The aim of this study was to examine if enzyme supplementation could improve the performance of early weaned piglets by increasing nutrient digestibility of diets in which energy content was reduced by replacing wheat with barley or sugar beet pulp.

The following diets were supplemented with (+) and without (-) stabilised multi-enzyme premixes (E1, E2 and E3 respectively): diet W containing 706g/kg wheat and formulated to supply 14 MJ DE/kg, diets B and SBP in which DE was reduced to 13.25 MJ/kg by completely replacing wheat with barley or 185g/kg sugar beet pulp respectively. All diets were formulated to provide 150g/kg of apparent ileally digestible ideal protein, giving a crude protein concentration of about 217g/kg. Soya bean (200g/kg) and fish meal (75g/kg) were added at equal levels to all diets. Main enzyme activities in E1 were xylanase (T . longibrachiatum), amylase (B. subtilis) and pectinase (A. niger), in E2 beta-glucanase (T. longibrachiatum), xylanase (T. longibrachiatum) and amylase (B.subtilis) and in E3 beta-glucanase (T. longibrachiatum), amylase (B. subtilis) and pectinase (A. niger). The feeds were pelleted (3mm).

Poor feed intake of conventional dry diets in the immediate post-weaning period can be a major factor limiting potential growth rate in the young pig. Feeding systems based on the automatic dispensing of liquid milk -substitute have been developed over the last 10-15 years but they have not achieved widespread usage within the U.K. industry for various reasons. Several studies have shown, however, the potential benefit of offering liquid or slurry diets over this critical period around weaning (eg. English, Maclean and MacPherson 1988; Anon 1991). Deprez et a] (1987) also demonstrated its beneficial effects on the morphology of the small intestine post-weaning. The present study examined the use of an experimental automated feeder (‘Autofeeder’, patent applied for) which could dispense a conventional pelleted starter diet plus water (1:1 ratio) 6, 8, 12 or 24 times throughout the day in varying quantities. It was compared against a conventional dry hopper (control) with ad libitum feeding.

Pig production 1s responsible for 65 per cent of all odour complaints and 10 per cent of water pollution incidents. In addition, the disposal of pig slurry effluent may create major difficulties in nitrate sensitive areas either from run off or leaching of liquids. In situ composting of pig manure has the potential to eliminate these problems whilst encouraging pig producers to use welfare positive, bedded systems. In situ composting is a system of housing in which pigs are contained on a deep bed of sawdust. The bed is actively managed by aeration and the use of commercial additives to encourage composting of excreta as it is produced. The system appears to give an odour and liquid free environment. Such systems cannot be encouraged however until it is clearly established that there are no environmental or health disadvantages.

Approximately 500 Justifiable complaints of offensive odours from pig farms are received annually. Slurry additives for odour control, if successful, would be of considerable public good. Earlier work at Institute of Grassland & Environmental Research (I.G.E.R.) Hurley on the efficacy of slurry additives for controlling odour emission from pig slurry, showed one product (Homogen; containing brown algae, calcium and magnesium alginates and substances to selectively support the multiplication of facultative anaerobes; Mycatec Laboratories) to give promising results on small scale stores (80 litre) of pig slurry. This experiment was designed to test the efficacy of the slurry additive Homogen on a commercial scale on pig finishing pens with slurry stores.

Housing sows in dynamic groups may increase stress compared with housing them in stable groups. The majority of producers with dynamic systems introduce their sows into the group after mating. This could result in an unsettled environment throughout the implantation phase in early pregnancy and consequently impair reproductive performance. An experiment was designed to test this hypothesis using commercially-managed sows.

The Codes of Recommendation for the Welfare of Livestock : Pigs (1991) suggest that the minimum total floor space for pigs growing to 20 kg should be 0.15 m2 per pig. This space allowance should be adequate for sleeping, feeding, dunging and exercise. However, no allowance has been made for the space the pig needs to signal submission during an aggressive interaction, and it may be that this is one of the reasons why weaning is associated with such a high level of aggression and a reduction in growth rate. The objective of this experiment was to try to reduce aggression and belly-nosing and to improve weight gain by building a hide area (using a barrier) into conventional weaner pens. The steel-framed barriers that were used took up very little space in the pens. Three trials involving 120 Large White X Landrace piglets were carried out. In each trial, piglets were weaned at 24 days and were assigned at random to one of four treatments; straw pen with a barrier, straw pen with no barrier, flatdeck cage with a barrier, flatdeck cage with no barrier, each group contained ten piglets.

The work was conducted to study the effect of varying the electrolyte balance in the diet on growth performance of post-weaning pigs. Dietary electrolyte balance (dEB) was calculated from:-

dEB (mEq) = (Na +K-C1)

The values for each element were calculated from:-

A diet was designed to comprise barley 262.5, wheat 225.5, cooked maize 200, soya bean meal 66, white fish meal 125, dried slrim milk 100, mineral/vitamin/amino acid supplement 5 and electrolyte mixture 16g/kg. The dietary specifications were 14.27 MJ DE, 223g crude protein, 24.2 crude fibre, 24.4g oil (acid ether extract), 54.7g ash, 13.7g lysine, 3.7g methionine and 8.6g threonine/kg.

