A survey of the contamination of maize with aflatoxins, fumonisins and zearalenone was carried out in the Southeastern and Central Highland provinces in Vietnam. Four provinces were chosen for sampling maize: Dong Nai (22), Binh Phuoc (25), Dak Lak (30) and Dak Nong (20). Aflatoxin B1 (AFB1), B2 (AFB2), G1 (AFG1), G2 (AFG2), fumonisin B1 (FB1), fumonisin B2 (FB2) and zearalenone (ZEA) were analysed by HPLC in 97 maize kernel samples. Fumonisins were the most common toxins found in all samples (67%), followed by aflatoxins (55.7%) and zearalenone (27.8%). The incidence of aflatoxin positive samples (61.7%) in the Southeastern provinces was higher than in the Central Highlands (50%), while fumonisins and zearalenone incidences were higher in the Central Highlands. The mean level of fumonisin B1 in samples from the Central Highlands provinces (1757 µg/kg) was significantly greater (p < 0.05) than in the Southeastern provinces (740 µg/kg). Importantly, the percentage of positive samples (about 70%) that had over 20 µg/kg (ppb) aflatoxin was very high. Moreover, many samples (53%) contained more than one mycotoxin and this result highlights the difficulty of diagnosing mycotoxicoses in the field and the need for ongoing research to reduce the occurrence of mycotoxins in Vietnamese maize.

Growth performance, digestibility, gut environment and health status were studied in weaned piglets (26–28 days of age) fed a diet without (C) or with supplementation of bacteria and a yeast (diets L, LB and LBS). Diet L was supplemented with a lactic acid bacteria (LAB) complex (Enterococcus faecium 6H2, Lactobacillus acidophilus C3, Pediococcus pentosaceus D7, and L. fermentum NC1), diet LB with the LAB complex and Bacillus subtilis H4, and diet LBS with the LAB complex, B. subtilis H4 and Saccharomyces boulardii Sb. Piglets fed diets L, LB and LBS had higher feed intake and daily gain, lower feed conversion ratio, higher ileal and total tract digestibility, and had a lower incidence of diarrhoea and a lower faecal score than piglets fed diet C (P < 0.01). Diets L, LB and LBS increased the intestinal LAB population and organic acid concentrations, and reduced E. coli counts. Supplementation with B. subtilis H4 and S. boulardii Sb resulted in higher digestibility than when supplementing with the LAB complex alone. Supplementation with S. boulardii Sb resulted in lower incidence of diarrhoea and lower faecal score than supplementation with the LAB complex alone or together with B. subtilis H4. The LAB complexes used in the current study had probiotic properties and could be used to improve the health status of weaned piglets under Vietnamese conditions.

This paper describes the results of a survey aimed at characterizing smallholder pig production systems in northern Lao PDR. A total of 341 households from five Northern provinces were interviewed in the survey. Village meetings and individual interviews, using a semi-structured questionnaire, were used to collect information. Three main pig rearing systems, free-scavenging, semi-scavenging and confinement (enclosures and pens), were found in the survey areas. These systems were practiced differently by smallholders depending on the level of intensity of crop production, ethnicity and purpose of keeping pigs. The confinement system was mainly practiced by Lao-Tai and Tibeto-Burman groups, who mainly bought piglets and fattened these pigs for sale. In contrast, the Mon-Khmer and Hmong-Mien reared pigs in free-scavenging and semi-scavenging systems, and usually keep sows for piglet production. The main factors that affected the changes in rearing systems were found to be level of intensity of crop production. local regulations and outbreaks of disease. The main constraints found in smallholder systems were outbreaks of disease, high mortality of piglets and the slow growth rate of fattening pigs.

Thirty castrated finishing male pigs were used to evaluate the effects of replacing fish meal (FM) with ensiled Tra catfish (Pangasius hypophthalmus) by-products (ECM) on performance and carcass quality. Pigs were allocated to individual pens and fed a control diet (ECMO) with FM as sole protein supplement, and experimental diets where 100 (ECM 100), 75 (ECM75), 50 (ECM50) and 25% (ECM25) of the crude protein (CP) from FM was replaced by the CP from ECM. Feed intake was highest in ECM25 and lowest in ECM75 (P<0.05), and daily weight gain was higher in ECM100 than in the other treatments (P<0.01). Feed conversion ratio was improved (P<0.05) with higher inclusion of ECM in the diets. Carcass yield and dressing percentage were not affected (P>0.05) by treatment, but leaf fat and backfat thickness were higher and loin eye area lower in ECM 100 compared with ECM (P<0.01). Ether extract and polyunsaturated fatty acid contents and meat colour values in Longissimus dorsi muscle increased (P<0.01) with ECM replacement level. Feed costs were lower in ECM 100 and ECM75 compared with ECM25 and ECM0.

