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Animal Science Journal (2014) 85, 427–434
doi: 10.1111/asj.12150
ORIGINAL ARTICLE Effects of dietary lysine/protein ratio and fat levels on growth performance and meat quality of finishing pigs Keisuke MAEDA,1 Fumika YAMAMOTO,2 Masanari TOYOSHI1 and Masakazu IRIE2 1
Livestock Experiment Station of Wakayama Prefecture, Susami, and 2Faculty of Agriculture, University of Miyazaki, Miyazaki, Japan
ABSTRACT This study aimed to evaluate the effects of dietary lysine/protein ratio and fat levels on the growth, carcass characteristics and meat quality of finishing pigs fed feed made from food waste, including noodles and chocolate. Four dietary treatments, 2 levels of lysine/protein ratio (0.035 and 0.046) and 2 levels of fat (3.3% and 6.0%), were adapted to a 2 × 2 factorial arrangement. Each diet for the finishing pigs contained the same levels of adequate crude protein (16%) and lysine (0.58–0.75%), and similar levels of high total digestible nutrients (90.2–92.6%). In total, 32 LWD pigs with an average body weight of 57.2 kg were assigned to 4 dietary groups. The pigs were slaughtered at about 115 kg. Growth performance was not influenced by the dietary treatments. Carcass characteristics were slightly influenced by the dietary fat level. As the dietary lysine/protein ratio decreased, the marbling score of Longissimus dorsi muscle increased and the intramuscular fat (IMF) increased from 6.82% to 9.46%. Marbling score was not significantly influenced by the dietary fat level. These results indicate that IMF increased without adverse effects on growth, carcass characteristics and meat quality, when pigs were fed a diet with low lysine/protein ratio.
Key words: intramuscular fat, lysine protein ratio, marbling, meat quality, pig.
INTRODUCTION In recent years, pig farming in Japan has been declining, owing to the high cost of grain feeds (Oh & Whitley 2011). Increased profitability in the sale of pork through improvements in quality, and the reduction in production costs are important for pig farmers. To improve pork quality, intramuscular fat (IMF) has attracted attention as an important factor for consumer acceptance. ‘Eco-feed’, which is made from food by-products and surplus food, was expected to markedly reduce pork production costs in Japan (Sugiura et al. 2009; Takahashi et al. 2012). An increase in the IMF content of the Longissimus dorsi muscle (LM) improves meat tenderness (DeVol et al. 1988; Hodgson et al. 1991) and palatability of consumers purchasing pork loin (Font-i-Furnols et al. 2012). Production of high-quality pork with rich IMF is possible through selective breeding and nutritional control (Ellis & McKeith 1999; Katsumata 2011). Various dietary control methods to increase the IMF content of pork have been previously reported, including low protein diet, low lysine diet, leucine supplementation, feeding of breadcrumbs, dietary conjugated linoleic acid and lysine imbalance diet © 2013 Japanese Society of Animal Science
(Unruh et al. 1996; Ellis & McKeith 1999; Ellis et al. 1999; Iwamoto et al. 2005; Ieiri et al. 2007; Katsumata 2011; Takahashi et al. 2012, 2013a,b). Lysine or protein deficient diets for increasing the IMF content are easy to implement; however, they have critical disadvantages with respect to feed conversion, weight gain and carcass lean contents (Kerr et al. 1995; Ellis & McKeith 1999; Ellis et al. 1999; Berg 2001; Katsumata et al. 2005; Katsumata 2011; Rodriguez-Sánchez et al. 2011). We have described the successful production of highly marbled pork by using dietary ‘Eco-feed,’ without adverse effects on growth and carcass characteristics. In this study, dietary control of lysine/protein ratio was more practical than using protein or lysine deficient diets in order to increase the IMF content, without any adverse effects on growth performance (Takahashi et al. 2012, 2013a,b). In addition, dietary
Correspondence: Masakazu Irie, Faculty of Agriculture, University of Miyazaki, Miyazaki 889-2192, Japan. (Email: irie @cc.miyazaki-u.ac.jp) Received 22 April 2013; accepted for publication 1 September 2013.
