Palm Kernel Expeller Research Articles

Frass Production From Black Soldier Fly Larvae Reared On Palm Oil Wastes

The availability of decanter cake (DC) and palm kernel expeller (PKE) from palm oil processing remains high owing to the major revenue earned from palm oil industry. Rearing black soldier fly larvae (BSFL) using DC and PKE as substrate to produce frass could solve the indiscriminate disposal of these wastes. Rearing BSFL was carried out by hatching the black soldier fly eggs in the trays size of 65 cm length x 37 cm width x 15 cm depth laid with processed soybean as starter diet for a week. After seven days, the DC and PKE were fed to the BSFL as main substrates and continued for another 38 days until the BSFL reached to pupae stage. Temperatures of the ambient and rearing substrate were monitored daily for 45 days. The frass of BSFL was analyzed for some selected physico-chemical properties and germination test to ascertain the quality of the BSFL frass to be used as organic fertilizer. Colour of the BSFL frass, electrical conductivity (EC), organic matter (OM), pH, total carbon (C), nitrogen (N), C/N ratio, ammonium, and nitrate contents were determined using standard procedures. Frass was produced at 45 days of rearing BSFL after which the larvae were turn to pupae. Frass consists of excretions, substrate residues, and shed exoskeletons of the BSFL. The pH of BSFL frass was 7.41, whereas the EC (1.21 mS/cm) was in the range of permissible level for its uses as organic fertilizer. The BSFL frass contain 1.68% total N, 8870.19 mg kg−1 ammonium, and 5453.20 mg kg−1 nitrate which were higher than those of initial mixture of the feeding substrate due to the decomposition process of the organic substrates which is related to the lower content of total OM (45.23%) and C (26.23%). Germination of white radish (test crop) on a distilled water and the different extractions of BSFL frass were not significantly different suggested that the frass produced from BSFL fed on DC and PKE had no toxic effects on plant. Decanter cake and PKE could be used as rearing substrate for BSFL to produce frass based on the appropriate values of pH, EC, total N, ammonium, nitrate, total organic matter and total organic C, and C/N ratio.

Fungal Fermented Palm Kernel Expeller as Feed for Black Soldier Fly Larvae in Producing Protein and Biodiesel.

Being the second-largest country in the production of palm oil, Malaysia has a massive amount of palm kernel expeller (PKE) leftover. For that purpose, black soldier fly larvae (BSFL) are thus employed in this study to valorize the PKE waste. More specifically, this work elucidated the effects of the pre-fermentation of PKE via different amounts of Rhizopus oligosporus to enhance PKE palatability for the feeding of BSFL. The results showed that fermentation successfully enriched the raw PKE and thus contributed to the better growth of BSFL. BSFL grew to be 34% heavier at the optimum inoculum volume of 0.5 mL/10 g dry weight of PKE as compared to the control. Meanwhile, excessive fungal inoculum induced competition between BSFL and R. oligosporus, resulting in a reduction in BSFL weight. Under optimum feeding conditions, BSFL also registered the highest lipid yield (24.7%) and protein yield (44.5%). The biodiesel derived from BSFL lipid had also shown good compliance with the European biodiesel standard EN 14214. The high saturated fatty acid methyl esters (FAMEs) content (C12:0, C14:0, C16:0) in derived biodiesel made it highly oxidatively stable. Lastly, the superior degradation rate of PKE executed by BSFL further underpinned the sustainable conversion process in attaining valuable larval bioproducts.

Blended Sewage Sludge–Palm Kernel Expeller to Enhance the Palatability of Black Soldier Fly Larvae for Biodiesel Production

