Determination of Trichinella spiralis in pig muscles using Mid-Fourier Transform Infrared Spectroscopy (MID-FTIR) with Attenuated Total Reflectance (ATR) and Soft Independent Modeling of Class Analogy (SIMCA)

The aim of this work was to study the feasibility of detection of Trichinella spiralis in swine meat using Middle Infrared Spectroscopy Fourier Transform with Attenuated Total Reflectance (ATR) and Soft Independent Modeling of Class Analogy (MID-FTIR-ATR-SIMCA). Five male Pigs were orally infected at different larvae concentrations (13,000, 6500, 3500, 1625, 812 larvae/pig) and after 24 weeks the animals were euthanized. Five types of muscles were studied (leg, loin, rib, masseter, and diaphragm). Results showed that MID-FTIR-ATR-SIMCA was useful to determine the presence of T. spiralis in the samples, as the interclass distance between infected and non infected muscles varied from 13.5 to 36.8. This technique was also useful to discriminate among pig muscles, where masseter showed the largest interclass distance, while rib presented the smallest one. In all cases the recognition and rejection rates were 100%, which means that the methodology is capable of accurately separating T. spiralis infected from non infected swine meat.     

Growth, yield of carcass and biochemical composition of meat and fat in nutria (Myocastor coypus) reared in an intensive production system

Growth, carcass yield and proximate composition were determined in intensively reared nutria (Myocastor coypus) fed different levels of protein. Growth, food intake and food utilization efficiency were not significantly affected, within the same sex, in animals receiving 16%, 19% or 22% of protein in the diet. Males consumed the same amount of food as females but had greater live and carcass weights at slaughter age than females. Males had the highest meat yield and females had the highest fat content. Independent of dietary protein level, the pectoral muscles of all animals ranged from 19.2% to 23.6% protein, 1.97% to 2.47% total lipids, and 70.1 to 72.0mg of cholesterol in 100g of tissue. In the thigh muscles, the observed ranges were between 21.4% and 22.9% in proteins, 1.83% and 2.07 in total lipids and 69.9 and 71.0mg of cholesterol in 100g of tissue. The determination of classes of lipids shows more phospholipids contents in animals receiving 16% of protein in diet.     

Salmonella, Escherichia coli O157:H7 and E. coli biotype 1 in a pilot survey of imported and New Zealand pig meats

A pilot survey for the pathogens Salmonella and Escherichia coli O157:H7, and E. coli biotype 1 was conducted on 100 New Zealand-produced (domestic) pig carcasses and 110 imported pig meat samples over an 8-month period to assess the likelihood of introduction of novel pathogen strains into New Zealand (NZ), and as a guide for development of a domestic pork National Microbiological Database programme. Salmonella was not isolated from domestic pig carcasses or from pig meat imported from Canada and the USA. The prevalence of Salmonella in imported pig meat was 3.6% (95% CI 1.0–9.0) with positive samples detected from Australian pig meat. The prevalence of E. coli O157:H7 on domestic pig carcasses was 1% (95% CI 0.03–5.4) while the overall prevalence of E. coli O157:H7 in imported pig meat was 1.8% (95% CI 0.2–6.4), detected mainly from Australian but not from Canadian or US pork. All except three samples have an E. coli biotype 1 count of <100 CFU cm⁻² or g⁻¹, indicating good hygiene quality of domestic and imported pig meat. The results demonstrated that importation of uncooked pig meat is a potential route for the introduction of new clones of Salmonella and E. coli O157:H7 into New Zealand.     

