• Asian-Australasian Journal of Animal Sciences
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• v.20 no.8
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• pp.1215-1221
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• 2007

Three Holstein steers fitted with ruminal and duodenal cannulae were fed grass silage-based diets supplemented with potato pulp silage as a substitute for rolled corn at levels of 0%, 50% and 100% on a DM basis in a $3{\times}3$ Latin square design to investigate the effect of potato pulp silage on nitrogen (N) utilization in ruminants. Organic matter (OM) intake, and rumen and total tract digestibilities did not differ among treatment diets. Rumen and post-rumen starch digestibilities were similar among treatments, although starch intake decreased (p<0.01) with potato pulp supplementation. There were no significant differences (p>0.05) in ruminal N utilization and non-ammonia N supply to the duodenum of steers fed grass silage supplemented with potato pulp silage as a substitute for rolled corn. There were no treatment differences (p>0.05) in rumen pH, volatile fatty acid (VFA) concentration or the molar percentages of acetate and propionate. The ammonia-N concentration in rumen fluid tended to decrease (p<0.1) when rolled corn was substituted with potato pulp silage. Ether extract intake and post-ruminal digestibility significantly (p<0.01) decreased in steers fed diets containing potato pulp silage. Concentrations of total cholesterol and phospholipids in serum markedly decreased (p<0.01) with potato pulp silage supplementation without adversely affecting liver function. These data suggested that potato pulp silage has a similar value as rolled corn as an energy source for rumen microorganisms.

• Asian-Australasian Journal of Animal Sciences
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• v.22 no.5
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• pp.756-764
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• 2009

Provision of an optimal environment for the calf is critical to establishing the patterns of growth and development essential to allow the heifer to express its genetic potential for milk output and reproductive capacity during its productive life. Maternal nutrition during gestation is now recognised as a key to genetic programming in utero and this influence is extended through the complexity of hormones, growth factors and immunostimulants incorporated into colostrum and milk consumed by the neonatal calf. This natural process is most often disrupted as calves are weaned abruptly to maximise milk output for commercial exploitation. The key then is to accelerate the rate of maturation of the ruminal epithelium through the provision of concentrate starter rations and high quality forage, which promote VFA production. Management systems to promote these processes in Holstein Friesian cattle are well developed, however, little is known of these processes with buffalo and Bos indicus dairy cattle such as the Sahiwal. The development of methods to program the neonate to grow faster to puberty in these species will be important to improving their productivity for the dairy industries in tropical and sub-tropical environments in the future.

• Asian-Australasian Journal of Animal Sciences
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• v.22 no.5
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• pp.674-680
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• 2009

The objective of this study was to investigate antimicrobial activity, during the storage period, of animal feed and any effects on in vitro rumen digestion by supplementing different levels (5.55, 11.1, and 22.2 g/kg) of freeze dried citrus peel (FDCP) to the feed compared to untreated feed and feed treated with an antifungal agent (AA) at 0.05 g/kg. In a preservation test, feed supplemented with FDCP showed no deterioration over 21 days. Untreated feed and AA-treated feed, however, showed signs of deterioration after 16 days storage. Yellow colour and red colour, measured by spectro chromameter, decreased in the untreated and AA-treated feeds, but not in feed supplemented with FDCP. Aflatoxin was detected in untreated and AA-treated feeds at 16 days (8 ppb and 2 ppb) and 21 days (8 ppb and 4 ppb), but aflatoxin was not detected in the feed supplemented with FDCP. In a second experiment, fermentation by rumen microorganisms of FDCP (22.2 g/kg) and AA (0.05 g/kg) supplemented feeds was studied in vitro. Feeds were incubated with buffered rumen fluid for 3, 6, 9, 12, 24, and 48 h. Dry matter digestibility (DMD) and organic matter digestibility (OMD) were affected by treatment, but ammonia-N, total, and individual volatile fatty acids (VFA) were not adversely affected by treatment. In conclusion, the results indicated that FDCP might be useful for inhibiting microbial growth of animal feed during storage without disrupting rumen fermentation.

• Asian-Australasian Journal of Animal Sciences
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• v.20 no.1
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• pp.75-81
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• 2007

The object of this study was to determine the influence of supplementation of concentrate containing high levels of cassava chip on rumen ecology, microbial protein and digestibility of nutrients. Four, rumen fistulated crossbred beef steers with initial body weight of 400${\pm}$10 kg were randomly assigned according to a 4${\times}$4 Latin square design. The dietary treatments were concentrate cassava chip based offering at 0, 1, 2 and 3% BW with urea-treated rice straw fed ad libitum. It was found that ruminal pH was significantly decreased with increase of concentrate. Volatile fatty acids (VFA) concentration in the rumen was significantly different among treatments. In addition, a molar proportion of propionate was higher in supplemented groups at 2 and 3% BW (p<0.05), leading to significantly decreased acetate:propionate ratio. Furthermore, microbial N supply was significantly improved and was highest at 2% BW supplementation. The efficiency of rumen microbial-N synthesis based on organic matter (OM) truly digested in the rumen was highest in level of concentrate supplementation at 2% BW (80% of cassava chip in diets). Moreover, bacterial populations such as amylolytic bacteria was linearly increased, while cellulolytic bacteria was linearly decreased (p<0.01) when cattle received concentrate supplementation in all levels. The total protozoal counts were significantly increased, while fungal zoospores were dramatically decreased in cattle receiving increased levels of concentrate. In conclusion, cassava chip can be use as energy source at 80% in concentrate and supplementation of concentrate at 2% BW with urea-treated rice straw as roughage could improve rumen fermentation efficiency in beef cattle.

