J. Dairy Sci. 88:2027-2036
© American Dairy Science Association, 2005.
Pre- and Postweaning Attributes in Faunated and Ciliate-Free Calves Fed Calf Starter With or Without Fish Meal
A. Sahoo,
D. N. Kamra and
N. N. Pathak
Rumen Microbiology Section, Animal Nutrition Division, Indian Veterinary Research Institute Izatnagar-243 122 (UP), India
Corresponding author: A. Sahoo; e-mail: ivriplp{at}sancharnet.in.
 |
ABSTRACT
|
|---|
In a 2 x 2 factorial design, 24 newborn, crossbred (Bos indicus x Bos taurus) calves were distributed in 4 equal groups involving dietary treatments of prestarter diets with (FM) or without fish meal (NFM) in a faunated (F) or ciliate-free (D) ruminal environment to study the ruminal fermentative development in pre-and postweaning periods. Defaunation was achieved by rearing calves in isolation and its effect was studied after first appearance of ciliate protozoa (observed after 8 wk of age) in the faunated animals. Calves were fed colostrum for 24 h and whole milk until weaning at 8 wk of age. Ruminal content samples were collected on d 4, 1 wk, weekly to 8 wk, and then biweekly at 9, 11, and 13 wk of age. The samples were analyzed for fermentation products [pH, total volatile fatty acids (VFA) and ammonia N] and enzyme [carboxymethyl (CM) cellulase, xylanase, ß-glucosidase, 
-amylase, ß-galactosidase, proteases, and urease] activities. Weekly feed intake increased with age, but was similar in both groups. Ruminal pH declined steadily during 0 to 4 wk of age and then stabilized. The total VFA concentration increased with the age. The ammonia N (mg/dL) concentration increased from 14.9 on d 4 to 32.4 at 4 wk, decreased to 17.6 at 8 wk, and then steadied during the postweaning period. Samples collected on d 4 had no fibrolytic activity. Xylanase (U/dL) appeared first (1 wk) followed by ß-glucosidase (U/dL) and CM cellulase (U/dL), which increased steadily from a low of 4.69, 0.08, and 2.95 to 31.8 (6 wk), 5.92 (7 wk), and 19.8 (8 wk), respectively, and the concentrations showed nonsignificant alterations during postweaning periods. The concentration of -amylase (U/dL) increased from 34.3 on d 4 to 87.2 at 8 wk, and then decreased to 56.6 (13 wk). ß-Galactosidase increased up to 6 wk then decreased to trace level (0.20 U/dL) at 13 wk of age. The concentrations of proteases and urease reached a steady state after 1 wk of age. The effect of diet type on ruminal fermentation products and enzyme parameters was nonsignificant. However, a steady and proportional alteration in both parameters in response to dry feed intake with the advancement of age was seen in all calves. Defaunation increased total VFA (97.3 vs. 75.8 mM/L) and -amylase activity (80.3 vs. 61.4 U/dL) and decreased ammonia N (16.4 vs. 21.1 mg/dL), whereas the effect on other parameters was nonsignificant. Ruminal fermentative changes responded to dry feed intake, but did not differ in response to animal protein in prestarter diet.
Key Words: rumen fermentation • calf starter • defaunation • animal protein
Abbreviation key: CM = carboxymethyl, D = defaunated, F = faunated, FM = fish meal, NFM = no fish meal.
|
INTRODUCTION
|
|---|
Dietary adjustments directed toward early development of ruminal function help the animal in early tolerance of fibrous components in their ration. In India, many of the organized farms or farmers have adopted the practice of weaning calves at or above 3 mo of age and including animal protein in the starter diet. Adoption of dry feed consumption in calves at an early age leads to early weaning because of rapid ruminal metabolic development (Anderson et al., 1987a; Quigley et al., 1991). Calves with early-developed microbial ecosystems can thus be exposed to low-cost feeding strategy based on fibrous crop residues. Additionally, the replacement of costly animal protein from the prestarter diet of young ruminants may have the added advantage of reducing the total cost of calf rearing. Quigley et al. (1985) observed no effect on the composition of essential amino acids in bacterial proteins due to age, weaning, or diet composition. According to Warner (1984), the crucial aspect of a calf starter is its total intake rather than its specific protein characteristics. Further, fish meal-containing diets produced lower total VFA and ammonia N concentrations (Zerbini and Polan, 1985; Sil et al., 1994), but no effect on polysaccharide-degrading enzymes (Sil et al., 1994) in the ruminal fluid of growing calves compared with plant protein.
