Attempts to improve nutrient utilization by the incorporation of proteolytic enzymes into dry diets for pigs have met with limited success (Dierick and Decuypere 1994) Liquid feeding provides an ideal environment for optimizing the action of feed additive enzymes, and an opportunity to pre-treat individual dietary components. Raw soya has a poor nutritive value and there is potential for improving the nutritional status by partial hydrolysis of native proteins that largely resist mammalian digestive tract enzymes. Such enzyme treatments may also improve protein availability in cooked soya. The objective of this experiment was to assess the effectiveness of pre-treating raw and autoclaved soya with a microbial protease on the growth performance of grower/finisher pigs.

The measurement of ileal digestibility of amino acids is recognized to be a valid tool for the estimation of availability of amino acids. One of the techniques used to obtain this measure - ileal rectal anastomosis - has, however, received a lot of criticism since it has been claimed that the removal of the colon from the active digestive tract leads to the development of a colon-like microflora in the ileum (Köhler et al, 1991). The aim of this experiment was to evaluate if the possible development of microflora affected the ileal digestibility results obtained.

Since the gut environment is generally assumed to be anaerobic, studies of the monogastric intestinal microflora have concentrated on the anaerobic microorganisms. However, the intestinal epithelium constitutes a very high surface area in relation to the volume of the gut contents, and all of this surface area is richly supplied with blood. Appreciable dissolved oxygen concentrations can be detected in the intestines of anaesthetised piglets (Hillman et al, 1993), although this is never detectable in the intestines of killed animals. It was considered important to investigate the persistence of intestinal oxygen after death, in order to determine the accuracy of postmortem measurements of this component of the intestinal environment. This report demonstrates the rapidity of removal of oxygen by porcine colon contents, and indicates that, since the oxygen supply to the intestine stops when the blood circulation stops, accurate measurements of dissolved oxygen can never be made in the intestines of killed animals.

Colon contents were obtained from three freshly slaughtered 20 kg piglets and diluted to 20% (w/v) slurries in quarter-strength Ringer's solution (Unipath, UK). The slurries were transferred (25 ml) to 50 ml conical flasks, stirred by magnetic follower (approx 400 rpm) and surrounded by a water jacket to maintain a temperature of 39°C in the vessel contents. A polarographic oxygen electrode was inserted so that the membrane was submerged. Gas flow through the headspace was provided by compressed air and nitrogen, mixed via a pair of needle valves to provide a constant flow rate of 600 ml min-1. Calibration of the system was performed in sterile Ringer's solution using air and oxygen-free nitrogen: calibration was repeated between each experiment.

Probiotics are live microbial cultures fed to animals with the intention of promoting intestinal health. However, one of the problems with these preparations is the variability in their effectiveness, reasons for which include genetic and physiological differences between herds of animals or between individuals, and the type of feed presented to the animals. This study has examined the effects of different food types on the efficacy of a strain of Lactobacillus plantarum as an inhibitor of Listeria monocytogenes. The strain of L. plantarum used (PF31) has been previously shown to inhibit the growth of the porcine enteric pathogen Escherichia coli O 149:K88:K91 in coculture (Hillman and Fox, 1994). In a subsequent series of tests, L. plantarum PF31 was also shown to inhibit the growth of List, monocytogenes in coculture.

Faeces may be representative of the microbial population present in the large intestine (LI) of monogastric animals, and is being used as the inoculum for in vitro procedures to investigate hindgut fermentation. To test this hypothesis, samples were taken from the caecum, mid-colon, and rectum of three pigs fed a simple diet (no antibiotics or copper). The in vitro cumulative gas production technique (Theodorou et a/., 1994) was used to measure the fermentation characteristics of four standard carbohydrate feedstuffs.

