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Three experiments were conducted to evaluate the feasibility of using a commercial slow-release urea product (SRU; Optigen®, Alltech Inc., Nicholasville, KY, USA) as a partial replacement for vegetable protein sources in cattle diets. The first experiment was an in vitro rumen fermentation that evaluated the effect of replacing soybean meal (SBM) nitrogen with nitrogen from either SRU or free urea in diets varying in forage:concentrate ratios. The second experiment examined the effect of replacing SBM with SRU on in situ dry matter and nitrogen degradability in the rumen. In the third experiment, a feeding trial was conducted to evaluate the effect of replacing SBM (0% as-fed SRU) with 1% or 3% as-fed SRU on feed carbon footprint (CFP; total greenhouse gas emissions associated with the life cycle of feed raw materials) and the toxicity potential of SRU in growing beef cattle. Results showed that replacing SBM with SRU up to 1.3% did not negatively affect in vitro rumen fermentation parameters. Supplementing SRU favourably decreased ruminal accumulation of ammonia and lactic acid when compared to free urea. There was no significant effect on effective rumen degradability of dry matter and nitrogen when one-third of SBM was replaced by SRU in the in situ study. Compared with the 0% SRU diet, feed CFP decreased by 18% and 54% in 1% SRU and 3% SRU diets, respectively. Additionally, feeding up to 3% SRU diet to beef cattle did not affect health and intake, and blood hematological and biochemical indices were within the physiological range for healthy bulls, suggesting no indication of ammonia toxicity. Overall, these results indicate that SRU can be used as a sustainable alternative to partially replace vegetable protein sources in ruminant diets without compromising rumen function and health of ruminants.
Saheed Salami; Maria Devant; Juha Apajalahti; Vaughn Holder; Sini Salomaa; Jason Keegan; Colm Moran. Slow-Release Urea as a Sustainable Alternative to Soybean Meal in Ruminant Nutrition. Sustainability 2021, 13, 2464 .
AMA StyleSaheed Salami, Maria Devant, Juha Apajalahti, Vaughn Holder, Sini Salomaa, Jason Keegan, Colm Moran. Slow-Release Urea as a Sustainable Alternative to Soybean Meal in Ruminant Nutrition. Sustainability. 2021; 13 (5):2464.
Chicago/Turabian StyleSaheed Salami; Maria Devant; Juha Apajalahti; Vaughn Holder; Sini Salomaa; Jason Keegan; Colm Moran. 2021. "Slow-Release Urea as a Sustainable Alternative to Soybean Meal in Ruminant Nutrition." Sustainability 13, no. 5: 2464.
In this work, adsorption of the carcinogenic mycotoxin aflatoxin B1 (AFB1) by two sequestrants—a yeast cell wall-based adsorbent (YCW) and a hydrated sodium calcium aluminosilicate (HSCAS)—was studied across four laboratory models: (1) an in vitro model from a reference method was employed to quantify the sorption capabilities of both sequestrants under buffer conditions at two pH values using liquid chromatography with fluorescence detection (LC-FLD); (2) in a second in vitro model, the influence of the upper gastrointestinal environment on the mycotoxin sorption capacity of the same two sequestrants was studied using a chronic AFB1 level commonly encountered in the field (10 µg/L and in the presence of feed); (3) the third model used a novel ex vivo approach to measure the absorption of 3H-labelled AFB1 in the intestinal tissue and the ability of the sequestrants to offset this process; and (4) a second previously developed ex vivo model readapted to AFB1 was used to measure the transfer of 3H-labelled AFB1 through live intestinal tissue, and the influence of sequestrants on its bioavailability by means of an Ussing chamber system. Despite some sorption effects caused by the feed itself studied in the second model, both in vitro models established that the adsorption capacity of both YCW and HSCAS is promoted at a low acidic pH. Ex vivo Models 3 and 4 showed that the same tested material formed a protective barrier on the epithelial mucosa and that they significantly reduced the transfer of AFB1 through live intestinal tissue. The results indicate that, by reducing the transmembrane transfer rate and reducing over 60% of the concentration of free AFB1, both products are able to significantly limit the bioavailability of AFB1. Moreover, there were limited differences between YCW and HSCAS in their sorption capacities. The inclusion of YCW in the dietary ration could have a positive influence in reducing AFB1′s physiological bioavailability.
Alexandros Yiannikouris; Juha Apajalahti; Hannele Kettunen; Suvi Ojanperä; Andrew N. W. Bell; Jason D. Keegan; Colm A. Moran. Efficient Aflatoxin B1 Sequestration by Yeast Cell Wall Extract and Hydrated Sodium Calcium Aluminosilicate Evaluated Using a Multimodal In-Vitro and Ex-Vivo Methodology. Toxins 2021, 13, 24 .
AMA StyleAlexandros Yiannikouris, Juha Apajalahti, Hannele Kettunen, Suvi Ojanperä, Andrew N. W. Bell, Jason D. Keegan, Colm A. Moran. Efficient Aflatoxin B1 Sequestration by Yeast Cell Wall Extract and Hydrated Sodium Calcium Aluminosilicate Evaluated Using a Multimodal In-Vitro and Ex-Vivo Methodology. Toxins. 2021; 13 (1):24.