428 K. MAEDA et al.
fat level affected the IMF content and growth of finishing pigs (Takahashi et al. 2013b). However, detailed control methods and the mechanism of increasing the IMF content by using dietary control have not been fully elucidated. In particular, it is necessary to determine whether the effect of dietary fat supplementation on IMF is because of the fat itself or because of the increase in dietary energy. Boiled Chinese noodles that have passed their freshness date were discarded from a supermarket. Boiled Chinese noodles have less crude fat content than instant foods such as deep-fried noodles (MEXT 2010a,b); further, they are useful as feed for finishing pigs because of low lysine/protein ratio and fat level. In general, feeding a high-fat diet to pigs results in soft pork (Irie & Ohmoto 1985; Irie 1986, 1989; Pettigrew & Esnaola 2001). Chocolate has high crude fat and is discarded by manufacturers when it is not in the standard form. Further, chocolate is useful as a feedstuff owing to its high saturated fatty acid content (MEXT 2010a). However, chocolate contains theobromine which has toxicity for some animals via cocoa bean shell, cocoa bean meal and cocoa germs (EFSA 2008), although no adverse effect was observed when finishing pigs were fed a diet containing 12.2% chocolate (Ashihara et al. 2011). The objective of this study was to increase the IMF content of the LM without an adverse effect on the growth performance in finishing pigs, using boiled Chinese noodles and chocolate as an eco-feed. In addition, this study was designed to evaluate the effect of dietary lysine/protein ratio and fat level on the growth, carcass characteristics and meat quality of finishing pigs that were fed with an eco-feed with high total digestible nutrients (TDN), sufficient crude protein and adequate lysine levels.
MATERIALS AND METHODS Management of the experimental animals and design of dietary treatment A total of 32 Landrace × Large White × Duroc (LWD) pigs were reared at the same commercial farm in Wakayama Prefecture and the same genetic line and were assigned to 4 groups (4 barrows and 4 gilts/group); they had an average initial body weight of 57.2 ± 4.1 kg (mean ± SD). The groups had similar total body weights and were randomly allotted to dietary treatments in a 2 × 2 factorial arrangement. The dietary treatments included 2 levels of lysine/protein ratio (low: 0.035, L-LPR and medium: 0.046, M-LPR) and 2 levels of fat (medium: 3.3%, M-Fat and high: 6.0%, H-Fat). The examined feed, eco-feed, containing boiled Chinese noodles and chocolate, was supplemented with grains (Table 1). Feed compositions of the experimental diet were calculated by using computer software (NIGLS 2009) such that they contained similar, and slightly high TDN (90.2–92.6%) and sufficient protein (16%) and adequate lysine levels for © 2013 Japanese Society of Animal Science
the nutrient requirement content of Japanese Feeding Standardized for Swine (NARO 2005). Nutrient composition data of boiled Chinese noodles was used from the Standard Tables of Food Composition Japan (MEXT 2010a,b), and lysine content, 0.128%, was used from analyzed data as wet basis. Sufficiency rates (content/requirement percentage) against feed standard percentages (100%) of lysine on the L-LPR and M-LPR were 103% and 133%, respectively. Sufficiency rate of TDN was 120–123%. The formulated feeds were put in plastic bags and sealed in flexible containers until use. The eight pigs in each group were reared in 3 × 6 m pigpens, and four pens were used to this experiment. The pigs were cared for according to the JBR (1987) and Standards of Rearing Hygiene Management on Livestock Experiment Station of Wakayama Prefecture. All pigs had free access to feed and water. Adequate feed was given the pigs twice a day, and the leftover feed was weighted next morning, every day. As a rough indication, the total feed intake/pen was calculated to subtract the supply feed from leftovers during the fattening periods, and were indicated on dry matter basis. The pigs were weighted 7 times at 6–15-day intervals until they weighed approximately 115 kg. The average daily gain was calculated by using the initial and final weights. The gain/ feed ratio was calculated by the total feed intake/pen and total weight gain/pen. The fattening periods were measured as number of days between the day the experiment started and the day on which the pigs were taken from the pen for slaughtering. The pigs were slaughtered at a commercial abattoir in Osaka city. After the carcasses were chilled for approximately 2 days at 1°C, the loin with the subcutaneous back fat was excised 20 cm from the 5–6th ribs to the caudal area at the right side of the carcass. The loins were vacuum-packed in plastic bags and refrigerated at −20°C in order to analyze the physical and chemical characteristics later.