The effect of treating alfalfa with Lactobacillus buchneri 40788 on silage fermentation,aerobic stability,and nutritive value for lactating dairy cows

Lactobacillus buchneri 40788 and enzymes (beta-glucanase, alpha-amylase, xylanase, and galactomannase) were applied to chopped alfalfa (39% DM) to study their effects on the fermentation and nutritive value of the silage. Alfalfa was treated with nothing, or L. buchneri 40788, for a final application rate of 1 x 10(5), 5 x 10(5), or 1 x 10(6) cfu/g of fresh forage and ensiled in laboratory silos for 2, 4, 8, and 56 d. Treatment with L. buchneri 40788 had few effects on the end products of fermentation through 8 d of ensiling. However, after 56 d of ensiling, treated silages had a higher pH (4.55 vs. 4.38) and higher concentrations of acetic acid (6.40 vs. 4.24%), propionic acid (0.18 vs. 0.06%), and ammonia-N (0.35 vs. 0.29%) when compared to untreated silage. Lactic acid was also numerically lower in treated (3.51%) than untreated (4.12%). Silages treated with the moderate and highest dose of L. buchneri 40788 also resulted in greater recoveries of DM than did untreated silage. Alfalfa (43% DM) was also untreated or treated with a commercial application of L. buchneri 40788 (4 x 10(5) cfu/g, a commercial dose) in farm-scale bag silo. Holstein cows were fed a diet comprised of 32% untreated or treated alfalfa silage, 11% corn silage, 5% chopped alfalfa hay, and 52% of concentrate (DMB) for a 6-wk treatment period. Dry matter intake and milk composition were unaffected by treatment, but cows fed silage treated with L. buchneri 40788 produced 0.8 kg more milk than did cows fed untreated silage. Treated silage had a higher concentration of acetic acid (5.67 vs. 3.35%) but lower lactic acid (3.50 vs. 4.39%) than untreated silage. When exposed to air, the total mixed ration containing treated alfalfa silage remained stable for 100 h, whereas the ration containing untreated silage spoiled after 68 h. Treating alfalfa silage with L. buchneri 40788 increased the concentration of acetic acid, and when the silage was combined into a total mixed ration and fed to lactating cows, it improved the aerobic stability of the ration and increased milk production.     

Short-term toxicological evaluation of Terminalia catappa, Pentaclethra macrophylla and Calophyllum inophyllum seed oils in rats

The purpose of this study was to evaluate the toxicological effects of feeding the oils of Calophyllum inophyllum, Pentaclethra macrophylla and Terminalia catappa to rats. The effects on physical appearance, feed intake, weight gain, plasma and tissue cholesterol and triacyglycerol levels in rats with 5% of the oils in normal rat feed were determined. Weekly monitoring of the rats showed good physical appearance and steady weight gain, with no mortality recorded for the period of the study. Haematological analysis of the rats indicated that they were not anaemic. Histopathotogical examination of the sections of the heart, liver, kidney and spleen revealed moderate (T. catappa oil) to severe fatty change and necrosis in the liver. Glomerulonephrotic changes in the kidneys of rats fed with T. catappa oil were moderate, while it was severe in the group fed with P. macrophylla oil. Severe myocardiac necrosis as well as atherosclerotic clefts in vasa vasori was observed in the vasa vasori of the hearts of rats fed with P. macrophylla oil. This change was moderate in the heart of rats fed with C. inophyllum, while no such observation was made in the group fed with T. catappa oil. There was a significant difference in the plasma cholesterol levels of the rats fed with C. inophyllum and T. catappa oils when compared with the control rats, while those fed with P. macrophylla oil had no significant difference. The oil of T. catappa appears more suitable for consumption than the oils from C. inophyllum and P. macrophylla. Fatty acid analysis of the oils showed that they have high amounts of unsaturated fatty acids with linoleic and oleic acids as the major ones.     

Weaving the Two Cultures of Aotearoa/New Zealand Together: From the Art of Making Traditional Off-Loom Garments to a Contemporary Practice of On-Loom Weaving

Abstract

This paper explores the artistry of a renowned Māori artist and weaver and how this had led to her weaving work with the community, helping to develop skills to produce fine quality contemporary Māori weaving. It explains how Raranga – the art of Māori weaving is much more than simply skills and techniques and embodies the spiritual values of Māori people. The action of artists like Roka to develop skills and weaving are aimed to give a sense of pride and cultural identity. In particular the Māori cloaks and their symbolic significance have a special place within the Māori culture. This chapter explains the various materials and techniques used in this off-loom weaving. It discusses exhibitions that explored Māori weaving as art and that have led to her teaching people within the community to do this prestigious work at the meeting centre that she and her husband have rebuilt with community help.     