Black soldier fly larvae (BSFL) have been employed for valorizing organic waste materials as the larvae are able to consume organic waste and transform it into valuable larval biomass. In this study, BSFL were found to potentially reduce blended sewage sludge. The addition of palm kernel expeller (PKE) fortified the protein and lipid content in blended sewage sludge substrates, leading to larval growth enhancement. In addition, the larval weight also influenced the lipid yield and fatty acid methyl ester (FAME) profile. However, the optimum ratio of sewage sludge to PKE had to be determined as excess PKE content could become a threat to larval growth by contributing to the reduction of non-fiber carbohydrates content in the feed, thereby resulting in the decrease in lipid yield and FAME content. In this work, a sewage sludge to PKE ratio of 2:3 proffered the highest larval weight gained at 46.99 ± 2.09 mg/larva. Meanwhile, a proportion of 3:2 of sewage sludge to PKE was able provide the highest lipid yield of 17 ± 1.77%. Furthermore, the FAME profile revealed the presence of a significant amount of saturated and monosaturated fatty acids, indicating a good quality biodiesel. Thus, BSFL-based biodiesel fed with blended sewage sludge and PKE could be utilized for producing a high quality biodiesel. However, further improvement on the amount of lipid yield and FAME content should be further investigated.

Effects of carbon sources on the culture of giant river prawn in biofloc system during nursery phase

A six-week nursery culture of giant river prawn Macrobrachium rosenbergii was conducted in a zero-water exchange biofloc technology (BFT) system. Water quality, microorganisms, proximate composition and growth performance of prawn were compared by using five different carbon sources: wheat bran (WB), rice flour (RF), molasses (MO), maize starch (MS) and palm kernel expeller (PKE). These carbon sources were added at a carbon-nitrogen ratio of 15:1. Fifteen 125 L polyethylene tanks with water volume of 100 L were used for this experiment. Each tank was stocked with 100 postlarvae (average initial weight 21.9 ± 2.3 mg). Each treatment was randomly assigned in triplicate. The water quality parameters viz. temperature, pH, dissolved oxygen and ammonia-N did not differ (P > 0.05) among five different carbon treatments. MO based BFT system had significantly (P < 0.05) lowest nitrite-N and the highest biofloc volume than other treatments. The postlarval survival (88.6 %) was significantly higher (P < 0.05) in MS treatment and followed by RF (73.0 %), MO (68.3 %), WB (61.0 %) and PKE (56.3 %) treatments, respectively. Significantly (P < 0.05) better FCR (2.21) was obtained in MS treatment. The final weight, weight gain and specific growth were similar (P> 0.05) among the five treatments. Higher gross return, net return and benefit-cost ratio were obtained in MS group than WB, MO and PKE. Significantly (P < 0.05) the highest lipid (1.97 % dry weight) was obtained in MS bioflocs and followed by RF, WB, MO and PKE bioflocs, respectively. The present study indicated that MS carbon source for biofloc technology enhanced M. rosenbergii postlarval survival and growth.

Enhancing Broilers Performance Fed Palm Kernel Expeller (PKE) Feeds Fortified with Supplements

Poultry production in Malaysia is heavily dependent on imported feed ingredients. There is a need to utilize local feed ingredients such as palm kernel expeller (PKE) to sustain poultry industry through physical treatments and so that it suitable to be incorporated into the feeds. Hence this study evaluates on the effects of control (0% PKE), untreated PKE (UPKE) , extruded PKE (EPKE), less-shell PKE (LSPKE) and extruded less-shell PKE (ELSPKE) at 10%, 20% and 30% inclusion rates in finisher diets (d 21-42) showed that growth performance of broilers (Cobb 500) fed 10% PKE, 20% LSPKE and ELSPKE, were comparable to control birds. At 30% PKE inclusion, broilers performance was significantly (P&lt;0.05) reduced. Birds fed PKE diets, irrespective of treatments and inclusion levels had lower LDL and total cholesterol, and similar villi height and crypt depth compared to control. At 30% PKE inclusion level, although energy metabolism was enhanced, as indicated by the up-regulation of hexokinase I and phosphofructokinase, but broilers growth performance did not improve. The feeding trial showed that broilers fed 25% or 30% LSPKE (grower feed, d 16-24), followed by 20% LSPKE (finisher feed, d 25-35) containing feed supplements 0.02% commercial enzymes and 0.30% humic acid), had comparable FI, BWG and FCR to broilers fed commercial feeds. Broilers fed 25% or 30% UPKE (grower feed, d 16-24) followed by 20% UPKE (finisher feed, d 25-35) showed significantly higher (P&lt;0.05) FCR compared to birds fed commercial feeds. The cost of feeds for production of birds fed LSPKE feeds (2.27-2.29 RM/kg liveweight), was lower than those fed commercial feeds (2.36 RM/kg liveweight). The study showed that physical treatments enhanced the nutritive value of PKE and feeds containing 25-30% and 20% LSPKE as grower and finisher rations, respectively, could attain broilers growth performance comparable to broilers fed commercial feeds.