Carcass and meat appearance The carcass weight, backfat thickness, and dressing rate were measured. Backfat thickness was measured at the thinnest section between the 9th and 13th ribs. The characteristics of meat appearance, such as meat color, marbling score, seam fat score of LM, Minolta L*a*b* values of LM and fat were measured. Meat color was measured by using the Japanese pork color standards based on a 6-point scale for meat (1 = extremely pale pink, 6 = extremely dark red). Marbling (indicating IMF contents of LM), seam fat (1 = little fat, 5 = much fat), and firmness/wetness (1 = very soft and watery exudative, 5 = very firm and dry) were assessed according to the National Pork Producers Council (NPPC) Standards.
Physiochemical analysis of the loin The LM was minced, and the moisture, IMF content, crude protein level, and ash were measured by using a dried oven (135°C for 2 h), ether extraction, the Kjeldahl method and muffle heating (600°C for 3 h), respectively. Water holding capacity of the LM was measured by the beads method using a high-speed cooling centrifuge (Irie 2002). The melting point of the inner layer of back fat on the LM was measured using a capillary tube. Lipids from the LM and backfat were extracted with chloroform and methanol Animal Science Journal (2014) 85, 427–434
DIETARY LYSINE PROTEIN RATIO & FAT ON SWINE 429
Table 1
Composition of finisher diets
Lysine / Protein Ratio Level
Crude fat level Ingredient, % Boiled Chinese noodles† Wheat bran Soybean meal Alfalfa meal (Sun cure) Corn gluten meal (60% crude protein) Lysine hydrochloride Chocolate‡ Sugar Tricalcium phosphate Calcium carbonate Vitamin mineral premix§ Calculated values¶ Digestible energy (Mcal/kg) Total digestible nutrient (%) Crude protein (%) Crude fat (%) Crude fiber (%) Ca (%) P (%) Lysine (%) Lysine / protein ratio (LPR) Analyzed values Fatty acids, % Saturated fatty acids Monounsaturated fatty acids Polyunsaturated fatty acids
Low lysine / protein ratio
Medium lysine / protein ratio
(0.035)
(0.046)
Medium fat (3.3%)
High fat (6.0%)
Medium fat (3.3%)
High fat (6.0%)
83.15 7.07 3.12 1.04 0.51
83.28 7.29 3.27 1.04
83.32 7.39 3.02 1.04
1.46 2.91 0.44 0.21 0.10
4.37 0.44 0.21 0.10
83.26 7.28 2.51 1.04 0.68 0.11 1.46 2.91 0.44 0.21 0.10
3.95 90.2 16.2 3.3 2.5 0.9 1.0 0.58 0.035
4.08 92.5 16.2 6.0 2.5 0.9 1.0 0.58 0.035
3.95 90.2 16.1 3.3 2.4 0.9 1.0 0.75 0.046
4.08 92.6 16.2 6.0 2.5 0.9 1.0 0.75 0.046
41.7 37.0 21.3
45.8 35.7 18.5
39.4 36.6 24.0
45.4 38.0 16.6
0.10 4.37 0.44 0.21 0.10
†Wet form, boiled. Dry matter = 35.0%. ‡Black and white chocolate were mixed. §Vitamin mineral premix: provided per kilogram diet; 2 500 000 IU vitamin A, 3 500 000 IU vitamin D, 500 mg α-tocoferol, 100 mg thiamin nitrate, 600 mg riboflavin, 50 mg pyridoxine hydrochloride, 1 mg cyanocobalamin, 120 mg nicotinic acid amide, 200 mg menadione, 500 mg D-(+)-pantothenic acid calcium salt, 10 g choline chloride,100 mg folacin, 602 mg MnCO3, 2170 ZnCO3, 4,200 mg FeSO4, 2,700 mg CuSO4, 250 mg CoSO4, 6 mg calcium iodate, 2 mg d-biotin, 10 g lysine hydrochloride. ¶Calculated by Ecofeed_ver2.xls in NARO Institute of Livestock and Grassland Science (NILGS). Nutrient content of boiled Chinese noodles was Standard Tables of Food Composition Japan (MEXT). Lysine content of boiled Chinese noodles was 0.128% as wet basis.