Four feeds representative of certain carbohydrate fractions were used. They were fructo-oligosaccharide (FOS- oligosaccharides), oat hulls (OatH- fibre), potato starch (PST- resistant starch), and wheat bran (WBR- fibre). The entire large intestine was taken to laboratory, where samples were removed from the caecum, mid-colon, and rectum, diluted, and mixed, under strictly anaerobic conditions before being used as inoculum. The cumulative gas data (144 hours) were fitted to the monophasic modified Michaelis-Menten model (Groot et a/., 1996). After fermentation, samples were taken for VFA analysis, and substrate losses and pH measured.

It is increasingly being realized that hindgut fermentation in monogastric animals has an important role in maintaining the health of the GIT and also of the animal itself. Thirty-five feedstuffs which were likely to be rich in fermentable carbohydrates were fermented in vitro using faeces from 28 day old piglets as the inoculum. The piglets had been offered a standard creep feed (no added antibiotics and copper). The in vitrocumulative gas production technique (Theodorou et al., 1994) was used to measure the fermentation characteristics of the feedstuffs.

The substrates were separated into groups according to the component present in the largest amounts as: fibre (pea hulls, oatbran, soya hulls, wheat bran, wheat straw); grain (barley, maize oats, wheat); gums (gum arabic, guar gum); oligosaccharides (fructo-, trans-galacto-oligosaccharide); pectin (low and high methylated citrus fruits, high methylated sugar beet pectin); starch (oatmeal, inulin from Jerusalem Artichokes and Chicory Root, maize starch, native & treated potato starch, wheat flour, pea starch). The cumulative gas data were fitted to the monophasic modified Michaelis-Menten model (Groot et al, 1996).

The large storage proteins of soya bean, glycinin and pconglycinin are relatively indigestible in their native state. Even when partially denatured by heat treatments these proteins may not be utilised fully by young pigs. Glycinin in particular has been implicated in causing immune hypersensitivity reactions that can lead to gut damage. Partial hydrolysis of these large proteins may increase their digestibility and improve the nutritional value of both raw and heat treated soya bean meals. The increased protein digestibility in humans of fermented soya foods compared with soya bean flour has been attributed to partial proteolysis by microbial proteases produced by the fermenting organisms. The objective of this study was to assess the proteolytic action of a microbial protease P#4 (Finnfeeds International Marlborough) on raw and autoclaved soya with a view to its inclusion into liquid diets for grower/finisher pigs.

Inclusion of lactose in dairy cow rations increases dry matter intake (DMI) and milk yield (Garnsworthy 1996). This may be due to the relatively slow rate of lactose fermentation ( Hussain and Miller, 1998) sustaining better regulation of rumen pH and also possible consequence for microbial protein synthesis (Chamberlain et al., 1993).This experiment was conducted to study the changes in rumen environment over the adaptation period and effect of these changes on the fermentation of lactose itself.

Three Suffolk wethers (b.wt 56± 7.36 kg) maintained on hay and concentrate (600:400) were offered 50g lactose per day for 16 days. Rumen liquor collected on dayO (before offering lactose), 4, 8, 12 and 16 was used to measure gas production from sucrose and lactose ( Menke et al., 1979). On these days rumen samples were collected at 0, 1, 2, 4, 6 and 8 hrs after the morning feed. Rumen pH, ammonia N (NH3 N) and volatile fatty acids (VFA) were measured. At 8 hrs time rumen samples were also taken for protozoa enumeration. Data obtained were analysed using ANOVA procedure of Genstat 5.

A lot of controversy in literature still surrounds the way in which free amino acids (AA), peptides and true protein nitrogen influence fibre digestion and the activity of bacteria which ferment structural carbohydrates in the rumen. One of the major impediments in the understanding of ruminal microbial protein synthesis is the lack of a simple and accurate procedure for measuring its yield. The aim of this study was two fold: firstly, to make further investigations into the effects of feeding different forms of supplementary nitrogen to a rapidly fermented high fibre diet on microbial activity, and secondly, to compare three different procedures of estimating microbial protein synthesis under the same conditions in continuous culture (CC).