• Asian-Australasian Journal of Animal Sciences
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• v.16 no.6
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• pp.823-829
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• 2003

Four different types of silage from new cultivars of Napier grass (Pennisetum purpureum), cv. NG 1 and NG 2, were fed to eight wethers in order to evaluate their preference and intake by sheep. The silages were prepared from direct-cut NG 1 herbage; pre-wilted NG 1 herbage; NG 1 herbage with maize meal (5% inclusion) and NG 2 herbage with maize meal (5% inclusion). All silages were palatable to sheep. Maize-treated silage had high quality fermentation, characterized by high Fleig scores and low pH, volatile fatty acids (VFA) and ammoniacal nitrogen contents. The pH, Fleig score, in vitro digestible organic matter (IVDOMD) and ammoniacal-N contents for maize-treated cv. NG 1 silage were 3.7, 78, $540g\;kg^{-1}$ dry matter (DM ) and $0.18g\;kg^{-1}$ DM whereas, in maize-treated cv. NG 2 they were 3.6, 59, $^458g\;kg{-1}$ DM and $0.18g\;kg^-1$ DM, respectively. The superior quality of maize-treated silages made them more preferable to sheep. Among the maize-fortified silages, palatability and intake were significantly (p<0.001) greater with cv. NG 1. Although direct-cut silage had better fermentation quality compared to wilted silage, wilted silage was significantly (p<0.001) more preferable to sheep. However, there were no significant differences (p<0.05) in the levels of preference and intake of wilted silage compared to maize-treated cv. NG 2 silage, even though the latter tended to be more palatable. There were indications that high pH (4.6 vs 3.5) and IVDOMD content (476 vs $457g\;kg^{-1}%$ DM) of wilted silage contributed to higher intake, compared to direct-cut silage. It was generally concluded that pre-wilting and treatment of Napier grass with maize meal at ensiling enhances intake and palatability.

• Asian-Australasian Journal of Animal Sciences
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• v.17 no.2
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• pp.213-220
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• 2004

The purpose of this experiment was to investigate the effect of the diets supplemented with lard or prilled fat ($Carolac^{(R)}$) on lactation performance, plasma constituents and ruminal characteristics of Holstein cows under a warm climate. In trial 1, 18 Holstein cows, 14 primiparas at 43 DIM and 4 multiparas at 55 DIM, were randomly assigned into six $3{\times3}$ Latin squares, in which three dietary treatments were isoproteinous but varying in energy contents and three 21 d periods. The treatments were basal diet (Control), basal diet supplemented with 2.5% lard (LD), and basal diet supplemented with 2.5% commercial Prilled fat (PF). In trial 2, three rumen canulated pregnant nonlactating Holstein cows with 550 kg average body weight were allotted into a $3{\times}3$ Latin square design with diets same as in trial 1 were fed to the cows at the level of 1.5% body weight on dry matter (DM) basis. The results indicated that the DM intake did not differ among the treatments. Milk yield and 4% FCM yield were greater (p<0.05) in PF than in Control. LD and PF resulted in greater milk fat percentage. Protein, lactose and solid contents in milk were not different among the three dietary treatments. The concentration of nonesterified fatty acids (NEFA) in plasma was significantly greater in LD and PF than that in Control. However, the concentrations of triglycerides, urea nitrogen, and cholesterol in plasma were not significantly different among the three treatments. Although the ruminal molar percentage of isobutyrate in LD and PF was greater, no significant difference was observed in ruminal pH, NH3-N concentration and VFA production among the three treatments. Diet supplemented with fat can improve milk yield and milk fat percentage without resulting in disadvantages of ruminal characteristics in cows at early lactation and under warm climate.

• Asian-Australasian Journal of Animal Sciences
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• v.20 no.9
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• pp.1444-1452
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• 2007

An in vitro experiment was conducted to evaluate the differences in microbial activity of five faecal inocula from weaned pigs and one faecal inoculum from unweaned pigs in combination with 6 substrates. The substrates tested were negative control diet, corn, soybean meal, oligofructose (OF), ground chicory roots and a mixture (60% chicory pulp and 40% OF). The inocula used were derived from pigs fed either a corn-soy based diet without antibiotics (NCON), the NCON diet supplemented with oligofructose (OF), a mixture of chicory pulp (40%) and OF (60%) (MIX), ground chicory roots (CHR) or the NCON diet supplemented with antibiotics (PCON). The cumulative gas production measured fermentation kinetics and end products, such as total gas production, ammonia and volatile fatty acids, were also determined. Both the substrate and the inoculum significantly affected the fermentation characteristics. The cumulative gas production curve showed that different substrates caused more differences in traits of fermentation kinetics than the different inocula. Inocula of weaned pigs gave a significantly higher VFA production compared to the inoculum from unweaned animals, whilst the rate of fermentation and the total gas produced did not differ. OF showed the highest fermentation kinetics and the lowest $NH_3$, pH and OM loss compared to other substrates. It was concluded that the microbial activity was significantly affected by substrate and inoculum. Inoculum from weaned pigs had more potential for microbial fermentation of the carbohydrate ingredients and oligofructose than that of unweaned pigs. A combination of high and low polymer inulin may be more beneficial to the gut ecosystem than using high- or low-polymer inulin alone.