Predation by Blattisocius tarsalis (Berlese) (Acari: Ascidae) on eggs of Ephestia kuehniella Zeller (Lepidoptera: Pyralidae)

The mean predation rate of female B. tarsalis on eggs of E. kuehniella was determined at 15°C, 21°C, and 27°C with prey densities of 3, 5, 10 and 15 eggs. Young eggs less than 24 h old were used as prey. Under all experimental conditions most eggs were only partially consumed, confirming the general theory that predatory mites leave most of the food content unutilized. A mean predation rate of 2.2-7.0 eggs destroyed in 24 h was found, reflecting that a large proportion of the available prey was destroyed. The result supports the view that the predatory mite B. tarsalis could be a relevant biological control agent against E. kuehniella in flour mills. It was further demonstrated that frozen moth eggs can be considered as an appropriate food source.     

Influence of a Spirulina platensis biomass on the microflora of fermented ABT milks during storage (R1)

The objective of this research was to investigate the effect of a cyanobacterial (Spirulina platensis) biomass on the microflora of a probiotic fermented dairy product during storage at two temperatures. Spirulina-enriched and control (plain) fermented acidophilus-bifidus-thermophilus (ABT) milks were produced using a fast fermentation starter culture (ABT-4) as the source of Lactobacillus acidophilus (A), bifidobacteria (B), and Streptococcus thermophilus (T). Incubation took 6 h at 40 degrees C. As for the cyanobacterial product, the S. platensis biomass was added to the process milk during stirring at pH 4.5 to 4.6. Thereafter, the ABT-type fermented milks were cooled to 25 degrees C in ice water, filled into sterile, tightly capped centrifuge tubes, further cooled at 4 degrees C for 24 h, and then stored either at 15 degrees C for 18 d or at 4 degrees C for 42 d. Microbiological analyses and acidity measurements were performed at regular intervals. Our results showed that the counts of the starter organisms were satisfactory during the entire storage period at both temperatures applied in this research. The S. platensis biomass had a beneficial effect on the survival of ABT starter bacteria regardless of storage temperature. Postacidification was observed at 15 degrees C, whereas pH remained stable during refrigerated storage at 4 degrees C. The abundance of bioactive substances in S. platensis is of great importance from a nutritional point of view because thus the cyanobacterial biomass provides a new opportunity for the manufacture of functional dairy foods.     

Cholesterol-lowering effect of whole lupin (Lupinus albus) seed and its protein isolate

This study describes the hypocholesterolaemic effect of whole lupin and its protein in hamsters. The diets were: casein (control group HC), lupin protein isolate (group HPI) and whole lupin seed (group HWS). Diets from HPI and HWS promoted a significant reduction of total cholesterol and non-HDL cholesterol in the hamsters’ plasma as compared with HC. The true digestibility of HPI and HC groups were similar and differed significantly from the HWS one, which in turn showed a significant difference in total sterol excretion as compared to the former groups. Histological analysis of the liver revealed that animals fed on HPI and HWS diets presented a low level of steatosis (level 1) as compared to the ones fed on HC diet (level 4). Our findings demonstrate that protein isolate from Lupinus albus from Brazil has a metabolic effect on endogenous cholesterol metabolism and a protector effect on development of hepatic steatosis.     

Isolation and characterisation of collagens from the skin of largefin longbarbel catfish (Mystus macropterus)

Acid-soluble collagen (ASC) and pepsin-soluble collagen (PSC) were extracted from the skin of largefin longbarbel catfish (Mystus macropterus) with yields of 16.8% and 28.0%, respectively, on the basis of dry weight. Both ASC and PSC contained α1 and α2 chains and the amino acid composition of collagen was close to that of calf skin type ? collagen. The intrinsic viscosities of ASC and PSC were 14.9 dl/g and 14.5 dl/g, respectively. Similar ultraviolet and FTIR spectra of ASC and PSC were observed. However, peptide maps of ASC and PSC, hydrolysed by trypsin, revealed some differences in primary structures between the two fractions. Denaturation temperatures of ASC and PSC were 32.1 °C and 31.6 °C, respectively. The higher T_m showed that it is possible to use largefin longbarbel catfish skin collagen as an alternative source of vertebrate collagens for industrial purposes.     

