| 1. |
- Boyner, Malin, et al.
(författare)
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Effect of hatching time on time to first feed intake, organ development, enzymatic activity and growth in broiler chicks hatched on-farm
- 2021
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Ingår i: Animal. - : Elsevier BV. - 1751-7311 .- 1751-732X. ; 15
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Tidskriftsartikel (refereegranskat)abstract
- The conventional commercial hatcheries used today do not allow the newly hatched chicks to consume feed or water. Combined with natural variation in hatching time, this can lead to early hatched chicks being feed-deprived for up to 72 h before being unloaded at the rearing site. This study investigated the effects of hatching time on time to first feed intake and development of organs, digestive enzymes and productivity in terms of growth and feed conversion ratio in chicks hatched on-farm. Chicks were divided into three hatching groups (early, mid-term and late), and assessed over a full production cyde of 34 days. The results revealed that chicks remain inactive for a considerable amount of time before engaging in eating-related activities. Eating activity of 5% ( i.e. when 5% of birds in each hatching group were eating or standing dose to the feeder) was recorded at an average biological age (BA) of 25.4 h and a proportion of 50% birds with full crop was reached at an average BA of 30.6 h. Considering that the hatching window was 35 h in this study, the average chick probably did not benefit from access to feed and water immediately post-hatch in this case. At hatch, mid-term hatchlings had a heavier small intestine (30.1 g/kg bw) than both early (26.4 g/kg bw) and late (26.0 g/kg bw) hatchlings. Relative length of the small intestine was shorter in late hatchlings (735 cm/kg bw) than in mid-term (849 cm/kg bw) and early (831 cm/kg bw) hatchlings. However, the relative weight of the bursa fabridi was greater in mid-term (130 g/kg bw) than in early hatchlings (1.01 g/kg bw). At hatch, late hatchlings were heavier than early and mid-term hatchlings (P < 0.05), but by 3 days of age early hatchlings were heavier than mid-term and late hatchlings (P < 0.01). The only effect persisting throughout the study was a difference in the relative weight of the small intestine, where late hatchlings had heavier intestines than early hatchlings (P < 0.05). Thus, while there were differences between hatching groups, this study showed that the hatchlings seemed capable of compensating for these as they grew. (C) 2020 The Authors. Published by Elsevier Inc. on behalf of The Animal Consortium.
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| 2. |
- Hedlund, Louise, 1987-, et al.
(författare)
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Effects of stress during commercial hatching on growth, egg production and feather pecking in laying hens
- 2022
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Ingår i: PLOS ONE. - San Francisco, CA, United States : Public Library of Science. - 1932-6203. ; 17:1
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Tidskriftsartikel (refereegranskat)abstract
- Every year, billions of egg layer chicks around the world are hatched under highly stressful, industrial circumstances. Here, it is investigated how the stressful procedure in the commercial hatchery, including incubation, hatching, processing, and transport affects the chicks with regards to traits relevant for the egg production industry. These traits were compared to those of a control group hatched in a small incubator and handled gently och quietly in a quiet room without any processing and transport. The chicks were weighed at hatch and at eight additional time points: 4 days, 1 week (w), 2 w, 3 w, 5 w, 8 w, 20 w and 25 w of age. Feather pecking was studied at 15 w of age and damages to the feathers and injuries on the comb and wattle were assessed at 25 w of age. From 19 w of age, eggs were collected on three days per week, counted and weighed. Chicks from a commercial hatchery had a lower hatch weight than control chicks (p<0.001). At 20 w of age, the weight of the commercial hatched chicks was still numerically lower, although this did not reach statistical significance. Commercially hatched chicks tended to show more feather pecking behaviour at 15 w of age compared to control chicks (p<0.1), although feather condition at 25 w of age showed the opposite pattern. Regarding production, commercially hatched chickens laid fewer (p<0.05) and smaller (p<0.05) eggs than chicks hatched and handled under calm circumstances. From this experiment, it is concluded that the stressful experience in the commercial hatchery has an overall negative effect on traits relevant for the industry.
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| 3. |
- Hedlund, Louise, et al.