• Asian-Australasian Journal of Animal Sciences
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• v.16 no.8
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• pp.1137-1142
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• 2003

In a balanced incomplete block design, two dry Holstein cows were used to investigate the effect of $\beta$ 1-4 galactooligosaccharides (GOS) supplementation on nitrogen (N) utilization, rumen fermentation and microbial N supply in the rumen. During the experiment, cows were fed four diets: orchardgrass (Dactylis glomerata L.) silage (OS), OS with GOS supplementation (OSG), OS mixed with alfalfa (Medicago sativa L.) silage (MS) and MS with GOS supplementation (MSG). GOS was supplemented at 2% of dry matter intake. Diets were fed at maintenance level of protein and energy. Results showed that N digestion was affected by silage and interaction of silage and GOS supplementation. Cows fed OSG had the highest N digested (p<0.05) followed by MS, OS and MSG. Supplementation of GOS to OS or MS diets tended to improve N utilization through reducing the N losses on dairy cows. There was no effect of GOS supplementation on rumen fermentation parameters (i.e. pH, $NH_3$-N and total VFA) at 1 h and 6 h after feeding. Compared to cows fed MS, cows fed OS silage had higher (p<0.05) allantoin excretion (80.8 vs. 67.1 mmol/d) and higher (p<0.05) total purine derivatives excretion (92.9 vs. 78.5 mmol/d). The microbial N supply in cows fed OSG was higher (p<0.05) than those fed OS, MS and MSG.

• Asian-Australasian Journal of Animal Sciences
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• v.15 no.5
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• pp.687-694
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• 2002

An in vitro study was conducted to examine the effect of addition level of concentrate on fermentation characteristics and long-chain unsaturated fatty acids composition, especially conjugated linoleic acid (CLA) and trans-octadecenoic acid (t-FA) by mixed ruminal bacteria when incubated with linseed or rapeseed. Four levels (0.83, 1.25, 1.67 and 2.08%, w/v) of concentrate and ground oilseeds (linseed or rapeseed; 0.83%, w/v) were added to mixed solution of strained rumen fluid with artificial saliva (1:1, v/v) in the glass jar with a glass lid equipped with stirrer, and was incubated anaerobically for 24 h at $39^{\circ}C$. Addition level of concentrate slightly reflect on pH and ammonia concentration of the culture solution at the various incubation times when incubated with both linseed and rapeseed. Total VFA concentration slightly increased with incubation times and concentrate levels for incubations with oilseeds. While CLA composition had a clearly increasing trend with incubation time when incubated with linseed, percent CLA was relatively stable when incubated with rapeseed. Percent CLA, however, had a clearly decreasing trend with concentrate level throughout incubation times with significances at 3 h incubations when incubated with linseed (p<0.038) and rapeseed (p<0.0009). The differences in compositions of t-FA were relatively small among concentrate levels for both incubations with linseed and rapeseed. The ratios of t-FA to CLA were lower for linseed with increased proportion of CLA than for rapeseed.

• Asian-Australasian Journal of Animal Sciences
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• v.7 no.2
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• pp.265-271
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• 1994

The effect of soybean meal and barley supplementation of the utilization of rice straw was investigated. Balance trials were conducted with three Japanese Corriedale wethers fed rice straw supplemented with soybean meal and barley at three different levels of protein: low (40 g CP/d, LCP), medium (67 g/d, MCP) and high (94 g/d, HCP). In addition, all the supplements were formulated to contain the same amount of TDN (275 g/d). Voluntary intake of rice straw was not affected by any supplementation, while digestibility of organic matter in sheep given HCO diet was significantly higher (p<0.05) than those on LCP diet. Crude protein, neutral detergent fiber (NDF) and acid detergent fiber (ADF) digestibilities of MCP and HCP diets were significantly improved (p<0.05) over the LCP diet. Average daily gain of the animals under MCP and HCP diets were significantly higher (p<0.05) than those under LCP diet. Differences of rumen pH among the treatments were not significant, while concentration of rumen $NH_3-N$ was significantly higher (p<0.05) for HCP diet than for LCP and MCP diets. Total volatile fatty acids ($VFA_s$) and blood urea nitrogen (BUN) concentrations were significantly higher (p<0.05) in sheep fed MCP and HCP diets than those fed LCP diet, while plasma total protein concentration was not affected by any supplementation. Sheep fed MCP diet had a higher nitrogen retention than those fed LCP and HCP diets. It was concluded that rice straw was utilized better by sheep when SBM and barley were supplemented at the medium level of protein.