The aim of the study was to evaluate the effects of fibre source (cassava residue, CR and sweet potato vines, SPV), particle size (1 mm and 3 mm screen size) and multi-enzyme supplementation (mixture of alpha-amylase, beta-glucanase, cellulase and protease) on growth performance and the coefficient of total tract apparent digestibility (CTTAD) in weaning and growing pigs (Landrace x Yorkshire). The experimental diets were based on maize, fish meal, full fat soybean, soybean meal, soybean oil and CR or SPV. The dietary levels of CR and SPV were 200 and 350 g/kg (as fed) in the post-weaning and growing period, respectively. The experiment was arranged according to a 2 x 2 x 2 factorial completely randomized design with five replications, and lasted 60 days with two periods: from 30 to 60 days of age (post-weaning) and 60 to 90 days of age (growing). In each period, pigs fed the CR diet had higher CTTAD of dietary components (except for ether extract), average daily gain and lower feed conversion ratio than those fed the SPV diet (P<0.05). The reduction in particle size increased the CTTAD of dietary components and average daily gain in the post-weaning period (P<0.05), but not in the growing period (P>0.05). Addition of the enzyme mixture improved the CTTAD and growth performance in the post-weaning period (P<0.05). There was an interaction between particle size and multi-enzyme supplementation on the CTTAD of crude protein and neutral detergent fibre (P<0.05) in the post-weaning period, such that multi-enzyme supplementation increased the CTTAD of CP and NDF in the larger particle size diet (0.80 versus 0.75, and 0.58 versus 0.51, respectively), while there was no changes in the small particle size diet (0.80 versus 0.78, and 0.59 versus 0.55, respectively). However, in the growing period multi-enzyme supplementation had no positive effect on the performance and the CTTAD of dietary components, with the exception of the CTTAD of crude protein and neutral detergent fibre.In conclusion, a reduction in particle size and multi-enzyme supplementation improved the CTTAD of dietary components and the growth performance in the post-weaning period, but not in the growing period. (C) 2011 Elsevier B.V. All rights reserved.

Two experiments were conducted to investigate the effect of dietary supplementation of Bacillus, Saccharomyces and lactic acid bacteria (LAB) on performance and nutrient digestibility in grower and finisher pigs. In Exp. 1, 80 pigs (32 females and 48 males), 28.7 +/- 0.9 kg body weight (BW), were randomly divided into 4 treatment groups balanced for sex and weight (5 pigs per pen, 4 pens per treatment). They were fed one of four diets: a basal grower (20-50 kg BW) and finisher (>50 kg BW) diet without any addition of probiotic or antibiotic (diet C), the basal diet supplemented with Bacillus subtilis H4 (diet B), diet B supplemented with Saccharomyces boulardi Sb (diet BS) and diet BS supplemented with a LAB complex (diet BSL). The LAB complex consisted of Enterococcus faecium 6H2, Lactobacillus acidophilus C3, Pediococcus pentosaceus D7, and Lactobacillus fermentum NC1. In Exp. 2, 16 male pigs, 29.2 +/- 0.8 kg BW, were kept in individual pens and divided into 4 groups (4 pigs in each group). All 4 groups were given exactly the same growing-period diets (diet C, B, BS and BSL) as in Exp I. The total faeces and urine were collected during 5 days (day 20-24) to determine nitrogen retention and total tract digestibility. In the growing period, average daily feed intake (ADP!), average daily gain (ADG) and feed conversion ratio (FCR) were not affected by diet B and BS (p>0.05), but ADG increased (+5.9%) (p<0.05) and FCR improved (+5.9%) (p<0.05) on diet BSL compared with the control, although ADFI was not different (p>0.05). Digestibility of crude protein and organic matter was higher (p<0.05) in diet BSI, and digestibility of crude fibre was higher (p<0.05) in diet BS and BSL than in diet C. Nitrogen retention was not affected by diet (p>0.05). The faecal LAB counts were increased in grower pigs fed diet BSL (p<0.05) and faecal E. coli counts were decreased in pigs fed diets BS and BSL (p<0.05). In the finishing period, no effects of diet were found in ADFI, ADG, FCR, nutrient digestibility, and nitrogen retention (p>0.05). Faecal LAB and E. coli counts in the finisher pigs were not affected by diet (p>0.05). In conclusion, the current study demonstrates that a mixture of bacteria and yeast has the potential to be used as a probiotic dietary supplement in grower pigs.