(författare)
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Incubation and hatching conditions of laying hen chicks explain a large part of the stress effects from commercial large-scale hatcheries
- 2021
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Ingår i: Poultry Science. - : ELSEVIER. - 0032-5791 .- 1525-3171. ; 100:1
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Tidskriftsartikel (refereegranskat)abstract
- In commercial egg production, laying hen chicks are exposed to several stressful events during incubation, hatching, and their first hours in life. We have previously shown that hatching and processing are associated with increased corticosterone concentration and further affect behavior and stress sensitivity in a short- as well as long-term perspective. However, it is not known whether these long-term stress effects are caused by the hatchery processing (sex sorting, vaccination, conveying, and loading for transport) or if they are mainly caused by potentially stressful events before processing, during incubation and hatching. In the present study, the aim was to assess the effects of incubation and hatching only, compared to stress effects from the entire hatchery processing. We compared Lohmann LSL chicks incubated, hatched, and processed in a commercial hatchery with chicks incubated and hatched at the same time but not further processed. We studied behavior in a novel arena and during tonic immobility, as well as weight development and corticosterone reaction during a stress challenge. Processed chicks had poorer weight development and were more active in the novel arena test. However, there were no significant differences between the groups in corticosterone reactivity or tonic immobility. When comparing with previous data, both groups had elevated corticosterone concentrations compared to what we had previously reported from chicks hatched under calm and nonstressful conditions. In conclusion, incubation and hatching alone caused long-term stress effects in chickens, but further processing exacerbated these effects to some extent.
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| 4. |
- Hedlund, Louise, et al.
(författare)
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Stress during Commercial Hatchery Processing Induces Long-Time Negative Cognitive Judgement Bias in Chickens
- 2021
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Ingår i: Animals. - : MDPI. - 2076-2615. ; 11:4
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Tidskriftsartikel (refereegranskat)abstract
- Simple Summary Worldwide, billions of laying hen chicks are incubated, hatched and processed in industrial hatcheries every year. When exposed to stress, hormones are incorporated in the feathers of the birds. Here, we measured levels of the stress hormone corticosterone to investigate possible stress during the incubation. Further, animals can perceive their environment either in a positive (optimistic) or a negative (pessimistic) way. We investigated how the early hatchery experiences affects "optimism" and "pessimism". Commercially hatched chicks were exposed to a positive cue, an aversive cue, and ambiguous cues, in order to evaluate the cognitive welfare state of the animals. These chicks were compared to a group of non-stressed animals. Commercially incubated chicks did not have elevated levels of feather corticosterone, which implies that the main part of the stress effects from the hatchery originates from the period around hatch. Latencies to approach ambiguous cues were longer for the stressed chicks, i.e., these showed a more pessimistic-like behaviour. We conclude that the main part of the stress effects in commercially hatched chicks originates in the period around hatch, and further, that these birds show lasting levels of increased pessimism. This strongly indicates a long-time poorer welfare state for the animals. Worldwide, billions of laying hen chicks are incubated and processed under highly industrialised circumstances every year, which, as we have previously shown, has long-lasting effects. Here, we measured corticosterone incorporated in down feathers to investigate possible stress during the incubation and showed that commercially incubated chicks did not have elevated levels of feather corticosterone, which implies that the main part of the stress effects from hatchery originates from the perinatal period and the handling immediately post-hatch. Further, we investigated how the early hatchery stress affects the chicks cognitive welfare state, i.e., "optimism" and "pessimism". We exposed commercially hatched chickens to a positive cue, an aversive cue and ambiguous cues. The birds were tested at 1 and 10 w of age and the behaviour was compared with that of non-stressed chicks. Latencies to approach ambiguous cues were longer for the stressed chicks, both at 1 (p = 0.008) and at 10 (p = 0.020) weeks of age, i.e., these showed a more pessimistic-like behaviour. We conclude that the main part of the stress effects in commercially hatched chicks originates in the perinatal period, and further, that these birds show lasting levels of increased pessimism. This strongly indicates a long-time poorer welfare state for the animals.
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| 5. |
- Guo, Haoyu, et al.
(författare)
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Evaluation of starvation status in the early developmental stages of black rockfish (Sebastes schlegelii) based on morphological and histological characteristics
- 2023
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Ingår i: Journal of Fish Biology. - 0022-1112 .- 1095-8649.
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Tidskriftsartikel (refereegranskat)abstract
- Assessing the nutritional status and identifying major causes of mortality in larvae experiencing varying degrees of starvation are crucial for establishing appropriate feeding protocols and enhancing the welfare of hatchery-reared fish. The black rockfish Sebastes schlegelii is an important species in aquaculture and stock enhancement efforts in China, Japan, and Korea. This study aimed to identify optimal diagnostic morphometric indicators of starvation in newly hatched (0–6 days post-hatch, DPH) and postlarval stages (27–37 DPH) of this valuable fish species through histological analyses. Our findings revealed that certain morphometric parameters, including body length, the ratios of eye diameter to head height, body height to body length, and abdomen height to body height, exhibit sensitivity to starvation during both larval and postlarval stages. Particularly, the ratios of body height to body length and abdomen height to body height emerged as the most sensitive morphometric indicators of starvation. Histological examinations of the digestive system revealed rapid alterations in the morphology of hepatic parenchymal cells, accompanied by a significant decrease in the number of lipid cells in the liver during episodes of food deprivation. Starvation induced cellular degeneration in the digestive organs, manifested by reduced heights of epithelial cells and mucosal layers in the intestine, oesophagus, and stomach, along with degeneration and separation of muscle fibers. Among these variables, the height of the intestinal submucosa and muscle layer emerged as the most sensitive indicators reflecting nutritional conditions in newly hatched larvae. In contrast, the height of intestinal striated borders and mucosal folds proved to be the most sensitive indicators in the postlarval stage. Furthermore, the height of intestinal epithelial cells and the number of lipid vacuoles in enterocytes exhibited high sensitivity to food deprivation in both newly hatched larvae and postlarvae. These findings underscore the varying resilience of fish to starvation during different developmental phases and highlight the utility of morphological sensitivity characteristics as reliable diagnostic indices for assessing nutritional status in relation to starvation or suboptimal feeding during the early developmental stages of black rockfish in hatchery-reared processes.