Chicago/Turabian StyleAlexandros Yiannikouris; Juha Apajalahti; Hannele Kettunen; Suvi Ojanperä; Andrew N. W. Bell; Jason D. Keegan; Colm A. Moran. 2021. "Efficient Aflatoxin B1 Sequestration by Yeast Cell Wall Extract and Hydrated Sodium Calcium Aluminosilicate Evaluated Using a Multimodal In-Vitro and Ex-Vivo Methodology." Toxins 13, no. 1: 24.
Background Docosahexaenoic acid (DHA) plays an important role in brain and retinal development in dogs. However, supranutritional dietary supplementation can result in health issues, including gastrointestinal bleeding, making the accurate analysis of DHA in dog food important for nutritional and welfare regulatory compliance. Objective The aim of this study was to conduct a validation and verification of the AOAC 996.06 method, and hence establish its fitness for purpose, for the analysis of DHA in dried dog food supplemented with a heterotrophically grown unextracted DHA-rich Aurantiochytrium limacinum biomass. Methods The AOAC 996.06 method, which involves the use of gas chromatography coupled to flame ionization detection (GC-FID), was used to conduct a validation of the analysis of DHA in dried dog food and the results were verified in a second laboratory. Results The method was found to be linear over the ranges analyzed and results were found to be within the acceptance criteria for precision and accuracy, verifying the applicability for this matrix. The selectivity and sensitivity of the method were also determined. Conclusions The AOAC 996.06 method is fit for purpose for the analysis of DHA in dry dog food kibble. Highlights The method can be applied to various dog food samples, supplemented with an unextracted Aurantiochytrium limacinum biomass, using alternative manufacturing methods, i.e. pelleted and extruded with no significant matrix effects being observed.
Gerald Patrick Dillon; Cathy Cardinall; Jason D Keegan; Alexandros Yiannikouris; Walter Brandl; Colm Anthony Moran. The Analysis of Docosahexaenoic Acid (DHA) in Dried Dog Food Enriched with an Aurantiochytrium limacinum Biomass: Matrix Extension Validation and Verification of AOAC Method 996.06. Journal of AOAC INTERNATIONAL 2020, 104, 68 -77.
AMA StyleGerald Patrick Dillon, Cathy Cardinall, Jason D Keegan, Alexandros Yiannikouris, Walter Brandl, Colm Anthony Moran. The Analysis of Docosahexaenoic Acid (DHA) in Dried Dog Food Enriched with an Aurantiochytrium limacinum Biomass: Matrix Extension Validation and Verification of AOAC Method 996.06. Journal of AOAC INTERNATIONAL. 2020; 104 (1):68-77.
Chicago/Turabian StyleGerald Patrick Dillon; Cathy Cardinall; Jason D Keegan; Alexandros Yiannikouris; Walter Brandl; Colm Anthony Moran. 2020. "The Analysis of Docosahexaenoic Acid (DHA) in Dried Dog Food Enriched with an Aurantiochytrium limacinum Biomass: Matrix Extension Validation and Verification of AOAC Method 996.06." Journal of AOAC INTERNATIONAL 104, no. 1: 68-77.
The purpose of this paper was to evaluate the toxicological potential of a heterotrophically grown unextracted Aurantiochytrium limacinum biomass (AURA) when used as a food additive. The following toxicological assessments were conducted on this novel docosahexaenoic acid rich feed ingredient: Mutagenic activity was tested by means of the Ames’ test using five Salmonella typhimurium strains; clastogenic activity was investigated using the micronucleus test in male and female Sprague Dawley rats; genotoxic activity was assessed by means of the in vitro metaphase analysis tests in human lymphocytes; oral toxicity was tested by administration of AURA at various concentrations; eye and skin irritation was assessed in rabbits according to OECD guidelines; skin sensitivity was established in guinea pigs by means of the Buehler test. All conducted tests were considered valid under the experimental conditions. No significant mutagenic activity or clastogenic activity was observed. Genotoxic activity in human lymphocytes was not induced. Oral administration of 276 mg AURA/kg bw1 and 2000 mg AURA/kg bw resulted in no mortality or signs of acute toxicity. Daily administration of 1000 mg AURA/kg bw caused no mortality or biologically relevant signs of toxicity and was established as the No Observable Adverse Effect Level. AURA was also found to be a non-irritant for the eye and skin of the rabbit and was non-sensitizing to guinea pig skin.
G.P. Dillon; J.D. Keegan; C.A. Moran. Toxicological evaluation of an unextracted Aurantiochytrium limacinum biomass, a novel docosahexaenoic acid rich feed ingredient. Food and Chemical Toxicology 2020, 141, 111397 .
AMA StyleG.P. Dillon, J.D. Keegan, C.A. Moran. Toxicological evaluation of an unextracted Aurantiochytrium limacinum biomass, a novel docosahexaenoic acid rich feed ingredient. Food and Chemical Toxicology. 2020; 141 ():111397.
Chicago/Turabian StyleG.P. Dillon; J.D. Keegan; C.A. Moran. 2020. "Toxicological evaluation of an unextracted Aurantiochytrium limacinum biomass, a novel docosahexaenoic acid rich feed ingredient." Food and Chemical Toxicology 141, no. : 111397.