Calves are generally separated from their dams and reared in separate hutches or in groups. Because of such isolation, those calves generally remain ciliate-free. The role of protozoa was investigated in various defaunation and refaunation studies (Hsu et al., 1991; Williams and Withers, 1993; Koenig et al., 2000; Santra and Karim, 2002). Significant change in microbial activities involved alterations in polysaccharide-degrading enzymes, ruminal ammonia N concentration, bacterial protein synthesis, and ruminal protein outflow.
The present investigation was aimed at assessing the developmental changes in ruminal fermentative attributes of preruminant calves before and after establishment of ciliated protozoa to feeding of prestarter diet with or without fish meal.
|
MATERIALS AND METHODS
|
|---|
Experimental Design
Twenty-four newborn crossbred calves (Bos indicus x Bos taurus; average BW, 22.5 ± 0.7 kg) were separated from their dams following 24 h of colostrum feeding, and reared in individual sheds. In a 2 x 2 factorial design, calves were equally distributed on a staggered basis when they were born into 4 treatment groups, involving feeding of calf starter with (FM) or without (NFM) fish meal, and faunated (F) or ciliate-free (defaunated; D) calves. Ciliate-free calves were raised in isolation, whereas the faunated group was allowed daily access (particularly during cleaning and drying of calf hutches) to adult animals in a separate enclosure adjacent to the calf running space, and had common watering facilities. The 4 treatment groups were faunated and fed fish meal (FFM), defaunated and fed fish meal (DFM), faunated and not fed fish meal (FNFM), and defaunated and not fed fish meal (DNFM).
Feeding Management
Lukewarm whole milk was fed to all calves in 2 equally divided doses at 0900 and 1700 h daily. The milk feeding schedule was as follows: 10% of BW up to 3 wk, followed by 8% during wk 4, 6% during wk 5 and 6, and 3% of BW to wean at 8 wk of age. Calves in groups FM and NFM were fed calf starter with or without fish meal, respectively. Both calf starters were isonitrogenous. The composition of calf starter and nutrient analysis are shown in Table 1
. The roughage source was oat hay (chaffed to 1 to 2 cm). Calf starter and oat hay were offered ad libitum. Clean drinking water was available at all times. The feeding trial was for a period of 13 wk comprising a preweaning period (0 to 8 wk) that included high (0 to 4 wk, phase 1) and reduced (5 to 8 wk, phase 2) milk feeding phases, and a postweaning period (9 to 13 wk).
Daily intake of DM was recorded from the DM offered and residue left. Periodic samples of milk, calf starter, oat hay, and residual feed were collected and oven-dried (100 ± 5°C) for estimation of DM. Body weights were recorded weekly before feeding and watering/milk feeding.
Collection and Analysis of Ruminal Fluid Samples
Approximately 50 mL of ruminal fluid was collected via a stomach tube at 3 h postfeeding from 4 of 6 calves in each group on d 4, then weekly up to wk 9, and then biweekly up to wk 13. Ruminal fluid was collected from all calves every week for observation of ciliate protozoa. Samples were collected in stoppered conical flasks and brought to the laboratory for immediate recording of pH. Approximately 20 mL of the sample was then frozen (below –20°C) for enzyme analysis. The ruminal fluid was sonicated twice at 80 W for 10 min each, and then centrifuged at 24,000 x g for 20 min to collect supernatant for enzyme analysis. The rest (about 30 mL) was strained through muslin cloth. One milliliter of ruminal fluid was preserved with 1 mL of formal saline (10% formalin in 0.9% sodium chloride solution) with methylene green indicator in a capped vial for counting of ciliate protozoa; the remainder was acidified with 2 to 3 drops of 10 N sulfuric acid and stored in capped vials in a freezer at –20°C for chemical analysis.
