 chickens were housed indoors (IN), 200 were provided with free-range access to grassland with artificial shelter (AS), and 200 were provided with free-range access to an area with short rotation coppice (SRC) from 4 until 10 weeks of age. Free-range use was monitored using photographs and live observations. Weather conditions and free-range use were monitored throughout the outdoor period. Tonic immobility (TI) as fearfulness assessment was done at the beginning (round 2 only) and the end of both production rounds; leg health and tibia bone health were assessed at the end of the production rounds.Mean percentage of birds using the free-range area was higher in SRC than in AS groups (42.8% vs. 35.1%; F1,7=1180.00, P<0.001). The mean percentage of animals located further than 5m from the house was 10.6±1.1% of the chickens that were outside in the SRC groups vs. 4.1±0.8% in the AS groups (F1,7=24.03, P=0.002). The interactions of shelter type with rainfall (F2,5578=70.59, P<0.001), increasing radiation (F2,5578=300.93, P<0.001) and increasing wind speed (F2,5578=14.77, P<0.001) showed that these factors were related with fewer chickens being outside; and that these effects were more pronounced in SRC than in AS chickens. An increasing temperature was related with more free-range use (F1,5578=32.24, P<0.001). A shorter TI duration in week 3 (at group level) was associated with more chickens further than 5m from the house (F1,250=13.79, P<0.001). The percentage of animals needing more than one induction to induce TI in week 10 was higher for chickens from SRC (29.7%) than from IN groups (4.8%; t102=−2.61, P=0.028) but not AS (14.8%). Hock dermatitis occurred less in AS (7.6%) than in IN (40.1%; t222=3.15, P=0.005) but not SRC (13.7%). These findings indicate that presence of SRC was most effective in encouraging chickens to use the free-range area, but that free-range access was only moderately related to better leg health and fearfulness (at group level).

Evaluating Pekin duck walking ability using a treadmill performance test

Gait scoring is the most popular method for assessing the walking ability of poultry species. Although inexpensive and easy to implement, gait scoring systems are often criticized for being subjective. Using a treadmill performance test we assessed whether observable differences in Pekin duck walking ability identified using a gait scoring system translated to differences in walking performance. One hundred and eighty ducks were selected using a three-category gait scoring system (GS0 = smooth gait, n = 55; GS0.5 = labored walk without easily identifiable impediment, n = 56; GS1 = obvious impediment, n = 59) and the amount of time each duck was able to sustain walking on a treadmill at a speed of 0.31 m/s was evaluated. The walking test ended when each duck met one of three elimination criteria: (1) The duck walked for a maximum time of ten minutes, (2) the duck required support from the observer's hand for more than three seconds in order to continue walking on the treadmill, or (3) the duck sat down on the treadmill and made no attempt to stand despite receiving assistance from the observer. Data were analyzed in SAS 9.4 using PROC GLM. Tukey's multiple comparison test was used to compare differences in time spent walking between gait scores. Significant differences were found between all gait scores (P < 0.05). Behavioral correlates of walking performance were investigated. Video recorded during the treadmill test was analyzed for counts of sitting, standing, and leaning behaviors. Data were analyzed in SAS 9.4 using a negative binomial model for count data. No differences were found between gait scores for counts of sitting, standing, and leaning behaviors (P > 0.05). In conclusion, the amount of time spent walking on the treadmill corresponded to gait score and was an effective measurement for quantifying Pekin duck walking ability. The test could be a valuable tool for assessing the development of walking issues or the effectiveness of treatments aimed at promoting leg health.

Evaluation of the effect of a highly soluble calcium source in broiler diets supplemented with phytase on performance, nutrient digestibility, foot ash, mobility and leg weakness

