Influence of varying level of sodium bicarbonate on milk yield and its composition in early lactating Nili Ravi buffaloes.
High nutrients demand of dairy animals in early lactation can usually be fulfilled by high concentrate diet (Khan et al., 2006a), which generally results in low acetate to propionate ratio (Nisa et al., 2006). This leads to decreased feed consumption because of ruminal acidosis and thus low milk yield and milk fat content. Decreased feed consumption not only reduces milk yield (Khan et al., 2006b; Touqir et al., 2007) but it also impairs reproductive performance through delayed onset of ovarian cycle (Butler and Smith, 1989; Staples et al., 1990; Butler, 2000; Reist et al., 2000). Delayed resumption of ovarian activity has been attributed to low insulin like growth factor (IGF-1; Moore et al., 2000) due to decreased dry matter intake (DMI; Staples et al., 1990). Moreover, low IGF-1 also reduces the ability of follicles to produce sufficient estradiol by stimulating granulosa cells for estradiol production and thus reduces the chances of successful ovulation.
There may be many ways and means to enhance the feed intake in early lactation. One of the most promising is supplementing of sodium bicarbonate (SB). Low cost and abundant availability of SB for the farmers of tropical region offer a potential nutritional economical tool to increase dairy animal productivity as SB increases DMI by counteracting ruminal and systemic acidosis. Sufficient scientific evidence is available regarding favourable effects of SB supplementation in dairy cows. However, limited scientific literature is available about its effects in buffalo (Bubalus bubalis). Moreover, physiological status, environmental condition and feeding strategies of buffaloes vary from that of exotic dairy cows in temperate region and SB responses of exotic dairy cow may not be of worth for direct application on buffaloes. Therefore, the present study was planned to determine the influence of varying levels of SB on nutrients intake, their digestibilities, nitrogen balance, milk yield and its composition and conception rate in early lactating Nili Ravi buffaloes during summer.
MATERIALS AND METHODS
The experiment was planned to determine the effect of varying levels of SB on nutrients (dry matter (DM), crude protein (CP), neutral detergent fiber (NDF) and acid detergent fiber (ADF)) intake, their digestibilities, nitrogen (N) balance, milk yield and its composition by early lactating Nili Ravi buffaloes. The experiment was conducted at Animal Nutrition Research Center, Institute of Animal Nutrition and Feed Technology, University of Agriculture, Faisalabad, Pakistan.
Four diets 0B, LB, MB and HB were formulated to have 0, 0.5, 1.0 and 1.5% SB supplementation, respectively. The diets were formulated to be iso-nitrogenous and iso-caloric using NRC (2001) values for energy and protein (Table 1). Twenty early lactating Nili Ravi buffaloes were randomly allocated, to four dietary treatments in a randomized complete block design. Average weight of the animal was 492[+ or -]24.5 kg. The experiment lasted for five months (June to October, 2005).
Buffaloes were housed on concrete floor in separate pens and no mechanical means were used to control the house temperature. The first month was adaptation period while last 10 days of each month was collection period. The diets were mixed daily and fed twice (0300 and 1400 h) a day at ad libitum but at 10% weigh back during collection period. The buffaloes were milked twice (0330 and 1430 h) daily.
Feed intake and milk yield were recorded daily and their representative samples were taken for analysis. Nutrient digestibility was determined by using total collection method. During four collection periods, each comprising of ten days, complete collections of urine and faeces were made according to the procedure described by Williams et al. (1984). The faeces of each animal were collected daily, weighed, mixed thoroughly and 20% of it was sampled and dried at 55[degrees]C. For urine collection, small special metal buckets fitted with plastic pipe were made to surround the vulva and plastic pipe. This plastic pipe ended in a large container (30 lit.). The urine excreted by each animal was acidified with 50% [H.sub.2][SO.sub.4] and 20% of it was sampled and preserved at -20[degrees]C (Nisa et al., 2006). In the end of each collection period, the preserved urine samples were composited by animal after thawing and 10% of the composited sample was used for analysis. During collection period, faeces were collected daily, dried at 55[degrees]C, bulked and mixed at the end of each collection period. Feed and faecal samples were analyzed for NDF by the method described by Von Soest et al. (1991). The AFD was determined by the method of Goering and Van Soest (1970). Feed samples were also analyzed for CP, Na, K, Cl, Ca, P, Mg, and S using methods described by AOAC (1990). Blood samples were collected in heprinized syringes from Juggler vein to determine the pH (AOAC, 1990). Blood serum was harvested to determine bicarbonate (HC[O.sub.3]) by the method devised by Harold (1976). Milk samples were also analyzed for protein, fat, solid not fat, total solids and lactose using the methods devised by AOAC (1990). The N balance was determined by using equations as described by NRC (2001).
