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British Poultry Science Publication details, including instructions for authors and subscription information: http://www.tandfonline.com/loi/cbps20
The effects of choline and inositol on hepatic lipid metabolism and the incidence of the fatty liver and kidney syndrome in broilers J. Pearce
a b
a
Department of Agricultural and Food Chemistry , The Queen's University of Belfast , Newforge Lane, Belfast, BT9 5PX b
Department of Agriculture , Northern Ireland Published online: 08 Nov 2007.
To cite this article: J. Pearce (1975) The effects of choline and inositol on hepatic lipid metabolism and the incidence of the fatty liver and kidney syndrome in broilers, British Poultry Science, 16:6, 565-570, DOI: 10.1080/00071667508416230 To link to this article: http://dx.doi.org/10.1080/00071667508416230
PLEASE SCROLL DOWN FOR ARTICLE Taylor & Francis makes every effort to ensure the accuracy of all the information (the “Content”) contained in the publications on our platform. However, Taylor & Francis, our agents, and our licensors make no representations or warranties whatsoever as to the accuracy, completeness, or suitability for any purpose of the Content. Any opinions and views expressed in this publication are the opinions and views of the authors, and are not the views of or endorsed by Taylor & Francis. The accuracy of the Content should not be relied upon and should be independently verified with primary sources of information. Taylor and Francis shall not be liable for any losses, actions, claims, proceedings, demands, costs, expenses, damages, and other liabilities whatsoever or howsoever caused arising directly or indirectly in connection with, in relation to or arising out of the use of the Content. This article may be used for research, teaching, and private study purposes. Any substantial or systematic reproduction, redistribution, reselling, loan, sub-licensing, systematic supply, or distribution in any form to anyone is expressly forbidden. Terms
Downloaded by [UQ Library] at 13:08 03 February 2015
& Conditions of access and use can be found at http://www.tandfonline.com/page/ terms-and-conditions
Br. Poult. Sci., i6: 565-570.
1975
Longman: printed in Great Britain
THE EFFECTS OF CHOLINE AND INOSITOL ON HEPATIC LIPID METABOLISM AND THE INCIDENCE OF THE FATTY LIVER AND KIDNEY SYNDROME IN BROILERS J. PEARCE Department of Agricultural and Food Chemistry, The Queen's University of Belfast, Newforge Lane, Belfast, BT9 5PX; and Department of Agriculture, Northern Ireland
Downloaded by [UQ Library] at 13:08 03 February 2015
Received for publication 28th November 1974
1. Diets high in wheat and low in protein (18%) produced 5 to 6% mortality from fatty liver and kidney syndrome (FLKS) in broiler chicks whereas there were no deaths from FLKS in birds fed on a maize/barley diet containing 20% protein. 2. Supplementation of the wheat-based diets with choline or inositol (2·5 g additive/kg diet) did not affect the incidence of FLKS or liver lipid metabolism. 3. The wheat-based diet did not significantly affect the activities of hepatic lipogenic enzymes suggesting that hepatic lipid biosynthesis is not a cause of the syndrome. 4. The biotin contents of the wheat and maize/barley diets were little different, which may suggest that factors other than this are implicated in FLKS.