Feeding bioassay for stored-product insect pests using an encapsulated food source

A procedure that was developed to encapsulate liquid and semiliquid diets was used to encapsulate dry diet for use in a feeding bioassay for beetles that are pests of stored products. Vacuum was used to form Parafilm^® into numerous 6 mm diameter wells. The wells were filled with clean sand (control) or ground dry dog food (test), and the Parafilm^® sealed to produce individual pellets. A single pellet was then placed in the center of a 9 cm diameter Petri dish and feeding activity of groups of ten adults of Sitophilus oryzae (L.), the rice weevil; Oryzaephilus surinamensis (L.), the sawtoothed grain beetle; and Tribolium castaneum (Herbst), the red flour beetle, was tested. The number of insects on the encapsulated pellet and the amount of food or sand scattered were checked hourly for the first 8 h of the study and after 24 h. Few insects were observed on pellets containing sand and little or no sand was observed scattered outside of the pellet, so the presence of dog food in the pellet was needed for insects to feed on the pellet. In tests with encapsulated dog food, the amount of food scattered provided a better quantitative measure of feeding than the number of insects on the pellet. Insects that were starved for 48 h caused greater amounts of food scatter than insects starved for 24 h prior to the test. In direct comparisons among all three species, T. castaneum responded the most slowly and the bioassay may be improved by increasing the amount of time starved. Sitophilus oryzae responded very quickly and the entire pellet was essentially consumed within the first 4-5 h of the study. The encapsulated diets provide a promising method to evaluate feeding behavior of stored-product insect pests.     

Prevalence of Salmonella in pig ear pet treats

Salmonella is one of the most important causes of foodborne disease throughout the world. In recent years there have been documented outbreaks of Salmonella infection in humans associated with pet treats of animal origin; in particular pig ear pet treats in Canada and the United States. The main objectives of this study were to determine the degree of Salmonella contamination in dried pig ear dog treats on sale in Limerick City, Ireland and to examine pet dogs for Salmonella carriage. Over a 12 month period, from October 2008 to September 2009, 102 pig ear pet treats were sampled using both a conventional culture detection method and a PCR method. Salmonella was detected in 24.5% of samples by the culture method, while 28.4% tested positive using a PCR method. Resistance to at least one antimicrobial agent was observed in 50% of Salmonella isolates. Salmonella was not detected in any of 86 rectal swabs from dogs attending 2 different veterinary clinics between February and April and August and October of that period. The contaminated ears were traced back to a single distributor. This study emphasises that there is a long term continuing risk of human exposure to Salmonella associated with pig ear treats.     

Rumen pH and fermentation characteristics in dairy cows supplemented with Megasphaera elsdenii NCIMB 41125 in early lactation

This study investigated the effect of using the lactate-utilizing bacterium Megasphaera elsdenii NCIMB 41125 as a probiotic supplement on rumen fermentation and pH in dairy cows in the immediate postcalving period. Fourteen multiparous rumen-fistulated Holstein cows, blocked according to 305-d milk yield in the previous lactation, were used in a randomized complete block design. From d 1 to 28 postcalving, cows were fed ad libitum a total mixed ration with a forage to concentrate ratio of 392:608 and a starch concentration of 299 g/kg of dry matter. Treatments consisting of a minimum of 10¹⁰ cfu of Megasphaera elsdenii NCIMB 41125 or autoclaved M. elsdenii (placebo) were administered via the rumen cannula on d 3 and 12 of lactation (n = 7 per treatment). Mid-rumen pH was measured every 15 min, and eating and ruminating behaviors were recorded for 24 h on d 2, 4, 6, 8, 11, 13, 15, 17, 22, and 28. Rumen fluid for volatile fatty acid and lactic acid analysis was collected at 11 time points on each of d 2, 4, 6, 13, and 15. Yields of milk and milk protein and lactose were similar, but milk fat concentration tended to be higher in cows that received the placebo. Time spent eating and ruminating and dry matter intake were similar across treatments. Ruminal lactic acid concentrations were highly variable between animals, and no cases of clinical acidosis were observed. Both treatment groups had rumen pH <5.6 for more than 3 h/d (a commonly used threshold to define subacute ruminal acidosis), but the length of time with rumen pH <5.6 was markedly reduced in the days immediately after dosing and fluctuated much less from day to day in cows that received M. elsdenii compared with those that received the placebo. Ruminal total volatile fatty acid concentrations were similar across treatments, but the acetate:propionate ratio tended to be smaller in cows that received M. elsdenii. Despite the lack of a measurable treatment effect on ruminal lactic acid concentration, supplementation of early lactation dairy cows with lactate-utilizing M. elsdenii altered the rumen fermentation patterns in favor of propionate, with potential benefits for energy balance and animal productivity.     