The data were analyzed using Randomized complete block design. In case of any significance means were separated by Duncan's Multiple Range Test (Steel and Torrie, 1984).
Nutrients intake and digestibilities
A linear increase in dry matter and water intake was recorded with increasing the level of SB (Table 2). The maximum (16.30 kg/d) and minimum (12.60 kg/d) DMI was recorded in buffaloes fed HB and OB diets, respectively. Buffaloes fed HB diet consumed 29.37% more feed than those fed 0B diet. The DMI by buffaloes fed LB and MB diets was 13.4 and 14.60 kg/d, respectively. However, DMI in buffaloes fed MB and HB diets remained unaltered.
A constant increase in CP and NDF intake was observed with increasing the SB level of diet. Buffaloes fed HB and 0B diets consumed maximum (2.61 kg/d) and minimum (2.02 kg/d) CP, respectively. Buffaloes fed LB and MB diets had 2.41 and 2.34 kg/d CP intake, respectively. Similar trend was observed for N intake (Table 4). Increase in N balance was also noticed with increasing the SB level of diets. The NDF intake was maximum (6.15 kg/d) and minimum (5.15 kg/d) in buffaloes fed HB and 0B diets, respectively. Similar trend was noticed for ADF intake (Table 2). However, a nonsignificant increase in nutrients digestibilities was noticed with decreasing the SB level of diets.
Blood pH and serum bicarbonate
The blood pH was maximum (7.516) in buffaloes fed HB and minimum (7.351) in those fed 0B diets (Table 5). Buffaloes fed LB and MB diets had 7.371 and 7.412 blood pH, respectively. A constant increase in serum HC[O.sub.3] was noticed with increasing the SB level of diets. The maximum (26.30 mmol/L) and minimum (21.55 mmol/L) HC[O.sub.3] was recorded in buffaloes fed HB and 0B diets, respectively. Buffaloes fed LB and MB diets had 23.52 and 26.31 mmol/L HC[O.sub.3], respectively (Table 5).
A linear increase in urine pH was observed with increasing the SB level of diet (Table 5). The minimum (6.05) and maximum (8.01) urine pH was noticed in buffaloes fed 0B and HB diets, respectively. Buffaloes fed LB and MB diets had 6.52 and 7.47 urine pH, respectively.
Milk yield and composition
The maximum (15.4 kg/d) and minimum (13.52 kg/d) milk yield was recorded in buffaloes fed HB and OB diets, respectively (Table 8). Buffaloes fed LB and MB diets produced 14.02 and 14.87 kg/d milk, respectively. However, the difference in milk yield in buffaloes fed MB and HB diets was non-significant.
Protein and lactose % remained unaltered due to SB alteration. However, protein and lactose yield increased with increasing the SB level (Table 6). Milk fat % increased with increasing the SB level of diets. The maximum milk fat was 6.7% in buffaloes fed HB diet while minimum was 6.3% in those fed 0B diet, respectively. Milk fat % in buffaloes fed MB and HB diets was non-significant, however, it was significantly higher than those fed 0B and LB diets. Total milk solids were higher in buffaloes fed MB and HB diets than those fed 0B and LB diets (Table 6).
Buffaloes fed HB and MB diets had 100% conception rate. Buffaloes fed OB and LB diets had 33.3 and 66.6% conception rate, respectively (Table 7). The services per conception was minimum (1.67) in buffaloes fed HB diet while buffaloes fed 0B, LB and MB diets had 2.67, 2.33 and 2.33 services per conception, respectively (Table 7).