There are various health benefits associated with people consuming sufficient quantities of omega-3 fatty acids, with docosahexaenoic acid (DHA) in particular impacting cardiovascular and mental health as well as influencing the immune response. Dietary deficiencies of omega-3 are common globally, and an emerging strategy to compensate is the enrichment of frequently consumed foods. Chicken meat represents a good target for enrichment as the fatty acid concentrations of the edible tissues can be easily altered by including omega-3 rich ingredients in their diets. However, the optimum duration of supplementation remains unclear. In this paper we describe the results of two studies in which the DHA-rich protist, Aurantiochytrium limacinum (AURA) was fed to broilers at a rate of 0%, 0.5%, 1% and 2% of the diet. In the first study the birds were supplemented for their whole lives (42 days) while in the second study the birds were supplemented for the final 21-day fattening period only. Productivity parameters were affected in the whole life study, but were unaffected in the fattening period study. In both studies, higher AURA inclusion rates led to higher levels of DHA enrichment. Supplementation at a rate of 1% resulted in 49 and 97 mg DHA/100 g of breast or thigh meat, respectively, while a 2% inclusion rate resulted in 97 and 156 mg DHA/100g of breast or thigh meat, respectively, enough DHA to be considered a source of omega-3 in the European Union and Canada.
Jason D. Keegan; Giorgio Fusconi; Mauro Morlacchini; Colm A. Moran. Comparing docosahexaenoic acid supplementation strategies in terms of broiler tissue enrichment, productivity, and cost. Journal of Applied Poultry Research 2020, 29, 636 -652.
AMA StyleJason D. Keegan, Giorgio Fusconi, Mauro Morlacchini, Colm A. Moran. Comparing docosahexaenoic acid supplementation strategies in terms of broiler tissue enrichment, productivity, and cost. Journal of Applied Poultry Research. 2020; 29 (3):636-652.
Chicago/Turabian StyleJason D. Keegan; Giorgio Fusconi; Mauro Morlacchini; Colm A. Moran. 2020. "Comparing docosahexaenoic acid supplementation strategies in terms of broiler tissue enrichment, productivity, and cost." Journal of Applied Poultry Research 29, no. 3: 636-652.
J.D. Keegan; D. Currie; A. Knox; C.A. Moran. Docosahexaenoic Acid Included in Layer Feed as an Unextracted Aurantiochytrium limacinum Biomass Is Efficiently Transferred to Eggs When Provided in Mash or Pellet Form. Journal of Applied Poultry Research 2019, 28, 1069 -1077.
AMA StyleJ.D. Keegan, D. Currie, A. Knox, C.A. Moran. Docosahexaenoic Acid Included in Layer Feed as an Unextracted Aurantiochytrium limacinum Biomass Is Efficiently Transferred to Eggs When Provided in Mash or Pellet Form. Journal of Applied Poultry Research. 2019; 28 (4):1069-1077.
Chicago/Turabian StyleJ.D. Keegan; D. Currie; A. Knox; C.A. Moran. 2019. "Docosahexaenoic Acid Included in Layer Feed as an Unextracted Aurantiochytrium limacinum Biomass Is Efficiently Transferred to Eggs When Provided in Mash or Pellet Form." Journal of Applied Poultry Research 28, no. 4: 1069-1077.
1. The consumption of adequate amounts of the long-chain polyunsaturated omega-3 fatty acids (n-3 LC-PUFA) has been associated with beneficial effects on human health. Eggs are commonly consumed worldwide, and their omega-3 content can be easily altered by changing the diets of laying hens and so represent an important target for enrichment. 2. In this study, the effect of supplementing laying hens with DHA-rich, Aurantiochytrium limacinum at three different inclusion levels was investigated over a 24-week period. 3. Significant increases in egg DHA concentrations were observed after four weeks and were maintained for the duration of the 24-week study. The supplemented eggs in the current study had a DHA content of 82, 101, and 129 mg/yolk when supplemented with 0.25%, 0.5% and 1% treatments, respectively, which meets the EU criteria to be considered 'high in omega-3'. 4. Using the sustainably grown protist Aurantiochytrium limacinum to supplement layer diets increased the egg DHA concentration and decreased the n-6/n-3 ratio, improving the nutritional value of the eggs for human consumers.
Jason D. Keegan; Doug Currie; Anne Knox; Colm A. Moran. Heterotrophic Aurantiochytrium sp. supplementation to layer diets sustainably increases the omega-3 concentration of eggs. British Poultry Science 2019, 60, 570 -578.
AMA StyleJason D. Keegan, Doug Currie, Anne Knox, Colm A. Moran. Heterotrophic Aurantiochytrium sp. supplementation to layer diets sustainably increases the omega-3 concentration of eggs. British Poultry Science. 2019; 60 (5):570-578.
Chicago/Turabian StyleJason D. Keegan; Doug Currie; Anne Knox; Colm A. Moran. 2019. "Heterotrophic Aurantiochytrium sp. supplementation to layer diets sustainably increases the omega-3 concentration of eggs." British Poultry Science 60, no. 5: 570-578.