solution and assessed for fatty acid composition. After methyl esterification with boron trifluoride methanol, fatty acid composition was determined by using a gas chromatograph (Shimazu Co. Kyoto, Japan) equipped with a capillary column (DW-WAX122-7062, 0.25 mm × 60 m). The temperatures of the column and detecting device were 160°C and 270°C, respectively. Eight fatty acids (14:0, 14:1, 16:0, 16:1, 18:0, 18:1, 18:2 and 18:3) were identified from the relative retention time of each standard material, and the total of these eight ingredients was expressed as 100%.
Statistical analysis A two-way analysis of variance (ANOVA) was performed to determine the effects of dietary lysine/protein ratio, fat levels, and their interaction on performance and meat quality using the GLM procedure. Differences among the means were compared by using Tukey’s multiple comparison tests. Pearson’s correlation coefficient analysis was used to assess the associations among IMF content, marbling score and physiochemical analysis data of the 32 pigs. Animal Science Journal (2014) 85, 427–434
RESULTS AND DISCUSSION Effects on production performance Effects of dietary lysine/protein ratio and fat levels on production performance are shown in Table 2. The average values of daily weight gain and fattening period were approximately 1 kg and 62 days, respectively. These values were similar among all the groups. The main effects of dietary lysine/protein ratio and fat level, as well as the interaction between them, on performance were not significant. The total feed intake/pen and gain/feed ratio were not measured correctly but the following data will serve as references. The total feed intake/pen in M-Fat + L-LPR, M-Fat + M-LPR, H-Fat + L-LPR, and H-Fat + M-LPR groups was 1247.9 kg, 1273.9 kg, 1301.7 kg and 1225.7 kg, respectively. The gain/feed ratio of M-Fat + L-LPR, M-Fat + M-LPR, H-Fat + L-LPR, and H-Fat + M-LPR groups was 0.39, 0.38, 0.38 and 0.41, respectively. © 2013 Japanese Society of Animal Science
430 K. MAEDA et al.
Table 2 Effects of lysine/protein ratio and fat levels on growth for finishing pigs
Lysine / protein ratio (LPR)
Initial body weight (kg) Final live weight (kg) Daily gain (kg/day) Fatting period (days)
Fat level
Low
Medium
Medium
High
(0.035)
(0.046)
(3.3%)
(6.0%)
57.7 119.2 0.99 62.4
56.7 118.3 1.01 62.0
57.2 117.8 0.99 61.9
57.2 119.7 1.01 62.5
Pooled SEM
P-value
0.72 0.77 0.02 1.12
LPR
Fat
LPR × fat
0.54 0.56 0.71 0.87
0.97 0.23 0.68 0.79
0.68 0.78 0.56 0.49
n = 16 (barrows = 8, gilts = 8). Low LPR + medium fat (n = 8), low-LPR + high fat (n = 8), medium LPR + medium fat (n = 8), medium LPR + high fat (n = 8).
