UTILIZATION OF LOCAL FOOD BY-PRODUCTS FOR
BEEF PRODUCTION: RESEARCH OUTCOMES FROM
JAPAN AND THAILAND
Hajime Kumagai1, Kaori Yasuda1, Takashi Sakai1, and Wanna Angthong2
1Graduate School of Agriculture, Kyoto University, Kyoto, Japan
2Khon Kaen Animal Nutrition Research and Development Center, Thailand
Experiments were conducted to investigate effects of replacements commercial concentrate with local food by-products in western Japan and northeastern Thailand. In Japan a study was conducted to determine the effects of dietary soybean curd residue (SCR) and soy sauce cake (SSC) on the growth performance, carcass traits and physiochemical and intramuscular fatty acid (FA) characteristics in Japanese Black steers. Ten steers (29.7±0.3 months old, 856.6±24.4 kg body weight) were assigned to either treatment; C, fed a conventional concentrate or T, fed the test diet including dried SCR and SSC for three months. In growth performance, dry matter (DM) intake and average daily gain, and carcass traits did not differ significantly between the treatments. Color of beef was affected by the dietary treatments and meat samples from T showed lower a* value and chroma than those in C. On FA composition, there was no significant difference between the treatments in the neutral lipids, whereas in the polar lipids, meat samples from T had higher C16:1 (P < 0.05) and tended to have higher C16:0 (P=0.05) and C18:1 (P=0.08), but lower C17:0 (P=0.098), C18:2 (P=0.06) and C20:4 (P=0.07) than those from C. The study suggested that SCR and SSC would be used as a substitute for the conventional concentrate and influence meat color and intramuscular FA composition of polar lipids.
In Thailand, Four Thai native bulls were used to determine the adequate levels of supplementary desalted mother liquor (DML) for energy and nitrogen balances and ruminal fermentation. The crude protein and sodium chloride contents of DML were 25.5% and 60.3% on a dry matter basis, respectively. A 4x4 Latin square design experiment was conducted by adding different amounts of DML to three experimental diets (T1: 1.1%, T2: 2.2%, T3: 3.4% sodium chloride concentration with supplementary DML on a dry matter (DM) basis) and comparing their effects with those of a control diet (C) containing 1.0% commercial salt on a DM basis. The animals were given the experimental diets and rice straw daily at 1.2% and 0.8% of body weight, respectively, on a DM basis. No significant differences in the apparent digestibility of nutrients were observed among the treatments. T3 achieved the lowest nitrogen retention (P<0.05), followed by C, T2 and T1. The ratios of energy retention to gross energy were higher in T1 and T3 than T2, and that in C was lowest (P<0.05). Supplementary NaCl concentration at 1% and 2% can be replaced with DML without an adverse effect on the digestibility of nutrients or on the nitrogen and energy retention.
Keywords: local food by-products, Japanese Black steers, soybean curd residue, soy sauce cake, Thai native bulls, desalted mother liquor
Increased demands from growing populations, bio-ethanol industries and climate changes have raised the world price of grains (Scott et al. 2009). The rise in grain prices has had a profound effect on the management of dairy and meat productions, especially in countries that import large quantities of feeds. The excessive importation of feeds from foreign countries may result in accumulations of nutrients that cause environmental pollution in the importing countries. In this context, several research groups have studied the use of domestically produced by-products as feeds for livestock animals in various regions. The types of by-products produced from food-processing industries vary among regions and seasons in accord with changes in human food consumption. The development of animal feeding systems using site-specific by-products from food-processing industries could improve the local nutrient cycling and lower the cost of dairy and meat production.
In Japan, tofu (also known as soybean curd) is a popular food, and soy sauce is also a popular traditional seasoning. In the processing of tofu and soy sauce, approx. 672,000 tons of soybean curd residue (SCR) and 86,000 tons of soy sauce cake (SSC) are produced annually in Japan (Kajikawa 1996). However, most of the SCR and SSC is incinerated or buried in landfill. Soybean curd residue is high in crude protein (CP) and metabolizable energy contents, and SSC is characterized by rich CP, salt and antioxidant fat-soluble vitamin contents. Soybean curd residue and soy sauce cake are not only nutritious feed resources; they also have relatively high fat content that is rich in unsaturated fatty acids (Lee et al. 2011; Hosoda et al. 2012). However, there are few scientific research data on the impact of SCR and SSC utilization on the fatty acid composition and quality of beef meat.
