| 1. |
- Morrell, Jane
(författare)
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In vitro Embryo Production in Llamas (Lama glama) from In vivo Matured Oocytes with Raw Semen Processed with Androcoll-E using Defined Embryo Culture Media
- 2012
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Ingår i: Reproduction in Domestic Animals. - : Wiley. - 0936-6768 .- 1439-0531. ; 47, s. 562-567
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Tidskriftsartikel (refereegranskat)abstract
- Contents The aim of this study was to carry out in vitro fertilization using spermatozoa selected with Androcoll-E (TM) and to evaluate the efficiency of the culture medium DMEM-F12 for in vitro embryo development in the llama. Twelve adult females from 18 superstimulated (67%) were used as oocyte donors. They were superstimulated with 1500 IU of eCG and after 5 days, received a single dose of buserelin. Twenty hours post-injection, follicular aspiration was conducted by flank laparotomy. Semen collections were performed under general anesthesia by electroejaculation of the male. The ejaculates were processed with a solution of collagenase (0.1%) and an Androcoll-E (TM) column was used to improve the sample. Sixty nine COCs were recovered from 79 aspirated follicles (87% recovery). Only expanded COCs were used (n = 67); they were randomly placed in groups of 15 in Fertil-TALP and the sperm suspension (20 x 106 live spermatozoa/ml) was added to each fertilization microdroplet. After 24 h, they were randomly placed in one of two culture media: SOF (n = 34) or DMEM-F12 (n = 33) and incubated for 6 days in humidified atmosphere of 5% CO2, 5% O2 and 90% N2 at 38 degrees C. The blastocyst rate was 20% (7/34) in SOF medium (3 hatched, 2 expanded and 2 early blastocysts) and 15% (5/33) in DMEM medium (all expanded blastocysts). In conclusion, using Androcoll-E (TM) it is possible to select good quality spermatozoa from llama ejaculates for in vitro fertilization and to produce blastocysts in DMEM-F12 medium. This is also the first time that hatched llama blastocysts have been produced after culture in a defined medium such as SOFaa.
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| 2. |
- Cuello, C., et al.
(författare)
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Superfine open pulled straws vitrification of porcine blastocysts does not require pretreatment with cytochalasin B and/or centrifugation
- 2010
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Ingår i: Reproduction, Fertility and Development. - : CSIRO Publishing. - 1031-3613 .- 1448-5990. ; 22:5, s. 808-817
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Tidskriftsartikel (refereegranskat)abstract
- The present study investigated the in vitro development of and cytoskeletal disruption suffered by in vivo-derived porcine blastocysts subjected to superfine open pulled straws (SOPS) vitrification. Blastocysts were either untreated prior to SOPS vitrification or were subjected to one of the following three pretreatment protocols: (1) centrifugation (12 min, 13 000g); (2) 25 min equilibration with 7.5 mu g mL(-1) cytochalasin B; or (3) equilibration with cytochalasin B followed by centrifugation. After 24 h culture, fresh (n = 32) and vitrified-warmed (n = 188) blastocysts were evaluated by stereomicroscopy, with survival and hatching rates recorded. Some blastocysts were stained with 4,6-diamidino2- phenylindole and processed for cytoskeletal evaluation. Three cytoskeletal patterns were identified: Grade I, intact cytoskeleton; Grade II, gross maintenance of integrity, but with some clumps of actin within the cytoplasm; and Grade III, a highly disrupted cytoskeleton. There were no differences in the survival, hatching and cell death rats, total cell number or cytoskeletal integrity between the different vitrification groups. Cell death was greater for vitrified blastocysts than for fresh blastocysts (3.6 +/- 0.4% v. 0.4 +/- 0.7%, respectively; P less than 0.05) and the percentage of blastocysts with a Grade I cytoskeletal pattern was lower for vitrified compared with fresh blastocysts (60.8% v. 92%, respectively; P less than 0.05). The vitrified-warmed blastocysts that hatched during culture exhibited a Grade I cytoskeletal pattern. In conclusion, successful SOPS vitrification of porcine blastocysts does not require pretreatment with cytochalasin B and/or centrifugation.
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| 3. |
- Larsson, Stefan, et al.