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| 6. |
- Gabrielle, Lunden, et al.
(författare)
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Play ontogeny in young chickens is affected by domestication and early stress
- 2022
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Ingår i: Scientific Reports. - : NATURE PORTFOLIO. - 2045-2322. ; 12:1
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Tidskriftsartikel (refereegranskat)abstract
- Play is common in young homeotherm animals and has an important role as a tentative indicator of positive states of welfare. Furthermore, during domestication play is believed to have increased in frequency in several species as part of the domestication syndrome. Here, we studied the ontogeny of play in chickens in two experiments. The first compared the behavioural development between domesticated White Leghorn (WL) laying hen chicks and ancestral Red Junglefowl (RJF) and the second compared the same between WL chicks that had experienced the stress of commercial hatchery routines and a control group, hatched under calm conditions. In both experiments, 10 groups of four chicks each from each of the groups were moved twice per week to an enriched and fully enclosed play arena, starting at day 8 and finishing day 39 or 53 after hatch. In the arena, the frequency of play behaviours was recorded during 30 min and divided into object, locomotory and social play. In experiment one, total play as well as object play was significantly more common in WL whereas locomotor and social play was more common in RJF. In experiment two, total play was significantly more frequent in commercially hatched chicks, despite that none of the sub-categories differed significantly between the groups. In conclusion, domestication as well as early stress does affect the occurrence of play in chickens, but the effects are complex and require further research.
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| 7. |
- Mehdipour, Mahdieh, et al.
(författare)
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Effect of crocin and naringenin supplementation in cryopreservation medium on post-thaw rooster sperm quality and expression of apoptosis associated genes
- 2020
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Ingår i: PLOS ONE. - : Public Library of Science. - 1932-6203. ; 15:10
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Tidskriftsartikel (refereegranskat)abstract
- The aim of our study was to examine the effects of crocin (0.5 (C0.5), 1 (C1) and 1.5 (C1.5) mM) and naringenin (50 (N50), 100 (N100) and 150 (N150) mu M) in cryopreservation extender for freezing rooster semen. Sperm motility, viability, abnormalities, membrane functionality, active mitochondria, apoptosis status, lipid peroxidation (LP), GPX, SOD, TAC, the mRNA expression of pro-apoptotic (CASPASE 3) and anti-apoptotic (Bcl-2) genes, fertile eggs, hatched eggs and hatching rate were investigated following freeze-thawing. C1 and N100 resulted in higher (P < 0.05) total motility and progressive motility in comparison to the control group. The C1 and N100 groups improved viability, membrane functionality and reduced lipid peroxidation. We found higher values for active mitochondria with C1 and N100 compared to control group. The C1 and N100 groups showed lower percentages of early apoptosis when compared with control group. Also, C1 and N100 had higher TAC, compared to the control group. The mRNA expressions of BCL-2 in the C1 and N100 groups were significantly higher than that of other treatments. The expression of CASPASES 3 was significantly reduced in C1 and N100 group (P < 0.05) when compared to control group. Significantly higher percentages of fertile eggs, hatched eggs and hatching rate were observed in C1 and N100 compared to the control group. In conclusion, crocin at 1 mM and naringenin at 100 mu M seem to improve the post-thawing rooster semen quality, fertility and could protect the sperm by reducing the pro-apoptotic (CASPASE 3) and increasing anti-apoptotic (Bcl-2) genes.
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| 8. |
- Raczynski, Mateusz, et al.
