MILK PRODUCTION AND QUALITY OF BALI COWS (Bibos banteng) GIVEN CONCENTRATE SUPPLEMENTATION OF GRASS-LEGUNIE BASED DIET AT EARLY LACTATION

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1 MILK PRODUCTION AND QUALITY OF BALI COWS (Bibos banteng) GIVEN CONCENTRATE SUPPLEMENTATION OF GRASS-LEGUNIE BASED DIET AT EARLY LACTATION I.A.M. Sukarini, S. Putra, I G. Mahardika, K. Suriasih, and M. Hartawan Faculty of Animal Husbandry, Udayana University, Denpasar-Bali, Indonesia ABSTRACT A study on milk. production and quality of Bali cows given improved diets was conducted by using 12 first lactating Bali cows (BW ± kg) during a period of 8 weeks starting immediately post calving. The experiment consisted of 4 dietary groups (Rl, R2, R3, and R4) and 3 blocks as replicates, where each replicate was represented by a single cow. Diet R1 consisting of 70% Pennisetum purpureum (PP) plus 30% Gliricidia septum leaves (GS), R2 was 30% PP plus 55% GS and supplemented with 13% Hibiscus tilliacius leaves (HT, defaunating effect), R3 was 75% R2 plus 25% concentrate, and R4 was R3 supplemented with 0.006% Zinc-diacetate. The cows were hand milked twice daily following injection of oxytocin (0.1 TU). Daily milk yields were measured and aliquots of milk were taken for analysis. A balance trial of 7 days was conducted during the 3 rd and 4 th week of lactation. Results indicated that quality of ration improved rumen total VFA concentration, increments being 52 to 65% for R2, R3 and R4 above Rl, with increments of acetate 31 to 48% while pmpionate was being doubled. Ammonia concentrations increased 5.24 to 7.07 mm, meeting the requirement for minimal microbial growth. Feed quality did not affect DM and ME intakes, but improved fat, CP, and GE intake significantly. Milk yield was increased with mean values reaching 2.23 kg/d (R4) versus 1.ll kg/d (R1). Milk fat, protein, and lactose of Bali cows in all diets groups have average values of 7.60%, 4.95%, and 4.99%, respectively. It can be concluded that milk production of first lactating Bali cows may exceed requirement of the calf when fed rations with adequate CP and energy plus micronutrients. Keywords: Bali cattle, concentrate, VFA, milk yield, fat, and protein INTRODUCTION Bali cattle are the domesticated wild banteng, (Bibos banteng) of the humid tropics - a breed that has truly native origins in lndonesia and has remained purebred on the island of Bali. Compared to other breeds of cattle, Bali cattle are considered to have superior traits, including good fertility, can survive on poor quality of forage, have

2 lean meat, resistant. to external and internal parasites. And relatively easy to handle. They are reported to be preferred by small holders as draught breed animal. Another remarkable feature of this cattle is the abil-it-ye to thrive under hot, and disease ridden conditions where other breeds of cattle oflen grow poorly (International Ltd, 1986). Beside of such superior traits, Bali cattle, however, has been reported as a late maturing animal; cow reaching a size averaging 250 kg body weight (BW) and rarely produce a calf before 4 years of age, which may be due to poor feeding early in life. At birth the male weight l6-i7 kg and female calves I4-I5 kg. Calves are not weaned at any specific time and dams may continuously nurse a calf until the next birth. Bali cows are poor milk producers with almost invisible udders and lactation varies from 6 to l0 months producing 0.9~2.8 kg milk/day. This condition causes, slower growth and even great mortality of calves ranging 20-45% during the preweaning period, especially for calves born during the dry season under extensive management (Soehadji, 1991; Wirdahayati, 1998). Liwa (1992) found that growth rate of calves up to l20 days of age were greatly influenced by milk production and that in turn depends on the nutritional status of the dam. Productivity of Bali cows were low due to the poor feeding management practices at the village level which just consisted of mostly grasses and some legumes. The nutritive value or tropical forages, however, tend to be low which may results in adequate nutrient supply to meet the physiological requirement of the dam to reach their maximum production. During, the lactation period, especially the dam needs abundance of nutrient supply to meet the requirement of the high metabolic rate of the mammary gland for milk synthesis (Collier, 1985) There is little information on the biology of Bali cattle. Among the factors afiecting the productivity of Bali cattle, the most propitious methods for itnprovenaent are feeding and nutrition. The present paper reports results of study to examine the response of lactating Bali cows in producing milk and its quality after given improved diets based on mixture of grass and legume, with or without concentrate supplementation. The grass~legume attempted to provide adequate energy and ammonia for rumen microbial growth; defaunation was secured by adding hibiscus leaves. Concentrate- Zink diacetate supplementation was provided to ensure supply of glucose as source of milk lactose and Zn to activate nnnen microbial fermentation and the growth of the secretory cells and finally to ensure nutrient utilization for milk synthesis of the mammary gland. MATERIAL AN-D METHODS This experiment used 12 immediately after calving first lactating Bali cows (initial BW ± kg), obtained from heard reared by farmers, for 8 weeks lactation period. A complete randomized group design was adopted with 4 ration treatments and 3 blocks as replicates where each replicate was represented by a