Carboxymethyl (CM) cellulase (EC 3.2.1.4), xylanase (EC 3.2.1.6), ß-glucosidase (EC 3.2.1.2), -amylase (EC 3.2.1.1), ß-galactosidase (EC 3.2.1.23), proteases, and urease (EC 3.5.1.5) were assayed using CM cellulose, oat spelt xylan, p-nitrophenyl ß-D-glucopyranoside, soluble starch, o-nitrophenyl ß- D-galactopyranoside, casein, and urea as substrates, respectively. The concentration of reducing sugar after incubation with enzyme extract was determined for CM cellulase, xylanase, and -amylase (Miller, 1959). ß-Glucosidase activity was measured from the concentration of reduced p-nitrophenol (Shewale and Sadana, 1981). For the determination of ß-galactosidase, the method of McFeters et al. (1967) was followed. The proteases-induced release of amino acids and peptides (expressed in milligrams of protein released) were estimated by Lowry’s method (Lowry et al., 1951). The ammonia produced from urease was determined by the method of Weatherburn (1967). Unit of enzyme activity (U) was calculated as the amount of enzyme that produced one unit of reducing product per milliliter per minute under the assay conditions. The acidified ruminal fluid was analyzed for total VFA (Barnett and Reid, 1956) and ammonia N (AOAC, 1980).
Weekly microscopic examination of ruminal fluid was made to observe the establishment of ciliated protozoa in the rumen; and their identification and counting were according to Kamra et al. (1991).
Statistical Analyses
The experimental data obtained during the pre- and postweaning periods were analyzed differently by AN-OVA using the model as described in Snedecor and Cochran (1989). Preweaning observations were compiled under the main dietary treatments of FM and NFM, and the postweaning observations were analyzed under the 4 treatments (FFM, DFM, FNFM, and DNFM). The main effects of diet and defaunation were analyzed by orthogonal contrasts. The effect of age and its interaction with different treatment combinations were also analyzed. In all cases, differences among treatment groups were contrasted by Tukey’s t-test. Significance was declared at P < 0.05 unless otherwise indicated.
where Yijk = dependent variables; µ = overall mean; Ti = effect of treatment i, C(i)j = effect of calf j nested within treatment i (or error due to treatment); tk = effect of time period k; Tt(ik) = effect of treatment x period interaction; and e(ijk) = residual.
|
RESULTS
|
|---|
Feed (DM) Intake and Live Weight Gain
Weekly intakes of milk, calf starter, and oat hay are presented in Table 2. Whole milk was the principal component of the diet during the first 2 wk of life. Thereafter, the calves were adapted to dry feed, particularly the calf starter. Refusal to consume calf starter was not seen in any of the calves, even during wk 1. In contrast, few calves (5) consumed oat hay in wk 2, and an appreciable intake was seen only after 5 wk of age in both groups. Rumination was observed as early as 2 wk of age in a few calves (5), which became more pronounced at 4 wk irrespective of dietary treatments. Intake of oat hay before weaning was quite low and averaged <5% of total DM intake and increased to 12% during the postweaning period. Inclusion of fish meal in the calf starter had no effect on feed intake. The average preweaning DM intake was nearly 600 g, with calf starter constituting >50% of the total intake. During the postweaning period, the intake of dry feed increased from 0.82 kg at 8 wk to 1.42 kg at 13 wk of age. The intakes of calf starter and oat hay increased from 612 to 1244 g and from 66 to 172 g, respectively. No significant effect of diet or defaunation was observed during the postweaning period.
Live BW of calves were similar in all treatment groups during the pre- and postweaning periods (Table 3).
Establishment of Ciliated Protozoa in the Rumen
Weekly examinations of ruminal fluid revealed no ciliated protozoa until 8 wk of age. First appearance of ciliate protozoa, with only a low concentration (0.06 x 104/mL) of large entodiniomorphs and no holotrichs, was in the samples collected at 9 wk of age (Table 4) from calves that were allowed contact with adult animals. The sample collected at 10 wk of age revealed both holotrichs and entodiniomorphs. No significant increase in total ciliate population was observed in ruminal fluid of calves at 12 wk of age, which showed an increase in the number of small entodiniomorphs. Ruminal fluid from the isolated calves did not reveal any protozoa during this period.
Ruminal Fermentation Products
The ruminal pH was not significantly different in groups FM and NFM in phases 1 and 2 (Table 5). The pH declined (P < 0.05) to 6.00 in wk 4 and then stabilized, showing only a marginal increase from 6 to 8 wk of age. The total VFA concentration (mM/L) in ruminal fluid increased with age from 30.0 to 73.4 in FM and from 27.9 to 80.5 in NFM during 8 wk. No significant effect of fish meal in calf starter was observed. Ammonia N (mg/dL) concentration showed an initial increase from 15.0 on d 4 to 32.9 at 4 wk, and then decreased to 17.6 at 8 wk.