Nutrients intake and digestibilities
Increased DM and water intake in buffaloes fed high SB might be attributed to higher rumen pH (Tucker et al., 1991; West et al., 1987) and blood HC[O.SUB.3] (Shahzad et al., 2007a), acid base balance (Sanchez et al., 1994). Increased rumen pH in dairy cows fed SB has also been confirmed by mixed model analysis of Hu and Murphy (2005). The buffaloes fed HB diet might have increased ruminal buffering capacity in addition to increased water intake and ruminal fluid dilution (Russel and Chow, 1993). Similar findings were reported by Rogers et al. (1982a) who observed increased DMI in dairy cows when high SB was supplemented. They stated that in addition to buffering effect, SB also increased ruminal osmotic pressure and liquid dilution rate. In rumen sodium bicarbonate is converted into sodium (Na) and bicarbonate (HC[O.SUB.3]) and they impart non-buffering and buffering effects, respectively (Schneider et al., 1986). It is hypothesized that rumen buffering reduces the extent of acidity produced by volatile fatty acids production in rumen and improves systemic acid base status (Erdman, 1988). It is also proposed that propionate decreases feed intake of ruminants by stimulating oxidative metabolism in the liver (Allen, 2000). Oxidative metabolism in the liver had been shown to affect satiety in rats (Langhans et al., 1985). They proposed that oxidative metabolism in the liver affected feed intake by hyperpolarizing cell membrane potentials. Moreover, non-buffering effect of SB due to solute action increases rumen osmotic pressure and liquid dilution rate (Rogers et al., 1979; 1982). The non-buffering effects, inturn, increase influx of water and acclerate flow of liquid digesta from the rumen (Rogers, 1979), which is associated with increased efficiency of fiber digestion and microbial protein synthesis (Rogers, 1988). A slight increase in nutrients digestibilities in buffaloes fed 0B diet might be due to increased retention time because of significantly reduced feed intake. It is documented that positive co-relation between nutrients retention time and digestibilities exist (Sarwar et al., 1996).
Blood pH and serum bicarbonate
A constant increase in blood pH with increasing the SB level of diets might be attributed to gradual increase in sodium intake. Sodium absorption takes place in posterior segment of the intestine, when excess of Cl, in exchanges of [H.sup.+] to maintain the electrical neutrality of the body. In the present study, absorption of high sodium content compared to Cl might have decreased serum [H.sup.+] concentration by giving birth to increased blood pH and HC[O.SUB.3] (Table 3) Similar findings have been reported by Jackson et al. (2001) who reported increased serum HC[O.sub.3] in calves fed SB (1.75%). Waterman et al. (1991) also reported an increase in blood [H.sup.+] with reducing cation level like Na.
The slight acidic blood pH in buffaloes fed 0B and LB diets might be attributed to the fact that phosphate and ammonia buffer system function for hydrogen ion excretion. Hydrogen ions combine with phosphate or ammonia after entering the renal tubules and a HC[O.SUB.3] ion is formed that enters the extracellular fluids to further buffer acid in the extracellular fluids (Guyton, 1991). The 0B diet had low Na and high Cl. The Cl is anionic in nature and high Cl in OB diet might have overcome the capacity of kidneys to excrete sufficient hydrogen ion to maintain a constant blood pH, resulting in slight systemic acidosis (Shahzad et al., 2007b). Moreover, buffaloes fed HB diet tended to have high blood pH because of high Na exchange in place of [H.sup.+] from the posterior segment of intestine which might have resulted in high HC[O.sub.3.sup.-] production and [H.sup.+] excretion (Tucker et al., 1992). However, the increased pH was within the normal range.
Alteration in urine pH reflected alteration in blood pH and kidneys played a vital role to minimize this change by making the urine pH alkaline due to more Na content in buffaloes fed MB and HB by means of excreting more HC[O.sub.3] and conserving [H.sup.+] (Roche et al., 2003). Increase in urine pH with increasing the dietary Na content has also been reported by Waterman et al. (1991). Moreover, increased urine pH had been used as an indicator of metabolic alkali load (Sanchez, 2003). The findings of the present study are in line with other workers (Jackson et al., 1992; Mosel et al., 1993; Jackson and Hemken, 1994; Pehrson et al., 1999) who reported increased urine pH with increasing the dietary Na when sodium bicarbonate was added in diet. Maximum (9.0) and minimum (4.50) fluctuation in urine pH had been reported by Roche et al. (1999) with supplementing varying sodium bicarbonate to increase dietary sodium concentrations. Similar findings are also reported by Jackson et al. (2001) who reported increased urine pH (8.09) in dairy claves fed high dietary Na or K content compared to those (6.80) fed low or without sodium or bicarbonate supplementation (Jackson et al., 2001).
Milk yield and composition
Increased milk production in buffaloes fed HB diet was due to increased DMI. These findings are supported by Tucker et al. (1988) who reported increased milk production in lactating cows fed high SB compared to those fed low SB diet. Similar results were reported by Block (1994) who indicated that high Na or K contents from sodium or potassium bicarbonate increased milk production in lactating cows. He further stated that lactating cows had higher metabolic rate that tended to make the cellular environment acidic due to more C[O.sub.2] production. A high SB diet due to high Na content has alkalogenic nature and reduces the extent of that acidity and thereby increases cellular glucose uptake.