High inclusion concentrations of dietary calcium (Ca) from limestone may have detrimental effects on broiler performance, such as increased gastric pH and a reduction in phosphorus (P) and amino acid digestibility. To assess the potential for feeding diets with lower total Ca concentrations, the effect of a novel highly soluble source of calcium (HSC) on bird performance, nutrient digestibility and skeletal integrity of 1120 male Cobb-500 broilers was compared with that of limestone. Eight dietary treatments in a 2 × 2 × 2 factorial design consisted of two sources of Ca (limestone or HSC), two concentrations of Ca (6.0 or 7.7 g/kg in the starter and 4.0 or 5.7 g/kg in the grower), two phytase levels (0 or 500 FTU/kg). The effect of dietary treatments on growth performance and feed intake were measured from Day 1 to Day 40 and foot ash and leg health on Day 40. At the end of the starter period, in the absence of phytase, changing Ca source from limestone to HSC at 6.0 g/kg total Ca decreased both bodyweight gain and feed intake (P &lt; 0.05). The addition of phytase to diets containing 6.0 g/kg total Ca provided by HSC increased bodyweight gain (P &lt; 0.05), as well as increasing feed intake (P &lt; 0.05). At the end of the grower period, diets supplemented with phytase increased bodyweight gain (P &lt; 0.001), birds fed the higher Ca concentration were also observed to have an increased bodyweight gain (P &lt; 0.001). Apparent ileal Ca digestibility significantly increased with the addition of phytase to diets containing 4.0 g/kg total Ca provided by HSC (P &lt; 0.05), this was also observed for P digestibility. Replacement of limestone with HSC when fed in conjunction with phytase has the potential to be an effective strategy to improve broiler performance and bone mineralisation.

Effect of rubber flooring on group-housed sows' gait and claw and skin lesions.

This study evaluated the influence of floor type on sow welfare in terms of lameness, claw lesions, and skin lesions. In a 2 × 3 factorial design, we have investigated the effect of rubber coverings on concrete floors and the effect of 3 levels of dietary zinc supplementation on locomotion and claw and skin lesions in group-housed sows. Six groups of 21 ± 4 hybrid sows were monitored during 3 successive reproductive cycles. The sows were group housed from d 28 after insemination (d 0) until 1 wk before expected farrowing date (d 108) in pens with either exposed concrete floors or concrete floors covered with rubber in part of the lying area and the fully slatted area. During each reproductive cycle, locomotion and skin lesions were assessed 4 times (d 28, 50, 108, and 140) and claw lesions were assessed twice (d 50 and 140). Results are given as least squares means ± SE. Locomotion and claw scores were given in millimeters, on analog scales of 150 and 160 mm, respectively. Here, we report on the effect of floor type, which did not interact with dietary zinc concentration ( > 0.10 for all variables). At move to group (d 28) and mid gestation (d 50), no differences between floor treatments were seen in locomotion ( > 0.10). At the end of gestation (d 108), sows housed on rubber flooring scored 9.9 ± 4.1 mm better on gait ( < 0.001). Regarding claw disorders, both parameters "heel overgrowth and erosion" (difference of 4.6 ± 1.8 mm; = 0.01) and "heel-sole crack" (difference of 3.1 ± 1.5 mm; = 0.04) scores were better for sows on rubber flooring at mid gestation (d 50). However, sows on rubber flooring scored worse for "vertical cracks in the wall horn" (difference of 3.4 ± 1.7 mm; = 0.04). At the end of lactation (d 140), both "white line" (difference of 2.9 ± 1 mm; = 0.02) and "claw length" (difference of 4.7 ± 1.4 mm; < 0.001) had better scores on rubber flooring. No differences for skin lesions were observed between floor treatments. The improved scores for gait toward the end of gestation and some types of claw disorders at mid gestation suggest that rubber flooring in group housing has a beneficial effect on the overall leg health of sows. The documented increase in vertical cracks in the wall horn at d 50 requires further investigation.

Changes in leg health, skin, and plumage condition in domestic male turkeys of varying body weights

Injurious pecking in turkeys is a serious welfare and economic concern in commercial production. Yet, very little is known about the development of this behaviour, and whether it relates to physical characteristics of the turkey. The objective of this study was to investigate the relationships among group variation in body weight, snood length, leg health, and skin and plumage damage over time in adult male turkeys. At 11 weeks of age, 50 male turkeys were allocated to one of three treatments based on body weight: HEAVY (8.22±0.11kg), AVERAGE (7.54±0.11kg), or LIGHT (7.14±0.11kg; mean±standard error of the mean (SEM)). Turkeys were housed in groups of 8–10 with two replicates per treatment. They were weighed and scored weekly for plumage and skin condition (separate scores for head, neck, back, wings, and tail) and leg health (gait, footpad health and cleanliness, and number and severity of deviated toes). The data were divided into three time periods: 11–13, 14–17, and 18–21 weeks of age, and analyzed with a mixed model procedure and principal components analysis in SAS. With time, gaits worsened (Live Gait: F2,65=14.72, P<0.0001, Video Gait: F2,43=2.00, P=0.15) and turkeys had more deviated toes (F2,71=177.10, P<0.0001) and a greater severity of toe deviations (F2,112=75.15, P<0.0001) across all weight treatments. All turkeys showed worse footpad cleanliness over time (F2,162=12.01, P<0.0001), which might have contributed to the increase in footpad health problems (F2,69=15.58, P<0.0001). Pecking injuries to the head (F1,66=17.71, P<0.0001) and neck (F1,46=4.40, P=0.042) became more prevalent after the first period, whereas pecking injuries to the back (t48=−4.37, P<0.0001) increased in the final period. Damage to the tails of these turkeys also increased significantly in the final period (t51=−6.80, P<0.0001). Snood length did not vary between treatments and showed no association to the head and neck condition of these turkeys. As turkeys aged, signs of injurious pecking increased while leg health deteriorated. However, group variation in early body weights was not predictive of leg health, snood length, or being the recipient of skin and plumage damage later in life.