The electrolyte mixture was initially solely anhydrous calcium chloride which was gradually replaced by sodium bicarbonate. Eight dietary treatments were calculated to contain dEB (mEq/kg) values of -114.5, -54.3, 14.5, 89.2, 155.1, 224.4, 296.1 and 365.0. Diets were offered an a scale calculated to be 0.85 of ad libitum.

The amount of water wasted by pigs from drinking utensils is difficult to measure directly. Bekaert et al.,(1970) claim that directly activated bite drinkers spill 66% of the water they dispense. However Olsson, (1983) estimated that water spillage accounts for 20% of the total volume of water used by pigs. If it were possible to determine indirectly the water intake of pigs, this value subtracted from the gross consumption value (metered) would give the amount of wastage. The aim of this experiment was to evaluate the use of urine relative density and creatinine concentration as indirect determinants of water intake.

Previous experiments indicated that protein level in the diet might affect intake and apparent digestibility of diets containing high levels of unmolassed sugarbeet pulp (SBP). As utilisation of dietary fibre depends on fermentation by the microflora in the gastro-intestinal tract, availability of nitrogen to the microflora could be important. It is generally assumed that most fermentation occurs in the hlndgut, although with SBP, fermentation does occur in the ileum. Therefore the source as well as level of dietary nitrogen might be important.

Four maize based diets were formulated to contain the same amount (600g/kg) of SBP (Table 1). The control diet (C) contained no added nitrogen rich material (dietary N 15 g/kg). In the other diets the N concentration was doubled by adding either soyabean meal (S), white fishmeal (F), or urea (U).

In a pre-trial period, voluntary food intake (VFI) of 17 individually housed gilts fed ad libitum on diet C was determined. The gilts were allocated to the treatments on the basis of this VFI, 5 gilts on diet C, 4 on each of S, F, and U. The diets were fed ad libitum from a hopper during a 3 week period in late gestation. After one week of adaptation, VFI was measured daily. On the last 5 days of the period, faecal samples were collected for overall apparent digestibility measurements using chromic oxide as inert marker (5 g/kg diet). Liveweight and backfat thickness of the gilts were determined at the beginning and at the end of the experiment.

Distillery products which are high in fibre have traditionally been fed only to ruminants, but might provide a cost effective feed for dry sows. If such bulky materials could be fed ad libitum, animal welfare might be enhanced by prolonging feeding time and providing the sows with a greater feeling of satiety in comparison with concentrate diets. To investigate such possibilities, voluntary intake and digestibility were determined with dry sows for three distillery products:

The three distillery products investigated were:

• 1) malt draff (MD), the barley residue remaining after starch extraction

• 2) maize curne gold (CG), evaporated spent wash plus maize cereal residue

• 3) wheat supergrains (SG), centrifuged spent wash plus wheat residue

Each material was offered ad libitum to three pens of 6 dry sows, initially in conjunction with 0.5 kg/sow/day of a balancer meal. The balancer meal contained barley (890 kg/t), limestone (100 kg/t) and a vitamin/trace element supplement at 4 times the normal inclusion rate (10 kg/t). Sows were grouped according to service date and allocated to the experimental treatments in early pregnancy. They were housed in straw bedded pens with individual stalls for feeding of the supplement. Voluntary intake, liveweight and backfat change were monitored over a minimum period of 9 weeks. Sows which failed to maintain acceptable body condition on this regime were given additional ground barley as the experiment progressed.

In commercial situations dry sows are fed a relatively small amount of food once or twice a day. In group feeding systems this can cause a lot of aggression at feeding time and result in an unequal distribution of food between sows when dominant sows prevent subdominant sows from eating. Ad libitum feeding of a suitable diet may be one way to overcome these problems.

Four groups of 12 multiparous sows were housed in deep straw pens (2.9 m2/sow). They were allocated to one of two feeding treatments involving high or low competition for food. Groups on the high competition (HC) treatment were floor-fed once a day 3.0 kg/sow of a barley-soyabean meal diet in pelleted (8 mm) form. Groups on the low competition (LC) treatment received ad libitum a diet containing 60% unmolassed sugarbeet pulp from a 3-space hopper. The composition of the diets is shown in table 1.

Groups were allocated to treatment after service. Feed intake was recorded regularly, liveweight and backfat thickness were measured every fortnight over a 10 week period.

Voluntary food intake of dry sows fed ad libitum diets containing high levels of unmolassed sugarbeet pulp (SBP) was low in comparison to those fed other high fibre diets (Brouns et al., 1991). It is not known whether this is caused by a taste aversion, or whether physical/metabolic effects during digestion restrict intake. In this experiment the feeding motivation of sows fed SBP diets was determined by measuring their rate of feeding.

Twelve multiparous pregnant sows housed in straw bedded pens, but individually fed in feeding stalls, were used for this experiment. The sows were allocated between two treatments according to their measured rate of eating when given a standard diet on 2 pretrial days. Treatments were 2.3 kg of a diet containing 500g/kg SBP or 2.0 kg of a barley-based diet (C) (Table 1) providing the same total DE. Both diets were fed once a day in pelleted form. Any refusals were recorded to calculate intake.