On the other hand, recently, large amounts of agro-industry by-products from the processing of seasonings have been generated in Thailand. Desalted mother liquor (DML) is by-product from nucleic acids related compounds [disodium inosine-5′-monophosphate (IMP) and disodium guanosine-5′-monophosphate (GMP)] for food additives produced by a seasoning company in the country. In the process of obtaining DML, culture medium containing carbohydrates from tapioca and crude sugar, ammonium as nitrogen source and various minerals is used for fermentation. The by-product, DML, contains large amount of salt and small amount of nucleic acid related compounds which might be utilized in the feeding of animals as salt and non-protein nitrogen supplements. In support of this potential use of DML, Kimura et al. (2010) performed in vitro fermentation using roughage and concentrate as substrates, and compared the resulting gas production and the digestibility of supplementary guanosine and inosine. They found that fermentation using the roughage substrate resulted in higher gas production and higher digestibility of DM when guanosine and inosine were added than when urea was added. Although DML has so far only been used as fertilizer for upgrading soil fertility, it has potential for use in animal additives.
Two research outcomes are presented in the present paper; 1) investigation on the growth performance, carcass traits and physiochemical characteristics and intramuscular fatty acid profiles of the meat from finishing Japanese Black steers fed concentrate with dried SCR and SSC, and 2) determination of an adequate level of supplementary DML utilizing the ingredients that could be fed to Thai native cattle in terms of the digestibility of nutrients, and energy and nitrogen balances.
FATTENING EXPERIMENT OF JAPANESE BLACK STEERS (EXP. 1)
Materials and methods
This experiment was conducted at the Kyoto University Livestock Farm from August to November, 2013 (for 83 days, Period 1) and from January to April, 2014 (for 91 days, Period 2). In Period 1, five Japanese Black steers (29.2 ± 0.4 months old, 804.8 ± 41.3 kg body weight [BW]), were assigned to either treatment C (2 steers), fed a conventional control diet, or T (3 steers), fed the test diet including dried SCR and SSC. In Period 2, five Japanese Black steers (29.1 ± 0.5 months old, 829.2 ± 18.4 kg BW) were assigned to either treatment C (3 steers) or T (2 steers). The steers were fed the test diets around 3 months until the finishing. In both periods, a 1-week period of adaptation to the diets was followed by the experimental period. Before the experiment, all animals were treated similarly with respect to nutrition and general management. The ingredient proportions of the test diet, shown in Table 1, were calculated to be at the same levels of CP, total digestible nutrients (TDN), calcium (Ca) and phosphorus (P) content as the control diet. The steers had individual access to the diets and rice straw was used as roughage.
The steers’ consumptions of concentrate and roughage were recorded every day, and the BWs of the steers were recorded every 4 weeks. A diet sample was taken from each treatment, and a diet refusal was sampled for DM determination after accumulating refusals for 2 weeks. The steers were transported to a slaughterhouse, and their BW at 6–15 days before slaughter were 844.8 ± 46.3 kg and 868.4 ± 21.8 kg for Period 1 and Period 2, respectively. Chilled carcass weights were recorded after 2 days of chilling, and Japan Meat Grading Association (JMGA) graders then graded the carcass. Meat samples were collected from the end of the longissimus muscle. The meat samples were vacuum-packed and stored at 4°C for 3 weeks for the analyses of the Warner-Bratzler shear force and cooking loss. The samples were stored at −20°C for further analyses.
We analyzed the data on the growth performance, carcass traits, physiochemical characteristics of the meat, and intramuscular fatty acid composition using the GLM procedure of the Statistical Analysis System (SAS 1998). The mathematical model was Yijk = μ + Ti + Pj + eijk, where μ = the overall mean, Ti = the effect of treatment, Pj = the effect of period, eijk = the residual error. Least-square means were computed and tested for differences by Tukey’s test (Kramer 1956). Significance was declared at P < 0.05.
Results and discussion
Table 2 shows the chemical and fatty acid compositions of the diets. Here, the CP and EE contents of the test diet were slightly higher than those of the control diet due to the high CP and EE contents of the SCR and SSC. In addition, SCR is rich in salt content, therefore, the presence of a large amount of SCR in a diet leads to excess salt intake. The calculated NaCl contents in the control and test diets were 1.13% and 0.99%, respectively , which are below the maximum tolerable level (9% on a DM basis; NARO 2009). Regarding the fatty acid composition, the test diet had a higher polyunsaturated fatty acids (PUFA) percentage than the control diet due to the high PUFA contents in SCR and SSC.