INTRODUCTION
Fatty liver and kidney syndrome (FLKS) is a disease which causes the accumulation of large amounts of lipid around the liver and kidneys of young chicks (LaursenJones, 1971). Mortality generally does not exceed 6% (Hemsley, 1965) but may reach 20% or more (Husbands and Laursen-Jones, 1969; Laursen-Jones, 1971; Payne et al., 1974; Whitehead and Blair, 1974a). It has been suggested that the condition occurs when diets of a high energy to protein ratio, in which wheat provides all or most of the cereal, are fed (Blair et al., 1969; Husbands and Laursen-Jones, 1969) and in particular low-protein diets containing animal protein have been implicated (Payne et al., 1974). The results of Blair et al. (1973) suggest that FLKS is due to a disorder of fat metabolism, especially when diets of low lipid content are fed, and the present experiment was carried out to investigate the effects of lipotropic agents on liver lipid metabolism in broiler chicks receiving diets which may produce the syndrome. While this experiment was in progress evidence appeared from elsewhere implicating biotin in FLKS (Blair and Whitehead, 1974; Payne et al., 1974). 565
566
J. PEARCE
Downloaded by [UQ Library] at 13:08 03 February 2015
MATERIALS AND METHODS
Three hundred and twenty broiler chicks (Ross), obtained from a local hatchery, were randomly divided into four groups, each of 80 birds. The birds were housed in rearing pens with wire-mesh floors. Initially a temperature of 30 °C was maintained and this was decreased to 20 °C after 3 weeks. A lighting pattern of 14 h light, 10 h dark was maintained throughout the experiment. Each group was fed on one of four experimental diets; food and water were provided ad libitum. The composition of the basal diets is shown in Table 1. Two other diets (diets 3 and 4) were prepared by supplementing the wheat-based diet (diet 2) with choline chloride and inositol respectively (2-5 g additive/kg diet). The diets were designed so that performance associated with the diets high in wheat and low in protein could be compared with that produced by a more conventional broiler diet (diet 1) and also so that lipid contents were low. These diets were fed from 1 day to 8 weeks of age when the experiment ended. At this time ten birds from each experimental group were taken at random for studies of hepatic lipid metabolism. TABLE 1 Percentage composition of the diets
Diet Ingredient Ground wheat Ground maize Ground barley Meat-and-bone meal Fish meal Dicalcium phosphate Vitamin-mineral premix1 Analyses Crude protein (%) Ether extract (%) Calculated metabolisable energy (MJ/kg) Energy to protein ratio 1
2
... 25
79
5° 20
4 078 0-22
20"I
47 11-56 0-58
20 ...
0-78 0'22
17-8 37 II-8I
o-66 6
The vitamin-mineral premix supplied per 1000 kg diet: retinol 8 x io IU; cholecalciferol, 2 x 1 0 ' IU; riboflavin, 4 g; cyanocobalamin, 6-8 mg; vitamin E, 8 g; vitamin K, 2 g; folic acid, 0-5 g; nicotinic acid, 20 g; pantothenic acid, 8 g; choline chloride, 100 g; Fe, 20 g; Cu, 8 g; Mn, 80 g; I, 5 g; Co, 3 g; Zn,
7° g-
The birds were killed by decapitation and exsanguination. The livers were removed rapidly and 20% (w/v) homogenates prepared in o-i M potassium phosphate buffer, pH 7-0, containing 7-0 mM 7-mercaptoethanol. The homogenates were centrifuged at 20,000 x g for 30 min at o to 5 °G (MSE Superspeed 50) and the resulting cell-free extracts were assayed for ATP-citrate lyase [EC 4.1.3.8] as described by Pearce (1968) and malate dehydrogenase (decarboxylating) (NADP) [EC 1.1.1.40] as described by Wise and Ball (1964). These assays were performed using a Unicam SP 8000 recording spectrophotometer at 40 °C and in all cases the recorded activity was linear with respect to both time and the protein concentration in the extract. The enzyme specific activities are expressed as units per mg protein where a unit is the amount of enzyme which will catalyse the
LIPOTROPIG AGENTS, LIPID METABOLISM AND FLKS
567
utilisation of i wmole substrate per minute at 40 °C. Liver total lipids were determined by the method of Folch et al. (1957). The statistical significance of the data was assessed by analysis of variance. RESULTS
During the experiment only one bird died among those receiving the conventional diet (diet 1). Of those fed on the three wheat-based diets a total of 23 birds died and post-mortem examination showed that mortality from FLKS was similar on each of these diets (Table 2). TABLE 2 Body weight and mortality of birds fed on wheat-based and conventional diets for 8 weeks
Downloaded by [UQ Library] at 13:08 03 February 2015
Diet Conventional 1588-5 (79)1 1 ° o
Body weight (g/bird) Numbers of birds dying Numbers dying from FLKS Mortality from FLKS (%) 1
Wheat-based 1065-8(76) 4 4 5
Wheat-based +choline 1005-1(73) 7 5 6
Wheat-based +inositol 997-3 (68) 12 5 6
Number of birds surviving after 8 weeks.