The fatty acid composition of broiler chicken tissues can be increased by adding omega-3 rich ingredients to their diets. The purpose of this study was to compare the levels of tissue enrichment observed following the supplementation of broilers with the docosahexaenoic acid (DHA)-rich protist, Aurantiochytrium limacinum (AURA) for their whole life (42 days) or for the final 21-day fattening period. Day-old chicks (n = 350) were distributed among 35 pens (10 birds per pen) with each pen randomly assigned to one of five treatments: Control; 0.5% AURA from day 0-42; 1% AURA from day 0-42; 0.5% AURA from day 21-42; 1% AURA from day 21-42. Production parameters were recorded over the course of the study and the fatty acid profile of the breast, thigh, liver, kidney and skin with adhering fat was quantified at the end of the feeding period. The level of supplementation had a significant impact on the degree of omega-3 tissue enrichment, however, no differences were observed when the same dose was provided for 21 or 42 days. These results indicate that supplementation with AURA for a period of 21 days does not negatively affect broiler productivity and is the most efficient strategy to increase the nutritional value of broiler products.
Jason Keegan; Giorgio Fusconi; Mauro Morlacchini; Colm A. Moran. Whole-Life or Fattening Period Only Broiler Feeding Strategies Achieve Similar Levels of Omega-3 Fatty Acid Enrichment Using the DHA-Rich Protist, Aurantiochytrium limacinum. Animals 2019, 9, 327 .
AMA StyleJason Keegan, Giorgio Fusconi, Mauro Morlacchini, Colm A. Moran. Whole-Life or Fattening Period Only Broiler Feeding Strategies Achieve Similar Levels of Omega-3 Fatty Acid Enrichment Using the DHA-Rich Protist, Aurantiochytrium limacinum. Animals. 2019; 9 (6):327.
Chicago/Turabian StyleJason Keegan; Giorgio Fusconi; Mauro Morlacchini; Colm A. Moran. 2019. "Whole-Life or Fattening Period Only Broiler Feeding Strategies Achieve Similar Levels of Omega-3 Fatty Acid Enrichment Using the DHA-Rich Protist, Aurantiochytrium limacinum." Animals 9, no. 6: 327.
Changes in modern human diets have resulted in a deficiency in omega-3 fatty acids. Rectifying this deficiency and increasing dietary levels of omega-3 fatty acids, such as docosahexaenoic acid (DHA), can improve overall human health. Fish are a rich source of omega-3 fatty acids; however, low levels of consumption in many parts of the world, coupled with declining fish stocks, mean that alternative dietary omega-3 sources are required. The enrichment of commonly consumed foods has been suggested as a strategy that could increase omega-3 consumption. Eggs are an obvious target for enrichment as they are consumed worldwide and can have their omega-3 content altered through dietary manipulation of hens. In the current study, algae were included in the diet of hens, at 3 inclusion levels, in order to increase the omega-3 content of their eggs. For each treatment, the DHA content of eggs reached a plateau, proportional to the level of inclusion in the diet, which was then maintained for the duration of the experimental period. Higher inclusion levels reached this plateau quicker; however, the efficiency of transfer was reduced with increased dietary DHA. This maintenance of an increased egg DHA content over a prolonged period of time emphasizes the suitability of dietary supplementation with algae as a means to improve the nutritional value of hen's eggs.
C.A. Moran; M. Morlacchini; J.D. Keegan; G. Fusconi. Increasing the Omega-3 Content of Hen's Eggs Through Dietary Supplementation with Aurantiochytrium limacinum Microalgae: Effect of Inclusion Rate on the Temporal Pattern of Docosahexaenoic Acid Enrichment, Efficiency of Transfer, and Egg Characteristics. Journal of Applied Poultry Research 2019, 28, 329 -338.
AMA StyleC.A. Moran, M. Morlacchini, J.D. Keegan, G. Fusconi. Increasing the Omega-3 Content of Hen's Eggs Through Dietary Supplementation with Aurantiochytrium limacinum Microalgae: Effect of Inclusion Rate on the Temporal Pattern of Docosahexaenoic Acid Enrichment, Efficiency of Transfer, and Egg Characteristics. Journal of Applied Poultry Research. 2019; 28 (2):329-338.
Chicago/Turabian StyleC.A. Moran; M. Morlacchini; J.D. Keegan; G. Fusconi. 2019. "Increasing the Omega-3 Content of Hen's Eggs Through Dietary Supplementation with Aurantiochytrium limacinum Microalgae: Effect of Inclusion Rate on the Temporal Pattern of Docosahexaenoic Acid Enrichment, Efficiency of Transfer, and Egg Characteristics." Journal of Applied Poultry Research 28, no. 2: 329-338.
1. The consumption of sufficient quantities of long chain omega-3 fatty acids (n-3 LCPUFA) from meat and other animal products can lead to a variety of health benefits in humans. The fatty acid content of poultry meat can be increased by feeding birds ingredients that are rich in n-3 LCFUFA 2. The effect of feeding a docosahexaenoic acid (DHA) rich Aurantiochytrium limacinum biomass (AURA) on the fatty acid content of breast and thigh tissues was investigated in a feeding trial with 2880 male Ross 308 broilers. The broiler diets were supplemented with either 0, 0.25, 0.5 or 1% AURA from day 21 to 42 of age. 3. Supplementation significantly increased the DHA content of both breast and thigh meat at an inclusion rate of 1% in the diet, leading to a total of 42 and 46 mg DHA/100 g of fresh breast or thigh tissue respectively. Significant increases in the tissue eicosapentaenoic acid (EPA) concentration were seen alongside a reduced omega-6/omega-3 ratio, improving the nutritional value of the meat for consumers and identifying supplementation of broiler diets with A. limacinum as an effective and sustainable method to increase n-3 LCPUFA consumption in the human population.