Influence of Soft or Hard Floors before and after First Calving on Dairy Heifer Locomotion, Claw and Leg Health.

Simple SummaryIn this study the effect of different flooring systems on locomotion, claw conformation, loading, claw- and leg disorders was assessed in heifers from one year before to one year after calving. After calving, heifers kept on alleys covered with rubber flooring were found to develop less lameness, fewer claw disorders of the sole horn and fewer leg lesions than those kept on concrete alleys. Recruitment heifers reared on soft deep straw bedding had fewer sole horn lesions and more overgrown claws before calving, but were more prone to severe sole horn lesions after calving, than those reared in cubicles with hard concrete floors.Claw health, an important dairy cow welfare parameter, may be affected by early-life foot/leg stresses. To investigate this, groups of pregnant heifers were allocated to deep straw bedding (Soft) or cubicles (Hard), both with scraped concrete feeding alleys. After the grazing season, they were re-housed in cubicle systems, half on slatted concrete (Hard) and half on slatted rubber (Soft) alleys. Claw measurements, contact area and pressure distribution claw/flooring, claw disorders and leg lesions were recorded at the start and end of each housing season. Locomotion and leg lesions were also scored monthly after calving. Prevalence of sole haemorrhages was higher among pregnant heifers in cubicles than in deep straw. After calving, first-calvers on Hard floors had higher odds for lameness (OR = 3.6; p < 0.01), sole haemorrhages/ulcers (OR = 2.2; p < 0.05), white-line haemorrhages (OR = 2.8; p < 0.01) and leg lesions (OR = 2.6; p < 0.02) than those on Soft floors. Lowest prevalence and severity of sole and white-line haemorrhages (non-significant) in first-calvers was found in those on Soft floors and reared on Hard floors and the highest prevalence and severity on those on Hard floors reared on Soft floors. Soft flooring after calving is of most importance for healthy feet and legs.

Animal health and welfare planning improves udder health and cleanliness but not leg health in Austrian dairy herds

Animal health and welfare planning is considered an important tool for herd management; however, its effectiveness is less well known. The aim of this study was to conduct animal health and welfare planning on 34 Austrian dairy farms and to evaluate changes in health and welfare after 1 yr. After an initial assessment using the Welfare Quality protocol (Welfare Quality Consortium, Lelystad, the Netherlands), results were reported back to the farmers. Health and welfare area(s) in which both the farmer and the researcher regarded improvement as important were discussed. Management practices and husbandry measures were chosen according to the respective farm situation. One year after interventions had been initiated, farms were reassessed, and the degree of implementation of improvement measures was recorded. The average implementation rate was 57% and thus relatively high when compared with other studies. High degrees of implementation were achieved related to cleanliness and udder health, at 77 and 63%, respectively. Intervention measures addressing udder health were mostly easy to incorporate in the daily routine and led to a reduced somatic cell score, whereas this score increased in herds without implementation of measures. The decrease in cows with dirty teats was more pronounced when measures were implemented compared with control farms. The implementation rate regarding leg health (46%) was comparably low in the present study, and leg health did not improve even when measures were implemented. Lying comfort, social behavior, and human–animal relationship did not require interventions and were therefore seldom chosen by farmers as part of health and welfare plans. In conclusion, the structured, participatory process of animal health and welfare planning appears to be a promising way to improve at least some animal health and welfare issues.