Table 3 Effects of lysine/protein ratio and fat levels on carcass caracteristics
Lysine / protein ratio (LPR)
Carcass weight (kg) Backfat thickness (mm) Dressing ratio
Fat level
Low
Medium
Medium
High
(0.035)
(0.046)
(3.3%)
(6.0%)
80.9 3.4 0.68
80.8 3.5 0.68
79.5 3.3 0.68
82.1 3.7 0.69
Pooled SEM
0.46 0.1 0.003
P-value LPR
Fat
LPR × Fat
0.90 0.42 0.46
Animal Science Journal (2014) 85, 427–434
doi: 10.1111/asj.12150
ORIGINAL ARTICLE Effects of dietary lysine/protein ratio and fat levels on growth performance and meat quality of finishing pigs Keisuke MAEDA,1 Fumika YAMAMOTO,2 Masanari TOYOSHI1 and Masakazu IRIE2 1
Livestock Experiment Station of Wakayama Prefecture, Susami, and 2Faculty of Agriculture, University of Miyazaki, Miyazaki, Japan
ABSTRACT This study aimed to evaluate the effects of dietary lysine/protein ratio and fat levels on the growth, carcass characteristics and meat quality of finishing pigs fed feed made from food waste, including noodles and chocolate. Four dietary treatments, 2 levels of lysine/protein ratio (0.035 and 0.046) and 2 levels of fat (3.3% and 6.0%), were adapted to a 2 × 2 factorial arrangement. Each diet for the finishing pigs contained the same levels of adequate crude protein (16%) and lysine (0.58–0.75%), and similar levels of high total digestible nutrients (90.2–92.6%). In total, 32 LWD pigs with an average body weight of 57.2 kg were assigned to 4 dietary groups. The pigs were slaughtered at about 115 kg. Growth performance was not influenced by the dietary treatments. Carcass characteristics were slightly influenced by the dietary fat level. As the dietary lysine/protein ratio decreased, the marbling score of Longissimus dorsi muscle increased and the intramuscular fat (IMF) increased from 6.82% to 9.46%. Marbling score was not significantly influenced by the dietary fat level. These results indicate that IMF increased without adverse effects on growth, carcass characteristics and meat quality, when pigs were fed a diet with low lysine/protein ratio.
Key words: intramuscular fat, lysine protein ratio, marbling, meat quality, pig.
INTRODUCTION In recent years, pig farming in Japan has been declining, owing to the high cost of grain feeds (Oh & Whitley 2011). Increased profitability in the sale of pork through improvements in quality, and the reduction in production costs are important for pig farmers. To improve pork quality, intramuscular fat (IMF) has attracted attention as an important factor for consumer acceptance. ‘Eco-feed’, which is made from food by-products and surplus food, was expected to markedly reduce pork production costs in Japan (Sugiura et al. 2009; Takahashi et al. 2012). An increase in the IMF content of the Longissimus dorsi muscle (LM) improves meat tenderness (DeVol et al. 1988; Hodgson et al. 1991) and palatability of consumers purchasing pork loin (Font-i-Furnols et al. 2012). Production of high-quality pork with rich IMF is possible through selective breeding and nutritional control (Ellis & McKeith 1999; Katsumata 2011). Various dietary control methods to increase the IMF content of pork have been previously reported, including low protein diet, low lysine diet, leucine supplementation, feeding of breadcrumbs, dietary conjugated linoleic acid and lysine imbalance diet © 2013 Japanese Society of Animal Science
(Unruh et al. 1996; Ellis & McKeith 1999; Ellis et al. 1999; Iwamoto et al. 2005; Ieiri et al. 2007; Katsumata 2011; Takahashi et al. 2012, 2013a,b). Lysine or protein deficient diets for increasing the IMF content are easy to implement; however, they have critical disadvantages with respect to feed conversion, weight gain and carcass lean contents (Kerr et al. 1995; Ellis & McKeith 1999; Ellis et al. 1999; Berg 2001; Katsumata et al. 2005; Katsumata 2011; Rodriguez-Sánchez et al. 2011). We have described the successful production of highly marbled pork by using dietary ‘Eco-feed,’ without adverse effects on growth and carcass characteristics. In this study, dietary control of lysine/protein ratio was more practical than using protein or lysine deficient diets in order to increase the IMF content, without any adverse effects on growth performance (Takahashi et al. 2012, 2013a,b). In addition, dietary
Correspondence: Masakazu Irie, Faculty of Agriculture, University of Miyazaki, Miyazaki 889-2192, Japan. (Email: irie @cc.miyazaki-u.ac.jp) Received 22 April 2013; accepted for publication 1 September 2013.