None of the birds which died from the syndrome showed typical symptoms of bio tin deficiency. Blair and Whitehead (1974) reported that FLKS occurs without the classical lesions of deficiency whereas Payne et al. (1974) observed dermatitis of the foot, a typical biotin deficiency symptom, in birds fed on wheat-based diets. Deaths from the syndrome occurred from 10 to 28 d of age and ceased thereafter. However, it was considered that if FLKS could be induced by diet, as suggested by other investigators, any treatment differences in metabolism would be similar during the 8 weeks of the experiment because the same diets were fed throughout. TABLE 3 The effect of conventional or wheat-based diets on liver weight, lipid content, dry matter and lipogenic enzyme activities
Diet
Body weight (g/bird) Liver weight (g) Liver weight (% body weight) Liver lipid (% liver weight) Liver dry matter (% liver weight) ATP-citrate lyase2 NADP malate dehydrogenase2 1 s
Conventional Wheat-based 1180-2 I5777 1 33-66 36-34 2-35 5-51 28-15 5-3i 100-36
2-88 5-60 27-47 6-68 122-62
Wheat-based Wheat-based + choline + inositol 1115-8 976-2 29-72 2-67 5-69 28-16 6-70
136-87
29-90 3-06 5-43 27-40 6-20 120-41
SEM
(36 df) i-97 0-14 o-37 0-50 0-50 8-90
Each result is the mean of 1 o observations. Enzyme specific activities expressed as nmoles/min mg/protein in the extract.
Growth rate was greatest in birds receiving the conventional diet (diet 1); that of birds fed on the wheat-based diets being about 25 to 40% less. Post-mortem
568
J. PEARCE
Downloaded by [UQ Library] at 13:08 03 February 2015
examination showed that there was substantially more fat around the kidneys of the birds fed on the wheat-based diets. The effects of diet on the liver are shown in Table 3. Liver weight was not significantly affected by diet, but if expressed as a percentage of body weight was larger in birds fed on the wheat-based diets and significantly (P
British Poultry Science Publication details, including instructions for authors and subscription information: http://www.tandfonline.com/loi/cbps20
The effects of choline and inositol on hepatic lipid metabolism and the incidence of the fatty liver and kidney syndrome in broilers J. Pearce
a b
a
Department of Agricultural and Food Chemistry , The Queen's University of Belfast , Newforge Lane, Belfast, BT9 5PX b
Department of Agriculture , Northern Ireland Published online: 08 Nov 2007.
To cite this article: J. Pearce (1975) The effects of choline and inositol on hepatic lipid metabolism and the incidence of the fatty liver and kidney syndrome in broilers, British Poultry Science, 16:6, 565-570, DOI: 10.1080/00071667508416230 To link to this article: http://dx.doi.org/10.1080/00071667508416230
PLEASE SCROLL DOWN FOR ARTICLE Taylor & Francis makes every effort to ensure the accuracy of all the information (the “Content”) contained in the publications on our platform. However, Taylor & Francis, our agents, and our licensors make no representations or warranties whatsoever as to the accuracy, completeness, or suitability for any purpose of the Content. Any opinions and views expressed in this publication are the opinions and views of the authors, and are not the views of or endorsed by Taylor & Francis. The accuracy of the Content should not be relied upon and should be independently verified with primary sources of information. Taylor and Francis shall not be liable for any losses, actions, claims, proceedings, demands, costs, expenses, damages, and other liabilities whatsoever or howsoever caused arising directly or indirectly in connection with, in relation to or arising out of the use of the Content. This article may be used for research, teaching, and private study purposes. Any substantial or systematic reproduction, redistribution, reselling, loan, sub-licensing, systematic supply, or distribution in any form to anyone is expressly forbidden. Terms
Downloaded by [UQ Library] at 13:08 03 February 2015
& Conditions of access and use can be found at http://www.tandfonline.com/page/ terms-and-conditions
Br. Poult. Sci., i6: 565-570.
