• Asian-Australasian Journal of Animal Sciences
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• v.23 no.8
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• pp.1034-1042
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• 2010

This study aimed to determine the optimum dietary crude protein level in a typical diet for fattening pigs fed ad libitum under normal climate conditions in Central Vietnam. One hundred and ninety two gilts of Mong Cai local breed (MC), $F_1$ Large White${\times}$Mong Cai and $F_2$ crossbreds of (Landrace${\times}$Mong Cai)${\times}$Large White were used. At the start of the experiment, Mong Cai pigs weighed 12 kg at 11 weeks of age, $F_1$ pigs 12.1 kg at 8 weeks of age and $F_2$ pigs 12.2 kg at 8 weeks of age. Four diets differing in crude protein (CP) content (10.1, 13.1, 16.1 and 18.9% in DM) were formulated from rice bran, corn meal, cassava meal and fish meal. Calculated digestible energy content of the diets ranged from 13.5 to 13.8 MJ per kg DM. Pigs were housed individually in pens of $2.5\;m^2$ each and had ad libitum access to feed in a trough as well as water in bowls. The final weights after a growing period of 150 days were 66, 86 and 96 kg for MC, $F_1$ and $F_2$, respectively. Feed intake of MC pigs was highest at 13.1% CP while $F_1$ and $F_2$ had the highest feed intake at 16.1% CP. The results showed that for MC the maximum gain was obtained at levels between 13 to 16% CP. For the $F_1$ the maximum gain was at dietary protein levels of 16-17%. For $F_2$ the max gain was obtained at CP levels of 16 to 18%. Feed conversion was highest in MC pigs (~4.0) followed by $F_1$ (~3.3) and $F_2$ (~3.1), and within genotypes was lowest at the optimum CP level (p<0.05). Back fat thickness in MC (33.1 mm), $F_1$ (23.0 mm) and $F_2$ (20.5 mm) pigs was different and within genotypes was the lowest at intermediate CP levels. In conclusion, increasing the dietary crude protein contents in practical diets for pigs in Vietnam can increase production on small holder farms. Optimal performance for MC, $F_1$ and $F_2$ pigs is achieved at different dietary crude protein contents.

• Asian-Australasian Journal of Animal Sciences
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• v.23 no.9
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• pp.1205-1212
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• 2010

The aim of the present study was to evaluate the effects of replacing 70% of the protein from fish meal by protein from ensiled or dry cassava leaves and sweet potato vines on the performance and carcass characters of growing F1 (Large White${\times}$Mong Cai) pigs in Central Vietnam. Twenty-five crossbred pigs (Large White${\times}$Mong Cai) with an initial weight of 19.7 kg (SD = 0.84) were allocated randomly to five treatment groups with 5 animals per group (3 males and 2 females). Pigs were kept individually in pens ($2.0{\times}0.8\;m$) and fed one of five diets over 90 days. The control diet was formulated with fish meal (FM) as the protein source while the other four diets were formulated by replacing 70% of fish meal protein by protein from ensiled cassava leaves (ECL), dry cassava leaves (DCL), dry sweet potato vines (DSPV) or ensiled sweet potato vines (ESPV). Animals were fed their diets at 4% of BW. Results showed that final BW, ADG, DMI and feed conversion ratio (FCR) among the experimental treatments were not significantly different (p>0.05). ECL or DCL and ESPV reduced feed cost per unit gain by 8-17.5% compared to the fish meal diet. There were no significant differences in carcass characters among the diets (p>0.05). Lean meat percentages and protein deposition ranged 41.5-45.8% and 40.2-52.9 g/d, respectively. Using ensiled or dry cassava leaves and sweet potato vine can replace at least 70% of the protein from fish meal (or 35% of total diet CP) without significant effects on performance and carcass traits of growing (20-65 kg) pigs. Including cassava leaves and sweet potato vines could improve feed cost and therefore has economic benefits.