Limousin myostatin F94L variant affects semitendinosus tenderness

Texture parameters (peak force and compression), muscle myofibre diameter, and hydroxyproline were measured in semitendinosus samples from a cattle gene-mapping herd. The data were analysed to determine the relationships between these traits. The traits were also mapped by genetic linkage analysis to identify quantitative trait loci, and hence, candidate genes for these traits. Neither texture parameters were affected by the muscle structural traits of myofibre diameter or collagen content (as measured by hydroxyproline), despite significant variation in these traits between animals. QTL for the texture parameters of peak force and compression, as well as collagen content, were found on cattle chromosome 2 (BTA2) and attributed to the myostatin gene. Within the cattle population used for the QTL mapping, a gene variant of myostatin, F94L, has been previously shown to increase muscle mass, predominantly in the semitendinosus. It was determined herein that the F94L myostatin homozygous animals had more tender meat as measured by both peak force and compression. The variant was also responsible for a reduction in the collagen/elastin content of muscle. The myostatin F94L variant had no effect on muscle myofibre diameter of the semitendinosus, even though the variant causes substantial increases in muscle mass. Consequently, the increase in muscle mass of the variant must be due to myofibre hyperplasia and not hypertrophy. In addition, myostatin effects on tenderness are caused by changes in the extracellular matrix rather than muscle myofibre diameter.     

Residual toxicities and persistence of organophosphorus insecticides mixed with carbaryl as structural treatments against three liposcelidid psocid species (Psocoptera: Liposcelididae) infesting stored grain

Four organophosphorus insecticides, azamethiphos, fenitrothion, chlorpyrifos-methyl, and pirimiphos-methyl were each mixed with carbaryl and evaluated as structural treatments on concrete and galvanized steel panels (0.3×0.3 m) against adults of three liposcelidid psocids: Liposcelis bostrychophila Badonnel, L. entomophila (Enderlein), and L. paeta Pearman. Residual toxicities and persistence of these insecticide mixtures were assessed at 30±1°C, 70±2% r.h., and a photoperiod of 12:12(L:D) h from 1 day after treatment (0 week) and at weeks 1, 2, 4, 6, and 8, and then every 4 weeks up to week 40. Mortality was recorded at exposure periods of 6 h and then every 24 h until end-point was achieved. Significant enhancement in residual toxicities was observed in azamethiphos plus carbaryl against L. entomophila, and chlorpyrifos-methyl plus carbaryl and pirimiphos-methyl plus carbaryl against all three species on steel surfaces, compared with the individual effectiveness of these insecticides reported earlier. We conclude that combining carbaryl with either azamethiphos, chlorpyrifos-methyl, or pirimiphos-methyl as a structural treatment will provide long-term protection (up to 40 weeks) against infestation by all three psocid species on steel storage structures, whilst carbaryl with fenitrothion will give shorter protection (up to 8 weeks). On concrete structures, however, only azamethiphos plus carbaryl will provide long-term protection against L. bostrychophila (up to 28 weeks) and L. paeta (up to 16 weeks). None of the four insecticide mixtures studied would provide long-term protection against an L. entomophila infestation on concrete surfaces.     