Rode et al (1997) reported a significant improvement in milk production and milk fat content when the ration was supplemented at the start of lactation with hydroxy-analogue of methionine (HMB) (DL,2 hydroxy 4 (methyl thio) butanoic acid. This could be explained either by the fact that HMB in the liquid form, in a manner similar to the calcium salt of HMB is used by the rumen microorganisms, resulting in the stimulation of the rumen microflora or that the HMB supplies by-pass methionine analogue to the duodenum. The objective of the present trial was to measure the effects of HMB in the rumen using a rumen simulation technique and to test the effect of different sources of methionine on the digestibility of the organic matter of maize silage.

Experiments were carried out using the in vitro rumen technique (Menke et al, 1988) (HFT). Different sources of methionine were tested : two sources of the hydroxy-analogue of methionine (HMB) : [A] AlimetTM (88,2%) (Novus Int Inc) and [B] RhodimetTM AT88 (88,9%) (Rhone Poulenc Animal Nutrition), [C] calcium salt of HMB (85,3%) [D] Rhodimet NP99 (99%) (DL methionine powder (RPAN)) [E] mineral sulphur in the form of sodium sulphate (99,5%).

Haemonchosis in cattle represents one of the biggest problem in Brazil, where an wide variations in dietary protein can be observed in pastures throughout the year. It is thought that this variation in protein intake might have influences on the impact of the parasite host metabolism arid productivity. This experiment was conducted to investigate the influence of dietary protein and the infection with Haemonchus placet upon parasitological parameters in growing calves.

Akhter et al.(1994) demonstrated bovine faeces to have considerable potential as a source of microorganisms to replace rumen liquor in the in vitro digestibility method of Tilley and Terry (1963) for evaluating temperate gramminaceous forages, under UK laboratory conditions. In view of the difficulties and costs of maintaining fistulated animals in tropical, less-developed countries, the present study was undertaken in Tanzania to investigate the potential of bovine faeces as a substitute for rumen liquor in the Tilley and Terry technique for evaluating local, gramminaceous forages. Use of equine faeces was also investigated in view of the prevalence of equines in some tropical countries. It was also hypothesised that equines, being hind-gut fermentors, would yield faeces containing more micro-organisms than faeces from bovines, with a consequent improvement in digestibility.

In the Brazilian savanna region, which covers 2.1 million km2, roughage production is irregular during the year. However the manufacture of passion fruit juice produces approximately 13,000,000 ton per year of industrial residue which consist of fruit pulp and seeds (FPSR) (Medina, 1980). Beef and dairy cattle farmers are feeding it to their livestock with no knowledge of its nutritive value or concern for its pollution aspects. The FPSR is left in piles outside on the ranches and fluid effluent is often observed reaching streams and contaminating the environment. Furthermore it is a good medium for fly proliferation which stresses the animals and reduces profits. The objective of this study was to demonstrate to the farmers a better way for storing the FPSR and to determine its nutritional value for ruminants.

The FPSR was stored in triplicate experimental mino-silos (200 1) in a complete 2x2 factorial design to observe the effects of 48-h wilting (sun dry) and anaerobic conditions. Open mini-silos were left uncovered while in anaerobic mini-silos the FPSR was sealed in plastic bags and covered with sacks of soil. Treatments were: Tl wilted and anaerobic; T2 wilted and open; T3 unwilted and anaerobic; T4 unwilted and open. The mini-silos were sampled at 30-day intervals for up to ll2 days. The samples were analysed for dry matter (DM), crude protein (CP), neutral detergent fiber (NDF), lignin (LIN), phenolic compounds (PHEN), ammonia nitrogen (NH3 -N), soluble carbohydrats (CHO sol) and pH. The DM effective degradability (DMED) was determined “in situ” using six Santa Inês male sheep fitted with rumen cannula and fed with a mixture 80:20 diet containing grass pasture and concentrate (160 g CP/kg DM). The effects of experimental conditions were analysed in a factorial treatment structure and tested by analysis of variance. Treatment means were compared by contrasts.