Unaltered protein and lactose % due to alteration in SB level are in concordance with findings of other workers (Tucker et al., 1988; Block, 1994). In the present study, increased milk fat % was recorded in buffaloes fed HB diet. High sodium bicarbonate diet had the tendency to increased ruminal pH, which might have shifted the fermentation pattern in favour of acetate and butyrate production (Kolver and De Veth, 2002). It might have resulted in increased de novo fatty acid synthesis which accounts for 60% of bovine milk fat (Bauman and Davis, 1974) and hence increased milk fat content. Decreased propionate and increased acetate molar proportion by increasing dietary SB level has also been reported by Staples and Lough (1989). Reduced milk fat content in buffaloes fed low SB diet might be attributed to high propionate and low acetate rumen molar concentrations as positive relationship between milk fat and molar proportion of acetate has been documented by Hu and Murphy (2005). Deceased propionate concentration has also been reported to negatively co- related with milk fat content (Coppock et al., 1986).
In the present study, 40% wheat straw, this is rich in effective fiber. A high sodium bicarbonate when fed in blend with high effective fiber counteracted the acidic environment of rumen and this might have ensured high acetate to propionate ratio by optimizing cellulolytic microbial activity. The combined effect of these two might have increased milk fat synthesis. These findings are supported by Roche et al. (2005) who reported an increased milk fat when sodium bicarbonate was added in diet.
Increased conception rate in buffaloes fed HB diet might be attributed to increased DMI which might have increased IGF-1 (Pate, 1999). Moreover, ability of follicles to produce sufficient estradiol for successful ovulation depends upon IGF-I that has stimulatory effect on granulosa cells for estradiol production, thus it is hypothesized that high level of IGF-I might have improved ovarian activity through accelerating the follicle growth (Butler and Smith, 1989). These findings are in concordance with those reported by Reist et al. (2000) who indicated that cows with higher serum IGF-1 (65 ng/ml) ovulated while low serum (47.5 ng/ml) IGF-1 cows could not ovulate at 21 days postpartum. Moore et al. (2000) also observed increased plasma IGF-1 in cows fed high bicarbonate compared to those fed low carbonate diet. They also observed delayed resumption of ovarian activity in cows with low IGF-1, indicating the effect of low DMI.
In buffaloes fed 0B diet, decreased DMI might have resulted low IGF-1 level which delayed onset of ovarian cycle, low conception rate and high services per conception (Butler and Smith, 1989; Staples et al., 1990; Butler, 2000; Reist et al., 2000). However, high conception rate (100%) in buffaloes fed HB and MB diets might be due to small number of animals per treatment which is the main limitation of this study but this facilitated the authors for closer observance of peak heat periods for more timely breeding as compared with large groups in pasture or paddock holdings. However, detailed study involving greater number of animals is warranted.
Received November 29, 2006; Accepted April 8, 2007
AOAC. 1990. Official Methods of Analysis. Assoc. Off. Anlyt. Chemist, 15th Ed. Arlington Virginia, USA.
Allen, M. S. 1997. Relationship between fermentation acid production in the rumen and the requirement for physically effective fiber. J. Dairy Sci. 80:1447-1462.
Bauman, D. E. and C. L. Davis. 1974. Biosynthesis of milk fat. Pages 31-75 in Lactation: A Comprehensive Treatise, Vol. 2 (Ed. B. L. Larson and V. R. Smith). Academic Press, New York, NY.
Block, E. 1994. Manipulation of dietary cation-anion difference on nutritionally related production diseases, productivity, and metabolic responses of dairy cows. J. Dairy Sci. 77:1437-1450.
Butler, W. R. 2000. Nutritional interactions with reproductive performance in dairy cows. Anim. Reprod. Sci. 60:449-457.
Butler, W. R. and R. D. Smith. 1989. Interrelation-ships between energy balance and postpartum reproductive function in dairy cattle. J. Dairy Sci. 72:767.
Coppock, C. E., G. T. Schelling, F. M. Bayers, J. W. West and J. M. Labore. 1986. A naturally occuring mineral as a buffer in the diet of lactating dairy cows. J. Dairy Sci. 69:111-123.
Erdman, R. A. 1988. Dietary buffering requirements of lactating dairy cow: a review. J. Dairy Sci. 71:3246.
Guyton, A. C. 1991. Textbook of Medical Physiology. Philadelphia: W.B. Saunders Company.
Goering, H. G. and P. J.Van Soest. 1970. Forage fiber analysis, Agricultural Handbook, Vol. 379. USDA.
Harold, V. 1976. Practical Clinical Biochemistry. 4th Ed. Arnold-Heinemann Publisher (Pvt.) New Delhi, India.