Preferences for pig breeding goals among organic and conventional farmers in Sweden

Organic and conventional pig farmers’ preferences regarding breeding goal traits important in pigs were investigated using an advanced internet-based questionnaire. Farmers were asked what pig traits they spontaneously considered important, to rank 15 given traits and to weigh traits against each other given the estimated genetic change (calculated based on selection index theory). Organic and conventional farmers ranked both functional and production traits highly. For example, more than 70 % of farmers from both production systems ranked piglet survival, fertility, sow longevity, leg health, feed conversion, piglet birth weight, piglet and slaughter pig growth as being of high or moderate importance (1–10/15). Litter size and shoulder ulcers were ranked higher by respondents from conventional farms, while parasite resistance and roughage consumption were ranked higher by respondents from organic farms. Regarding estimated desired genetic change, respondents from organic farms favoured health traits while conventional farmers favoured growth traits. In order to obtain genetic improvement in those traits, farmers gave low priority to carcass quality and litter size. Due to the variations in farmers’ breeding goal trait preferences demonstrated here, it is clearly important to take farmers’ preferences into consideration when developing future pig breeding strategies.

Effect of broiler breeder feeding programme and feeder space change at photostimulation using maize- or wheat-based diets on broiler progeny growth performance and leg health

1. The aim of this study was to evaluate the effects of diet type, maternal feeding programme at 29 weeks of age and breeder feeder space change at photostimulation on broiler progeny performance and leg health at 6 weeks of age.2. Fast-feathering Cobb 500 broiler breeders were fed on either maize- or wheat-based diets that had been formulated to have similar nutrient composition during growing and layer phases. Two feeding programmes, fast or flow, were used from 14 to 29 weeks of age. At 22 weeks, 69 females from each pen were placed in a layer house where feeder space was either similar to that in rearing (6.3 to 6.5 cm/female) or was increased from 6.3 to 8.4 cm/female. Eggs produced at 32 and 44 weeks of age were collected and incubated for two broiler experiments. A total of 16 male and 16 female one-d-old chicks were placed in floor pens in two experiments, respectively, with 6 and 4 replicate pens. Broiler gait scores and leg problem prevalence were evaluated at 6 weeks of age.3. Data were analysed as a 2 × 2 × 2 factorial design with diet type, feeding programme and feeder space change as main factors.4. The wheat diet increased the probability of observing crooked toes in broiler progeny compared to the use of maize, but only when breeders were fed according to the fast feeding programme and given similar feeder space as during rearing.5. Breeders given more feeder space in the laying period produced progeny with more locomotion problems compared with those provided similar feeder space, but only when maize was used and the slow feeding programme was applied to the breeders.6. The maternal feeding programme interacted with other factors to influence progeny leg health, but it did not solely influence walking ability or leg problems of progeny.7. In conclusion, an increased probability of observing walking impairment of broiler progeny was detected when breeders were given greater feeder space at photostimulation rather than no change and fed according to the slow feeding programme using maize diets in breeders and progeny.

Incidence of Footpad Dermatitis and Hock Burns in Broilers as Affected by Genotype, Lighting Program and Litter Type

Abstract The aim of this study was to define the conditions for improving broiler leg health, thus ultimately promoting broiler welfare and greater economic efficiency of production, by investigating the effects of litter type, lighting program, or genetic predisposition on the incidence and severity of footpad dermatitis and hock burns. The study was conducted on broiler genotypes (G) Hubbard Classic and Ross 308. Litter (L) was either chopped straw or wood shavings. Lighting programs (LP) were applied when broilers were eight days old. One lighting program (LP1) was designed so that chicks between 8 to 39 days of age were exposed to 16L:4D:2L:2D, and received 23L:1D between 40 to 42 days of age. The other lighting program (LP2) was a gradual extension of photoperiod after restrictions in the second week: 16L:8D (8-14 days), 16L:3D:2L:3D (15-21 days), 16L:2D:4L:2D (22-28 days), 16L:1D:6L:1D (29-35 days) and 23L:1D (36-42 days). Evaluations of footpad lesions and hock burn, according to the method described by Thomas et al. (2004), were carried out individually for each bird, on days 21 and 42. Based on the average score and the frequency of the worst forms of footpad dermatitis, better growing conditions for broilers were found when wood shavings were used as litter material rather than the chopped straw (P&lt;0.01), and when a lighting program with gradual lengthening of photoperiod and with intermittent light/ dark periods (LP2) was applied, compared to a moderate-constant photoperiod lighting program (LP1) (P&lt;0.01). The Ross 308 broiler genotype, despite its lower body weight, showed a greater tendency to develop footpad dermatitis and hock burns. Hock burns developed more slowly than footpad dermatitis, and thereby, would be likely to exhibit a smaller adverse effect on broiler welfare and quality of chicken feet.