Rumen microorganisms have variable requirements for a nitrogen source. Cumulative gas production (Theodorou et al., 1994) is often measured using media containing both ammonia (NH3) and mixed peptides (trypticase-TRYPT) to ensure that all microbes will have sufficient nitrogen (N) of the appropriate quality for growth and metabolism. This experiment was conducted to assess the effect of N source in the medium on the fermentation characteristics of citrus pulp, which was used as being representative of a readily fermentable carbohydrate.

Ammonia plays an important role in providing N for protein synthesis by rumen microorganisms. Studies using [15N]ammonia or [15N]urea indicate that the proportion of microbial nitrogen derived from ammonia is highly variable, ranging from 18 to 100% (Nolan, 1975; Salter et al., 1979). Peptides and amino acids are also incorporated by rumen microorganisms. They generally stimulate growth (Argyle & Baldwin, 1989), but little is known about the factors which govern the relative proportions of microbial amino acids which are derived from pre-formed amino acids and from ammonia. The present study was undertaken to determine how the concentration of peptides affects ammonia incorporation and the de novo synthesis of individual amino acids by mixed rumen microorganisms.

Studies with sugar beat pulp (SBP) have suggested that high levels (up to 650/kg dry matter (DM)) in the diet may beneficially reduce voluntary intake and live-weight gain (LWG) in pregnant sows. (Brouns, Edwards and English, 1995). Similarly, increasing the ratio of SBP: barley from 0.5:0.5 to 0.8:0.2 in the diet of growing sheep reduced LWG, DMI and apparent rate of ruminal digestion (Rouzbehan, Galbraith, Rooke and Perrott, 1994). The effects recorded have been associated with increases in viscosity of digesta due to the presence of non-starch polysaccharides (NSPs). The objective of this study was to determine whether pre-treatment with enzymes (a) may reduce NSP concentrations, measured by breakdown to reducing sugars, and (b) increase the rate of utilisation of NSP in ruminant diets.

The inoculum represents one of the greatest sources of uncontrolled variation in digestibility estimates via in vitro rumen fermentation methods (Marten and Barnes 1980). Microbial activity of rumen inoculum may be influenced by animal and diet factors. The objective of this work was to evaluate the effects of the level of inclusion of concentrate in the diet of the donor animal on the measurement of the in vitro digestibility of hay.

In vitro embryo production strategies have been considered as possible means to protect wild and endangered animal species through assisted breeding programmes. They also offer the possibility to preserve genetic material from such stock or to facilitate breeding in captivity. The relevant technologies, however, have been developed to meet the needs of oocytes and embryos of domesticated animals and their suitability for wild species remains largely unknown. This study investigated the ability of in vitro maturation procedures, designed for oocytes of domestic pigs (Sus scrofa domesticus), to support the development of oocytes from wild boar (Sus scrofa)gilts.

Lactogenesis is triggered by a rapid decline in plasma progesterone concentration combined with a peak in plasma prolactin concentration; in mice, there is a concurrent loss of mammary progesterone receptors (Haslam and Shyamala, 1980). The aims of this experiment were to determine the pattern of change of progesterone receptor and prolactin receptor mRNA during late gestation and early lactation and to determine whether abundance of mRNA for the two receptors are related to each other, to plasma concentrations of progesterone and prolactin or to piglet performance.

Porcine embryo production in vitrois providing the impetus for the development of cryopreservation strategies aimed at welfare-friendly domestic and international marketing and movement of stock in a manner that minimises risks of disease transmission. In the context of disease risks, defined media, which avoid the use of serum and other biohazardous products, are likely to become essential in the production of embryos for international markets. In preparing for this situation, the present comparative study investigated in vitronuclear maturation of porcine oocytes in the presence of either foetal calf serum (FCS) or polyvinyl alcohol (PVA). In addition, the effect of restricting the maturation time to 33 rather than 44 hours was examined.