View this table:
[in this window]
[in a new window]
|
Table 5. Effects of fish meal and ciliated protozoa on ruminal pH and total VFA and ammonia N concentrations in calves.1
|
|
During the postweaning period, ruminal pH was around 6.3. The total VFA concentration (mM/L) varied with lower concentration in faunated than the defaunated calves, i.e., 68.7 in FNFM vs. 98.7 in DNFM at 9 wk, and 79.1 in FFM vs. 111.7 in DFM at 13 wk of age. No significant effect of fish meal was observed in any period. The ammonia N concentration decreased at 9 wk of age in DNFM (12.6 mg/dL) and was generally lower in defaunated than faunated groups.
Ruminal Microbial Enzymes
The concentrations of different enzymes in ruminal fluid as an index of microbial activity are presented in Tables 6 and 7. The results from the postweaning period are presented to show the effects of fish meal and protozoa and their interactions.
Preweaning period – fibrolytic enzymes.
There was no cellulolytic or hemicellulolytic activity in the ruminal fluid of 4-d-old calves. The calves did not have cellulolytic activity at 1 wk of age. At 2 wk of age, the activity of CM-cellulase was observed in only 7 of 24 calves (about 30%), which increased to 52% in wk 3, and was present in all calves at 4 wk. Xylanase activity appeared at 1 wk of age in 48% of calves, which increased to 78% at 2 wk, and was present in all calves (17.9 U/dL) at wk 3. Another fibrolytic enzyme, ß-glucosidase, showed sporadic activity, i.e., only one animal at 1 wk of age, 4 animals in wk 2, and 16 (67%) in wk 3. All calves showed enzyme activities from 4 wk, which increased with age. No significant effect of fish meal was observed for any of the 3 fibrolytic enzymes.
Preweaning period – amylase and ß-galactosidase activities.
Amylolytic activity (U/dL) was observed in all calves at 4 d of age (34.6), which then increased (P < 0.05) with age (Table 7
). ß-Galactosidase activity was also present at 1 wk. The enzyme activity (U/dL) was 1.48 and 1.65 on d 4, which increased to 2.06 and 2.83 at 6 wk, and then declined to 1.00 and 0.97 at 8 wk in FM and NFM groups, respectively. The protein source in calf starter had no significant effect on amylolytic or ß-galactosidase activity.
Preweaning period – proteolytic and ureolytic enzymes.
There was a significant proteolytic activity (U/dL) in ruminal fluid of calves even at d 4 (10.1), which increased to 15.0 at 1 wk, and remained similar up to 8 wk of age. Urease activity (U/dL) showed a similar increase (8.5 on d 4 to 13.5 at 1 wk), and then reached a steady concentration. No significant difference in protease and urease activity was observed between FM and NFM groups during phases 1 and 2.
Postweaning period.
Establishment of ciliated protozoa was observed after 8 wk of age and thus the effects of fish meal and ciliated protozoa on the development of fermentative activity in the rumen were studied.
Postweaning period – fibrolytic enzymes.
The cellulolytic activity remained unaffected during 9 to 13 wk of age. Protein source in the calf starter did not have any significant effect on cellulolytic activity. The establishment of ciliates in calves did not contribute to any significant change in cellulolytic activity. Further, no significant protozoa x protein interaction was seen in any period. The effects of protozoa and protein on xylanase activity were also nonsignificant. The ß-glucosidase activity followed a similar pattern and did not show any significant difference between the groups.
Postweaning period – amylase and ß-galactosidase activities.
The amylolytic activity (U/dL), showed a declining trend in the postweaning periods (85.8 at 9 wk to 56.6 at 13 wk). The mean amylase activity was higher (P < 0.01) in defaunated than faunated calves showing a significant treatment x period interaction at 11 wk of age. No significant effect of fish meal on amylase was observed. The declining trend of ß-galactosidase activity (U/dL) continued until 13 wk of age, showing a very feeble activity (0.20) compared with its peak activity (2.38) at 6 wk of age. The effects of ciliate protozoa and fish meal were not significant.
Postweaning period – proteolytic and ureolytic enzymes.