The intake and growth performance data are shown in Table 3. The C and T steers showed similar intakes of diets and intakes of DM, OM and CP. The average daily gain (ADG) and feed conversion did not differ significantly between the treatment groups. Several studies revealed a relationship between the ADG and DM intake when steers were fed SCR. Kim et al. (2012) reported the increases of DM intake and ADG when Hanwoo steers were fed diets including raw SCR at 30%, 25% and 15% on an fresh matter (FM) basis in the growing, early-fattening and late-fattening periods, respectively, compared to the basal diet feeding. In contrast, Takizawa et al. (2001) reported decreases of DM intake and ADG when Holstein steers were fed a diet including raw SCR at 20% and 10% on a TDN basis in the first and second halves of the fattening periods, respectively. In the present study, the DM intake and ADG did not differ significantly between the treatments.
Several studies have been conducted to evaluate the effect of feeding SCR on carcass traits, but the results are inconsistent. Yamada et al. (1993) reported a slight improvement in the carcass dressing percentage when Japanese Black steers were fed diets including SCR silage at 40% on an FM basis throughout the fattening period. Imai (2002) reported slight increases in the loin-eye area, rib thickness and beef marbling when Holstein steers were fed diets including SCR silage at 20%, 10% and 10% in the early, mid- and late-fattening periods, respectively. These inconsistent findings may be attributed to the interactions of several factors such as differences in genotype, initial conditions, nutritional regimens and various environments. In the present study, the dietary treatments did not have any effect on any measured carcass traits and produced similar values (Table 4).
Color is the main quality measurement that consumers use to gauge desirability when buying beef products. The change in meat color is considered to be associated with fat content , animal age and diet. The meat color shows redder tonalities in older cattle because the myoglobin content of the muscles increases with age. Maltin et al. (1998) reported an increase in heme pigments in meat from bulls finished on barley rather than silage-based diets, suggesting that the meat from cattle fed a barley-based diet should be redder. In the present study, the redness (a* value) and chroma in the T were less than those in the C (P < 0.05; Table 5). The numerically higher fat content (39.4% vs. 32.5%), earlier finishing age (32.2 month-old vs. 33.1 month-old) and lower proportion of barley grains in the test diet (Table 1) might have contributed to those differences.
Table 1. Ingredient proportions of the diets (% on a dry matter basis; Exp. 1)
Table 2. Chemical and fatty acid compositions of the diets (%; Exp. 1)
Intramuscular fat, often termed marbling fat, is composed mainly of NL. Several studies examined the effect of feeding SCR during the fattening period on the fatty acid composition of beef (Imai 2002; Inada et al. 2005; Takizawa et al. 2001). Inada et al. (2005) reported the increases of C18:2 and C18:3 acid proportions in fat tissue when Holstein steers were fed dried SCR for 12 months in total. Takizawa et al. (2001), on the other hand, reported that the unsaturated fatty acid composition in subcutaneous fat was not affected when Holstein steers were fed total mixed ration (TMR) including SCR silage for 8.5 months in total. Regarding the dietary fat content derived from SCR, Inada et al. (2005) replaced dietary fat at 55% or more with fat derived from SCR. Takizawa et al. (2001) replaced at 18% - 25%. In the present study, the fatty acid composition in NL was not affected by the diets, and the levels of fatty acids were similar between the treatments (Table 6). This might have resulted from the shorter feeding period (approx. 3 month) than the previous report and the content of dietary fat derived from SCR and SSC (estimated about 32% of the total fat).
Table 3. Effects of feeding the diets on the intake and growth performance of the fattening steers (Exp. 1)
Table 4. Effect of feeding the diets on carcass traits† (Exp. 1)
Table 5. Effect of feeding the diets on physiochemical characteristics (Exp. 1)
Table 6. Effect of feeding the diets on fatty acid composition in neutral lipid fraction (%; Exp. 1)
There were significant and notable differences in the PL fatty acid composition between the present control and test treatments (Table 7), although the treatment effects were not significantly apparent in the NL fatty acid composition. This was consistent with the results of Larick and Turner (1989), who reported less C18:3 but greater C18:2 percentages in the PL fraction due to the grain feeding, though there were no significant differences in the NL fraction. The present T meat samples contained less C18:2 and PUFA (P = 0.06) percentages compared to the C samples despite the higher C18:2 and C18:3 percentages in the test diet. This result was inconsistent with the report of Yang et al. (1999), who found that the amount of C18:2 in muscle lipids depends mainly on its dietary intake. The lower C18:2 percentage of the T meat samples in the present study would have resulted from the high bio-hydrogenation rates of C18:2 and C18:3. Wu and Palmquist (1991) reported that the bio-hydrogenation rates of C18:2 and C18:3 ranged from 63% to 79% and 78% to 90%, respectively, which was much higher than those of C18:1, ranging from 44% to 68%. Therefore, C18:2 and C18:3, which were present at high levels in the present study’s test diet, were considered to be completely bio-hydrogenated to C18:0 in the rumen. Ntambi (1999) reported that the lipid composition of phospholipids is regulated to maintain membrane fluidity, and that membrane-bound Δ9-desaturase is the key enzyme involved in the membrane stability. Thus, in the present study, the C16:0 and C18:0 might have been converted to C16:1 and C18:1 to maintain the membrane fluidity, which resulted in the lower PUFA and higher MUFA proportions in the T meat samples.
