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Influence of Isobutyric Acid Supplementation on Nutrient Intake, Its Utilization, Blood Metabolites and Growth Performance of Cr

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Influence of Isobutyric Acid Supplementation on Nutrient Intake, Its Utilization, Blood Metabolites and Growth Performance of Cr 200 Influence of Isobutyric Acid Supplementation on Nutrient Intake, Its Utilization, Blood Metabolites and Growth Performance of Crossbred Calves Fed Wheat Straw Based Low Protein Diets A. K. Misra* and S. S. Thakur Dairy Cattle Nutrition Division, National Dairy Research Institute, Kamal 132001, India ABSTRACT : The effects of dietary supplementation with the sodium salt of isobutyric acid in a low protein (10% CP) wheat straw based diet on nutrient utilization, blood metabolites and growth performance were studied with male crossbred calves. The calves were divided into two equal groups of 6 each. The animals of the control group were fed a basal diet consisting of wheat straw, concentrate mixture and green oat fodder in 40:40:20 proportion whereas BCFA supplemented group received the basal diet+isobutyric acid at 0.75 percent of basal diet. The duration of study was 120 days. The feed intake between experimental groups did not differ significantly and the average total DMI (% BW) was 1.99 and 1.95 kg day'1 in control and BCFA supplemented diets. The dietary supplementation of BCFA improved (p<0.01) the DM, OM, CP (p<0.05), NDF and cellulose digestibilities by 8.50, 9.01, 5.39, 17.78 and 18.44 per cent over those fed control diet. The total N retention on BCFA supplementation was improved (p<0.01) due to the decreased (p<0.05) faecal N excretion. The BCFA supplementation did not alter the blood circulatory levels of glucose, total protein, albumin, urea N and amino acids. However after 120 days of experimental feeding a significant (p<0.05) increase in the concentrations of non-esterified fatty acid was observed in control group. The DCP intake and the DCP content of experimental diets was similar in both groups. However, the TDN content of BCFA supplemented diet was significantly (p<0.01) higher (64.35%) than that of control (59.60%). The total live weight gain in BCFA supplemented diet increased by 15.94% over control. The average daily gain and efficiency of feed conversion were also improved in BCFA fed calves by 13.38 and 26.71% respectively, compared to control. It is concluded that dietary supplementation with isobutyric acid improved the digestibility of nutrients and growth performance of calves. (Asian-Aust. J. Anim. Sci. 2001. VoL 14, No. 2 : 200-205) Key Words : Branched Chain Volatile Fatty Acid, Sodium Salt, Isobutyric Acid, Nutrient Utilization, Growth, Cattle INTRODUCTION solely based on crop residues with meager amounts of energy and protein supplements. Studies have shown The branched chain volatile fatty acids (BCFA) that such feeding regimens lead to ruminal BCFA isobutyric (IB), 2-methyl butyric (2-MB) and isovaleric deficiency and their concentrations may reach even (IV) are considered as essential nutrients for many below the detectable limits (Judkins et al., 1987; Krysl predominant rumen cellulolytic bacteria (Bryant, 1973) et al., 1989). The present experiment was conducted to and any of these can be used to meet their determine the effect of dietary supplementation of the requirements (Gorosito et al.s 1985). Inclusion of a sodium salt of isobutyric acid in a low protein wheat mixture of BCFA in the diet resulted in improved straw (WS) based diet on nutrient utilization and microbial growth in vitro (Russel and Sniffen, 1984), growth performance in crossbred calves. cellulose digestion (Gorosito et al., 1985), nitrogen utilization (Oltjen et al., 1971; Umunna et al., 1975), MATERIALS AND METHODS milk production (Papas et al., 1984; Peirce-Sandner et al., 1985) and feedlot performance of steers (Deetz et Animals and diets al., 1985). Under normal feeding conditions, Twelve healthy crossbred male calves (age 7 to 13 particularly if the diet is sufficient in protein, the months) were randomly divided into two groups on deficiency of BCFA is unlikely to occur and de novo the basis of body weight (BW) and housed in synthesis of BCFA would meet microbial requirements. individual pens. The animals were vaccinated against However, in spite of de novo synthesis, a BCFA common contagious diseases and routinely treated for deficiency is possible in ruminants fed low protein ecto- and endo-parasitic infestations. Animals were fed diets and such a deficiency would not be corrected by ad libitum a basal diet consisting of WS, concentrate non-protein nitrogen or urea supplementation (Umunna mixture (maize grain, 65; ground nut cake, 26; wheat et al., 1975). In