J. D. Keegan; D. Currie; A. Knox; C. A. Moran. Redressing the balance: including DHA-rich Aurantiochytrium limacinum in broiler diets increases tissue omega-3 fatty acid content and lowers the n-6:n-3 ratio. British Poultry Science 2019, 60, 414 -422.
AMA StyleJ. D. Keegan, D. Currie, A. Knox, C. A. Moran. Redressing the balance: including DHA-rich Aurantiochytrium limacinum in broiler diets increases tissue omega-3 fatty acid content and lowers the n-6:n-3 ratio. British Poultry Science. 2019; 60 (4):414-422.
Chicago/Turabian StyleJ. D. Keegan; D. Currie; A. Knox; C. A. Moran. 2019. "Redressing the balance: including DHA-rich Aurantiochytrium limacinum in broiler diets increases tissue omega-3 fatty acid content and lowers the n-6:n-3 ratio." British Poultry Science 60, no. 4: 414-422.
C. Moran; M. Morlacchini; J. D Keegan; H. Warren; G. Fusconi. Dietary supplementation of dairy cows with a docosahexaenoic acid-rich thraustochytrid, Aurantiochytrium limacinum: effects on milk quality, fatty acid composition and cheese making properties. Journal of Animal and Feed Sciences 2019, 28, 3 -14.
AMA StyleC. Moran, M. Morlacchini, J. D Keegan, H. Warren, G. Fusconi. Dietary supplementation of dairy cows with a docosahexaenoic acid-rich thraustochytrid, Aurantiochytrium limacinum: effects on milk quality, fatty acid composition and cheese making properties. Journal of Animal and Feed Sciences. 2019; 28 (1):3-14.
Chicago/Turabian StyleC. Moran; M. Morlacchini; J. D Keegan; H. Warren; G. Fusconi. 2019. "Dietary supplementation of dairy cows with a docosahexaenoic acid-rich thraustochytrid, Aurantiochytrium limacinum: effects on milk quality, fatty acid composition and cheese making properties." Journal of Animal and Feed Sciences 28, no. 1: 3-14.
Docosahexaenoic acid (DHA) is an omega-3 fatty acid that is considered an essential part of the human diet. Increasing the amount of DHA in commonly consumed foodstuffs can benefit people predisposed to heart problems, depression, and even some forms of cancer. One of the best sources of DHA is oily fish, but the majority of people do not eat fish regularly. By formulating diets for livestock or poultry to include ingredients rich in omega-3 fatty acids, we can increase the omega-3 content of their respective meat and tissues. In this study we fed broilers diets supplemented with increasing amounts of a DHA-rich microalgae to investigate whether it was safe for the birds, in terms of their health and productivity and effective in terms of DHA transfer from feed to meat. The results of the present study showed that feeding the microalgae to chickens had no negative effects on their health in terms of their level of survival or growth. Moreover, we found that supplementing the microalgae resulted in a large increase in the DHA content of meat. This study demonstrated that feeding algae is a safe and effective way to improve the nutritional value of chicken meat. It is well established that the docosahexaenoic acid (DHA) content of commonly consumed meats, such as chicken, can be increased through dietary supplementation with DHA-rich ingredients. The purpose of this study was to investigate the tolerance of broilers to dietary supplementation with the unextracted biomass of a DHA-rich microalgae Aurantiochytrium limacinum, so as to ensure its safety, since it is accumulated in broiler meat. Healthy day-old male Ross 308 chicks (n = 1120) were evenly distributed to 32 pens (35 chicks per pen), with pens randomly allocated to one of four dietary treatments, each having eight replicates. The dietary groups included one untreated control and three treatments corresponding to three inclusion levels (0.5, 2.5, and 5.0%) of All-G-Rich®, with the birds receiving the experimental diets ad libitum during the study (day 0–42). Bird survival, blood parameters, productivity, and breast and thigh DHA content were determined after 42 days of feeding. Supplementation at up to 10 times the intended use level had no negative effects on the mortality, blood parameters or productivity of the birds, while significant increases in the meat DHA content were observed. These results indicate that supplementation with Aurantiochytrium limacinum is a safe and effective way to increase broiler tissue DHA content.
Colm A. Moran; Douglas Currie; Jason Keegan; Anne Knox. Tolerance of Broilers to Dietary Supplementation with High Levels of the DHA-Rich Microalga, Aurantiochytrium Limacinum: Effects on Health and Productivity. Animals 2018, 8, 180 .
AMA StyleColm A. Moran, Douglas Currie, Jason Keegan, Anne Knox. Tolerance of Broilers to Dietary Supplementation with High Levels of the DHA-Rich Microalga, Aurantiochytrium Limacinum: Effects on Health and Productivity. Animals. 2018; 8 (10):180.
Chicago/Turabian StyleColm A. Moran; Douglas Currie; Jason Keegan; Anne Knox. 2018. "Tolerance of Broilers to Dietary Supplementation with High Levels of the DHA-Rich Microalga, Aurantiochytrium Limacinum: Effects on Health and Productivity." Animals 8, no. 10: 180.