The proteolytic activity did not change significantly in the postweaning period. No significant effect of protein, protozoa, or their interaction was observed at any period. The activity of urease (U/dL) ranged from 12.5 to 19.2. The effect of protein x protozoa interaction was also nonsignificant.
|
DISCUSSION
|
|---|
Establishment of Ciliated Protozoa
The establishment of ciliated protozoa relates to transfaunation from adult faunated animals through contact and the strategic incorporation of dry feed (prestarter, calf starter, hay, etc.) in the dietary regimen of preweaned calves. The acidic condition of rumen with milk/milk replacer and starchy calf starter prevents the establishment of protozoal population (Hungate, 1966). In the present study, acidic conditions (pH around 6.0) prevailed in the rumen up to 6 wk, which showed an increased shift in the following periods, and the establishment of ciliated protozoa after 8 wk of age corresponded to increase in ruminal pH. Bryant et al. (1958) observed ciliated protozoa after 13 wk of age in calves with entodinia, the first to be established followed by diplodinia and holotrichs. Minato et al. (1992) also observed establishment of protozoa in calves at 8 to 10 wk of age. In most of the studies, entodinia in association with holotrichs were the most common ciliates, when the diet was rich in soluble sugars (Bonhomme, 1990). Klapacova and Klapac (1991) observed very small numbers (x10) of ciliates (1.48/mL of ruminal content) at 3 wk of age, which did not increase significantly until the age of 7 wk in calves on a milk diet. In the present study, the total number of ciliated protozoa increased considerably (>15x) after initial establishment at 10 wk of age, with both holotrichs and entodiniomorphs present. With the change in feed (milk discontinued at 8 wk of age) to a more fibrous type, the pH increased and the protozoal population changed from single (entodinium) to a mixed type (Bonhomme, 1990). Moreover, the interactions between flora and fauna have an important role in the development of different ciliate population.
Ruminal Fermentative Development
Fermentation products.
The initial drop in pH was in response to milk and calf starter intake with no or negligible rumination. Subsequent increase and stabilization may be attributed to the consumption of calf starter and oat hay and chewing of cud resulting in increased salivation. Assane and Dardillat (1994) also observed a decrease in pH due to intake of solid feed in the first month compared with control animals on whole milk alone. With the increase in consumption of dry feed, the total VFA started to increase from the first week and reached a static level as in adult cattle at 4 wk of age. A consistent increase in total VFA in ruminal contents in response to dry feed intake was indicative of ruminal development. The high ammonia N concentration coincided with the period when calves were consuming more milk and then decreased with the increase in dry feed consumption. This result was in agreement with the studies that suggested low absorption and use of ammonia during first 3 wk of age (Godfrey, 1961) and then the concentration decreased, possibly because of increased bacterial assimilation, absorption, and use by ruminal epithelium, and the dilution effect from a larger total rumen volume (Vazquez-Anon et al., 1993). Consequent to increased dry feed consumption, a decrease in pH and concentration of ammonia in the rumen was indicative of increased VFA production, and development of absorptive papillae (Assane and Dardillat, 1994). Diet-induced changes in ruminal fermentation products were clearly seen from the second week onwards as evidenced by the increased consumption of calf starter. Acceleration in adaptation to dry feed consumption appeared to increase the ruminal activity, which was indicated by lower ruminal pH, increased total VFA, and changes in ammonia N concentration.
The postweaning change in fermentation products was more or less in response to solid feed intake, i.e., pH remained static between 6.2 to 6.4, total VFA showed an increasing trend (79 to 91 mM/L), and ammonia N varied between 13 and 24 mg/dL in different treatment groups. Bomba and Zitnan (1992) observed a similar increase in total VFA during 5 to 7 and 9 to 11 wk of age, with a level similar to that of adult animals being reached at 11 wk of age. Luchini et al. (1993) advocated preweaning drenching of calf starter to stimulate post-weaning adaptation to dry diets; thus, the postweaning intake would depend more on physiological adaptation. Cozzi et al. (2002) were of the same view that solid feed promoted forestomach development. Although the general development of the rumen is considered age-dependent, it is principally modulated by VFA produced by microbial fermentation of solid feed (Sutton et al., 1963; Singh et al., 1982). In the present study, calves were weaned at 8 wk of age and an initial boost for dry feed consumption was provided at 3 wk of age by reducing the milk intake to 8% of live weight.
Ruminal microbial enzymes.