The influence of providing perches and string on activity levels, fearfulness and leg health in commercial broiler chickens

The aim of this study was to assess the effect of providing environmental enrichment in the form of perches and string on the behaviour and welfare of commercial broiler chickens. Houses containing ~23 000 broiler chickens were assigned to one of four treatments in a 2×2 factorial design. Treatments involved two levels of access to perches (P) (present (24/house) ‘+P’ or absent ‘−P’) and two levels of access to string (S) (present (24/house) ‘+S’ or absent ‘−S’). All houses contained windows, and 30 straw bales were provided from day 10 of the rearing cycle. Treatments were applied in one of four houses on a single farm, and were replicated over four production cycles. Behaviour and leg health were observed in weeks 3 to 5 of the rearing cycle. Production performance and environmental parameters were also measured. There was an interaction between perches and age in the percentage of birds observed lying, with higher percentages of birds observed lying in the +P treatment than in the −P treatment during weeks 4 and 5. There was also a significant interaction between string and age in the percentage of birds observed in locomotion, with higher percentages observed in locomotion in the −S treatment than in the +S treatment during weeks 4 and 5. There was also an interaction between string and age in average gait scores, with lower gait scores in the +S treatment than in the −S treatment during weeks 3 and 5 but not within week 4. Daytime observations showed that perches and strings were used frequently, with one bout of perching occurring approximately every 80 s/perch, and one bout of pecking at string occurring every 78 s/string on average. There was a significant effect of age on use of perches (P<0.001) and string (P<0.001), with perching peaking during week 5 and string pecking peaking during week 3. We conclude that commercial broilers in windowed houses with access to straw bales display an interest in additional enrichment stimuli in the form of perches and string, and therefore that these stimuli have the potential to improve welfare. In addition, provision of string as a pecking device appeared to positively influence walking ability. However, this effect was numerically small, was only shown in certain weeks and was not reflected in the other leg health measure (latency to lie). The results also showed an apparent negative effect of string and perches on the activity levels of birds (recorded away from the immediate vicinity of these enrichments) towards the end of the production cycle. These results emphasise the need for further research into optimum design and layout of enrichment stimuli for modern broilers in windowed houses to ensure that their provision leads to clear welfare benefits.

The effect of level of straw bale provision on the behaviour and leg health of commercial broiler chickens

This study aimed to assess the effect of the number of straw bales (SBs) provided on the behaviour and leg health of commercial broiler chickens. Houses containing ~23 000 broiler chickens were assigned to one of two treatments: (1) access to 30 SBs per house, ‘30SB’ or (2) access to 45 SB per house, ‘45SB’. This equated to bale densities of 1 bale/44 m2 and 1 bale/29 m2 of floor space within houses, respectively. Treatments were applied in one of two houses on a commercial farm, and were replicated over six production cycles. Both houses had windows and were also artificially lit. Behaviour was observed in weeks 3 to5 of the cycle. This involved observations of general behaviour and activity, gait scores (0: perfect to 5: unable to walk) and latency to lie (measured in seconds from when a bird had been encouraged to stand). Production performance and environmental parameters were also measured. SB density had no significant effect on activity levels (P>0.05) or walking ability (P>0.05). However, the average latency to lie was greater in 30SB birds compared with 45SB birds (P<0.05). The incidence of hock burn and podo dermatitis, average BW at slaughter and levels of mortality and culling were unaffected by SB density (P>0.05). The results from this study suggest that increasing SB levels from 1 bale/44 m2 to 1 bale/29 m2 floor space does not lead to significant improvements in the welfare of commercial broiler chickens in windowed houses.

Genomic Selection: Status in Different Species and Challenges for Breeding

Technical advances and development in the market for genomic tools have facilitated access to whole-genome data across species. Building-up on the acquired knowledge of the genome sequences, large-scale genotyping has been optimized for broad use, so genotype information can be routinely used to predict genetic merit. Genomic selection (GS) refers to the use of aggregates of estimated marker effects as predictors which allow improved individual differentiation at young age. Realizable benefits of GS are influenced by several factors and vary in quantity and quality between species. General characteristics and challenges of GS in implementation and routine application are described, followed by an overview over the current status of its use, prospects and challenges in important animal species. Genetic gain for a particular trait can be enhanced by shortening of the generation interval, increased selection accuracy and increased selection intensity, with species- and breed-specific relevance of the determinants. Reliable predictions based on genetic marker effects require assembly of a reference for linking of phenotype and genotype data to allow estimation and regular re-estimation. Experiences from dairy breeding have shown that international collaboration can set the course for fast and successful implementation of innovative selection tools, so genomics may significantly impact the structures of future breeding and breeding programmes. Traits of great and increasing importance, which were difficult to improve in the conventional systems, could be emphasized, if continuous availability of high-quality phenotype data can be assured. Equally elaborate strategies for genotyping and phenotyping will allow tailored approaches to balance efficient animal production, sustainability, animal health and welfare in future.