Targeted selective treatment (TST) has been proposed as a sustainable method of gastrointestinal nematode control that reduces the number of anthelmintic treatments administered, thereby preserving a susceptible nematode population in refugia. In order to minimise the impact of withholding treatment on animal performance, animals that would benefit most should be selected for treatment. However, the most suitable criteria for selecting which animals to treat remain a subject of research. The impact of implementing a TST strategy based on lamb live weight was investigated, and whether heavy lambs were more resilient than light lambs if left untreated. The study was conducted using weaned lambs on 3 sheep farms, and over 2 years. On each farm lambs were weighed and divided into heavy, medium and light weight classes. Within the heavy (n = 225) and light (n = 218) weight classes lambs were randomly allocated to two treatments; anthelmintic treatment or no anthelmintic treatment. All lambs in the medium weight class were treated. Animal performance and parasitological parameters were assessed over a 28-day period. Anthelmintic treatment had a significant effect (P < 0.01) on faecal egg count, average daily weight gain, body condition score and dag score; there was no treatment by weight class interaction. Anthelmintic treatment had no effect on plasma pepsinogen concentration or on blood leukocyte numbers. Withholding anthelmintic treatment from lambs therefore had a negative effect on worm egg count and animal performance with no evidence that heavy lambs were more resilient than light lambs when left untreated.
Jason Keegan; Barbara Good; James P. Hanrahan; Ciaran Lynch; Theo de Waal; Orla M. Keane. Live weight as a basis for targeted selective treatment of lambs post-weaning. Veterinary Parasitology 2018, 258, 8 -13.
AMA StyleJason Keegan, Barbara Good, James P. Hanrahan, Ciaran Lynch, Theo de Waal, Orla M. Keane. Live weight as a basis for targeted selective treatment of lambs post-weaning. Veterinary Parasitology. 2018; 258 ():8-13.
Chicago/Turabian StyleJason Keegan; Barbara Good; James P. Hanrahan; Ciaran Lynch; Theo de Waal; Orla M. Keane. 2018. "Live weight as a basis for targeted selective treatment of lambs post-weaning." Veterinary Parasitology 258, no. : 8-13.
Gerald Patrick Dillon; Jason D. Keegan; Geoff Wallace; Alexandros Yiannikouris; Colm Anthony Moran. The validation & verification of an LC/MS method for the determination of total docosahexaenoic acid concentrations in canine blood serum. Regulatory Toxicology and Pharmacology 2018, 95, 198 -203.
AMA StyleGerald Patrick Dillon, Jason D. Keegan, Geoff Wallace, Alexandros Yiannikouris, Colm Anthony Moran. The validation & verification of an LC/MS method for the determination of total docosahexaenoic acid concentrations in canine blood serum. Regulatory Toxicology and Pharmacology. 2018; 95 ():198-203.
Chicago/Turabian StyleGerald Patrick Dillon; Jason D. Keegan; Geoff Wallace; Alexandros Yiannikouris; Colm Anthony Moran. 2018. "The validation & verification of an LC/MS method for the determination of total docosahexaenoic acid concentrations in canine blood serum." Regulatory Toxicology and Pharmacology 95, no. : 198-203.
These results indicate that dietary supplementation with 1% AURA over a 31 days period can increase the FA composition of pork LL and backfat, specifically the DHA, with no major impact on growth performance and carcass traits.
Colm Anthony Moran; Mauro Morlacchini; Jason D. Keegan; Giorgio Fusconi. Dietary supplementation of finishing pigs with the docosahexaenoic acid-rich microalgae, Aurantiochytrium limacinum: effects on performance, carcass characteristics and tissue fatty acid profile. Asian-Australasian Journal of Animal Sciences 2018, 31, 712 -720.
AMA StyleColm Anthony Moran, Mauro Morlacchini, Jason D. Keegan, Giorgio Fusconi. Dietary supplementation of finishing pigs with the docosahexaenoic acid-rich microalgae, Aurantiochytrium limacinum: effects on performance, carcass characteristics and tissue fatty acid profile. Asian-Australasian Journal of Animal Sciences. 2018; 31 (5):712-720.
Chicago/Turabian StyleColm Anthony Moran; Mauro Morlacchini; Jason D. Keegan; Giorgio Fusconi. 2018. "Dietary supplementation of finishing pigs with the docosahexaenoic acid-rich microalgae, Aurantiochytrium limacinum: effects on performance, carcass characteristics and tissue fatty acid profile." Asian-Australasian Journal of Animal Sciences 31, no. 5: 712-720.
Two 125-day experiments of the same design were conducted to evaluate the effects of a heterotrophically grown microalgae (AURA) containing docosahexaenoic acid (DHA) on pig performance, carcass traits and the fatty acid composition of lean and adipose tissue. In each experiment, 144 Hypor pigs were blocked by sex, allocated to three treatment groups, and fed 0, 0.25% or 0.50% AURA in isonutritive, isocaloric diets. Pigs were weighed on days 0, 28, 56, 84 and 112. Feed and water intakes were measured every 28 days. Pigs were slaughtered on day 125. Data from the two studies were analysed as a single data set. Performance and carcass traits did not differ between treatments. Both microalgae treatment levels enriched (p < .05) Longissimus lumborum (LL) and backfat in DHA and improved (p < .05) their ratios of n-6 to n-3 fatty acids.