(författare)
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Phenological Shifts in a Warming World Affect Physiology and Life History in a Damselfly
- 2022
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Ingår i: Insects. - : MDPI. - 2075-4450. ; 13:7
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Tidskriftsartikel (refereegranskat)abstract
- Simple Summary Climate warming affects phenological events of cold-blooded organisms. In this analysis we studied, in laboratory conditions, the impact of warming and hatching dates on key life history and physiological traits in a cannibalistic damselfly, Ischnura elegans. Larvae were reared in groups from hatching to emergence through one or two growth seasons, depending on the voltinism. Larvae were equally divided by hatching dates (early and late) and temperature treatment (current and warming). Early and late hatched groups were not mixed. Despite no difference in cannibalism rate between different hatching dates and temperatures, early hatched larvae reared under warming had elevated immune function measured as phenoloxidase (PO) activity. This increased PO activity was not traded off with life history traits. Instead, age and mass at emergence, and growth rate were mainly affected by temperature and voltinism. Our results confirm the importance of phenological shifts in a warming world for shaping physiology and life history in a freshwater insect. Under climate warming, temperate ectotherms are expected to hatch earlier and grow faster, increase the number of generations per season, i.e., voltinism. Here, we studied, under laboratory conditions, the impact of artificial warming and manipulated hatching dates on life history (voltinism, age and mass at emergence and growth rate) and physiological traits (phenoloxidase (PO) activity at emergence, as an indicator of investment in immune function) and larval survival rate in high-latitude populations of the damselfly Ischnura elegans. Larvae were divided into four groups based on crossing two treatments: early versus late hatching dates and warmer versus control rearing temperature. Damselflies were reared in groups over the course of one (univoltine) or two (semivoltine) growth seasons, depending on the voltinism. Warming temperature did not affect survival rate. However, warming increased the number of univoltine larvae compared to semivoltine larvae. There was no effect of hatching phenology on voltinism. Early hatched larvae reared under warming had elevated PO activity, regardless of their voltinism, indicating increased investment in immune function against pathogens. Increased PO activity was not associated with effects on age or mass at emergence or growth rate. Instead, life history traits were mainly affected by temperature and voltinism. Warming decreased development time and increased growth rate in univoltine females, yet decreased growth rate in univoltine males. This indicates a stronger direct impact of warming and voltinism compared to impacts of hatching phenology on life history traits. The results strengthen the evidence that phenological shifts in a warming world may affect physiology and life history in freshwater insects.
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| 9. |
- Robertson, Stephanie, et al.
(författare)
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Microstructures of high strength steel welding consumables from directed thermal cycles by shaped laser pulses
- 2020
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Ingår i: The International Journal of Advanced Manufacturing Technology. - : Springer. - 0268-3768 .- 1433-3015. ; 109:9-12, s. 2653-2662
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Tidskriftsartikel (refereegranskat)abstract
- Filler wire metallurgy was modified through temporally shaped laser pulses, controlling cooling cycles in a recently developed method. Trends were identified through efficient mapping while maintaining representative thermal cycles of welding processes. A primary pulse melted preplaced filler wires while a secondary, linearly ramped-down pulse elevated the nugget to re-austenization temperatures. Ramped-down pulses resulted in linear cooling rates comparable with and exceeding furnace-based methods, between 50 and 300∘C/s. The linear decay of laser output power guided the temperature through a regime to obtain desired microstructures. For three very high-strength steel filler wire chemistries, quenching resulted in smaller plates with cross-hatched microstructures, accompanied by grain boundary ferrite. Finer bainite microstructures started forming for fast linear temperature decay, about 250∘C/s. Slower decay or a weaker third cycle formed coarser microstructures with coalescent sheaves and less cross-hatching.
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| 10. |
- Boyner, Malin
(författare)
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A flying start : Adapted hatching and post-hatch feeding in broiler chickens
- 2023
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Conventional hatching practices do not involve provision of feed and water to broiler chickens before placement at the rearing farm. This can pose problems, especially for early hatchlings, which remain feed-restricted for a considerable period due to biological variation in hatch time. The individual requirements of modern fast-growing chickens in order to remain robust and resilient may have changed in recent decades. This thesis studied the effect of hatching time on interval to first feed intake, growth and organ development in chicks hatched on-farm. It also examined the effects of providing hatching chicks with access to feed and water in the hatcher, combined with two different probiotics, on productivity, organ development, immune traits and development of caecal microbiota. Physiological differences between chicks hatched at different times during the hatching window generally levelled out during the production period. Eating-related activities were low immediately post-hatch, and early hatchlings showed compensatory growth as they were lightest at hatch but heaviest at three days of age. Feed deprivation during hatch resulted in depressed feed intake and associated depressed growth, which in some cases was reversed during the growing phase. Supplementation with probiotics had some negative effects on productivity, especially for chicks deprived of feed and water at hatch. There were no long-term differences due to early feeding on microbiota development or immune traits measured. These results suggest that modern broiler chickens are at least partly capable of compensating for setbacks in early life, and that some early effects of feed and water deprivation are transient. However, the studies in this thesis were performed in highly sanitary conditions and at lower stocking densities than in commercial production. Further research is needed to confirm the effects of adapted hatching and post-hatch feeding strategies in conditions that resemble more closely the challenges faced by the modern broiler.
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