3 single cow. The rations Rl, R2, R3, and R4 compared of locally available feedstuff were offered. Rl consisted of 70% elephant grass (Pennicetum purpureum, PP) plus 30% Gliricidia sepium leaves (GS); R2 was 30% PP plus 55% GS plus 15% Hibiscus tilliacius leaves (HT); R3 was 75% R2 plus 25% concentrate; and R4 was R3 supplemented with 0,006% Zinc-diacetatei The cows, were accustomed to the diet from 2 months before calving and water was given ad-libitum. The calf was allowed to feed on colostrums during the first week and subsequently, starting from the second week the cows were hand milked twice daily following injection of oxytocin (1.0 IU), daily yield were recorded. Through out the experiment, body weight (BW) was monitored bi-weekly. In the 3 rd to 4 th week of the experiment, the animals were placed for 7 days in individual pens for balance trials. Excreta and refused feed were wholly collected before morning feeding, weight recorded, and sampled daily for composite proximate analysis. Daily sample of 500 g forage and 200 g concentrate were used and 5% of feces sample were collected for analysis and urine samples for N determination. Aliquots of daily milk were composite for milk analysis. Energy contents of feed and feces were determined by bomb calorimeter, energy loss via ruminal methane was estimated to be 7.75% of gross energy (GE) intake (Waiman et al., 1989). Milk protein, fat, lactose, milk dry matter GJM), Ca, and P were estimated according to common laboratory procedures (AOAC, 1970). At the end of the balance trials, 3 hours post-morning feeding, rumen fluid from each cow was taken by way of a stomach tube for measuring rurninal characteristics. Ruminal NH3 concentration was determined by the diifusion method of Conway. Individual VFAs in rumen fluid were measured by Gas Chromatography and total VFA was found by summation of acetate, propionate and butyrate. Non glycogenic ratio (NGR) was calculated by summation of acetate and butyrate divided by propionate proportion. The significance of difference between means was compared using Duncan s Multiple Range Test after ANOVA for one way classified data (Steel and Torrie, 1980). RESULT AND DISCUSSION Te present experiment embraced the grass- legume mixture as basal diet (R1) and successive improvement were made with other diets R2, R3, and R4 by defaunation, supplementation with concentrate and addition of Zinc diacetate, respectively. The defaunation effect of hibiscus leaves were attributed to its saphonine content which would accomplish as component of many metaloloenzyme: carbonic anhydrace, carboxy peptidase (Church and Pond, 1982) aand synthesis of nucleic acids (RNA and DNA polymerase) and synthesis of protein (Liberman and Bruning, 1990).