(författare)
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Characteristics of anadromous whitefish (Coregonus lavaretus (L.)) rivers in the Gulf of Bothnia
- 2013
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Ingår i: BIOLOGY AND MANAGEMENT OF COREGONID FISHES - 2011. - 9783510470662 ; 64, s. 189-201
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Konferensbidrag (refereegranskat)abstract
- In order to study anadromous whitefish spawning river requirements, we sampled 41 rivers in the Gulf of Bothnia for newly hatched whitefish larvae for one to three consecutive years. Chemical and morphological data (e.g. flow rate, topography, pH, estuary fetch and distance to coastal sandy areas) were collected for each river. Newly-hatched whitefish were caught in 19 rivers whereas whitefish were not confirmed present in 22 rivers. By applying partial least squares discriminant analysis (PLS-DA), data for rivers confirmed to support whitefish were contrasted with data for rivers in which whitefish were not found. The single most important factor was annual average water flow rate. Whitefish larvae were observed in 93% of the rivers with annual mean flow rate > 5 m(3) s(-1) (N = 14). In contrast, newly-hatched whitefish were only found in 22% of the smaller rivers (N = 27).
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| 4. |
- Ivarsson, Emma, et al.
(författare)
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Effects of algal supplementation in feed to broiler breeders on transfer of nutrients and antibodies to chicks and quality of hatchlings
- 2023
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Ingår i: Animal. - 1751-7311 .- 1751-732X. ; 17:12
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Tidskriftsartikel (refereegranskat)abstract
- Breeder nutrition is an important factor for chick quality since the chick embryo relies on nutrients available in the egg for growth and development. In addition, the egg is providing the chick with important antibodies that are vital during the first weeks of life. Brown algae contains several bioactive compounds, and dietary supplementation with algal extracts have shown improved gut health and immune responses in both pigs and poultry. The aim of this study was to investigate if feeding the brown algae Saccharina latissima, intact or as an extract, to broiler breeders can affect breeder hens’ antibody responses to vaccination, egg quality and transfer of antibodies and nutrients to the egg and thereby improve the quality of newly hatched chicks. Forty-five hens and nine roosters of the parent lines of the fast-growing broiler Ross 308 were included in the experiment where hens were 31 weeks at the start. The hens were housed individually and fed one of three dietary treatments for seven weeks; (a) control, (b) addition of 0.6% algal meal or (c) addition of 0.08% algal extract. The hens were given a booster vaccination against infectious bronchitis virus (IBV) 21 days after the start of experiment. During experimental days 32–42, hens were naturally mated every 5th day and hatching eggs were collected. A total of 255 chicks were hatched, and chick quality was assessed. Moreover, on chick day three, blood was collected from 48 focal chickens and total immunoglobulin Y levels and specific titres to IBV in serum were determined. The results showed that feeding the brown algae Saccharina latissima, intact or as an extract to broiler breeders did not affect egg production, egg quality, antibody responses to vaccination or transfer of antibodies from hen to chick. However, feeding intact algae significantly increased the levels of iodine and decreased the level of selenium in the eggs and resulted in a lower proportion of chicks with maximum quality score. Interestingly, algal feeding, both intact and as an extract, increased the abdominal fat pad in broiler breeders by about 17% without affecting BW. In conclusion, supplementation of broiler breeder diets with algal extract from Saccharina latissima, but not intact algal meal is a promising dietary strategy to increase the abdominal fat pad without causing any adverse effects on nutrient level in eggs or chick quality.
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| 5. |
- 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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| 6. |
- Forabosco, Flavio, et al.
(författare)
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Genetically modified farm animals and fish in agriculture : A review
- 2013
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Ingår i: Livestock Science. - : Elsevier BV. - 1871-1413 .- 1878-0490. ; 153:1-3, s. 1-9
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Forskningsöversikt (refereegranskat)abstract
- Developments in biotechnology over the past 25 years have allowed scientists to engineer genetically modified (GM) animals for use in various areas of agriculture and medicine. The great majority of GM animals and fish are currently only at the research stage. However, some animals with an anticipated use in food production are close to reaching the grocery shelf at least, they will be soon available for marketing. GM livestock include many different kinds of animals and species modified with the intention of improving economically important traits such as growth-rate, quality of meat, milk composition, disease resistance and survival. Pigs have been engineered to grow faster and to produce more meat with less feed; the composition of pork has also been improved for healthier human consumption. Scientists have paid particular attention to pig health, raising piglet survival rates, reducing the risks of infectious disease, and fortifying the porcine immune system. Sheep have been modified to improve wool production and immunity, and to reduce the risk of mortality following infections by bacteria and lethal viruses. Growth-rate in chickens has been increased with only limited success, because conventional selection has already improved this trait close to its biological limit. However, disease resistance (e.g. to H5N1) and the survival of newly hatched chicks have been improved. Udder health and survival are the most important traits improved by transgenic technology in cattle. GM cows with resistance to BSE have been bred. Similar traits are targeted in fish, dominated by salmon, carp and tilapia species, where the focus is on meat production, meat quality, and disease resistance. The number of GM farm animals and fish developed in laboratories is increasing, but for the present the number of species close to entering the market remains small.