Effects of carboxymethylation, acidic treatment, hydroxypropylation and heating combined with enzymatic hydrolysis on structural and physicochemical properties of palm kernel expeller dietary fiber

Effects of acidic treatment, hydroxypropylation, carboxymethylation and heating combined with enzymatic hydrolysis on structural and physicochemical properties of palm kernel expeller dietary fiber (PKEDF) were studied. The carboxymethylation, hydroxypropylation and heating combined with enzymatic hydrolysis effectively improved soluble dietary fiber (SDF) content, water retention capacity (WRC), emulsifying ability index (EAI), water swelling capacity (WSC), viscosity and α-amylase inhibition activity of PKEDF. The carboxymethylation also significantly (p < 0.05) increased emulsion stability index (ESI), but decreased oil retention ability (ORA) and brightness of PKEDF. Besides, the enzymatic hydrolysis with heating significantly enhanced ORA of PKEDF (p < 0.05). In contrast, the acidic treatment decreased the WRC, ORA and EAI of PKEDF. These effects were mainly attributed to the composition and structural modifications as evident from scanning electron microscopy, Fourier-transformed infrared spectroscopy and X-ray diffraction analysis. The changes in physicochemical properties of PKEDF caused by these modification methods can expand its applications in food and other industries.

Replacing Barley and Soybean Meal With By-products, in a Pasture Based Diet, Alters Daily Methane Output and the Rumen Microbial Community in vitro Using the Rumen Simulation Technique (RUSITEC).

Plant based by-products (BP) produced from food and bioethanol industries are human inedible, but can be recycled into the global food chain by ruminant livestock. However, limited data is available on the methanogenesis potential associated with supplementing a solely BP formulated concentrate to a pastoral based diet. Therefore the objective of this in vitro study was to investigate the effects of BP inclusion rate (in a formulated concentrate) to a pasture based diet on dietary digestibility, rumen fermentation patterns, methane production and the prokaryotic microbial community composition. Diets consisted of perennial ryegrass and one of two supplementary concentrates, formulated to be isonitrogenous (16% CP) and isoenergetic (12.0 MJ/ME/kg), containing either 35% BP, barley and soybean meal (BP35) or 95% BP (BP95) offered on a 50:50 basis, however, starch, NDF and fat content varied. The BPs, included in equal proportions on a DM basis, were soyhulls, palm kernel expeller and maize dried distillers grains. The BP35 diet had greater (P < 0.05) digestibility of the chemical constituents DM, OM, CP, NDF, ADF. Greater total VFA production was seen in the BP35 diet (P < 0.05). Daily methane production (mmol/day; +22.7%) and methane output per unit of total organic matter digested (MPOMD; +20.8%) were greatest in the BP35 diet (P < 0.01). Dietary treatment influenced microbial composition (PERMANOVA; P = 0.023) with a greater relative abundance of Firmicutes (adj P < 0.01) observed in the BP35. The Firmicutes:Bacteroidetes ratio was significantly reduced in the BP95 diet (P < 0.01). The relative proportions of Proteobacteria (adj P < 0.01), Succinivibrionaceae (adj P < 0.03) and Succinivibrio (adj P = 0.053) increased in the BP95 diet. The abundance of Proteobacteria was found to be negatively associated with daily methane production (rs, −0.71; P < 0.01) and MPOMD (rs, −0.65; P < 0.01). Within Proteobacteria, the relationship of methane production was maintained with the mean abundance of Succinivibrio (rs, −0.69; P < 0.01). The abundance of the Firmicutes phyla was found to be positively correlated with both daily methane production (rs, 0.79; P < 0.001) and MPOMD (rs, 0.75; P < 0.01). Based on in vitro rumen simulation data, supplementation of an exclusively BP formulated concentrate was shown to reduce daily methane output by promoting a favorable alteration to the rumen prokaryotic community.