Hu, W. and M. R. Murphy. 2005. Statistical evaluation of early and mid lactation dairy cow responses to dietary sodium bicarbonate addition. Anim. Feed Sci. Technol. 119:43-54.
Jackson, J. A., J. Akay, S. T. Franklin and D. K. Aaron. 2001. The effect of cation-anion difference on calcium requirement, feed intake, body weight gain, and blood gasses and mineral concentrations of dairy calves. J. Dairy Sci. 84:147-153.
Jackson, J. A. and R.W. Hemken. 1994. Calcium and cation-anion difference effects on feed intake, body weight gain, and humoral response of dairy calves. J. Dairy Sci. 77:1430-1436.
Jackson, J. A., D. M. Hopkins, Z. Xin and R. W. Hemken. 1992. Influence of cation-anion balance on feed intake, body weight gain, and humoral response of dairy calves. J. Dairy Sci. 75:1281.
Khan, M. A., M. Sarwar, M. Nisa, M. S. Khan, S. A. Bhatti, Z. Iqbal, W. S. Lee, H. J. Lee and H. S. Kim. 2006a. Feeding value of urea treated wheat straw ensiled with or without molasses in Nili Ravi buffaloes. Asian-Aust. J. Anim. Sci. 19: 645-652.
Khan, M. A., M. Sarwar, M. Nisa, Z. Iqbal, M. S. Khan, W. S. Lee, H. J. Lee and H. S. Kim. 2006b. Chemical composition, In situ Digestion kinetics and Feeding value of grass (Avena sativa) ensiled with molasses for Nili Ravi buffaloes. Asian-Aust. J. Anim. Sci. 19:1127-1136.
Kolver, E. S. and M. J. Veth. 2002. Prediction of ruminal pH from pasture-based diets. J. Dairy Sci. 85:1255-1266.
Moore, S. J., M. J. Vandehaar, K. Sharma, T. E. Pilbeam, T. E. Beede, D. K. Bucholtz, F. Liesman, R. L. Horst and J. P. Goff. 2000. Effect of altering dietary cation and anion difference on calcium and energy metabolism in prepartum cows. J. Dairy Sci. 83:2095-2104.
Mosel, V., M. Klooster, V. Mosel and J. Kuilen. 1993. Effects of reducing dietary ((Na+[K.sup.+])-(Cl.sup.-]+S[O.sub.4])) on the rate of calcium mobilisation by dairy cows at parturition. Res. Vet. Sci. 54:1-9.
National Research Council. 2001. Nutrient Requirements of Dairy Cattle. 7th rev. Ed. Natl. Acad. Sci., Washington, DC, pp. 131-132.
Nisa, M., M. A. Khan, M. Sarwar, W. S. Lee, H. J. Lee, K. S. Ki, B. S. Ahn and H. S. Kim. 2006. Influence of corn steep liquor on feeding value of urea treated wheat straw in buffaloes fed at restricted diets. Asian-Aust. J. Anim. Sci. 19:1610-1616.
Nisa, M. Sarwar and M. A. Khan. 2004. Influence of ad libitum feeding of urea treated wheat straw with or without corn steep liquor on intake, insitu digestion kinetics, nitrogen metabolism and nutrient digestion in Nili Ravi buffalo bulls. AJAR. 55: 229-236.
Pate, J. L. 1999. Effects of energy balance on ovarian function. Tristate-State Dairy Nutrition Conference. April 20-21. Ohio, USA.
Pehrson, B., C. Svensson, I. Gruvaeus and M. Virkki. 1999. The influence of acidic diets on the acid-base balance of dry cows and the effect of fertilization on the mineral content of grass. J. Dairy Sci. 82:1310-1316.
Reist, M., A. Koller, A. Busato, U. Kuepfer and J. W. Blum. 2000. First ovulation and ketone body status in the early postpartum period of dairy cows. Theriogenol. 54:685-701.
Roche, J. R. 1999. Dietary Cation-Anion Difference for Pasture-fed Dairy Cows. Ph.D. Diss., University College, Dublin, Ireland.
Roche, J. R., S. Petch and J. L. Kay. 2005. Manipulating the dietary cation anion difference via drenching to early lactating dairy cows grazing pasture. J. Dairy Sci. 88:264-276.
Roche, J. R., D. Dalley, P. Moate, C. Grainger, M. Rath and F. O. Mara. 2003. Dietary cation-anion difference and the health and production of pasture-fed dairy cows 2.Non-lactating Prepartum Cows. J. Dairy Sci. 86:979-986.