• Asian-Australasian Journal of Animal Sciences
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• v.21 no.2
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• pp.245-251
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• 2008

The effects of feeding diets containing 20% (L) or 30% (H) neutral detergent fiber (NDF) (DM basis) on performance and carcass traits were studied in three breeds of pig, including pure Mong Cai (MC), crossbred Landrace$\times$Yorkshire (LY) and crossbred MC$\times$Yorkshire (F1). The experiment had a factorial design with two factors, breed and diet. Eighteen piglets of each breed ($60{\pm}3days$) were randomly allocated to three treatments: L-L, low fiber diet in both growing and finishing periods; L-H, low and high fiber diet in the growing and finishing period, respectively; and H-H, high fiber diet in both periods. The diets were iso-energetic and iso-nitrogenous within feeding period. The main fibrous ingredients of the diets were rice bran and cassava residue. There were no effects of fiber level on daily dry matter feed intake (DMI), expressed as g/kg metabolic body weight (BW0.75), in both feeding periods (p>0.05). DMI was highest for MC, followed by F1 and LY (p<0.001). Average daily gain (ADG) in L-L and L-H was higher than in H-H in the growing period (p<0.001) and overall (p<0.05), while feed conversion ratio (FCR) was higher in H-H than in L-L and L-H in the growing period (p<0.05) and overall, but no significant differences between treatments were found in the finishing period. In both periods, Landrace$\times$Yorkshire had the highest ADG and the lowest FCR, followed by F1 and Mong Cai (p<0.001). There were no interactions between breed and diet for performance and carcass traits. Carcass and dressing percentage was lower for L-H and H-H than for L-L (p<0.05). There were no significant differences among treatments in back fat thickness and lean meat percentage, or in crude protein and ether extract contents of lean meat. Carcass, dressing and lean meat percentage was highest for LY, lowest for MC and intermediate for F1 (p<0.001). It can be concluded that feeding a high fiber diet in the growing period reduced pig performance, but there was no effect in the finishing period. Pure Mong Cai pigs are not particularly suitable for meat purposes, although the F1 cross with Large White had reasonably good growth performance and carcass quality.

• Asian-Australasian Journal of Animal Sciences
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• v.25 no.12
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• pp.1726-1733
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• 2012

The effect of genotype, fibre level and fibre source on gut morphology, environment and microflora was studied using 18 Mong Cai (MC) and 18 Landrace${\times}$Yorkshire (LY) pigs, aged around 60 d. The diets were based on maize, rice bran, soybean meal, fish meal and soybean oil, and cassava residue (CR) or brewer's grain (BG) as fibrous ingredient sources in the high-fibre diets (HF). A low-fibre diet (LF), containing around 200 g NDF/kg dry matter (DM), was formulated without CR and BG as feed ingredients. The HF diets (HF-CR and HF-BG) were formulated to contain around 270 g NDF/kg DM. The experiment was arranged according to a $2{\times}3$ factorial completely randomized design with six replications, and lasted 30 d. Crypt density in ileum was lowest (p<0.05) and villus height in jejunum and ileum were the greatest (p<0.05) in pigs fed diet HF-BG. Villus width in ileum was greatest in pigs fed diets HF-CR and HF-BG (p<0.05). Lactic acid bacteria (LAB) counts in stomach were greatest (p<0.05) and E. coli counts in ileum and colon were lowest (p<0.05) in pigs fed diet HF-CR. The concentration of total organic acids in ileum, caecum and colon were greatest (p<0.05), and pH in ileum and colon were lowest (p<0.05) in pigs fed diet HF-CR. Crypt density in ileum was lowest, and villus height in ileum and villus width in jejunum and ileum was greatest in LY pigs (p<0.05). LAB counts in stomach and ileum were greatest, and E. coli counts in ileum were lowest in MC pigs (p<0.05). The concentration of total organic acids in ileum, caecum and colon were greatest (p<0.05) and pH lowest (p<0.05) in MC pigs.