The potential use of torrefied Nigerian biomass for combustion applications

Many countries are seeking to expand their use of solid biomass for electricity and heat generation. Nigeria, too, is exploring its own potential energy crops and indigenous residues. The use of this biomass for energy production is, however, limited by factors such as high moisture content, low bulk and low energy density. This study examines the torrefaction and combustion properties of four readily available Nigerian woody biomass, Gmelina arborea, Terminalia superba, Nauclea diderrichii, Lophira alata and a residue, palm kernel expeller (PKE). They are considered for their suitability for use in large scale power stations, especially as pulverized fuels.The Fuels were torrefied at 270 and 290 °C for either 30 or 60 min, and assessed for pyrolysis and combustion characteristics in comparison to their untreated counterparts. Energy densities of the woods improved from 19.2 to 21.2 MJ/kg for the raw fuels to 21.5–24.6 MJ/kg for the torrefied fuels. The milling behaviour of the torrefied fuels improved upon torrefaction, especially for Nauclea; however, torrefaction had very little effect on the grindability of PKE. The apparent first order kinetics for pyrolysis were determined by thermogravimetric analysis (TGA). After torrefaction, the fuels become less reactive; Nauclea and Gmelina were the most reactive fuels, whilst PKE was the least reactive. The combustion behavior of selected fuels was visually examined in a methane air flame. This showed that torrefaction resulted in shorter ignition delay, shorter duration of volatile combustion and longer duration of char burn out.

Prebiotic effects of oligosaccharides extracted from palm kernel expeller on different levels of &lt;i&gt;Salmonella typhimurium&lt;/i&gt; infection in chicks

Prebiotic effects of oligosaccharides extract from palm kernel expeller (OligoPKE) on Salmonella typhimurium were investigated in chicks in two experiments. Results of the first experiment showed that OligoPKE reduced the colonization of Salmonella typhimurium in the cecum and increased the immunoglobulin A (IgA) production in the blood and jejunum. The second experiment further investigated the prebiotic efficacy of dietary supplementation of OligoPKE on three levels of Salmonella typhimurium infection (1.0 x 10 4 Colony-forming unit (CFU)/mL; 1.0 x 10 6 CFU/mL and 1.0 x 10 8 CFU/mL) in chicks. OligoPKE reduced the colonization of Salmonella in the medium and high levels of infection. IgA level in serum and jejunum content increased significantly in all the three levels of infection when chicks received OligoPKE in their diet. Interleukin 8, and 10; interferon-α; and tumour necrosis factor genes were up-regulated in the jejunum of the infected chicks, and OligoPKE down-regulated these gene expressions. Results of the current study indicated that OligoPKE, an oligosaccharides extract from palm kernel expeller, is capable of reducing colonization of Salmonella typhimurium in young chicks, and boosted their immunity. Keywords: chicken, immunoglobulin, immune gene, microbial population

Influence of Supplemental Feed Choice for Pasture-Based Cows on the Fatty Acid and Volatile Profile of Milk.

The purpose of this study was to examine the impact of a variety of supplemental feeds on the composition and quality of milk in a pasture-based dairy system. Four pasture-supplemented feeding systems were compared: Group 1 supplementation with 16% crude protein parlour concentrate (CONC); Group 2 supplementation with palm kernel expeller plus parlour concentrate (PKE); Group 3 supplemented with soya hulls plus parlour concentrate (SOYA); Group 4 was supplemented with molassed beet pulp plus parlour concentrate (BEET). Supplemental feeding system was demonstrated to have a significant effect on the size of native casein micelles and the gelation properties of milks. While CONC feeding produced significantly higher casein micelle size, gel strength (Young’s Modulus) was significantly negatively correlated with casein micelle size. Supplemental feeding system had a significant effect on a number of fatty acids (FA) and indices derived therefrom, including total saturated and unsaturated fatty acids, de novo produced FA, omega 3, and omega 6 FA. The volatile profile of milks was also affected by supplemental feed choice, whereby multivariate analysis demonstrated that the CONC diet was distinctly different to that of the PALM, SOYA, and BEET milks. Multivariate analysis demonstrated that it is possible to distinguish milks from different pasture-supplemented feeding systems by their FA profile.

