| 1. |
- Machado Tahamtani, Fernanda
(författare)
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Are changes in behavior of fast-growing broilers with slight gait impairment (GS0-2) related to pain?
- 2021
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Ingår i: Poultry Science. - : Elsevier BV. - 0032-5791 .- 1525-3171. ; 100
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Tidskriftsartikel (refereegranskat)abstract
- Impaired walking ability in terms of slight or definite defects is more common in broiler production than lameness that obviously hinders movement, but it has received limited scientific attention. This study aimed to compare behavior of conventional broilers with impaired walking ability (assessed as gait score (GS) 2) with those walking normally (GS0) and those with only a slight gait defect (GS1). Behavior in the home environment was registered, and an analgesic intervention to quantify changes in time budgets indicating pain relief was applied. The study included 192 Ross 308 broilers. On day 27 of age, the birds were distributed as evenly as possible into birds of GS0 and GS2 of each sex based on obtained gait score. Following this, each experimental bird was housed with 3 companion birds. On days 30 and 32 of age, the behavior in the home pens was recorded. All experimental birds were injected with the NSAID carprofen on one of the 2 d and saline on the other. The statistical analyses used the GS scored on the day of recording as explanatory factor. Compared to GS0 birds, GS2 birds tended to be more inactive (mean (CI): 4,193 (3,971-4416) vs. 4,005 (3,753- 4,257) s; P = 0.074), spent more time sitting while feeding (306 (266-353) vs. 213 (180-251) s; P = 0.026), were less likely to perch (probability: 0.78 (0.69-0.85) vs. 0.91 (0.85-0.95); P = 0.012), and spent less time performing comfort behavior (749 (689-814) s vs. 875 (792-967) s; P = 0.043). Compared to GS1 birds, GS2 birds spent more time inactive (GS1: 4,022 (3,818-4225) s; P = 0.027), less time foraging (289 (253-329) vs. 347 (309-388) s; P = 0.047), and were less likely to perch (GS1: 0.90 (0.86-0.93); P = 0.001). For some of these behavioral variables, administration of carprofen led to behavioral changes across the GSs, which may suggest that the behavioral expression of the broilers was limited by pain. These findings are of relevance to animal welfare, but the underlying causes are still not fully clarified.
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| 2. |
- Machado Tahamtani, Fernanda
(författare)
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Assessment of mobility and pain in broiler chickens with identifiable gait defects
- 2021
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Ingår i: Applied Animal Behaviour Science. - : Elsevier BV. - 0168-1591 .- 1872-9045. ; 234
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Tidskriftsartikel (refereegranskat)abstract
- Gait defects, assessed as gait score (GS), is a common welfare problem in broiler chicken production. The aim of this study was to examine whether birds with GS2 experience pain and poor locomotor ability compared to birds of lower GS. From day 0–27 of age, 600 Ross 308 birds were housed in simulated commercial conditions (stocking density 40 kg/m2). On day 27, all birds were gait scored and 192 birds (4 blocks of 48 birds) were selected as experimental birds based on gait score (GS0 or GS2). On day 28, a runway test with and without obstacles was performed to examine the locomotor ability of the birds. Approximately 3 h before testing, the experimental birds were injected with the NSAID carprofen (25 mg/kg s.c.) or saline (equivalent volume). A Conditioned Place Preference (CPP) test was conducted on day 38, after 4 days of conditioning to a chamber (70 × 70 cm; painted either green with vertical stripes or orange with horizontal stripes) after injection with carprofen or saline. The broilers were expected to show a preference for the place in which they experienced a positive emotional state as induced by the mitigation of pain by carprofen. In the runway test, GS0 birds reached the end of the runway with obstacles faster compared to GS2 birds (P = 0.04) and tended to be faster than GS1 birds (P = 0.08). No effect of carprofen was found on the behaviour in the runway and no effect of GS on the behaviour in the runway without obstacles. In the CPP test, there was no effect of GS or carprofen on chamber preference (P > 0.05). The results showed clear differences between birds of GS2 and lower GSs in terms of locomotor response in the runway, indicating that locomotor ability was compromised with increased GS. The results could not confirm whether these differences in locomotor ability are related to or due to increased pain with increased GS.