A series of experiments were conducted at the farm of CelAgrid in Kandal Province, Cambodia. Experiment 1 consisted of two related cafeteria trials which were conducted to determine the feed preferences of local chickens when fed different feeds separately. The first trial was conducted for 4 weeks with 40 chickens allocated to 4 pens with 10 birds per pen. They were given free access to three types of chopped green forage (taro leaf, duckweed and water spinach) and broken rice as source of energy. The daily dry matter (DM) intake of duckweed (3.9 g) was higher than that of water spinach (2.1 g), while the intake of taro leaf was relatively low (0.02 g). The crude protein (CP) intakes were 1.1 g, 0.5 g and 0.02 g for duckweed, water spinach and taro leaf, respectively. The second trial was conducted with the same duration and the same number of birds per pen. They were given free access to 3 types of fresh chopped carbohydrate feed (cassava root, sweet potato tuber and banana fruit) and duckweed as the only source of protein The daily DM and CP intakes of sweet potato and cassava root were 16 g and 0.5 g for DM and CP, respectively, while the banana fruit intake was low. Experiment 2 was carried out for 2 weeks with 240 local chickens at the age of 60 days (144 females and 96 males). The chicks were housed 10 per pen (4 males and 6 females). The experiment was a 4*2 factorial arrangement in a completely randomized design (CRD) with 3 replications. The chickens had free access to each of the carbohydrate feeds (broken rice, cassava root, sweet potato tuber, and banana fruit) and each of two proteins feeds (soybean meal and duckweed). The total daily DM intake of the broken rice diet was 32.0 g, and was 26.6 g, 24.0 g and 22.5 g of fresh cassava root, sweet potato tuber and banana fruit, respectively. The CP intake of chickens on duckweed was 19.2 g, which was lower than of those fed on soybean meal (34 g). The CP intake of chickens fed different carbohydrates was similar (5-7 g) but the CP intake of the chickens fed on soybean meal was higher (10.4 g) than on duckweed (2 g). The chicks did not gain weight on duckweed, except on the broken rice diet, and had normal growth on soybean meal (4-6 g). Through linear regression analysis, the DM intake was shown to have close relationship to the average daily gain (R 2 =0.70).

Two experiments were conducted to determine i) the fermentation characteristics of catfish by-product (C) ensiled with rice bran (RB) or sugarcane molasses (M) in different ratios, and ii) the digestibility of the silages in growing pigs. In the ensiling experiment, there were three ratios of C, ensiled with RB or M, of 8:2, 7:3 and 6:4 (wet basis for C and air-dry basis for RB and M). The six treatments were CRB8:2, CRB7:3, CRB6:4, CM8:2, CM7:3 and CM6:4, with 3 replications per treatment and seven sampling times. The pH of CRB7:3 and CRB6:4 decreased (p<0.05) from the first week and stayed stable until 8 weeks of ensiling, but the pH did not decrease in CRB8:2. The pH of CM8:2, CM7:3 and CM6:4 decreased rapidly from the first week until week 8. Dry matter (DM) and crude protein (CP) contents were slightly lower when catfish by-product was ensiled with RB than with M. Ammonia content in all treatments increased (p<0.05) during ensiling. Lactic acid content in silages with molasses increased from the first week, with the highest value at week 4. However, the lactic acid content in CRB8:2 did not increase with time and had the lowest value of all treatments. Acetic acid proportions of total volatile fatty acids were low at day 0, with the highest value at day 7, decreasing slowly until 8 weeks. The butyric acid proportion was highest at day 0 and decreased up to week 8. The proportion of propionic acid increased during ensiling. The digestibility experiment had a 4x4 Latin-square design and included 4 castrated crossbreed (Yorkshire×Landrace) male pigs fed four diets. The basal diet (BD) included rice bran, broken rice and maize meal, and the other three diets included fish meal (FMD) or catfish by-product ensiled with rice bran (CRBD) or sugarcane molasses (CMD). The silages chosen were those which gave the best results in the ensiling experiment for each additive. The coefficient of total tract apparent digestibility (CTTAD) of DM and organic matter (OM) was not significantly different among treatments. The CTTAD of CP was not different among the silage diets, but was lower in BD (p<0.01). The CTTAD of ether extract (EE) was higher in the catfish by-product silage diets than in FMD and BD. There was no significant difference in the digestibility of DM, OM, CP and EE between the fish meal and the by-product silages. In conclusion, catfish by-product can be successfully preserved by ensiling. Moreover, the total tract apparent digestibility of OM, CP and EE in ensiled catfish by-product was comparable with that of fish meal.