A wild strain of Plodia interpunctella (Hübner) (Lepidoptera: Pyralidae) from farm-stored maize in South Carolina: Development under different temperature, moisture, and dietary conditions

The purpose of this study was to determine the duration of immature development and survivorship of Plodia interpunctella (Hübner) on maize over a range of temperatures and grain moisture contents encountered in maize stored on farms in the southeastern states (USA). Laboratory cultures were established with moths collected from farm-stored maize in South Carolina and maintained on cracked maize at 30 °C and 60% r.h. The incubation period and percentage hatch of eggs was determined at 18 combinations of temperature and r.h. Hatch was <1% at 15 and 40 °C. In the range 20-35 °C, percentage hatch declined as temperature increased, and the mean incubation period ranged from 3.1 to 8.5 d. Neither percentage hatch nor incubation period were affected by r.h. between 43% and 76%. The relationship between mean developmental period (oviposition to adult eclosion) and temperature was well described by a quadratic polynomial that predicted a decline from 67.6 to 30.1 d as temperature increased from 20 to 31.1 °C, followed by an increase to 38.5 d as temperature increased further to 35 °C. The results suggest a lower temperature threshold for development near 15 °C and an upper limit slightly greater than 35 °C. Moisture content had a significant effect on developmental period at all the temperatures studied, but the pattern of variation with moisture depended upon the temperature.     

Forage feeding to reduce preharvest Escherichia coli populations in cattle,a review

Although Escherichia coli are commensal organisms that reside within the host gut, some pathogenic strains of E. coli can cause hemorrhagic colitis in humans. The most notable enterohemorrhagic E. coli (EHEC) strain is O157:H7. Cattle are asymptomatic natural reservoirs of E. coli O157:H7, and it has been reported that as many as 30% of all cattle are carriers of this pathogen, and in some circumstances this can be as high as 80%. Feedlot and high-producing dairy cattle are fed large grain rations in order to increase feed efficiency. When cattle are fed large grain rations, some starch escapes ruminal microbial degradation and passes to the hind-gut where it is fermented. EHEC are capable of fermenting sugars released from starch breakdown in the colon, and populations of E. coli have been shown to be higher in grain fed cattle, and this has been correlated with E. coli O157:H7 shedding in barley fed cattle. When cattle were abruptly switched from a high grain (corn) diet to a forage diet, generic E. coli populations declined 1000-fold within 5 d, and the ability of the fecal generic E. coli population to survive an acid shock similar to the human gastric stomach decreased. Other researchers have shown that a switch from grain to hay caused a smaller decrease in E. coli populations, but did not observe the same effect on gastric shock survivability. In a study that used cattle naturally infected with E. coli O157:H7, fewer cattle shed E. coli O157:H7 when switched from a feedlot ration to a forage-based diet compared with cattle continuously fed a feedlot ration. Results indicate that switching cattle from grain to forage could potentially reduce EHEC populations in cattle prior to slaughter; however the economic impact of this needs to be examined.     

Feeding saponin-containing Yucca schidigera and Quillaja saponaria to decrease enteric methane production in dairy cows