Amino acid digestibility in plant protein sources fed to growing pigs.

ObjectiveThe objective was to determine standardized ileal digestibility (SID) of amino acids (AA) in 11 plant protein sources fed to growing pigs.MethodsEleven feed ingredients used were sesame meal, two sources of soybean meal (SBM) produced in the Republic of Korea, a source of SBM produced in India, high-protein distillers dried grains (HPDDG), perilla meal, canola meal, copra meal, corn germ meal, palm kernel expeller, and tapioca distillers dried grains (TDDG). Experimental diets were prepared to contain each test ingredient as a sole source of AA, and a nitrogen-free diet was also prepared to estimate the basal ileal endogenous losses of AA. Twelve barrows surgically fitted with T-cannulas at the distal ileum with an initial body weight of 29.0 kg (standard deviation = 3.0) were individually housed in metabolism crates equipped with a feeder and a nipple drinker. A 12×9 incomplete Latin square design was employed with 12 experimental diets, 12 animals, and 9 periods. After a 5-d adaptation period, ileal digesta were collected on d 6 and 7 in each experimental period.ResultsValues for apparent ileal digestibility of most indispensable AA in three sources of SBM were greater compared with other test ingredients except HPDDG and canola meal (p<0.05). Pigs fed diets containing SBM sources had also greater SID of most indispensable AA compared with those fed diets containing other test ingredients (p<0.05) except for HPDDG and canola meal. There was no difference in the apparent ileal digestibility and SID of AA among sources of SBM. The TDDG had the least value for the SID of methionine among test ingredients (p<0.05).ConclusionThe SID of most AA in SBM, HPDDG, and canola meal were greater than those in sesame meal, perilla meal, copra meal, and TDDG.

Palm kernel expellers as an alternative ingredient in growing pig diets

This study evaluated the effects of palm kernel expellers in growing diets on growth performance, nutrient digestibility, and carcass and meat quality characteristics of growing-finishing pigs. A total of 88 growing pigs were randomly assigned to two dietary treatment groups. The control diet (CON) was a typical growing or finishing diet based on corn-soybean meal, and the treatment diet (PKE) was formulated by replacing CON with 20% palm kernel expellers. The PKE-CON group was fed the PKE diet during the growing period (six weeks) and the CON diet during the finishing period (12 weeks). The CON-CON group was fed the CON diets during both growing and finishing periods. The PKE-CON group showed significantly depressed growth performance and lower nutrient digestibility than the CON-CON group during the growing period. However, after feeding the typical finisher diets during the finishing period, the PKE-CON group showed no difference in growth performance in comparison with the CON-CON group during both the finishing and overall experimental periods. In addition, carcass and meat quality characteristics were not significantly different between the PKE-CON and the CON-CON groups. The results of this study imply that palm kernel expellers can be an alternative ingredient in the growing diets of growing-finishing pigs if the combined feeding strategy (PKE for the growing period and CON for the finishing period) is used. Keywords : Feed alternatives, growing pig diet, growth performance, meat quality traits, palm kernel expeller

Metagenomics analysis reveals significant modulation of cecal microbiota of broilers fed palm kernel expeller diets