A survey was carried out in the North of Lao PDR to study feeding systems and the performance of pigs in smallholder systems. A total of 341 farmers from five provinces were interviewed. To feed their pigs, farmers mainly rely on feedstuffs produced on the farm and collected from areas near the village. The feedstuffs used included by-products such as rice bran and distiller's waste, planted feeds, mainly maize and cassava, and various green plant materials. The feedstuffs used are usually high in energy and low in protein content, and the only readily available protein source is green plant material. This results in nutritionally imbalanced diets and as a result poor pig performance. The average growth rate of pigs in these systems was found to be only approximately 100 g/day. The reproductive performance of sows was found to be relatively low, as is the case of local breeds in the region, with an average litter size at birth of 6.8 piglets. The mortality of piglets was as high as 50% and was a main concern of farmers. In order to improve the productivity of pigs in smallholder systems, there is a need to find alternative feed resources to improve the nutritional feed quality, and to develop management systems which are suited to the needs and practices of smallholders.

A feeding trial with growing pigs was carried out in which fish meal was replaced by different levels of Tra catfish (Pangasius hypophthalmus) by-product processing waste water (WW). A control diet included fish meal (FM) as the sole protein supplement (WW0), and there were four experimental diets in which 100% (WW100), 75% (WW75), 50% (WW50), and 25% (WW25), respectively, of the crude protein from FM in WW0 was replaced by WW. Thirty crossbred castrated (Yorkshire × Landrace) male pigs with an initial average body weight of 23.6 ± 1.6 kg were allocated into 30 individual pens in a randomized complete block design with six replications. Average daily feed intake and essential amino acid intakes were higher (P < 0.01) in WW0 and WW25 compared with the other three diets, and ether extract intake was highest in WW100 (P < 0.01). The highest average daily gain was in WW0 (582 g/day) and lowest in WW100 (501 g/day; P < 0.01). Dry matter feed conversion ratio was lowest in WW100 (2.16 kg feed/kg gain) and highest in WW0 (2.42 kg feed/kg gain) (P < 0.01).The cost/gain in pigs fed WW100 was lowest (12,476 VND/kg gain), and was highest in WW0 (18,312 VND/kg gain). In conclusion, although performance is reduced, it is possible to replace up to 100% of the fish meal by catfish by-product processing waste water in diets for growing pigs, resulting in much lower feed costs.

The impact of supplementing a diet with lactic acid bacteria (LAB) complexes of LAB selected for probiotic properties, on growth performance, digestibility, gut environment and health status was studied in weaned piglets. Ninety-six (48 females and 48 males) piglets (L×Y) from 12litters, weaned at 21–23days of age (6.6±0.5kg body weight), were selected and divided randomly into 4 groups balanced for sex, weight and litter origin. In each group, the piglets were divided randomly into 4 pens (replicates), and each group was fed one of 4 diets for 35days. A basal diet without antibiotics or probiotics was used as control, and the other 3 groups were fed the control diet supplemented with 600ppm of one of three different LAB complexes, comprising combinations of Enterococcus faecium 6H2, Lactobacillus acidophilus C3, Pediococcus pentosaceus D7, L. plantarum 1K8 and L. plantarum 3K2. Supplementation with LAB complexes increased (P<0.05) daily feed intake and weight gain and improved feed conversion ratio, but there were no differences among the LAB treatments (P>0.05). In the first 2weeks after weaning, supplementation with LAB complexes increased (P<0.05) the ileal apparent digestibility of crude protein (CP), crude fibre (CF) and organic matter, and the total tract apparent digestibility of CP and CF. Supplementation with LAB complexes increased the LAB counts at all sampling sites (P<0.05) at days 14 and 35 post-weaning and increased the concentrations of lactic acid and acetic acid (P<0.05) in ileum and colon. Counts of E. coli remained unaffected by LAB complex supplementation (P>0.05). In the first 2weeks after weaning, piglets fed diets supplemented with LAB complexes were less affected by diarrhoea than piglets fed the control diet suggesting that the LAB complexes tested have probiotic properties in weaned piglets.