Rogers, J. A., C. L. Davis and J. C. Clark. 1982. Alteration or rumen fermentation milk fat synthesis, and nutrient utilization wiai mineral salts in dairy cattle. J. Dairy Sci. 65:577.
Roger, J. A., B. C. Marks, C. L. Davis and J. H. Clark. 1979. Alteration of rumen fermentation in steers by increasing rumen fluid dilution rate with mineral salts. J. Dairy Sci. 62:1599.
Sanchez, W. K. and D. K. Beede. 1994. Cation-anion concepts for lactating dairy rations. Cation-anion applications for lactating dairy cattle. Pages 1-13 in Proceedings of Mallinckrodt Feed Ingredients Conference. Rochester, NY.
Sanchez, W. K. 2003. The latest in dietary cation-anion difference (DCAD) nutrition. proceeding of 43nd Annual Dairy Cattle Day. 26th March. Main Theater. University of California. Davis Campus.
Sarwar, M., J. L. Firkins and M. L. Estridge. 1996. Effects of varying forage and concentrate carbohydrates on nutrients digestibilities and milk production by dairy cows. J. Dairy Sci. 75:1533.
Schneider, P. L., D. K. Beede and C. J. Wilcox. 1986. Responses of lactating cows to dietary sodium source and quantity and potassium quantity during heat stress. J. Dairy Sci. 69:99-110.
Shahzad, M. A., M. Sarwar and M. Nisa. 2007a. Nutrient intake, acid base status and growth performance of growing buffalo male calves fed varying level of dietary cation anion difference. Livest. Sci. 111:136-143.
Shahzad, M. A., M. Sarwar and M. Nisa. 2007b. Influence of varying dietary cation anion difference on serum minerals, mineral balance and hypocalcaemia in Nili Ravi buffaloes. Livest. Sci. doi:10.1016/j.livsci.2007.02.013.
Staples, C. R., W. W. Thatcher and J. H. Clark. 1990. Relationship between ovarian activity and energy status during the early postpartum period of high producing dairy cows. J. Dairy Sci. 73:938-947.
Staples, C. S. and D. S. Lough. 1989. Efficacy of supplemental dietary neutralizing agents for lactating dairy cows. A review. Amin. Feed Sci. Technol. 23:277-303.
Touqir, N. A., M. A. Khan, M. Sarwar, M. Nisa, C. S. Ali, W. S. Lee, H. J. Lee and H. S. Kim. 2007. Feeding value of jumbo grass silage and mott grass silage for lactating buffaloes. Asian-Aust. J. Anim. Sci. 20:523-528.
Tucker, W. B., J. K. Harrison and R. W. Hemken. 1988. Influence of dietary cation-anion balance on milk, blood urine, and rumen fluid in lactating dairy cattle. J. Dairy Sci. 71:346.
Tucker, W. B., J. F. Hogue, D. F. Waterman, T. S. Swenson, Z. Xin. R. W. Hemken, J. A. Jackson, G. D. Adams and L. J. Spicer. 1992. Sulfur should be included when calculating the dietary cation-anion balance of diets for lactating dairy cows. Pages 141-150 in Anim. Sci. Res. Rep., Oklahoma Res. Stat. Oklahoma City, OK.
Tucker, W. B., B. Z. Xin and R. W. Henken. 1991. Influence of calcium chloride on systemic acid-base status and calcium metabolism in dairy heifers. J. Dairy Sci. 74:1401.
Van Soest, P. J., H. B. Robertson and B. A. Lewis. 1991. Methods of dietary fiber, NDF and non-starch polysaccharides in relation to animal material. J. Dairy Sci. 74:3583-3597.
Waterman, D. F., T. S. Swenson, W. B. Tucker and R. T. Henkin. 1991. Role of magnesium in the dietary cation-anion balance equation for ruminants. J. Dairy Sci. 74:1866-1873.
West, J. W., C. E. Coppock, D. H. Nave and G. T. Schelling. 1987. Effects of potassium carbonate and sodium bicarbonate on rumen function in lactating holstein cows. J. Dairy Sci. 70:8190.
Williams, P. E. V., G. M. Innes and A. Brewer. 1984. Ammonia treatment of straws via the hydrolysis of urea: 1. Additions of soybean (urease), sodium hydroxide and molasses; effects on the digestibility of urea treated straw. Anim. Feed Sci. Technol. 11:103-114.