The potential use of palm kernel expeller (PKE) as an alternative energy source in broiler diets is limited by the high fiber content. Although enzymatic treatment could alleviate the fiber component and increase the nutritive value of PKE, this apparent improvement is not reflected in the growth response of birds fed with the treated-PKE. As chicken's ceca are the most heavily populated with microflora within their gastrointestinal tract, it was hypothesized that any modulation of the intestinal environment by dietary treatments should be reflected by the composition and activities of the cecal microflora. There is a correlation between cecal microbiota composition and the efficiency of the host to extract energy from the diet and to deposit that energy into improved feed conversion ratio. At present, little is known about the changes on cecal microflora of broilers fed with PKE diets. Hence, this study was designed to assess the effects of feeding different forms of PKE; namely untreated PKE (UPKE), enzyme-treated PKE (EPKE), and oligosaccharides extracted from PKE (OligoPKE), on the cecal microbiota of broiler chickens at 14 d old (day 14) and 28 d old (day 28) using 16S rRNA gene high-throughput next-generation sequencing method. The results showed that temporal changes in cecal microbiota of broiler chickens were evident on day 14 and day 28. The relative abundance of phylum Firmicutes, known to be involved in nutrient uptake and absorption in both age groups was higher in the UPKE as compared to EPKE group. In addition, supplementation of OligoPKE increased (P < 0.05) the relative abundance of Lactobacillus on both D14 and D28, signifying its effect as prebiotics in enhancing growth of indigenous Lactobacillus. Our results showed that cecal microbiota was significantly modulated by dietary treatments and that the lower relative abundance of phylum Firmicutes in chickens fed with EPKE could be a reason why broiler chickens fed with EPKE of higher metabolizable energy (ME) content did not show improvement in their growth performance.

The effect of by-product inclusion and concentrate feeding rate on milk production and composition, pasture dry matter intake, and nitrogen excretion of mid-late lactation spring-calving cows grazing a perennial ryegrass-based pasture

Interest is growing in the use of by-products as economical sources of nutrients that complement grazed grass, particularly at times when grass supply is insufficient to meet the nutritional demands of lactating dairy cattle. The objective of this research was to assess the effect of the amount of by-product inclusion and concentrate feeding rate on pasture dry matter intake, milk production and composition, and N excretion from spring-calving cows grazing summer pasture during mid-late lactation. Forty-eight Holstein Friesian dairy cows were randomly assigned to 1 of 4 dietary treatments in a 2 × 2 factorial design. Cows were grazed in one group on a perennial ryegrass-based sward, with pelleted concentrates offered twice daily during milking over a 63-d experimental period. The dietary treatments were 3 kg of concentrate containing 35% by-products; 6 kg of concentrate containing 35% by-products; 3 kg of concentrate containing 95% by-products; and 6 kg of concentrate containing 95% by-products on a fresh matter basis. The by-products used were soybean hulls, palm kernel expeller, and maize dried distillers grains with solubles, included in equal proportions on a dry matter basis. Pasture dry matter intake (14.5 kg/d) was not affected by the amount of by-product inclusion or feeding rate. By-product inclusion had no effect on milk yield (27.1 kg/d) or milk solids (MS) yield (2.0 kg/d). Cows offered 6 kg of concentrate had a greater milk (+1.6 kg/d) and MS (+0.13 kg/d) yield, consumed more N (+0.08 kg/d), and excreted a lower proportion of N in the milk (0.25 vs. 0.27) and feces (0.39 vs. 0.41) and a higher proportion in the urine (0.39 vs. 0.32) compared with cows offered 3 kg of by-product-based concentrate. In conclusion, by-products can be included at up to 95% of the concentrate fed to cows grazing pasture without affecting pasture dry matter intake, milk production or composition, or N excretion. Cows offered 6 kg of concentrates produced more milk and MS than cows offered 3 kg but had higher urinary N excretion. Economics of this yield response will depend on milk and concentrate prices.

Effect of grain- or by-product-based concentrate fed with early- or late-harvested first-cut grass silage on dairy cow performance