Table 7.Effect of feeding the the diets on fatty acid composition in phospholipid fraction (%; Exp. 1)
ENERGY AND NITROGEN BALANCES AND RUMINAL FERMENTATION EXPERIMENTS OF THAI NATIVE BULLS (Exp. 2)
Materials and methods
The experiment was conducted at the Khon Kean Animal Nutrition Research and Development Center, Khon Kean, Thailand, from July to September 2013. The DM content of DML was 25.2%, and the CP and NaCl contents were 25.5% and 50.2% on a DM basis, respectively. The DML contained 9.83% IMP and 7.94% GMP on a DM basis. The proportions of the ingredients and chemical composition of test diets in the present study are shown in Tables 8 and 9. The composition of the control (C) diet was 15.2% rice bran, 23.4% soy bean meal, 27.1% palm kernel cake, 14.7% cassava chip, 17.6% cassava pulp, 1.0% vitamin mixture and 1.0% commercial salt on a DM basis. Three alternative diets with different levels of added DML were prepared as the treatments (T1: 1.0%, T2: 2.0%, T3: 3.0% NaCl concentrations with supplementary DML on a DM basis). All the diets were formulated using the National Research Council guidelines (NRC 1996) to contain 16% CP and 68% TDN. To balance the CP and TDN levels among the diets, the rice bran, soybean meal and cassava pulp contents were decreased, and the palm kernel cake and cassava chip contents were increased as the DML contents increased.
Four castrated male Thai native cattle (226.5 ± 14.2 kg) were used in a 4 × 4 Latin square design experiment. The animals were housed individually in metabolic crates. A 14-day preliminary adjustment period was followed by a 5-day period during which all feces and urine were collected to evaluate apparent digestibility and nitrogen balance. The animals were given the experimental diets and rice straw daily at levels equal to 1.2% and 0.8% of BW, respectively, on a DM basis. Water was accessible at all times. The feed intake was calculated as the difference between the amounts of feed supplied to and rejected by each animal during the 5-day collection periods. The BW of the animals was measured before and after each collection period.
During the sample collection period, all feces and urine were obtained and weighed daily after the morning feeding. Ruminal fluid was sampled via orogastric tubing from each animal at 4 h after feeding on day 19 of each period. Respiration experiments were carried out on all animals after each treatment and period. In the sample collection period, a 5-day total feces and urine collection period was followed by a 2-day period (excluding the calibration time required for the analyzers) during which air was collected for a period of 24 h (from the 09.00 hours feeding to the next day’s 09.00 hours feeding). Expiratory gas was collected using a ventilated hood system as described by Suzuki et al. (2008). The system consisted of a head box, flow cell, oxygen analyzer, and carbon dioxide and methane analyzers.
Data on digestion, ruminal VFA, and methane emission were analyzed according to treatment using the MIXED procedure of SAS (1998). The statistical model was Yijkl = μ + Pi + Tj + Ak + eijkl, where Yijkl = the observed value, μ = the overall mean, Pi = the fixed effect with the experimental period, Tj = the fixed effect with treatment, Ak = the random effect of animal and eijkl = the residuals. Least-square means were computed and tested for differences by Tukey’s test (Kramer 1956). Significance was declared at P < 0.05.
Results and discussion
The purchased cost of rice bran, soy bean meal, palm kernel cake, cassava chip, cassava pulp, salt, and vitamin and mineral mixture were 11.0, 15.8, 4.3, 1.6, 0.01, 6.7 and 33.5 Thai Bahts (TBs/kg) on a FM basis, respectively, and DML supplemented in the present study were not for sale so far. Thus the feed costs (TBs FM/head/day) of C, T1, T2 and T3 diets were calculated as 46.6, 44.9, 38.3 and 30.3, respectively. Since the feed cost of C and T1 diets were similar, T2 and T3 diets could reduce approximately 18% and 35% of the feed cost compared to C diet.