Many calves showed fibrolytic activity at 1 wk (xylanase), which became prominent at 4 wk of age. The range in values for CM cellulase activity was wide at 3 wk of age, and it narrowed with age. The main fiber-degrading enzymes (CM cellulase and ß-glucosidase) were detected when calves started consuming oat hay along with an appreciable amount of calf starter at 4 wk of age. Anderson et al. (1987b) observed cellulolytic bacteria as early as 3 d of age. Amylolytic, proteolytic, and lactate-utilizing bacteria were also found, which increased progressively with age, and in calves weaned early and subjected to an increased intake of prestarter diet. They observed the most significant changes in bacterial population and metabolic activity between 4 and 6 wk of age. In the present study, presence of nonfibrolytic enzymes even at d 4 indicated their probable function at birth. These enzymes, particularly -amylase, were reflective of an increase in dry feed intake (starch). In response to milk feeding, ß-galactosidase activity increased up to 6 wk and then decreased to a nonsignificant level due to weaning at 8 wk of age.
Effect of protein source.
A nonsignificant difference between FM and NFM groups with regards to ruminal fermentation products and enzymes, DM intake, and live weight gain suggest no benefit of incorporating fish meal in the prestarter diet. Sil et al. (1994) did not observe any significant change in pH, ammonia N, protease, and urease activities except for a low total VFA concentration in bull calves fed fish meal. The earlier dry feed is introduced to the rumen of calves, the earlier microbial establishment will occur, resulting in higher ruminal fermentative activity and earlier onset of functional rumen. It may thus be hypothesized that as long as milk is fed, it meets the requirement of amino acids lacking in plant protein vis-à-vis animal protein; and later, ruminal microbial protein synthesis makes up the deficit.
Effect of defaunation.
Increased total VFA and decreased ammonia N concentrations in defaunated animals were indicative of a shift in microbial population in the rumen due to establishment of ciliated protozoa that occurred after 8 wk of age. Pal et al. (1998) observed no effect on pH and total VFA, but a decreased ammonia N in defaunated animals. However, the observations in the present study were similar to that of Santra and Karim (2002).
A positive shift in -amylase, xylanase, and urease activities in defaunated animals may be seen in terms of an adaptive increase in bacterial population due to absence of protozoa. Kurihara et al. (1978) found twice the digestion of cellulose with predominant cellulolytic population in faunated rumen compared with major amylolytic population in defaunated animals. Mendoza et al. (1993) also observed increased amylolytic activity by defaunation. Pal et al. (1998) observed higher amylase but lower urease activity with a nonsignificant effect on cellulase and xylanase in defaunated calves. Many reports have suggested protozoan engulfment of feed particles and bacteria, as the cause of decreased degradation of starch and an increased recycling of N (Bird, 1989; Williams and Withers, 1993; Jouany, 1996; Santra and Karim, 2002). This mechanism helps in stabilizing pH, on a high grain diet. Eugene et al. (2004) opined that protozoa prevent the abrupt drop of pH in the rumen showing an interaction with the level of concentrate in the diet. However, there is decreased N use due to continuous recycling of bacterial and feed N and autolysis of heavier protozoa in the rumen. Hsu et al. (1991) observed increased ruminal microbial protease activity and an inconsistent effect on deaminase activity. Fejes and Varady (1996) studied the level of rumen faunation to affect inversely the proportion of bacterial N. Quantitative meta-analysis on the effects of defaunation refers to a lower ammonia N and higher duodenal microbial N flow (Eugene et al., 2004). A lower ammonia N in ciliate-free animals may be attributed to higher microbial synthesis and less bacterial recycling (Koenig et al., 2000). Bird (1989) was of the opinion that the development of a normal microbial population was slower in defaunated (by isolation) compared with faunated animals that were inoculated with a complete package of microorganisms (bacteria, protozoa, and fungi) through rumen inoculum or through mouth-to-mouth contact as practiced in the present experiment. However, the enzyme activities, representing functional microbial population, indicated that both faunated and defaunated calves had similar age- and substrate-dependent changes.
|
CONCLUSION
|
|---|
The fermentative changes that take place in the rumen are evidence of the gradual development of the rumen, which, may be further stimulated by the inclusion of good calf starter and hay. Inclusion of a fish meal-based calf starter in the diet of preruminant calves seemed to have no advantage over plant (e.g., peanut cake) protein in influencing dry feed consumption or ruminal fermentative development. The presence of various enzyme activities in the rumen at an early age may be seen as representative of functional microbial communities, and stimulation through dry feed consumption seems to be a useful strategy.