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| 3. |
- Machado Tahamtani, Fernanda
(författare)
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Effects of qualitative feed restriction in broiler breeder pullets on behaviour in the home environment
- 2021
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Ingår i: Applied Animal Behaviour Science. - : Elsevier BV. - 0168-1591 .- 1872-9045. ; 235
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Tidskriftsartikel (refereegranskat)abstract
- Conventional broiler breeders are severely feed restricted during the rearing period, resulting in an unfulfilled behavioural need for performing feeding behaviour and likely in a sensation of hunger. As a response to the feed restriction, behavioural changes have been observed, including increased foraging and drinking and reduced resting behaviour. This study aimed to investigate effects of four dietary treatments, differing in fibre types and content, on behaviour of broiler breeder females during rearing. The dietary treatments were: 1) standard feed (Control), 2) standard feed diluted with insoluble fibres (Insoluble), 3) standard feed diluted with both insoluble and soluble fibres (Mixed) and 4) standard feed supplemented with maize silage (Roughage). The amount of the different diets allocated was adjusted for the birds within different treatments to achieve the growth rate recommended under commercial conditions. In total, 1200 female breeder chicks of the genotype Ross 308 were housed in 24 pens from day-old to 19 weeks of age, six pens of 50 birds per treatment. Birds were observed every second week during three different periods of the day relative to feeding time: 1 h before, 1 h after and 5 h after. During each period, the observer noted the behaviour of focal birds (n = 6/pen) for 2 min. Body weight was monitored weekly. For each behaviour the likelihood of whether it was performed and the duration (only including those observation periods where the behaviour was performed) during the observation periods were analysed. Compared to the Control birds, Mixed birds were less likely to forage (P = 0.001) and walk (P < 0.008) but more likely to drink (in weeks 8 and 10 only, P < 0.0001). The birds showed more anticipatory behaviour in terms of standing and walking in the hour before feeding (P < 0.002). There was an effect of the interaction between treatment and age on body weight where all treatments differed from each other (P < 0.0009). Mixed birds had the least steep growth curve. In conclusion, the fibre-rich dietary treatments had limited effects on behaviour of broiler breeders compared to the standard feed. Only the Mixed treatment showed some effects, but the cause of these behavioural changes remains to be clarified. However, the lower growth rate of Mixed birds may indicate that this diet had an unintentional negative impact on animal welfare.
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| 4. |
- Machado Tahamtani, Fernanda, et al.
(författare)
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Feeding live Black Soldier Fly larvae (Hermetia illucens) to laying hens: effects on feed consumption, hen health, hen behavior, and egg quality
- 2021
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Ingår i: Poultry Science. - : Elsevier BV. - 0032-5791 .- 1525-3171. ; 100
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Tidskriftsartikel (refereegranskat)abstract
- The use of insects in animal feed has the potential to reduce the demand for soybean production and reduce the deforestation and loss of natural resources. In particular, the black soldier fly (BSF, Hermetia illucens) larvae have received attention due to their ability to convert organic waste into high-value biomass. Several studies have investigated the effects of providing BSF larvae to both broilers and laying hens. However, knowledge gaps regarding hens' voluntary intake of live larvae and the effects of larvae consumption on egg production still remain. Therefore, the aim of the present study was to determine the effects of the consumption of 4 different amounts of live BSF larvae on laying hen feed consumption, hen health and fearfulness, and egg production and quality. To this end, 40 Bovans White laying hens were housed individually and provided with 0, 10, 20% or ad libitum daily portions of live larvae from 18 to 30 wk of age. The larvae consumption and concentrate consumption, hen weight, egg production, and egg quality were monitored. Overall, differences were found between the hens given ad libitum access to larvae compared to the other treatments. Ad libitum hens, consumed 163 41 g larvae/hen/day, consumed less concentrate (P = 0.03) and gained more weight (P = 0.0002) than all other treatments. They also had an overall higher consumption of protein, fat and energy (P 0.03). There was no effect of larvae consumption on egg production, egg weight, shell thickness, shell breaking strength, or Haugh unit (P 0.05). There was also no effect on hen behavior toward a novel object or in an open field test. This study is the first to provide different amounts of live BSF larvae, including an ad libitum portion to laying hens. The 20% diet could promote sustainability in the egg industry and be economically advantageous if BSF larvae can be bought in bulk for less than 40% of the cost of the concentrate.
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| 5. |
- Machado Tahamtani, Fernanda
(författare)
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Motivation for feeding in broiler breeder pullets fed different types of restricted high-fibre diets
- 2020
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Ingår i: Applied Animal Behaviour Science. - : Elsevier BV. - 0168-1591 .- 1872-9045. ; 230
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Tidskriftsartikel (refereegranskat)abstract
- High-fibre diets have been suggested as alternative feeding strategies that potentially may alleviate the hunger felt by feed-restricted broiler breeders and fulfil their behavioural need for feeding behaviour. The aim of the present study was to investigate the effects of four dietary treatments, differing in fibre types and content, on the motivation for performing feeding behaviour, including both the appetitive and consummatory phase, in broiler breeder pullets. In total, 1200 female breeder chicks of the genotype Ross 308 were housed in 24 pens, six pens of initially 50 birds per treatment. The dietary treatments were: 1) standard feed (Control), 2) feed containing insoluble fibres (Insoluble), 3) feed containing a mix of insoluble and soluble fibres (Mixed) and 4) standard feed supplemented with maize silage (Roughage). Four measures of feeding motivation were obtained: feeding rate, behaviour indicating frustration during thwarted feeding, compensatory feed intake over 5 days and motivation to gain access to fresh litter. The latter was performed at 12-13 weeks of age, whereas the other measures were obtained both at 8-9 and 17-18 weeks of age. Litter quality in the home pens was assessed at age 13 weeks and dry matter content at 5, 13 and 14 weeks of age. Feeding rate was not affected by treatment (P = 0.26). Insoluble and Mixed birds showed fewer behavioural transitions, i.e. changes in activity, during thwarted feeding at 17/18 weeks of age than Control birds (P = 0.004), indicating less frustration and thus a lower feeding motivation. The compensatory feed intake was lower for Insoluble birds compared to Control birds, indicating that the Insoluble treatment reduced the hunger experienced by the birds. Mixed birds were clearly more motivated to gain access to the fresh litter with more and faster crossings into the litter compartment (P <= 0.01). Although foraging was the predominant behaviour performed in the litter compartment, Mixed birds spent less time on locomotion (P = 0.002), more time on comfort behaviour (P = 0.02) and more time resting (P < 0.0001) than Control birds, suggesting that they were also motivated to gain access to litter for increased comfort. The litter quality in the home pens was poorest in the Mixed treatment (P = 0.0001). In conclusion, none of the treatment diets seemed to improve the welfare of broiler breeders markedly during the rearing period, although the Mixed and Insoluble diets may, to some extent, have reduced the feeding motivation.