An experiment was conducted in vitro to determine whether the addition of saponin-containing Yucca schidigera or Quillaja saponaria reduces methane production without impairing ruminal fermentation or fiber digestion. A slightly lower dose of saponin was then fed to lactating dairy cows to evaluate effects on ruminal fermentation, methane production, total-tract nutrient digestibility, and milk production and composition. A 24-h batch culture in vitro incubation was conducted in a completely randomized design with a control (no additive, CON) and 3 doses of either saponin source [15, 30, and 45 g/kg of substrate dry matter (DM)] using buffered ruminal fluid from 3 dairy cows. The in vivo study was conducted as a crossover design with 2 groups of cows, 3 treatments, and three 28-d periods. Six ruminally cannulated cows were used in group 1 and 6 intact cows in group 2 (627 ± 55 kg of body weight and 155 ± 28 d in milk). The treatments were 1) early lactation total mixed ration, no additive (control; CON); 2) CON diet supplemented with whole-plant Y. schidigera powder at 10 g/kg of DM (YS); and 3) CON diet supplemented with whole-plant Q. saponaria powder at 10 g/kg of DM (QS). Methane production was measured in environmental chambers and with the sulfur hexafluoride (SF₆) tracer technique. In vitro, increasing levels of both saponin sources decreased methane concentration in the headspace and increased the proportion of propionate in the buffered rumen fluid. Concentration of ammonia-N, acetate proportion, and the acetate:propionate ratio in the buffered rumen fluid as well as 24-h digestible neutral detergent fiber were reduced compared with the CON treatment. Medium and high saponin levels decreased DM digestibility compared with the CON treatment. A lower feeding rate of both saponin sources (10 g/kg of DM) was used in vivo in an attempt to avoid potentially negative effects of higher saponin levels on feed digestibility. Feeding saponin did not affect milk production, total-tract nutrient digestibility, rumen fermentation, or methane production. However, DM intake was greater for cows fed YS and QS than for CON cows, with a tendency for greater DM intake for cows fed YS compared with those fed QS. Consequently, efficiency of milk production (kg of milk/kg of DM intake) was lower for cows fed saponin compared with controls. The results show that although saponin from Y. schidigera and Q. saponaria lowered methane production in vitro, the reduction was largely due to reduced ruminal fermentation and feed digestion. Feeding a lower dose of saponin to lactating dairy cows avoided potentially negative effects on ruminal fermentation and feed digestion, but methane production was not reduced. Lower efficiency of milk production of cows fed saponin, and potential reductions in feed digestion at high supplementation rates may make saponin supplements an unattractive option for lowering methane production in vivo.     

Effect of a supplementation of Euphorbia heterophylla on nutritional meat quality of Guinea pig (Cavia porcellus L.)

The aim of the present work was to study the effect of dietary supplementation of Euphorbia heterophylla on the quality of the Guinea pig meat. Forty guinea pigs were divided into two groups fed ad libitum during 46 days a Panicum maximum diet (Panicum diet) or a mixed diet (75% Panicum maximum + 25% Euphorbia heterophylla) (Paneuphorbia diet) to compare their effects on performances and on the composition of guinea pig tissues and carcass. Daily weight gain, liver weight, carcass yield, and the lipid content of both the carcass and the perirenal fat were significantly increased by the Paneuphorbia diet. Feeding Paneuphorbia diet increased (P < 0.05) the n-3 PUFA content in perirenal fat, muscle, liver and in the carcass and decreased (P < 0.05) the n-6/n-3 ratios in all these tissues and the carcass. In conclusion, this study shows that Euphorbia heterophylla is a source of n-3 fatty acids which can improve significantly the n-3 PUFA content of Guinea pig meat and carcass.     

Thermal inactivation of Escherichia coli O157:H7 and Salmonella on catfish and tilapia

Thermal inactivation kinetics of individual cocktails of Escherichia coli O157:H7, or of Salmonella meat isolates or seafood isolates were determined in catfish and tilapia. Determinations were done at 55, 60 and 65 °C using a circulating-water bath and calculated using linear regression analysis. Salmonella seafood and meat isolates D-10 values on the finfish were the same and ranged from 425 to 450, 27.1 to 51.4, 2.04-3.8 s (z = 4.3 °C) at 55, 60 and 65 °C, respectively. The E. coli O157:H7 D-10 values ranged from 422 to 564, 45.2 to 55.5 and 3.3-4.2 s (z = 4.3 °C) at 55, 60 and 65° C, respectively. The only statistical difference (P ≤ 0.05) was found when comparing the D-10 values for E. coli O157:H7 at 55 °C on catfish and tilapia. The other D-10 values for the Salmonella at all temperatures and E. coli O157:H7 at 60 and 65 °C on the catfish or tilapia showed no statistical difference. D-10 values for the catfish and tilapia were significantly lower than the reported values in other food systems, but the z-values were within the literature reported range. These D-10 values can be used to determine cooking parameters of finfish.