M. Sarwar *, M. Aasif Shahzad and Mahr-un-Nisa
Institute of Animal Nutrition and Feed Technology, University of Agriculture, Faisalabad-38040, Pakistan
* Corresponding Author: M. Sarwar. Tel: +92-41-9201088, E-mail: firstname.lastname@example.org
Table 1. Ingredients and chemical composition of experimental diets varying in sodium bicarbonate for early lactating buffaloes Ingredients OB LB MB HB Wheat straw 40.0 40.0 40.0 40.0 Corn grain cracked 15.0 15.0 15.0 15.0 Molasses 12.0 12.0 12.0 12.0 Wheat bran 10.2 9.70 9.20 8.70 Sunflower meal 10.0 10.0 10.0 10.0 Canola meal 6.25 6.25 6.25 6.15 Vegetable oil 3.0 3.0 3.0 3.0 Urea 1.80 1.80 1.80 1.90 DCP (1) 1.50 1.50 1.50 1.50 Salt 0.25 0.25 0.50 0.50 NaHC[O.sub.3] 0 0.5 1.00 1.50 Chemical composition [NE.sub.1] (Mcal/kg) 1.50 1.51 1.51 1.51 CP (2) 16.0 16.0 15.9 16.0 RDP (3) 10.50 10.50 10.50 10.70 RUP (4) 5.5 5.5 5.4 6.3 NDF (5) 40.90 40.70 40.70 40.20 ADF (6) 26.20 26.10 26.00 25.91 NFC (7) 30.12 30.02 30.01 30.25 Ca 0.69 0.69 0.70 0.69 P 0.66 0.66 0.67 0.66 Na 0.19 0.32 0.46 0.59 K 1.54 1.53 1.52 1.52 Mg 0.28 0.28 0.29 0.28 Cl 0.43 0.43 0.43 0.43 S 0.22 0.23 0.23 0.22 Means within the same row having different subscripts differ significantly (p<0.05). Diet 0B contained no supplementation of SB while LB, MB and HB diets contained 0.5%, 1.0% and 1.5% SB, respectively. (1) Dicalcium phosphate. (2) Crude protein. (3) Rumenly degradable protein. (4) Rumenly undegradable protein. (5) Neutral detergent fiber. (6) Acid detergent fiber. (7) Non-fermentable carbohydrate. Table 2. Influence of varying levels of sodium bicarbonate on nutrients intake in early lactating buffaloes Nutrients (kg/d) OB LB MB Intake Dry matter 12.60 (c) 13.40 (b) 14.60 (ab) Dry matter 2.61 (c) 2.85 (b) 2.97 (ab) (as % BW) Crude protein 2.02 (c) 2.14 (b) 2.34 (ab) ADF (1) 3.30 (c) 3.51 (b) 3.81 (ab) NDF (2) 5.15 (c) 5.45 (b) 5.91 (ab) Water (L/d) 75.8 (c) 78.6 (b) 86.5 (ab) Nutrients (kg/d) HB SE Intake Dry matter 16.3 (a) 0.46 Dry matter 3.19 (a) 0.074 (as % BW) Crude protein 2.61 (a) 0.86 ADF (1) 4.22 (a) 1.78 NDF (2) 6.55 (a) 2.82 Water (L/d) 98.5 (a) 4.12 Means within the same row having different subscripts differ significantly (p<0.05). Diet 0B contained no supplementation of SB while LB, MB and HB diets contained 0.5%, 1.0% and 1.5% SB, respectively. (1) Acid detergent fiber. (2) Neutral detergent fiber. Table 3. Influence of varying levels of sodium bicarbonate on nutrients digestibilities in early lactating buffaloes Nutrient OB LB MB HB SE Digestibility (%) Dry matter 68.5 67.1 67.1 66.12 0.21 Crude protein 73.51 72.85 72.77 72.78 0.11 ADF (1) 63.01 62.51 62.33 62.41 0.27 NDF (2) 62.11 61.45 61.33 61.02 0.12 Means within the same row having different subscripts differ significantly (p<0.05). Diet OB contained no supplementation of SB while LB, MB and HB diets contained 0.5%, 1.0% and 1.5% SB, respectively. (1) Acid detergent fiber. (2) Neutral detergent fiber. Table 4. Influence of varying levels of sodium bicarbonate on nitrogen balance in early lactating buffaloes Items OB LB MB Nitrogen intake (g/d) 322.56 (c) 343.04 (b) 373.76 (ab) Faecal nitrogen (g/d) 80.64 85.71 94.66 % of intake 25.01 25.48 24.68 Apparent absorption (g/d) 241.92 (c) 257.33 (b) 279.1 (ab) % of intake 75.01 70.01 74.67 Urinary nitrogen (g/d) 65.04 (c) 69.23 (b) 78.87 (ab) Apparent retention (g/d) 176.88 (c) 188.1 (b) 200.24 (ab) % of intake 54.83 54.83 53.57 Nitrogen balance (g/d) 103.12 (c) 107.3 (b) 119.44 (ab) % of intake 31.97 31.23 31.96 Items HB SE Nitrogen intake (g/d) 417.28 (a) 18.22 Faecal nitrogen (g/d) 104.09 3.01 % of intake 23.66 0.28 Apparent absorption (g/d) 313.19 (a) 9.66 % of intake 75.05 1.56 Urinary nitrogen (g/d) 83.6 (a) 2.05 Apparent retention (g/d) 229.59 (a) 10.13 % of intake 55.02 1.26 Nitrogen balance (g/d) 134.3 (a) 11.23 % of intake 31.98 0.25 Means within the same row having different subscripts differ significantly (p<0.05). Diet 0B contained no supplementation of SB while LB, MB and HB diets contained 0.5%, 1.0% and 1.5% SB, respectively. Table 5. Influence of varying levels of sodium bicarbonate on blood pH, bicarbonate, urine pH of early lactating buffaloes Nutrients OB LB MB Blood pH 7.351 (d) 7.371 (c) 7.412 (b) HC[O.sub.3] (mmol/L) 21.55 (d) 22.92 (c) 24.91 (b) Urine pH 6.05 (d) 6.52 (c) 7.47 (b) Nutrients HB SE Blood pH 7.516 (a) 0.03 HC[O.sub.3] (mmol/L) 26.3 (a) 0.98 Urine pH 8.01 (a) 0.32 Means within the same row having different subscripts differ significantly (p<0.05). Diet OB contained no supplementation of SB while LB, MB and HB diets contained 0.5%, 1.0% and 1.5% SB, respectively. Table 6. Influence of varying levels of sodium bicarbonate on milk yield and its composition in early lactating buffaloes OB LB MB Milk yield (kg/d) 13.52 (c) 14.02 (b) 14.87 (ab) Protein (kg/d) 0.461 (c) 0.474 (b) 0.5.05 (ab) Fat (kg/d) 0.852 (c) 0.904 (b) 0.981 (ab) Total solids (kg/d) 2.23 (c) 2.32 (b) 2.58 (ab) Solid not fat (kg/d) 1.38 (c) 1.42 (b) 1.60 (ab) Lactose (kg/d) 0.757 (c) 0.784 (b) 0.836 (ab) Concentrate (%) Fat 6.3 (b) 6.45 (b) 6.6 (a) Protein 3.41 3.38 3.4 Total solids 16.5 (b) 16.55 (b) 17.35 (a) Solid not fat 10.2 10.1 10.75 Lactose 5.6 5.59 5.62 HB SE Milk yield (kg/d) 15.4 (a) 0.378 Protein (kg/d) 0.601 (a) 0.11 Fat (kg/d) 1.032 (a) 0.14 Total solids (kg/d) 2.68 (a) 0.25 Solid not fat (kg/d) 1.65 (a) 0.17 Lactose (kg/d) 0.867 (a) 0.11 Concentrate (%) Fat 6.7 (a) 0.10 Protein 3.9 0.10 Total solids 17.42 (a) 0.12 Solid not fat 10.72 0.12 Lactose 5.63 0.10 Means within the same row having different subscripts differ significantly (p<0.05). Diet OB contained no supplementation of SB while LB, MB and HB diets contained 0.5%, 1.0% and 1.5% SB, respectively. Table 7. Influence of varying levels of sodium bicarbonate on conception rate and services /conception in early lactating buffaloes Diets Parameter OB LB MB HB CR2 (%) 33.33 66.67 100.0 100.0 S/C3 (No) 2.67 2.33 2.33 1.67 (1) Diet OB contained no supplementation of SB while LB, MB and HB diets contained 0.5%, 1.0% and 1.5% SB, respectively. (2) Conception rate. (3) Services per conception.
|Printer friendly Cite/link Email Feedback|
|Author:||Sarwar, M.; Shahzad, M. Aasif; Mahr-un-Nisa|
|Publication:||Asian - Australasian Journal of Animal Sciences|
|Date:||Dec 1, 2007|
|Previous Article:||Estimation of ruminal degradation and intestinal digestion of tropical protein resources using the nylon bag technique and the three-step in vitro...|
|Next Article:||Effects of dietary metabolizable energy and lysine on carcass characteristics and meat quality in Arbor Acres broilers *.|