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| 6. |
- Machado Tahamtani, Fernanda
(författare)
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Post-mortem examination of fast-growing broilers with different degrees of identifiable gait defects
- 2021
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Ingår i: Veterinary Record. - : Wiley. - 0042-4900 .- 2042-7670. ; 189
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Tidskriftsartikel (refereegranskat)abstract
- Background: The walking ability of many broilers is characterised by slight or definite defects categorised as gait scores (GS) 1 and 2. The present study aimed to examine potential relationships between GSs and indicators of body morphology, leg pathology, tibia strength and wooden breast in Ross 308 broilers assessed as GS <= 2.Methods: At 38 days of age, GS and live body weight of 179 birds was recorded. Each bird was examined post-mortem for signs of wooden breast, contact dermatitis and a range of leg pathologies. Weights of different body parts and tibia strength were quantified.Results: Within sex, GS increased with increasing live bodyweight (p = 0.020). There was a tendency for an effect of GS on prevalence of footpad dermatitis (p = 0.086) and dislocated femoral joint cartilage (p = 0.059) where both pathologies increased in frequency with increasing GS. Greater load was required to fracture tibia from GS2 than GS0 birds (p = 0.040).Conclusions: Within this relatively small data set, no strong relationships between GS = 2 and indicators of body morphology, leg pathology, tibia strength and wooden breast in Ross 308 broilers were found, except for the live terminal body weight. Further studies, involving larger data sets are required for full clarification.
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| 7. |
- Machado Tahamtani, Fernanda
(författare)
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The effect of qualitative feed restriction in broiler breeder pullets on fear and motivation to explore
- 2020
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Ingår i: Applied Animal Behaviour Science. - : Elsevier BV. - 0168-1591 .- 1872-9045. ; 228
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Tidskriftsartikel (refereegranskat)abstract
- Restrictively fed broiler breeders are known to have increased motivation to explore and reduced fearfulness because hunger increases the motivation to search for and to acquire food, forcing the birds to face and engage with aversive stimuli that they would otherwise avoid. The aim of this study was to compare the effects of four dietary treatments on the level of fear and motivation to explore during rearing. In total, 1200 female breeder chicks of the genotype Ross 308 were housed in 24 pens, six pens of 50 birds per treatment. The treatments were: 1) standard feed (Control), 2) feed containing insoluble fibres (Insoluble), 3) feed containing a mix of both insoluble and soluble fibres (Mixed) and 4) standard feed supplemented with maize silage (Roughage). The treatments followed a qualitative restriction feeding strategy meant to allow the birds to consume larger portions of feed, increasing feeding time and reducing hunger and frustration. A novel object (NO) test was performed in the home pens at 6, 13 and 18 weeks of age. The test was performed two times at each age: 1 h before feeding and 5 h after feeding. In addition, at 7 weeks of age, 12 birds from each pen from all treatment groups were subjected to a tonic immobility (TI) test. We hypothesised that the Control birds would be less fearful in the TI test and keep a shorter distance to the NO than the treatment birds. For the NO test, there was an effect of the interaction between treatment and time of day on the likelihood of the birds to approach the NO at all ages (P <= 0.0001). At 13 weeks of age, in the afternoon, birds from the Mixed treatment were more likely to approach the NO compared to the birds from the Insoluble and Roughage treatments (P = 0.003) and tended to be more likely to approach than Control birds (P = 0.009). This suggests that the Mixed birds were in a hungrier state at that moment and therefore more willing to approach a NO than the birds fed the other dietary treatments. There was no effect of treatment on the latency to touch the NO or on the TI test. The results show minimal effects of the three qualitative dietary treatments on fearfulness and motivation to explore in female broiler breeders during rearing and, therefore, do not provide evidence of decreased sensation of hunger.
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