428 K. MAEDA et al.
fat level affected the IMF content and growth of finishing pigs (Takahashi et al. 2013b). However, detailed control methods and the mechanism of increasing the IMF content by using dietary control have not been fully elucidated. In particular, it is necessary to determine whether the effect of dietary fat supplementation on IMF is because of the fat itself or because of the increase in dietary energy. Boiled Chinese noodles that have passed their freshness date were discarded from a supermarket. Boiled Chinese noodles have less crude fat content than instant foods such as deep-fried noodles (MEXT 2010a,b); further, they are useful as feed for finishing pigs because of low lysine/protein ratio and fat level. In general, feeding a high-fat diet to pigs results in soft pork (Irie & Ohmoto 1985; Irie 1986, 1989; Pettigrew & Esnaola 2001). Chocolate has high crude fat and is discarded by manufacturers when it is not in the standard form. Further, chocolate is useful as a feedstuff owing to its high saturated fatty acid content (MEXT 2010a). However, chocolate contains theobromine which has toxicity for some animals via cocoa bean shell, cocoa bean meal and cocoa germs (EFSA 2008), although no adverse effect was observed when finishing pigs were fed a diet containing 12.2% chocolate (Ashihara et al. 2011). The objective of this study was to increase the IMF content of the LM without an adverse effect on the growth performance in finishing pigs, using boiled Chinese noodles and chocolate as an eco-feed. In addition, this study was designed to evaluate the effect of dietary lysine/protein ratio and fat level on the growth, carcass characteristics and meat quality of finishing pigs that were fed with an eco-feed with high total digestible nutrients (TDN), sufficient crude protein and adequate lysine levels.
MATERIALS AND METHODS Management of the experimental animals and design of dietary treatment A total of 32 Landrace × Large White × Duroc (LWD) pigs were reared at the same commercial farm in Wakayama Prefecture and the same genetic line and were assigned to 4 groups (4 barrows and 4 gilts/group); they had an average initial body weight of 57.2 ± 4.1 kg (mean ± SD). The groups had similar total body weights and were randomly allotted to dietary treatments in a 2 × 2 factorial arrangement. The dietary treatments included 2 levels of lysine/protein ratio (low: 0.035, L-LPR and medium: 0.046, M-LPR) and 2 levels of fat (medium: 3.3%, M-Fat and high: 6.0%, H-Fat). The examined feed, eco-feed, containing boiled Chinese noodles and chocolate, was supplemented with grains (Table 1). Feed compositions of the experimental diet were calculated by using computer software (NIGLS 2009) such that they contained similar, and slightly high TDN (90.2–92.6%) and sufficient protein (16%) and adequate lysine levels for © 2013 Japanese Society of Animal Science
the nutrient requirement content of Japanese Feeding Standardized for Swine (NARO 2005). Nutrient composition data of boiled Chinese noodles was used from the Standard Tables of Food Composition Japan (MEXT 2010a,b), and lysine content, 0.128%, was used from analyzed data as wet basis. Sufficiency rates (content/requirement percentage) against feed standard percentages (100%) of lysine on the L-LPR and M-LPR were 103% and 133%, respectively. Sufficiency rate of TDN was 120–123%. The formulated feeds were put in plastic bags and sealed in flexible containers until use. The eight pigs in each group were reared in 3 × 6 m pigpens, and four pens were used to this experiment. The pigs were cared for according to the JBR (1987) and Standards of Rearing Hygiene Management on Livestock Experiment Station of Wakayama Prefecture. All pigs had free access to feed and water. Adequate feed was given the pigs twice a day, and the leftover feed was weighted next morning, every day. As a rough indication, the total feed intake/pen was calculated to subtract the supply feed from leftovers during the fattening periods, and were indicated on dry matter basis. The pigs were weighted 7 times at 6–15-day intervals until they weighed approximately 115 kg. The average daily gain was calculated by using the initial and final weights. The gain/ feed ratio was calculated by the total feed intake/pen and total weight gain/pen. The fattening periods were measured as number of days between the day the experiment started and the day on which the pigs were taken from the pen for slaughtering. The pigs were slaughtered at a commercial abattoir in Osaka city. After the carcasses were chilled for approximately 2 days at 1°C, the loin with the subcutaneous back fat was excised 20 cm from the 5–6th ribs to the caudal area at the right side of the carcass. The loins were vacuum-packed in plastic bags and refrigerated at −20°C in order to analyze the physical and chemical characteristics later.