4 The result on nutrient intake and ruminal metabolite were presented in Table 1. In general, all data supported the expectation of better response by the improved diets. Although the difference among treatment groups were found for DM intake ranging from 86.5 to 97.4 g/w 0.75 /d, protein, fat (P<0.01) and energy (P<0.05) intake were improved. These result were attributed to the differet nutritional compositions of the diets and may indicate better palatability of improved diets. R1 being the lowest in CP and energy contents, while R2 had the highest CP content. Diets R3 and R4 were supplemented with concentrate, which contained residual corn oil, rice brand and pressed cake from oil-rich feeds causing realtively higher fat contents. The favorable response on intakes with the improved diets was supported by rumen metabolites data, reflecting improved feed acceptance. The data on ruminal ammonia (NH3) concentration were within the range reported in the literature. Table 1 shows that with the R1 diet, NH3 level of 2.63 nm was reached which is equal to 3.68 mg NH3-N/100 ml rumen fluid. Satter and Roffler (1981) stated that the crirical concentration of NH3-N for maintaining maximum rumen microbial growth is about 2 mg NH3-N/100 ml rumen fluid and a normal fluctuation between 3 and 8 mg NH3-N due to feeding regime would support normal microbial growth. The actual levels of ammonia required for growth and activity of rumen microbial depend on a wide variety of factors including diet and feeding regime. With diets R2, R3, and R4, NH3. Concentration increased to 5.24 to 7.07 mm or 7.34 to 9.90 mg NH3~N/100 ml rumen fluid, which met the requirement for maximum microbial growth. Putra (1999) reported that for late pregnant Bali cows fed the same type of diets as in the present study, ruminal NH3 values ranging from 2.54 (grass-legume diets) to M (concentrate supplemented diet). The increment of NI-I3 concentration on improved diets was due to the present of gliricidia leaves and urea which a source of degradable protein or as feed with high ammoniogenesis rates. Table l Nutrient intakes and ruminal metabolites of first lactating Bali cows at early lactation Parameters R1 R2 R3 R4 Statistical test Nutrient Intakes DM (g/day.w ) ns Fat (g/day.w ) 2.05 a 2.92 b 5.16 c 5.17 c ** GE (g/day.w ) c b b * ME (g/day.w ) Ns

5 CP (g/day.w ) a b b b ** Ruminal Fermentation (mm) NH b 7.07 c 6.27 c ** Total VFA a b b b ** Acetate a b b b * Propionate 9.38 a b b b ** Butyrate 4.31 a 8.01 b 8.58 b 8.53 b * No-Glycogenic (NGR) Ratio 5.52 a 4.02 b 3.46 b 3.80 b ** Value of different superscript in same row were signicant (*) and (**) highly significant different; ns = non significant. Rmninal metabolites data demonstrated that partial and total concentration of VFA were increased for R2, R3, and R4 compared to R1, indicating a favorable supply of this primary source of energy for ruminant animal. Total VFA concentration was increased by 52 to 65% for R2, R3, and R4, with acetate increments being less (31 to 48%). Moreover, propionate increments were being doubled in comparison to total VFA. l he increment of propionate was supported by the declining of the NGR values. Diet R1, gave rise to mixtures of VFA, which is typical of a forage diet, while R2, R3, and R4 with their relatively higher proportion of propionate and butyrate were typical for moderate level CP concentrate-supplemented forage diet (This phenomena were fol-lowed by declining of NGR values). The defaunating advantage of diet R2 was not demonstrated with diets R3 and R4, which may be caused by the presence of (abundance) concentrate masking the action of hibiscus leaves. The result on milk production and chemical composition are presented in Table 2, and daily milk yield measured (at weekly intervals) during the 8 weeks of lactation period. Milk yield increased with the improved diets (P < 0.01) with mean values reaching 2.23 kg/d (R4) which was twice the average yield with R1 (1.11 kg/d). The chemical composition of milk did not change significantly except for lactose (P < 0.01) which had values for R1, R2, R3, and R4 of 4.78%; 532%; 5.07%; and. 5-11%, respectively- Bali cow milk protein ranges to 5.09%; milk fat 7.37 to 7.95%; total milk DM 18.1 to 18.72%; calcium 0.2l to 0.22%; and phosphorus 0.17 to 0.18%. Milk of Bali cows containing relatively higher fat and protein compared to milk of other breed of cattle may be due to the low milk production.