C. A. Moran; M. Morlacchini; J. D. Keegan; R. Delles; G. Fusconi. Effects of a DHA-rich unextracted microalgae as a dietary supplement on performance, carcass traits and meat fatty acid profile in growing-finishing pigs. Journal of Animal Physiology and Animal Nutrition 2018, 102, 1026 -1038.
AMA StyleC. A. Moran, M. Morlacchini, J. D. Keegan, R. Delles, G. Fusconi. Effects of a DHA-rich unextracted microalgae as a dietary supplement on performance, carcass traits and meat fatty acid profile in growing-finishing pigs. Journal of Animal Physiology and Animal Nutrition. 2018; 102 (4):1026-1038.
Chicago/Turabian StyleC. A. Moran; M. Morlacchini; J. D. Keegan; R. Delles; G. Fusconi. 2018. "Effects of a DHA-rich unextracted microalgae as a dietary supplement on performance, carcass traits and meat fatty acid profile in growing-finishing pigs." Journal of Animal Physiology and Animal Nutrition 102, no. 4: 1026-1038.
The omega-3 fatty acid (n-3 FA) content of broiler tissues can be increased through dietary supplementation of hens with n-3 FA-rich microalgae. The aim of this study was to evaluate the effect of three different dietary inclusion levels of a docosahexaenoic acid (DHA)-rich microalgae (AURA) on broiler performance and the enrichment of tissues with n-3 FA. The randomized study was conducted using 352 birds, housed in 32 pens with 11 birds per pen. Pens were randomly assigned to one of four treatments, with each treatment replicated 8 times. The treatments included one unsupplemented control (0%) and three wheat-soya based experimental diets supplemented with AURA at a level of 0.5%, 1.5% and 2.5% for the starter, grower and finisher periods. Birds were weighed on days 0, 10, 24, 35 and 41, and feed intake was recorded per pen. On day 41, five birds per treatment were euthanized and individually weighed. Thigh muscle, breast muscle, liver, kidney and skin samples were taken post-mortem, freeze dried and DHA content quantified, following fat extraction and methylation, by GC-FID (AOAC 996.06 method). Performance and tissue data were analyzed by ANOVA with Dunnett’s (2-sided) post-hoc test to determine the differences between the mean values for each treatment. Dietary supplementation with AURA had no effect on body weight or feed intake during any period of the study. For thigh muscle, kidney and skin the DHA increased linearly (P < 0.05) with increasing level of dietary AURA, whilst there was a quadratic response in uptake of DHA in breast muscle and liver. The study demonstrated the potential of efficiently enriching broiler meat and organs with DHA by feeding AURA.
Colm A. Moran; Jason Keegan; Kirsi Vienola; Juha Apajalahti. Broiler Tissue Enrichment with Docosahexaenoic Acid (DHA) through Dietary Supplementation with Aurantiochytrium limacinum Algae. Food and Nutrition Sciences 2018, 09, 1160 -1173.
AMA StyleColm A. Moran, Jason Keegan, Kirsi Vienola, Juha Apajalahti. Broiler Tissue Enrichment with Docosahexaenoic Acid (DHA) through Dietary Supplementation with Aurantiochytrium limacinum Algae. Food and Nutrition Sciences. 2018; 09 (10):1160-1173.
Chicago/Turabian StyleColm A. Moran; Jason Keegan; Kirsi Vienola; Juha Apajalahti. 2018. "Broiler Tissue Enrichment with Docosahexaenoic Acid (DHA) through Dietary Supplementation with Aurantiochytrium limacinum Algae." Food and Nutrition Sciences 09, no. 10: 1160-1173.
The aim of this study was to investigate the effect of dietary supplementation with the docosahexaenoic acid (DHA)‐rich microalgae, Aurantiochytrium limacinum (AURA), on a variety of health and productivity parameters in lactating cows. Twenty‐four cows were blocked by parity and number of days in milk and then randomly assigned to a control (CON; n = 12) group with no algal supplementation, or a treatment group (AURA; n = 12) provided with 100 g AURA cow−1 day−1 or 16 g DHA cow−1 day−1. A variety of health and productivity measurements were taken, and results indicated that supplementation had no negative effects on animal health in terms of somatic cell count, haematological and biochemical blood parameters, while body condition was marginally improved by algal supplementation. No differences were found for the various production parameters measured; however, a tendency towards increased milk production was observed for the AURA group during the final stage of the study (+4.5 kg cow−1 day−1, day 78–84). The fatty acid profile of milk was improved by supplementation, with significantly lower saturated fatty acids, significantly higher omega‐3 fatty acids and an improved omega‐3/omega‐6 ratio observed when compared to the control group. The amount of DHA in the milk of cows provided 105 g AURA head−1 day−1 was 4.7 mg/100 g milk with a peak transfer efficiency from feed to milk at day 49 of 8.3%. These results indicate that supplementation with 105 g AURA head−1 day−1 resulted in the successful enrichment of milk with DHA without negatively impacting the health or productivity of the animals.
C. A. Moran; M. Morlacchini; J. D. Keegan; G. Fusconi. The effect of dietary supplementation with Aurantiochytrium limacinum on lactating dairy cows in terms of animal health, productivity and milk composition. Journal of Animal Physiology and Animal Nutrition 2017, 102, 576 -590.
AMA StyleC. A. Moran, M. Morlacchini, J. D. Keegan, G. Fusconi. The effect of dietary supplementation with Aurantiochytrium limacinum on lactating dairy cows in terms of animal health, productivity and milk composition. Journal of Animal Physiology and Animal Nutrition. 2017; 102 (2):576-590.