1975
Longman: printed in Great Britain
THE EFFECTS OF CHOLINE AND INOSITOL ON HEPATIC LIPID METABOLISM AND THE INCIDENCE OF THE FATTY LIVER AND KIDNEY SYNDROME IN BROILERS J. PEARCE Department of Agricultural and Food Chemistry, The Queen's University of Belfast, Newforge Lane, Belfast, BT9 5PX; and Department of Agriculture, Northern Ireland
Downloaded by [UQ Library] at 13:08 03 February 2015
Received for publication 28th November 1974
1. Diets high in wheat and low in protein (18%) produced 5 to 6% mortality from fatty liver and kidney syndrome (FLKS) in broiler chicks whereas there were no deaths from FLKS in birds fed on a maize/barley diet containing 20% protein. 2. Supplementation of the wheat-based diets with choline or inositol (2·5 g additive/kg diet) did not affect the incidence of FLKS or liver lipid metabolism. 3. The wheat-based diet did not significantly affect the activities of hepatic lipogenic enzymes suggesting that hepatic lipid biosynthesis is not a cause of the syndrome. 4. The biotin contents of the wheat and maize/barley diets were little different, which may suggest that factors other than this are implicated in FLKS.
INTRODUCTION
Fatty liver and kidney syndrome (FLKS) is a disease which causes the accumulation of large amounts of lipid around the liver and kidneys of young chicks (LaursenJones, 1971). Mortality generally does not exceed 6% (Hemsley, 1965) but may reach 20% or more (Husbands and Laursen-Jones, 1969; Laursen-Jones, 1971; Payne et al., 1974; Whitehead and Blair, 1974a). It has been suggested that the condition occurs when diets of a high energy to protein ratio, in which wheat provides all or most of the cereal, are fed (Blair et al., 1969; Husbands and Laursen-Jones, 1969) and in particular low-protein diets containing animal protein have been implicated (Payne et al., 1974). The results of Blair et al. (1973) suggest that FLKS is due to a disorder of fat metabolism, especially when diets of low lipid content are fed, and the present experiment was carried out to investigate the effects of lipotropic agents on liver lipid metabolism in broiler chicks receiving diets which may produce the syndrome. While this experiment was in progress evidence appeared from elsewhere implicating biotin in FLKS (Blair and Whitehead, 1974; Payne et al., 1974). 565
566
J. PEARCE
Downloaded by [UQ Library] at 13:08 03 February 2015
MATERIALS AND METHODS
Three hundred and twenty broiler chicks (Ross), obtained from a local hatchery, were randomly divided into four groups, each of 80 birds. The birds were housed in rearing pens with wire-mesh floors. Initially a temperature of 30 °C was maintained and this was decreased to 20 °C after 3 weeks. A lighting pattern of 14 h light, 10 h dark was maintained throughout the experiment. Each group was fed on one of four experimental diets; food and water were provided ad libitum. The composition of the basal diets is shown in Table 1. Two other diets (diets 3 and 4) were prepared by supplementing the wheat-based diet (diet 2) with choline chloride and inositol respectively (2-5 g additive/kg diet). The diets were designed so that performance associated with the diets high in wheat and low in protein could be compared with that produced by a more conventional broiler diet (diet 1) and also so that lipid contents were low. These diets were fed from 1 day to 8 weeks of age when the experiment ended. At this time ten birds from each experimental group were taken at random for studies of hepatic lipid metabolism. TABLE 1 Percentage composition of the diets
Diet Ingredient Ground wheat Ground maize Ground barley Meat-and-bone meal Fish meal Dicalcium phosphate Vitamin-mineral premix1 Analyses Crude protein (%) Ether extract (%) Calculated metabolisable energy (MJ/kg) Energy to protein ratio 1
2
... 25
79
5° 20
4 078 0-22
20"I
47 11-56 0-58
20 ...