Received for publication August 4, 2004.
Accepted for publication February 11, 2005.
|
REFERENCES
|
|---|
Anderson, K. L., T. G. Nagaraja, and J. L. Morill. 1987a. Ruminal metabolic development in calves weaned conventionally or early. J. Dairy Sci. 70:1000–1006.
Anderson, K. L., T. G. Nagaraja, J. L. Morill, T. B. Avery, S. J. Galitzer, and J. E. Boyer. 1987b. Ruminal microbial development. II. Conventionally or early weaned calves. J. Anim. Sci. 64:1215–1226.
AOAC. 1980. Official Methods of Analysis. 12th ed. Association of Official Analytical Chemists, Washington, DC.
Assane, M., and C. Dardillat. 1994. Effect of a supplement of solid feed on the digestive physiopathology of preruminant calves. Rev. Med. Vet. (Toulouse) 145:461–469.
Barnett, J. G. A., and R. L. Reid. 1956. Studies on the production of volatile fatty acids from the grass by rumen liquor in an artificial rumen. 1. Volatile acid production from grass. J. Agric. Sci. 48:315–325.
Bird, S. H. 1989. Production from ciliate-free ruminants. Pages 233–246 in The Roles of Protozoa and Fungi in Ruminant Digestion. J. V. Nolan, R. A. Leng, and D. I. Demeyer, ed. Penambul Books, Armidale, Australia.
Bomba, A., and R. Zitnan. 1992. Development of ruminal fermentation in calves during milk feeding. Vet. Med. (Praha) 37:75–82.
Bonhomme, A. 1990. Rumen ciliates: Their metabolism and relationships with bacteria and their hosts. Anim. Feed Sci. Technol. 30:203–266.
Bryant, M. P., N. Small, C. Bouma, and I. Robinson. 1958. Studies on the composition of the ruminal flora and fauna of young calves. J. Dairy Sci. 41:1747–1767.[Abstract/Free Full Text]
Cozzi, G., F. Gottardo, S. Mattiello, E. Canali, E. Scanziani, M. Verga, and I. Andrighetto. 2002. The provision of solid feeds to veal calves: I. Growth performance, forestomach development, and carcass and meat quality. J. Anim. Sci. 80:357–366.[Abstract/Free Full Text]
Eugene, M., H. Archimede, and D. Sauvant. 2004. Quantitative meta-analysis on the effect of defaunation of the rumen on growth, intake and digestion in ruminants. Livest. Prod. Sci. 85:81–97.
Fejes, J., and J. Varady. 1996. The level of faunation of rumen in relation to some factors of nitrogen metabolism. Physiol. Res. 45:117–123.[Medline]
Godfrey, N. W. 1961. The functional development of the calf. II. Development of rumen function in the calf. J. Agric. Sci. 54:177–183.
Hsu, J. T., G. C. Fahey, Jr., N. R. Merchen, and R. I. Mackie. 1991. Effects of defaunation and various nitrogen supplementation regimes on microbial numbers and activity in the rumen of sheep. J. Anim. Sci. 69:1279–1289.[Abstract]
Hungate, R. E. 1966. Pages 91–147 in The Rumen and its Microbes. Academic Press, New York, NY.
Jouany, J. P. 1996. Effects of rumen protozoa on nitrogen utilization by ruminants. J. Nutr. 126:1335S–1346S.
Kamra, D. N., R. K. Sawal, N. N. Pathak, N. Kewalramani, and N. Agarwal. 1991. Diurnal variation in ciliate protozoa in the rumen of black buck (Antilope cervicapra) fed green forage. Lett. Appl. Microbiol. 13:165–167.
Klapacova, K., and S. Klapac. 1991. Protozoan counts in the rumen of calves on a milk diet. Vet. Med. (Praha) 36:331–334.
Koenig, K. M., C. J. Newbold, F. M. McIntosh, and L. M. Rode. 2000. Effects of protozoa on bacterial nitrogen recycling in the rumen. J. Anim. Sci. 78:2431–2445.[Abstract/Free Full Text]
Kurihara, Y., T. Takechi, and F. Shibata. 1978. Relationship between bacteria and ciliate protozoa in the rumen of sheep fed on a purified diet. J. Agric. Sci. 90:373–381.