The NaCl contents in the C, T1, T2 and T3 treatments were 1.1%, 1.2%, 2.2% and 3.4% on a DM basis, respectively. None of the treatments had adverse effects on feed intake (Table 10). No significant difference in the apparent digestibilities of DM, OM, CP, EE, NFC, NDF and ADF were observed among the treatments. Total VFA concentration in C was higher than those in T1 and T3 (P < 0.05; Table 11). This was likely due to the greatest amounts of cassava chip and cassava pulp in the C diet containing high amount of NFC highly digestible in the rumen, and to the largest amount of palm kernel cake in the T3 diet containing high amount of EE prohibiting fiber digestibility.
Previous studies stated the relationship between water intake and urine volume in cattle (Winchester and Morris 1956; Weeth and Lesperance 1965). The average amounts of water intake and urine in the present study were highest in animals fed the T3 diet (17.3 L/day and 10.7 kg/day), followed by those administered the T2 (11.0 L/day and 7.5 kg/day), C (16.7 L/day and 7.0 kg/day) and T1 (9.6 L/day and 4.7 kg/day) diets. Spek et al. (2012) reported that the increased water intake with increased dietary Na levels raised outflow of rumen microbial protein to the intestine, which in turn, led to an increase in intestinal absorption of derivatives of microbial nucleic acids, resulting in increased urinary non-urea (non-protein) nitrogen. In the present study, the urinary excretion of nitrogen was the highest in animals given the T3 diet (P < 0.05), which might have been due to an increase in water intake due to the high DML-derived salt content of this diet (Table 12). Consequently, the highest content of nucleic acid (non-protein nitrogen) related compounds in DML in T3 might have been affected directly to an increase in intestinal absorption of derivatives of microbial nucleic acids.
While no significant difference was observed in the GE and DE intakes on the basis of metabolic body size, the ME intake on the basis of metabolic body size was higher in the T1 and T3 diets compared to the C diet (P < 0.05; Table 13). This was likely due to the energy loss into methane and urine, i.e., to the lower methane emission in T3 and the lower energy excretion in urine in T1. The methane emissions from cattle on the basis of metabolic body size (g/kgBW0.75) in the present study were lowest in the animals given the T3 diet (P < 0.05; C: 1.53; T1: 1.44; T2: 1.47; T3: 1.36). This was not likely due to the amount of NaCl concentrate but rather to the EE contents in the experimental feed. Generally, high-fat feed is considered to inhibit methane production by stimulating propionate production and inhibiting the protozoa activity, in addition to inhibiting cellulolytic bacteria and feed digestion in the rumen. The EE content in the present study was highest in the T3 feed, and the molar proportions of propionic acid tended to be higher in the T1 and T3 feeds (P = 0.09; Table 11). In addition, the energy loss into urine in the present study was lowest in the animals fed the T1 diet (Table 12). The value of the combined energy loss into methane and urine was related to the lower ME intake on the basis of metabolic body size in animals fed the C diet compared to those fed the T1 or T3 diets.
Table 8. Proportions of ingredients in the diets (% on a dry matter basis; Exp. 2)
Table 9. Chemical composition and gross energy of the diets (Exp. 2)
Table 10. Nutrient intake, apparent digestibility and TDN of the diets (Exp. 2)
Table 11. Effect of feeding the diets on rumen fermentation at 4 h after feeding (Exp. 2)
Table 12. Nitrogen balances of animals fed the diets (g/day; Exp. 2)
Table 13. Energy balance of animal fed the diets (Exp. 2)
The study in Japan implies that the feeding of the test diet containing SCR and SSC for 3 months for finishing Japanese Black steers did not have negative effects on the growth performance, carcass traits or physiochemical characteristics. There were also no significant differences in the fatty acid composition in the NL fraction, however, the meat color and the fatty acid composition in the PL fraction was affected by the dietary treatments. The study in Thailand suggests that the animal feeds utilizing the ingredients such as palm kernel cake, cassava chip or cassava pulp with DML supplementation at NaCl concentration 3% might be reduced the nitrogen balance for Thai native bulls, however, that at 1% or 2% can be replaced with commercial salt without adverse effects on the digestibility of nutrients, and nitrogen and energy balances in the animals. Therefore, the by-products could be a valuable alternative ingredient due to its low cost and high nutrient content, resulting in a reduction in the feed cost.
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