Carcass and meat appearance The carcass weight, backfat thickness, and dressing rate were measured. Backfat thickness was measured at the thinnest section between the 9th and 13th ribs. The characteristics of meat appearance, such as meat color, marbling score, seam fat score of LM, Minolta L*a*b* values of LM and fat were measured. Meat color was measured by using the Japanese pork color standards based on a 6-point scale for meat (1 = extremely pale pink, 6 = extremely dark red). Marbling (indicating IMF contents of LM), seam fat (1 = little fat, 5 = much fat), and firmness/wetness (1 = very soft and watery exudative, 5 = very firm and dry) were assessed according to the National Pork Producers Council (NPPC) Standards.
Physiochemical analysis of the loin The LM was minced, and the moisture, IMF content, crude protein level, and ash were measured by using a dried oven (135°C for 2 h), ether extraction, the Kjeldahl method and muffle heating (600°C for 3 h), respectively. Water holding capacity of the LM was measured by the beads method using a high-speed cooling centrifuge (Irie 2002). The melting point of the inner layer of back fat on the LM was measured using a capillary tube. Lipids from the LM and backfat were extracted with chloroform and methanol Animal Science Journal (2014) 85, 427–434
DIETARY LYSINE PROTEIN RATIO & FAT ON SWINE 429
Table 1
Composition of finisher diets
Lysine / Protein Ratio Level
Crude fat level Ingredient, % Boiled Chinese noodles† Wheat bran Soybean meal Alfalfa meal (Sun cure) Corn gluten meal (60% crude protein) Lysine hydrochloride Chocolate‡ Sugar Tricalcium phosphate Calcium carbonate Vitamin mineral premix§ Calculated values¶ Digestible energy (Mcal/kg) Total digestible nutrient (%) Crude protein (%) Crude fat (%) Crude fiber (%) Ca (%) P (%) Lysine (%) Lysine / protein ratio (LPR) Analyzed values Fatty acids, % Saturated fatty acids Monounsaturated fatty acids Polyunsaturated fatty acids
Low lysine / protein ratio
Medium lysine / protein ratio
(0.035)
(0.046)
Medium fat (3.3%)
High fat (6.0%)
Medium fat (3.3%)
High fat (6.0%)
83.15 7.07 3.12 1.04 0.51
83.28 7.29 3.27 1.04
83.32 7.39 3.02 1.04
1.46 2.91 0.44 0.21 0.10
4.37 0.44 0.21 0.10
83.26 7.28 2.51 1.04 0.68 0.11 1.46 2.91 0.44 0.21 0.10
3.95 90.2 16.2 3.3 2.5 0.9 1.0 0.58 0.035
4.08 92.5 16.2 6.0 2.5 0.9 1.0 0.58 0.035
3.95 90.2 16.1 3.3 2.4 0.9 1.0 0.75 0.046
4.08 92.6 16.2 6.0 2.5 0.9 1.0 0.75 0.046
41.7 37.0 21.3
45.8 35.7 18.5
39.4 36.6 24.0
45.4 38.0 16.6
0.10 4.37 0.44 0.21 0.10
†Wet form, boiled. Dry matter = 35.0%. ‡Black and white chocolate were mixed. §Vitamin mineral premix: provided per kilogram diet; 2 500 000 IU vitamin A, 3 500 000 IU vitamin D, 500 mg α-tocoferol, 100 mg thiamin nitrate, 600 mg riboflavin, 50 mg pyridoxine hydrochloride, 1 mg cyanocobalamin, 120 mg nicotinic acid amide, 200 mg menadione, 500 mg D-(+)-pantothenic acid calcium salt, 10 g choline chloride,100 mg folacin, 602 mg MnCO3, 2170 ZnCO3, 4,200 mg FeSO4, 2,700 mg CuSO4, 250 mg CoSO4, 6 mg calcium iodate, 2 mg d-biotin, 10 g lysine hydrochloride. ¶Calculated by Ecofeed_ver2.xls in NARO Institute of Livestock and Grassland Science (NILGS). Nutrient content of boiled Chinese noodles was Standard Tables of Food Composition Japan (MEXT). Lysine content of boiled Chinese noodles was 0.128% as wet basis.