This study compared the effects of a grain-based conventional concentrate (GC) and a concentrate based on agro-industrial by-products (BC), fed with grass silage harvested at early (ES) or late (LS) maturity stage, on dairy performance, CH4 and CO2 emissions, and metabolic status of dairy cows. Twenty lactating Nordic Red cows averaging 81 d in milk and 31.9 kg of milk/d pre-trial were assigned to a replicated 4 × 4 Latin square design. Dietary treatments were in a 2 × 2 factorial arrangement. The silages were harvested 2 wk apart from the same primary growth grass ley. The GC was made from oats, barley and wheat, and soybean meal, whereas the BC contained sugar beet pulp, wheat bran, canola meal, distillers dried grains, palm kernel expeller, and molasses. The diets were fed ad libitum as total mixed rations and were formulated from 661 g/kg of silage, 326 g/kg of concentrate, and 13 g/kg of minerals on a dry matter basis. The BC supplied the cows with less energy. Despite this, milk yield and composition were unaffected by concentrate type, except that milk protein was 0.7 g/kg lower in cows fed BC than in those fed GC. These results were accompanied by a 44 g/kg decrease in total-tract digestibility of crude protein and a 54 g/kg increase in neutral detergent fiber digestibility for cows fed BC. Cows fed ES on average consumed 2 kg/d more dry matter and yielded 3.5 kg/d more milk, 149 g/d more protein, and 141 g/d more fat than cows fed LS. There were few interaction effects between concentrate and silage sources on daily intake and dairy performance. However, edible feed conversion ratio (human-edible output in animal/potentially human-edible feed) showed greater improvements with ES than LS when replacing GC with BC. Feeding diets with late-cut silage generally reduced digestibility and energy utilization efficiency, but improved N utilization efficiency. Feeding LS also led to greater CH4 yield and CH4/CO2 ratio, and higher plasma concentration of nonesterified fatty acids. Plasma parameters reflecting energy metabolism and inflammation were all within the normal ranges, indicating that the cows were in good health during the experiment. In conclusion, a conventional concentrate can be replaced by agro-industrial by-products without compromising production in early lactation dairy cows. However, silage maturity has a stronger effect on the production traits of dairy cows than type of concentrate.

Enzymatic hydrolysis drastically reduces fibre content of palm-kernel expeller, but without enhancing performance in broiler chickens

The effectiveness of enzymatic hydrolysis of palm-kernel expeller (PKE) is dependent on various factors that influence the stability and functionality of the enzymes. In the present study, parameters influencing the enzymatic treatment of PKE were optimised employing response surface methodology. In addition, the effectiveness of enzymatic hydrolysed PKE in increasing inclusion rates in broiler diets was evaluated. Results showed that temperature, enzyme concentration and duration of hydrolysis had significant (P &amp;lt; 0.01) effects on the enzymatic hydrolysis of PKE. Using the crude enzyme produced by Aspergillus terreus K1 isolated in our laboratory, maximum reduction of crude fibre (40%) was achieved by fermenting the PKE at 60% initial moisture with 9.0 U/g PKE mannanase at 51°C for 18 h, with the production of 9.9% (w/w) of monosaccharides and oligosaccharides. Results of the growth-performance study indicated that inclusion rate of PKE with or without enzyme treatment in broiler diet is 5% for starter period and 20% for the finisher diet, without any detrimental effect on animal performance. Although the inclusion rate of enzyme-treated PKE can be increased to 30% without affecting average daily gain, feed conversion ratio of the birds will be compromised.

Palm kernel expeller increases milk fat content when fed to grazing dairy cows

Palm kernel expeller (PKE) is a feed by-product that is used by the dairy and beef industries. This study investigated the effect of partially replacing maize with PKE in a dairy concentrate on milk and ruminal fermentation parameters of Jersey cows grazing kikuyu-ryegrass pasture. Seventy-two multiparous cows were blocked according to milk yield, days in milk, and lactation number and randomly allocated within blocks to one of four treatment concentrates: PKE0, PKE10, PKE20, and PKE30, containing 0, 100, 200, and 300 g PKE/kg dry matter (DM), respectively. Eight rumen-cannulated lactating cows were used in a 4 x 4 Latin square design. All cows grazed pasture as one group, and concentrate was fed at 5.4 kg DM/cow per day. Pasture was allocated at 11.1 kg DM/cow per day. Milk yield was lower with PKE30 than PKE0 (14.3 versus 15.6 kg/cow per day, respectively). Feeding PKE20 and PKE30 was associated with a higher milk fat content of 50.6 and 52.9 g/kg, respectively, than that of 46.3 and 49.3 g/kg of cows fed PKE0 and PKE10, respectively. However, feeding PKE30 compromised fibre degradability. Increased milk fat content and sustained milk yield indicated that 200 g PKE/kg DM can partially replace maize in a dairy concentrate, resulting in a possible added economical advantage, which is dependent on the milk payment system. The lack of a significant effect on milk fat yield and the negative linear relationship of milk protein to milk fat ratio, induced by PKE inclusion, may be unfavourable for certain milk payment systems. Keywords: By-product, fibre-based concentrate, Jersey cow, pasture, ruminal fermentation

Purification and identification of antioxidative peptides of palm kernel expeller glutelin-1 hydrolysates

Four antioxidant peptides were identified from enzymatic hydrolysates of palm kernel expeller glutelin-1 in the current study.