• Asian-Australasian Journal of Animal Sciences
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• v.24 no.8
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• pp.1157-1163
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• 2011

This study was conducted to determine the effect of the inclusion of different levels of ensiled cassava leaves (variety KM94) in the diets on performance and carcass characteristics of growing pigs in Vietnam. A total of 40 crossbreds pigs (Large White${\times}$Mong Cai, 20 males and 20 females) with an initial live weight of 23.5 kg (SD = 0.86) were randomly allocated to one of the four pens across 5 units. Four experimental diets were formulated for two growth periods, period 1 (60 days) for 20 to 50 kg and period 2 lasted 30 days, from 50 kg until slaughter. Four diets were formulated containing inclusion levels of ensiled cassava KM94 leaves diet of 0, 10, 15 and 20% in the DM. Diets were formulated based on previously determined ileal amino acid digestibility values of the KM94 products and were isonitrogenous and isocaloric on a metabolizable energy basis. Each pen of pigs was randomly assigned to one of the four dietary treatments. Dry matter intake and final weight tended to decreased with increasing levels of ensiled cassava KM94 leaves in the diet while there was a significant (p = 0.022) decrease in average daily gain. Protein depositions of the F1 pigs tended (p = 0.093) to decrease with increasing inclusion levels of ensiled cassava KM94 leaves. There was no significant difference in feed conversion ratio, carcass quality and fat gain between the groups of pigs. There were clear differences in feed costs among the experimental diets (p = 0.001) with increasing levels of ensiled cassava KM 94 leaves in the diet reducing feed costs. It was concluded that, in diets for growing pig, inclusion of ensiled cassava leaves reduces growth rate of pigs in Vietnam but increases profitability as measured by feed costs.

• Asian-Australasian Journal of Animal Sciences
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• v.14 no.1
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• pp.82-87
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• 2001

A feeding trial was conducted to evaluate the effects of replacing fish meal (FM) with ensiled shrimp by-product (ESB) in a cassava root meal and rice bran-based diet on the performance and carcass characteristics of growing pigs. Thirty six crossbred (Large White$\times$Mong Cai) pigs, with an average initial BW of 19.4 kg, were randomly allocated to one of three different dietary treatments in which the crude protein of the FM was replaced with 0, 50 or 100% ESB. The animals were fed restrictedly and at the end of the experiment at a BW of about 90 kg, 6 representative animals in each treatment group were slaughtered for carcass quality evaluation. Animal growth performance and daily feed intake were significantly reduced (p<0.05) by the inclusion of shrimp by-products in the diets, whereas feed conversion ratios and carcass measurements were not significantly affected (p>0.05). Daily weight gains of the pigs fed the 100% FM diet and 50% ESB diet were significantly (p<0.05) higher than those of pigs fed the 100% ESB diet. In conclusion, from an economical as well as performance point of view, ESB can replace 50% of the crude protein of FM in cassava root meal and rice bran-based diets for growing pigs with a low genetic growth potential.

• Asian-Australasian Journal of Animal Sciences
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• v.14 no.2
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• pp.216-223
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• 2001

The digestibility of organic matter (OM), crude protein (CP), ether extract and amino acids of a cassava root meal and rice bran diet, without (Basal) and with inclusion of fish meal (FM) or fresh (FSB) or ensiled (ESB) shrimp by-product in growing pigs (Large White$\times$Mong Cai) fitted with post-valve T-caecum (PVTC) cannulas was studied in a $4{\times}4$ change-over experiment. Significantly higher ileal digestibility of OM in the basal and FM diets and lower ileal digestibility of CP in the basal and ESB diets were found (p<0.05). Total tract digestibilities of OM and CP of diet ESB were lower (p<0.05) than in the other diets. The apparent ileal digestibilities of most amino acids were higher (p<0.05) in diets FM, FSB and ESB than in the basal diet. There was no difference (p>0.05) in the ileal digestibility of individual amino acids between diets FM, FSB and ESB, except for threonine, alanine and glycine. The estimated apparent ileal digestibility of individual amino acids in ensiled shrimp by-product was lower (p<0.05) than in fresh shrimp by-product and fish meal. In conclusion, as a result of the reduced daily intake of the diets containing shrimp by-products and lower ileal and total tract digestibility of both fresh and ensiled shrimp by-products complete replacement of fish meal cannot be recommended. The ensiled shrimp by-product was inferior nutritionally compared with fresh shrimp by-product. However, lower daily feed intakes of both the FSB and ESB diets suggest that the replacement should only be made partially, in order not to reduce the overall performance.