0-78 0'22
17-8 37 II-8I
o-66 6
The vitamin-mineral premix supplied per 1000 kg diet: retinol 8 x io IU; cholecalciferol, 2 x 1 0 ' IU; riboflavin, 4 g; cyanocobalamin, 6-8 mg; vitamin E, 8 g; vitamin K, 2 g; folic acid, 0-5 g; nicotinic acid, 20 g; pantothenic acid, 8 g; choline chloride, 100 g; Fe, 20 g; Cu, 8 g; Mn, 80 g; I, 5 g; Co, 3 g; Zn,
7° g-
The birds were killed by decapitation and exsanguination. The livers were removed rapidly and 20% (w/v) homogenates prepared in o-i M potassium phosphate buffer, pH 7-0, containing 7-0 mM 7-mercaptoethanol. The homogenates were centrifuged at 20,000 x g for 30 min at o to 5 °G (MSE Superspeed 50) and the resulting cell-free extracts were assayed for ATP-citrate lyase [EC 4.1.3.8] as described by Pearce (1968) and malate dehydrogenase (decarboxylating) (NADP) [EC 1.1.1.40] as described by Wise and Ball (1964). These assays were performed using a Unicam SP 8000 recording spectrophotometer at 40 °C and in all cases the recorded activity was linear with respect to both time and the protein concentration in the extract. The enzyme specific activities are expressed as units per mg protein where a unit is the amount of enzyme which will catalyse the
LIPOTROPIG AGENTS, LIPID METABOLISM AND FLKS
567
utilisation of i wmole substrate per minute at 40 °C. Liver total lipids were determined by the method of Folch et al. (1957). The statistical significance of the data was assessed by analysis of variance. RESULTS
During the experiment only one bird died among those receiving the conventional diet (diet 1). Of those fed on the three wheat-based diets a total of 23 birds died and post-mortem examination showed that mortality from FLKS was similar on each of these diets (Table 2). TABLE 2 Body weight and mortality of birds fed on wheat-based and conventional diets for 8 weeks
Downloaded by [UQ Library] at 13:08 03 February 2015
Diet Conventional 1588-5 (79)1 1 ° o
Body weight (g/bird) Numbers of birds dying Numbers dying from FLKS Mortality from FLKS (%) 1
Wheat-based 1065-8(76) 4 4 5
Wheat-based +choline 1005-1(73) 7 5 6
Wheat-based +inositol 997-3 (68) 12 5 6
Number of birds surviving after 8 weeks.
None of the birds which died from the syndrome showed typical symptoms of bio tin deficiency. Blair and Whitehead (1974) reported that FLKS occurs without the classical lesions of deficiency whereas Payne et al. (1974) observed dermatitis of the foot, a typical biotin deficiency symptom, in birds fed on wheat-based diets. Deaths from the syndrome occurred from 10 to 28 d of age and ceased thereafter. However, it was considered that if FLKS could be induced by diet, as suggested by other investigators, any treatment differences in metabolism would be similar during the 8 weeks of the experiment because the same diets were fed throughout. TABLE 3 The effect of conventional or wheat-based diets on liver weight, lipid content, dry matter and lipogenic enzyme activities
Diet
Body weight (g/bird) Liver weight (g) Liver weight (% body weight) Liver lipid (% liver weight) Liver dry matter (% liver weight) ATP-citrate lyase2 NADP malate dehydrogenase2 1 s
Conventional Wheat-based 1180-2 I5777 1 33-66 36-34 2-35 5-51 28-15 5-3i 100-36
2-88 5-60 27-47 6-68 122-62
Wheat-based Wheat-based + choline + inositol 1115-8 976-2 29-72 2-67 5-69 28-16 6-70
136-87
29-90 3-06 5-43 27-40 6-20 120-41
SEM
(36 df) i-97 0-14 o-37 0-50 0-50 8-90
Each result is the mean of 1 o observations. Enzyme specific activities expressed as nmoles/min mg/protein in the extract.
Growth rate was greatest in birds receiving the conventional diet (diet 1); that of birds fed on the wheat-based diets being about 25 to 40% less. Post-mortem
568
J. PEARCE
Downloaded by [UQ Library] at 13:08 03 February 2015
examination showed that there was substantially more fat around the kidneys of the birds fed on the wheat-based diets. The effects of diet on the liver are shown in Table 3. Liver weight was not significantly affected by diet, but if expressed as a percentage of body weight was larger in birds fed on the wheat-based diets and significantly (P