solution and assessed for fatty acid composition. After methyl esterification with boron trifluoride methanol, fatty acid composition was determined by using a gas chromatograph (Shimazu Co. Kyoto, Japan) equipped with a capillary column (DW-WAX122-7062, 0.25 mm × 60 m). The temperatures of the column and detecting device were 160°C and 270°C, respectively. Eight fatty acids (14:0, 14:1, 16:0, 16:1, 18:0, 18:1, 18:2 and 18:3) were identified from the relative retention time of each standard material, and the total of these eight ingredients was expressed as 100%.
Statistical analysis A two-way analysis of variance (ANOVA) was performed to determine the effects of dietary lysine/protein ratio, fat levels, and their interaction on performance and meat quality using the GLM procedure. Differences among the means were compared by using Tukey’s multiple comparison tests. Pearson’s correlation coefficient analysis was used to assess the associations among IMF content, marbling score and physiochemical analysis data of the 32 pigs. Animal Science Journal (2014) 85, 427–434
RESULTS AND DISCUSSION Effects on production performance Effects of dietary lysine/protein ratio and fat levels on production performance are shown in Table 2. The average values of daily weight gain and fattening period were approximately 1 kg and 62 days, respectively. These values were similar among all the groups. The main effects of dietary lysine/protein ratio and fat level, as well as the interaction between them, on performance were not significant. The total feed intake/pen and gain/feed ratio were not measured correctly but the following data will serve as references. The total feed intake/pen in M-Fat + L-LPR, M-Fat + M-LPR, H-Fat + L-LPR, and H-Fat + M-LPR groups was 1247.9 kg, 1273.9 kg, 1301.7 kg and 1225.7 kg, respectively. The gain/feed ratio of M-Fat + L-LPR, M-Fat + M-LPR, H-Fat + L-LPR, and H-Fat + M-LPR groups was 0.39, 0.38, 0.38 and 0.41, respectively. © 2013 Japanese Society of Animal Science
430 K. MAEDA et al.
Table 2 Effects of lysine/protein ratio and fat levels on growth for finishing pigs
Lysine / protein ratio (LPR)
Initial body weight (kg) Final live weight (kg) Daily gain (kg/day) Fatting period (days)
Fat level
Low
Medium
Medium
High
(0.035)
(0.046)
(3.3%)
(6.0%)
57.7 119.2 0.99 62.4
56.7 118.3 1.01 62.0
57.2 117.8 0.99 61.9
57.2 119.7 1.01 62.5
Pooled SEM
P-value
0.72 0.77 0.02 1.12
LPR
Fat
LPR × fat
0.54 0.56 0.71 0.87
0.97 0.23 0.68 0.79
0.68 0.78 0.56 0.49
n = 16 (barrows = 8, gilts = 8). Low LPR + medium fat (n = 8), low-LPR + high fat (n = 8), medium LPR + medium fat (n = 8), medium LPR + high fat (n = 8).
Table 3 Effects of lysine/protein ratio and fat levels on carcass caracteristics
Lysine / protein ratio (LPR)
Carcass weight (kg) Backfat thickness (mm) Dressing ratio
Fat level
Low
Medium
Medium
High
(0.035)
(0.046)
(3.3%)
(6.0%)
80.9 3.4 0.68
80.8 3.5 0.68
79.5 3.3 0.68
82.1 3.7 0.69
Pooled SEM
0.46 0.1 0.003
P-value LPR
Fat
LPR × Fat
0.90 0.42 0.46