A farm-scale framework to assess potential farm- and regional-scale implications of removing palm-kernel expeller as a supplementary feed for dairy cows

Farm-scale models were integrated with spatially discrete estimates of pasture production to examine the potential farm and regional implications of removing palm-kernel expeller (PKE) as a supplementary feed from dairy farms in Southland, New Zealand. The following two farm-production systems representing the majority of dairy farms in the region were modelled: a System 3 farm (D3; mid-intensification, with 10–20% of imported feed) and a System 4 farm (D4; mid- to high intensification, with 20–30% of imported feed). Within each system, the impact of the following four PKE options was explored: (1) a control with PKE (Baseline); (2) no PKE, with fewer cows producing the same amount of milk per cow as in Baseline; (3) no PKE, with the same number of cows producing less milk per cow than in Baseline; and (4) PKE replaced with barley grain. Barley grain provides for similar flexibility (timing of purchase and feeding), and can be sourced locally. Faced with the need to remove PKE as a dietary ingredient, farmers would benefit from adopting the second PKE option (no PKE, with fewer cows producing the same amount of milk per cow as in Baseline); farm-operating profits were reduced by only 3% (compared with 30% of System 4 farms adopting the third PKE option, i.e. no PKE, with the same number of cows producing less milk per cow than in Baseline) relative to the Baseline farms. The narrow range of mean annual nitrate-nitrogen (nitrate-N) leaching losses (estimates ranged from 30 to 33 kg N/ha) reflects similar estimates of N intake and N excreted in urine across the modelled options. Substantial amounts of barley grain would need to be transported into the region or produced locally to replace PKE.

Effects of enzymatic treatment and shell content of palm kernel expeller meal on performance, nutrient digestibility, and ileal bacterial population in broiler chickens

The objective of this study was to examine the effects of enzymatic treatment and shell content of palm kernel expeller meal (PKE) on the performance, nutrient digestibility, and ileal bacteria population in broiler chickens. Part of the PKE sample was sieved (3 mm) to remove the shell (lower shell PKE) and part was used as is. The primary mannan-oligosaccharides in the experimental diets were determined using HPLC analysis. During the finisher phase, one hundred male broiler chickens (Cobb-500) were fed a control diet or the diets containing 200 g/kg of normal PKE (70 g/kg shell), low shell PKE (30 g/kg shell), enzymatically (cellulase and mannanase) treated PKE, or low shell, enzymatically treated PKE. The DM, CP, and ether extract digestibility coefficients were measured using acid insoluble ash as an insoluble marker. The quantitative rea-time PCR was used to determine the ileal bacteria populations. The enzymatic treatment significantly increased the mannose and also mannan-oligosaccharides content of PKE. Feed intake was not affected by dietary inclusion of PKE. In the birds fed the low shell PKE diet the average daily weight gain was lower and the feed conversion ratio was higher than those in the control and other PKE fed groups. The digestibility coefficients of dry matter and ash were lower in PKE containing diets than the control diet. However, there were no differences in the crude protein and ether extracts digestibility coefficients between the diets containing the enzymatic treated PKE (normal or low shell) and the control diet. The lowest ileal Lactobacilli population was found in the chickens fed the low shell PKE diet. Dietary normal PKE or low shell-enzymatic treated PKE decreased the Escherichia coli population compared to the control diet. The results suggested that PKE could be included up to 200 g/kg in the finisher diet without any apparent adverse effect on performance in broilers; however, any screening practice to reduce the shell content of PKE without enzymatic degradation of β-mannan, decreased its nutritive value.