Lowry, D. H., N. J. Rosebrough, A. L. Farr, and R. C. Randall. 1951. Protein measurement with Folin-phenol reagent. J. Biol. Chem. 193:265–275.[Free Full Text]
Luchini, N. D., S. F. Lane, and D. K. Combs. 1993. Preweaning intake and postweaning dietary energy effects on intake and metabolism of calves weaned at 26 days of age. J. Dairy Sci. 76:255–266.[Abstract]
McFeters, G. A., W. E. Sandine, and P. P. Elliker. 1967. Purification and properties of Streptococcus lactis ß-galactosidase. J. Bacteriol. 93:914–919.[Abstract/Free Full Text]
Mendoza, G. D., R. A. Britton, and R. A. Stock. 1993. Influence of ruminal protozoa on site and extent of starch digestion and ruminal fermentation. J. Anim. Sci. 71:1572–1578.[Abstract]
Miller, G. L. 1959. Modified DNS method for reducing sugars. Anal. Chem. 31:426–428.
Minato, H., M. Otsuka, S. Shirasaka, H. Itabashi, and M. Mitsumori. 1992. Colonization of microorganisms in the rumen of young calves. J. Gen. Appl. Microbiol. 38:447–456.
Pal, D. T., D. N. Karma, N. N. Pathak, and G. S. Bisht. 1998. Influence of rumen ciliate protozoa and protein level on rumen fermentation, enzyme activities and blood metabolites in crossbreed cattle calves. J. Appl. Anim. Res. 13:153–159.
Quigley, J. D., III, C. G. Schwab, and W. E. Hulton. 1985. Development of rumen function in calves: Nature of protein reaching the abomasum. J. Dairy Sci. 68:694–702.
Quigley, J. D., III, Z. P. Smith, and R. N. Heitmann. 1991. Changes in plasma volatile fatty acids in response to weaning and feed intake in young calves. J. Dairy Sci. 74:258–263.[Abstract]
Santra, A., and S. A. Karim. 2002. Influence of ciliate protozoa on biochemical changes and hydrolytic enzyme profile in the rumen ecosystem. J. Appl. Microbiol. 92:801–811.[Medline]
Shewale, J. G., and J. Sadana. 1981. Purification, characterization, and properties of beta-glucosidase enzymes from Sclerotium rolfsii. Arch. Biochem. Biophys. 207:185–196.[Medline]
Sil, B., D. N. Kamra, N. Agarwal, L. C. Chaudhary, and N. N. Pathak. 1994. Effect of conventional protein sources in urea containing diets on biochemical characteristics and enzymes in the rumen of crossbred calves. Int. J. Anim. Sci. 9:69–71.
Singh, N., O. P. Nangia, Y. Singh, J. P. Puri, and S. L. Garg. 1982. Early development of rumen function in buffalo calves: Histological and histochemical changes as affected by age and diet. Ind. J. Anim. Sci. 52:490–496.
Snedecor, G. W., and W. G. Cochran. 1989. Statistical Methods. 8th ed. Iowa State Univ. Press, Ames, IA.
Sutton, J. D., A. D. McGilliard, and N. L. Jacobson. 1963. Functional development of rumen mucosa. 1. Absorptive ability. J. Dairy Sci. 46:426–436.[Abstract/Free Full Text]
Vazquez-Anon, M., A. J. Heinrichs, J. M. Aldrich, and G. A. Varga. 1993. Post weaning age effects on rumen fermentation end-products and digest kinetics in calves weaned at 5 weeks of age. J. Dairy Sci. 76:2742–2748.[Abstract]
Warner, R. G. 1984. The impact of protein solubility in dairy calf starter. Pages 42–45 in Proc. Cornell Nutr. Conf. Cornell Univ., Ithaca, NY.
Weatherburn, M. W. 1967. Phenol-hypochlorite reaction for determination of ammonia. Anal. Chem. 39:971–974.
Williams, A. G., and S. E. Withers. 1993. Changes in rumen microbial population and its activities during the refaunation period after the reintroduction of ciliate protozoa into the rumen of defaunated sheep. Can. J. Microbiol. 39:61–69.[Medline]
Zerbini, E., and C. E. Polan. 1985. Protein sources evaluated for ruminating Holstein calves. J. Dairy Sci. 68:1416–1424.
TOP
ABSTRACT
INTRODUCTION