• Asian-Australasian Journal of Animal Sciences
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• v.24 no.6
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• pp.834-843
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• 2011

Bacterial diversity was studied using PCR-DGGE, cloning and sequencing. DNA was isolated from digesta samples from stomach, ileum and colon of 28 weaned piglets (Large White${\times}$Mong Cai) fed dry control feed, naturally fermented liquid feed (FE) and a liquid diet with inclusion of rice distiller's residue feed. General bacterial diversity was described using DGGE analysis of the V3 region of 16S rDNA. The microbial populations in the stomach and the ileum were considerably influenced by the diet, while only marginal effects were observed in the colon. There was a large variation of the microbial flora in the stomach between individuals fed non-fermented diets. In contrast, animals fed diet FE had a more uniform microbial flora in the stomach and the ileum compared to the other diets. In total 47 bands from the DGGE profiles were cloned. In stomach, most frequently lactic acid bacteria were found. Feeding diet FE resulted in the occurrence of Pediococcus species in stomach and ileum. In pigs fed the other diets, Lactobacillus gallinarum, Lactobacillus johnsonii and Lactobacillus fermentum were found in stomach and ileum. Most of the sequences of bands isolated from colon samples and several from ileum matched to unknown bacteria, which often grouped within Prevotellaceae, Enterobacteriaceae, Bacteroidaceae and Erysipelotrichaceae. This study demonstrates that fermented liquid feed affects bacterial diversity and the specific microflora in stomach and ileum, which provides a potential to modulate the gut microflora with dietary means to increase the abundance of beneficial bacteria and improve piglets' health.

• Asian-Australasian Journal of Animal Sciences
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• v.13 no.9
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• pp.1278-1284
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• 2000

An experiment was performed to evaluate different methods for preserving shrimp by-products and to determine their chemical composition. In the first experiment three ratios of shrimp by-product (SBP) to molasses (6:1, 4:1 and 3:1, wet weight), and to cassava root meal (3:1, 2:1 and 1:1, wet weight of shrimp by-product and air-dry weight of cassava root meal) were investigated. The pH of the SBP ensiled with molasses at a ratio of 3:1, and with cassava root meal at a ratio of 1:1, decreased during the first week to below 4.5 and remained low up to day 56 of ensiling, whereas the pH of the mixtures with higher ratios of SBP remained above 7.0, and the material deteriorated rapidly. The dry matter decreased initially in all treatments but then increased slightly from day 28 in the treatment where shrimp by-product was ensiled with cassava root meal at a ratio of 1:1. The crude protein (CP) and ammonia-N $(NH_3-N)$ contents of the preserved shrimp by-product material ensiled with molasses at a ratio of 3:1 increased significantly one week after ensiling. The CP content then remained constant, while the $NH_3-N$ concentration continued to increase up to 56 days after ensiling. When SBP was ensiled with cassava root meal at a ratio of 1:1 the CP content of the silage increased significantly up to 21 days after ensiling and then decreased back to the original level after 56 days, whereas $NH_3-N$ increased markedly up to 14 days and then remained fairly constant up to 56 days. However, the $NH_3-N$ content was significantly higher when SBP was ensiled with cassava root meal than with molasses. A balance experiment was carried out, arranged as a double Latin-square and including 6 F1 (Large White ${\times}$ Mong Cai) castrates fed randomly one of three diets based on cassava root meal, rice bran, and fish meal (FM) or shrimp by-product ensiled with molasses (SBEMO) or with cassava root meal (SBECA) as the main protein source. Apparent organic matter and CP digestibilities were significantly (p<0.001) higher for the fish meal diet than for the two shrimp by-product diets, although CP digestibility in SBEMO and SBECA was similar (p>0.05). N-retention was significantly higher for the fish meal diet than for the SBEMO diet, which in turn was significantly higher than for the SBECA diet (p<0.01). It can be concluded that shrimp by-product can be preserved by ensiling with molasses at a ratio of 3:1 or with cassava root meal at a ratio of 1:1. Nutrient digestibility and N-retention of diets based on these shrimp by-product silages were lower than for similar diets based on fish meal, probably due to their high chitin content and inferior amino acid balance.