Ninety-six weaned (21–23days of age) piglets (L×Y) from 12litters were divided into 4 groups and fed a piglet diet ad libitum without and with supplementation of 600ppm of one of three selected probiotic complexes in a 35-day growth trial. Piglets fed probiotic diets had higher feed intake and daily gain, and better feed conversion, than the control group (P<0.05) during the 1st two weeks after weaning. There was no effect of probiotic supplementation on performance (P>0.05) during weeks 3 to 5 after weaning. The concentration of lactic and acetic acid was higher (P<0.05) in ileum and colon of piglets fed probiotic diets on days 14 and 35, while propionic acid was higher only in the ileum on day 35 (P<0.05). There were no differences among the different probiotic complexes (P>0.05).

Ileal and total tract digestibility and nitrogen (N) balance of diets with four different protein sources were determined in growing pigs The diets were based on rice bran, broken rice and maize meal and contained Tra catfish by-product (CBP). processed using three different methods, and marine fish meal (FM) The CBP diets consisted of the by-product in meal form, ensiled with molasses. and CBP waste water (WWBD) The four diets were fed to four growing pigs fitted with post-valve T-cecum (PVTC) cannulas in a 4x4 Latin Square design All experimental diets included Cr(2)O(3) at 5 g/kg feed as an indigestible marker The ileal apparent digestibility of organic matter and ether extract was higher on diet WWBD than on the other three diets (p<0 05). and the total tract apparent digestibility was higher on diet WWBD than on the FM diet (p<0 05) The deal and total tract apparent digestibility of crude protein and amino acids was not significantly different among diets (p>0 05) No significant effects of diet were found on N-retention and N utilization In conclusion, the catfish by-product meal, ensiled catfish by-product and processing waste water diets and the fish meal diet had similar ileal and total tract apparent digestibility, and similar N utilization in growing pigs

Ileal and total tract digestibility of low and high-fibre diets (100 and 200 g/kg neutral detergent fibre), with or without enzyme supplementation (mixture of cellulase, beta-glucanase, alpha-amylase and protease) was determined in piglets of two breeds weaned at 30 days of age. The breeds were local (pure-breed Mong Cai, MC) and exotic (Landrace x Yorkshire, LY). The experimental diets were based on maize meal, soybean meal, fish meal, cassava residue meal, and rice bran. Cassava residue meal and rice bran were the main fibrous feeds in the high-fibre diet. The experiment was arranged according to a 2 x 2 x 2 factorial, completely randomized design with 4 replications, and lasted for 30 days. The coefficient of ileal apparent digestibility (CIAD) was measured by analyzing ileal digesta collected from piglets killed at 60 days of age. The coefficient of total tract apparent digestibility (CTTAD) was measured by analyzing faecal samples collected for 5 consecutive days immediately before the experiment finished. The CIAD and CTTAD of organic matter, crude protein, crude fibre, neutral detergent fibre, acid detergent fibre and amino acids in the high-fibre diet were lower than in the low-fibre diet (P<0.01). The CIAD of nutrients and amino acids was similar (P>0.05) between MC and LY, while the CTTAD of nutrients was higher for the MC than for LY (P<0.05). Enzyme supplementation of the high-fibre diet improved daily gain and the digestibility of all dietary components at the ileum and in the total tract (P<0.05), but there was no effect of enzyme supplementation of the low-fibre diet (P>0.05). (C) 2009 Elsevier B.V. All rights reserved.