India, animal production systems are bran, 6; mineral mixture, 2; common salt, 1) and green oat fodder in a 40:40:20 (DM basis) proportion * Corresponding Author: A. K. Misra. Division of Animal Nutrition, Central Sheep and Wool Research Institute, (control) and basal diet+IB at 0.75 percent of basal Avikanagar 304501, India. Tel: +91-1437-28143, Fax: +91- diet (BCFA). The WS and concentrate mixture (CM) 1437-28163, E-mail: [email protected],nic.in. were offered at 09:00, while the oat fodder was Received August 2, 2000; Accepted September 28, 2000 offered at 14:00. The sodium salt of IB (1.88 kg pure DIETARY SUPPLEMENTATION OF ISOBUTYRIC ACID IN CALVES 201 isobutyric acid, w/w 100 kg1 DM of CM-II) was analysis of variance procedure of SPSS Base 10.0 added at 0.75 per cent of total diet (on DM basis) in (SPSS software products, Marketing department, SPSS the form of aqueous solution in CM-II. All the diets Inc., Chicago, IL 60606-6307, USA): were iso-nitrogenous at 10% CP. Animals were offered Yijk=(//+Ti+Pj+(TP)jj+ejjk clean drinking water twice a day at 10:00 and 14:00. Where, General mean, Ti=Effect of ith treatment, Pj=Effect of j，period, (TP)jj=Interaction effect of ilh Experimental procedure treatment with jlh period, eijk=Random error. Metabolism trial RESULTS After a 60 day preliminary period during which the assigned diets were fed, a 7 day metabolism trial Chemical composition of dietary components was carried out in individual metabolism stalls with The chemical composition of the dietary facility for quantitative collection of feces and urine. components used is presented in table 1. The chemical Samples of feed offered, residue left and feces and urine voided were collected daily and representative samples were collected for further analysis. Pooled Table 1. Chemical composition (g kg'1 DM) of samples were dried at 60 °C and ground for chemical wheat straw (WS), oat fodder and concentrate analysis. Separate sets of samples of feces and urine mixtures (CM) used in metabolic trial from the daily collections were preserved in dilute Particulars WS Oat CM4 CM-II sulfuric (40% v/v) acid for nitrogen (N) estimation. DM 89.48 14.87 91.93 91.66 The BW of animals was recorded on two consecutive OM 88.40 89.05 89.70 89.30 days at 15 d intervals as well as before and after the CP 3.940 7.66 18.10 18.06 metabolism trial. NDF 79.00 61.00 23.00 23.00 ADF 48.00 32.00 7.00 6.50 Chemical analysis of feeds, feces and urine Hemicellulose1 31.00 29.00 16.00 16.50 The DM, N, and ash contents were determined Cellulose2 39.00 29.00 6.00 5.50 according to AOAC (1984), while the neutral detergent Acid detergent lignin 9.00 3.00 1.00 1.00 fiber (NDF), acid detergent fiber (ADF) and acid detergent lignin (ADL) were determined according to NDF-ADF; 2 ADF-ADL. the methods described by Goering and Van Soest (1970). The NDF in CM was estimated by the method of Robertson and Van Soest (1977) using amylase Table 2. Intake and digestibility of experimental enzyme (Sigma chemicals, USA). diets used in metabolic trial Attributes Control BCFA Blood metabolites DMI Blood samples were collected by jugular vein Total 3.02 ±0.20 2.96 ±0.32 puncture in the morning hours before the meal, at Body weight (%) 1.99±0.16 1.95±0.18 initiation and at the end of the 120 days feeding g kg'1 W0'75 70.23 ±5.25 68.35 土 6.38 period. Glucose was determined in whole blood Proportion of dietary components (%) (Somogyi, 1945), while urea-nitrogen (Varley et al., 1980), total protein, albumin (Oser, 1971) and Wheat straw 44.57±2.10 43.34±0.90 non-esterified fatty acids (Shipe et al., 1980) were Concentrate mixture 40.53 ±0.95 41.40±0.85 determined in blood plasma. Blood plasma samples Oat 14.90±1.12 15.26±0.75 were also analyzed for their amino acid content on an DCP intake (g day1) 217.90±6.55 226.94 ±2.49 HPLC system (Waters, Model 510) according to the DCP of ration (%) 7.19±0.13 7.51±0.30 Waters PICO-TAG amino acid analysis method TDN intake (kg day1) 1.80±0.11 1.90±0.20 (Waters Chromatography division, Millipore TDN of ration (%)** 59.60 ±0.49 64.35 ±0.45 corporation, Milford, USA). Nutrient digestibility (%) Dry matter** 60.25 ±0.41 65.43 ±0.46 Statistical analysis Organic matter** 62.99 ±0,55 68.71 ±0.49 Means for intake and digestibility were compared Crude protein* 70.63 ±1.30 74.44 ±0,70 by using t test as described by Snedecor and Neutral detergent fiber** 44.15 ±1.45 52.00 士 0.68 Cochran (1989). Blood biochemical variables were Acid detergent fiber** 39.44 ±1.16 48.78 士 0.58 analyzed for treatment and sampling time as main Hemicellulose** 49.20 土 2.16 56.26±1.26 effects and treatment by sampling time interaction Cellulose** 55.41+0.89 65,63 ±0.94 using the following mathematical model in a two way * p<0.05; ** p<0.01.
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