Prevalence and risk factors for lameness in insulated free stall barns in Finland

Lameness is a painful condition that alters physiology and behavior of dairy cattle. The main objective of this study was to explore the prevalence of lameness in dairy cows, and its association with housing and herd management. Another aim was to identify poorly functioning structures and equipment that may contribute to increased lameness. Data on herd management, and barn design and functionality were collected in 87 herds, and the gait of 3459 cows was scored. Of the cows scored, 23% were lame (lameness scores 3–5; from slightly abnormal gait to severe lameness). The median within-herd lameness prevalence was 21%, ranging from 2 to 62%. The association between cow level lameness risk and cow specific risk factors was modeled with a logistic regression analysis. The odds ratio (OR) for lameness was for Holstein cows 1.6 (CI 1.3–1.9) times higher than for Ayrshire cows. Second and 3+parity cows were more likely to be lame than first lactation cows; OR 2.1 (CI 1.7–2.8) and 6.0 (CI 4.8–7.7), respectively. A herd level lameness prevalence estimate, accounting for the effects of cow’s breed and parity, was used as an outcome in modeling housing and management related risk factors. Lameness prevalence was lower in herds with a feed barrier divided to separate feeding places (0.17), compared to the ones with a post-and-rail (0.24). The lameness estimate was higher in herds with very slippery floors (0.31) than in herds with slightly slippery (0.16) or firm floors (0.16). The prevalence of lameness was associated with the width of a walking alley next to the feeding table, being 0.17 for herds that had alleys wider than 340cm, and 0.23 for herds with an alley narrower than 320cm. Lameness estimate (0.18) was lower if water was supplied from water cups only compared to water being supplied water from both cups and troughs (0.23). Most farmers had not adjusted neck and front rails properly in stalls, and had hard stall surfaces, compromising cow comfort. More than a half of the studied herds had problems with manure removal and urine drainage. Those findings suggest that there is a great need to educate dairy farmers and construction planners of the benefits and factors contributing to claw and leg health. Also, more emphasis should be placed to proper manure removal and urine drainage.

BEHAVIOUR, WELFARE AND PERFORMANCE OF BROILER CHICKS REARED ON DIFFERENT LITTER MATERIALS

Two hundred forty day-old Ross broiler chicks were used in this experiment. Chicks were weighed on arrival and randomly assigned to six litter treatments (20 birds per pen) with two replicates for each treatment. The litter treatment consists of six different litter types: Wood shavings (WS), whole rice straw (straw), sand, rice straw covered by a layer of wood shavings (WS + straw), sand covered with wood shavings (WS + sand) and sand covered by a layer of rice straw (straw + sand). Behavioral observation was carried out twice daily, two days a week for 6 consecutive weeks. Body weight (BW) and Feed intake per pen were measured weekly, from which body weight gain (BWG) and feed conversion ratio (FCR) were measured. At 42 days of age, welfare parameters were measured including fear, stress, fluctuating asymmetry, feather score and leg health and problems. Also, some carcass traits and moisture content of the litter were assessed. Dead birds were recorded for each treatment. Results revealed that birds reared on (WS + sand) exhibited significantly higher feeding behavior, BW and BWG than birds reared on straw and (straw + sand). Bedding types had no significant effect (p>.05) on feeding behavior and other productive performance when litters were used separately (WS, straw or sand). Standing and walking behaviors decreased on sand and wood shavings whereas sitting increased. Contrarily, birds reared on straw and (straw + sand) beddings exhibited significantly more standing and walking behaviors and less sitting behavior. FCR and welfare parameters were not affected by the type of litter materials either used separately or in combination. Percentage of gizzard to live weight was significantly higher in birds reared on wood shavings. Percentage of heart to live weight was significantly higher in birds reared on (WS + sand). Other carcass traits were not affected by litter types. Straw had significantly more moisture content compared to other litter types whereas sand had significantly lower moisture content compared to straw (WS + straw). It is concluded that, behaviors of broiler chicks affected by different bedding types. Rice straw and sand could be used as alternative bedding materials to wood shavings without adverse implications of birds performance and welfare.