Chicago/Turabian StyleC. A. Moran; M. Morlacchini; J. D. Keegan; G. Fusconi. 2017. "The effect of dietary supplementation with Aurantiochytrium limacinum on lactating dairy cows in terms of animal health, productivity and milk composition." Journal of Animal Physiology and Animal Nutrition 102, no. 2: 576-590.
Resistance to benzimidazole (BZ) anthelmintics is common in ovine nematodes of economic importance. Single nucleotide polymorphisms (SNP) at three positions in the isotype 1 β– tubulin gene have been associated with BZ resistance and molecular tests for the detection of BZ resistance have been developed. In order to determine if such tests are practicable in Ireland the polymorphisms associated with BZ resistance must be identified. To this end, BZ-resistant nematodes were recovered from four farms in Ireland. Resistant Teladorsagia circumcincta, Cooperia curticei and Trichostrongylus colubriformis were recovered, with resistant T. circumcincta the most common and the only species studied further. Sequencing of the isotype 1 β–tubulin gene from resistant T. circumcincta identified a T - A transition, resulting in an F200Y substitution known to be responsible for BZ-resistance, on three of the farms. However, on the fourth farm the frequency of the resistant A allele was only 0.33 indicating another BZ resistance mechanism may be present on this farm. An additional polymorphism resulting in a substitution of glutamate for leucine (E198L) was also found on this farm at low frequency (0.17). No polymorphisms at position 167 were identified on any farm. Therefore, molecular tests to detect BZ resistance in T. circumcincta in Ireland could prove useful; however, they may result in some instances of resistance remaining undetected.
Jason D. Keegan; Barbara Good; Theo De Waal; June Fanning; Orla M. Keane. Genetic basis of benzimidazole resistance in Teladorsagia circumcincta in Ireland. Irish Veterinary Journal 2017, 70, 8 .
AMA StyleJason D. Keegan, Barbara Good, Theo De Waal, June Fanning, Orla M. Keane. Genetic basis of benzimidazole resistance in Teladorsagia circumcincta in Ireland. Irish Veterinary Journal. 2017; 70 (1):8.
Chicago/Turabian StyleJason D. Keegan; Barbara Good; Theo De Waal; June Fanning; Orla M. Keane. 2017. "Genetic basis of benzimidazole resistance in Teladorsagia circumcincta in Ireland." Irish Veterinary Journal 70, no. 1: 8.
Between 2013 and 2015 the Department of Agriculture, Food and the Marine (DAFM) administered a sheep technology adoption programme (STAP), with the aim of increasing profitability on Irish sheep farms by encouraging the adoption of best management practices. One of the options available to STAP participants was to test the efficacy of the anthelmintic treatment (benzimadazole, levamisole or macrocyclic lactone) used in their flocks by means of a drench test, which is a modification of the faecal egg count reduction test; individual faecal samples were collected from the same group of lambs before and after anthelmintic treatment, the number of eggs present pre and post treatment was subsequently determined from a pooled sample. In total, 4211 drench tests were undertaken by farmers during the 3 years of the programme. Information on the anthelmintic product used was available for 3771 of these tests; anthelmintics from the classes benzimidazole (BZ), levamisole (LV) and macrocyclic lactone (ML) (avermectins (AVM) plus moxidectin (MOX)) were used in 42.0%, 23.4% and 32.5% of tests, respectively. The remaining 2.1% of tests involved an inappropriate product. The efficacy of treatment against 'other trichostrongyles' (excluding Nematodirus spp and Strongyloides papillosus.) could be established for 1446 tests, and 51% of these tests were considered effective (i.e. a reduction of faecal egg count (FEC) ≥ 95%). There was a significant difference among the drug groups in efficacy; 31.5%, 51.9%, 62.5% and 84% of treatments were considered effective for BZ, LV, AVM, MOX, respectively. The efficacy of treatment against Nematodirus spp. could be established for 338 tests and the overall efficacy was 96%. Due to the significant difference among the anthelmintic classes for efficacy against 'other trichostrongyles' along with the high level of efficacy against Nematodirus spp., a genus for which anthelmintic resistance is rarely reported, it is concluded that anthelmintic resistance was responsible for the majority of the anthelmintic treatment failures observed.
Jason D. Keegan; Orla M. Keane; Barbara Good; Theo De Waal; Marian Denny; James P. Hanrahan; William Fitzgerald; Maresa Sheehan. A nationwide survey of anthelmintic treatment failure on sheep farms in Ireland. Irish Veterinary Journal 2017, 70, 7 .
AMA StyleJason D. Keegan, Orla M. Keane, Barbara Good, Theo De Waal, Marian Denny, James P. Hanrahan, William Fitzgerald, Maresa Sheehan. A nationwide survey of anthelmintic treatment failure on sheep farms in Ireland. Irish Veterinary Journal. 2017; 70 (1):7.
Chicago/Turabian StyleJason D. Keegan; Orla M. Keane; Barbara Good; Theo De Waal; Marian Denny; James P. Hanrahan; William Fitzgerald; Maresa Sheehan. 2017. "A nationwide survey of anthelmintic treatment failure on sheep farms in Ireland." Irish Veterinary Journal 70, no. 1: 7.