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| 7. |
- Westerberg, Håkan
(författare)
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Spawning by the European eel across 2000 km of the Sargasso Sea
- 2019
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Ingår i: Biology Letters. - : The Royal Society. - 1744-9561 .- 1744-957X. ; 15
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Tidskriftsartikel (refereegranskat)abstract
- It has been known for about a century that European eels have a unique life history that includes offshore spawning in the Sargasso Sea about 5000-7000 km away from their juvenile and adult habitats in Europe and northern Africa. Recently hatched eel larvae were historically collected during Danish, German and American surveys in specific areas in the southern Sargasso Sea. During a 31 day period of March and April 2014, Danish and German research ships sampled for European eel larvae along 15 alternating transects of stations across the Sargasso Sea. The collection of recently hatched eel larvae (<= 12 mm) from 70 degrees W and eastward to 50 degrees W showed that the European eel had been spawning across a 2000 km wide region of the North Atlantic Ocean. Historical collections made from 1921 to 2007 showed that small larvae had also previously been collected in this wide longitudinal zone, showing that the spatial extent of spawning has not diminished in recent decades, irrespective of the dramatic decline in recruitment. The use of such a wide spawning area may be related to variations in the onset of the silver eel spawning migration, individual differences in their long-term swimming ability, or aspects of larval drift.
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| 8. |
- Jeuthe, Henrik, et al.
(författare)
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Effects of variable egg incubation temperatures on the embryonic development in Arctic charr Salvelinus alpinus
- 2016
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Ingår i: Aquaculture Research. - : Hindawi Limited. - 1355-557X .- 1365-2109. ; 47, s. 3753-3764
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Tidskriftsartikel (refereegranskat)abstract
- An evaluation of different thermal regimes during incubation of Arctic charr Salvelinus alpinus L. egg was conducted with regard to embryo survival and development. The study consisted of two major parts: In experiment A, a range of commonly used thermal regimes, constant and variable ranging from 2.7 degrees C to 7 degrees C, were tested for differences in embryo survival and developmental status of newly hatched alevins. Experiment B assessed the timing of a shift from autumn (6 degrees C) to winter temperature (2.5 degrees C) and its effect on embryo survival and the occurrence of spinal deformities in newly hatched alevins. In general, incubations that were initiated at temperatures below 3 degrees C resulted in significantly higher mortality rates and spinal deformity frequencies than other treatments. Hence, Arctic charr eggs require an initial warmer period for unimpaired embryonic development. A general negative correlation was found between the duration of this warmer period (6 degrees C) and both mortality rates and frequency of spinal deformities. The total absence of the 6 degrees C period had the most detrimental effect, with deformity frequencies at least four times higher than all treatments with an initial warmer period. The upper incubation temperature threshold was not reached in the study. The highest temperature tested (7 degrees C) did not result in excess mortality or increased deformity frequency. Higher incubation temperature resulted in less developed alevins at hatching, i.e. alevins were smaller with more yolk remaining. However, measurements on alevins from incubations at variable temperatures revealed different temperature effects on growth and yolk consumption during different parts of embryonic development.
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| 9. |
- 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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| 10. |
- Filipsson, Karl, et al.
(författare)
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Do predator odours and warmer winters affect growth of salmonid embryos?
- 2023
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Ingår i: Ecology of Freshwater Fish. - : John Wiley & Sons. - 0906-6691 .- 1600-0633. ; :1
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Tidskriftsartikel (refereegranskat)abstract
- Conditions early in ontogeny can have considerable effects later on in life. Many salmonids spawn during the autumn, and temperature during subsequent embryogenesis may have far-reaching effects on life-history traits, especially when considering ongoing climate change. Even biotic conditions during embryogenesis, such as predation threat, may affect later life stages. Here, we examined how predator odours and increased temperatures affect embryonic growth and development of a fish (brown trout Salmo trutta). We found that embryos had lower body mass and greater yolk volume close to hatching when subjected to predator odours. Trout embryos incubated at temperatures representing natural winter conditions were larger than embryos incubated at higher temperatures, although the latter hatched earlier. Fry sizes at emergence did not differ between treatments, perhaps because of compensatory growth during spring. This study shows that predator presence can have similar effects on embryonic growth of salmonids as warming winters, with possible impact later in ontogeny.
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