6 The increments of milk yield for improved diet (R4) was due to the presence of concentrate + Zn-diacetate in which concentrate acts as a source of energy (glucose from propionate) which was the limiting nutrient for lactose synthesis and afterward lead to increase milk synthesis of the mammary gland. While the addition of Zinc (Zn) as a component of many metallo-enzyme would acts to activate the rumen metabolism such as Carbonic anhydrase and Carboxy peptidase (Church and Pond, 1982), to ensure the nutrient supply as precursor for milk synthesis of the mammary gland. Zn also acts in synthesis of nucleic acids (RNA and DNA) polymerase and protein synthesis (Lieberman and Bruning, 1990) to increase the growth of secretory cells of the mammary gland Subsequently, the increment of nutrient supply to mammary cells. followed by the increments of total and activity of secretory cells, will lead to increment of milk yield. Collier (1985) stated that milk yield very much influenced by the availability of precursors, blood» flow and activities of mammary secretory cells. The increments of milk yield of the dam would contribute to the higher growth of their calves. Table 2 Milk yield and chemical composition of first lactating Bali cows at early lactation Parameters R1 R2 R3 R4 Statistical test Milk Yield (kg/day) ** Chemical Composition (%) DM ns Fat ns GE (MJ/kg) ns Lactose 4.78 a 5.02 ab 5.07 ab 5.11 b ** Protein ns Non Fat DM ns Mineral ns Calcium ns Phosphorus ns Characteristics of milk ph ns BJ/Density ns Value of different superscript in same row were signicant (*) and (**) highly significant different; ns = non significant.

7 CONCLUSION The present study with first lactating Bali cows reveals that the lactation potential of the Bali cow of the humid tropics still allows elevation of milk production by nutritional manipulation. Milk production of Bali cows may exceed requirement of the calf when fed adequate CP and energy plus micronutrients. The milk potential has not been fully achieved the present study which could still be reached by providing more glucose precursors. REFERENCES AOAC Official Methods of Analysis. 11 th edition. Association of Official Agricultural Chemist, Washington DC. Churc, D.C. and W.G. Pond. Basic Animakl Nutrition and Feeding. 2 nd ed. John Wiley & Son. N,.Y. and. Singapore. Collier, R. J Nutritional Metabolic and Environmental. Aspect of Lactation. In Lactation (Ed. B.L. Larson). The Iowa State University Press-Ames International Embryos Ltd A strategyt and development Plan for the use of embryo transfer Technology in Indonesia. In L Embryo Ltd. UK.pp.340 Lieberman, S and Bruning The real vitamin and mineral Book. A very Publ. Group Inc. Garden Cirty Park. N.Y. Putra. S Peningkatan performance sapi Bali melalui perbaikan mutu pakan dan suplementasi seng asetat. Disertasi Doktor. Program Pascasarjana Institut Pertanian Bogor. Liwa, A.H Pengaruh umur induk terhadap produksi susu dan pertumbuhan anak sapi selama pra sapih. In. Proc. Pertemuan Pengolahan dan Komunikasi Hasil Penelitian Peternakan di Sulawesi Selatan. (Ed. A Prabowo, D. Buto, A. Tikupadang, Bakar,H., H. Winugroho dan R. Salam) Sub- Balitnak Gowa, Sulawesi Selatan. Pp Rutledge, J.J., D.W. Robinson, W>T> Ahlseckwede and J.E. Legateas Milk yield and its influence on 205-day weight of beef calves. J.Anim. Sci. 35: 563 Salter, L.D. and R.E. Roffler Influence of nitrogen and carbohydrate input rumen fermentation. In. Recent Developments in Ruminant Nutrition (ED. W. Haresign and D.J.A. Cole). Butter Worths. London- Boston- Sydney- Wellington-Durbon-Toronto. Pp

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