The large appetite of dry sows generally leads to an excessive nutrient intake when they are fed ad libitum. A previous experiment showed that only a diet with high levels (650g/kg) of unmolassed sugarbeet pulp (SBP) was able to reduce voluntary food intake (VFI) to an acceptable level when several high fibre diets were fed ad libitum to dry sows. This paper reports the results of 2 experiments designed to investigate which parameters affect VFI of diets containing high levels of SBP.

In the first experiment, 4 diets with increasing levels of SBP (400, 500, 580, and 650 g/kg; diet 40, 50, 58, and 65 resp.) were formulated by substituting SBP for barley, giving a similar crude protein concentration, but allowing the DE to decrease with increasing SBP level. To a fifth diet (diet oil) containing 650 g/kg SBP extra vegetable oil was added to increase the DE to the same level as in diet 40. The diets were fed ad libitum to 40 sows, 8 sows on each diet, during a 3 week period in late gestation.

Studies with beef cattle (Kennedy and Carson, 1991) and dairy cattle (Chamberlain et al, 1990) have shown responses in dry matter intake of silage and animal performance through applying Maxgrass silage additive to unwilted herbage ensiled in clamps. Maxgrass (BP Chemicals Ltd) contains (weight/volume) 68% ammonium hexamethanoate, 11% ammonium hexapropanoate and 2% octanoic acid.

Research at Aberdeen has shown the benefits of using both inoculant (Weddell, 1990a) and formic acid based (Weddell, 1990b) additives on big bale silage which now constitutes around 15% of the total silage dry matter ensiled in the UK. The present study compared the effects on silage composition, animal performance and storage losses of Maxgrass treated with untreated big bale silage.

Second cut perennial ryegrass herbage was wilted to a mean DM content of 230 g/kg then baled by fixed chamber baler. Mean water soluble carbohydrate was 100 g/kg DM. Alternate groups of six bales were left untreated or treated with Maxgrass silage additive at 7.4 1/tonne wilted grass.

Proteolysis during ensilage results in a reduction in the nutritive value of the crop due to the degradation of protein to peptides, amino acids and ammonia. Williams et al. (1990) characterised these nitrogenous constituents in ryegrass silages prepared with no additive or with formic acid or an enzyme additive. Although all the silages appeared well fermented neither of the additives reduced proteolysis. The present study was designed to follow changes in the microbiological as well as the chemical composition of ryegrass silages made without or with a wider range of additives thought likely to reduce proteolysis and to control it in different ways.

Perennial ryegrass was ensiled in laboratory silos (1 kg fresh matter), either untreated (U) or treated with formic acid (F) (ADD-F, BP Chemicals, UK; 3.3 1/tonne), aliphatic carboxylic acids (A) (Maxgrass, BP Chemicals, UK; 6.0 1/tonne), 1.75M Na diethyl dithiocarbamate (D) (BDH, UK; 6.0 1/tonne) or an inoculant (I) (Live System, Genus Animal Health, UK; 3.01/tonne at 106 Lactobacillus plantarum cells/g fresh matter (FM). Triplicate silos for each treatment were opened after storage for periods of 1, 2, 4, 14, 60 and 90d.

The nutritive value of ensiled grass can be modified by the fermentation process. Compared to industrial fermentation, silage fermentation is still a relatively uncontrolled process. Consequently, considerable variation in the pattern of silage fermentation occurs on farms (Wilson and O'Kiely, 1990). This makes animal performance difficult to predict accurately and may alter the composition of the most appropriate concentrate to be fed with the silage. The objectives of the present experiment were (1) to compare the growth and rumen fermentation in cattle fed silage, where silage fermentation was altered using organic acids and (2) to determine the relative effects on growth when the silages were supplemented with two forms of concentrate.

Maxgrass is a silage additive consisting of a premixture of carboxylic acids containing ammonium hexamethanoate (68%) and ammonium hexapropanoate (10%). In theory, this additive when used on grass for ensiling at a high rate (6.0 1/t) should restrict fermentation, thereby reducing the level of VFA and lactic acid production and increasing the amount of residual WSC in the silage. It is claimed that silage with these characteristics should result in higher dry matter intakes and better animal performance. The objective of this experiment was to compare the performance of dairy cows fed either maxgrass or formic acid treated silages at two levels of concentrate supplementation.

Silage was harvested unwilted from a primary growth sward of perennial ryegrass on May 21 and 22, 1990. The additive treatments applied through the harvester were: (i) Maxgrass - 6 1/t grass and (ii) formic acid - 2 1/t grass. Cows calving between mid-September 1990 and early January 1991 were used to evaluate the silages.

Recent research at this Institute has shown marked improvements in animal performance following the use of bacterial inoculants as silage additives (Gordon, 1989 and Mayne, 1990). Other studies with additives based on antimicrobial carboxylic salts (Maxgrass - BP Chemicals) have also shown large improvements in animal performance relative to untreated silage (Chamberlain et al, 1990). However with constraints on milk output in the form of milk quotas, it is important to investigate the potential “concentrate sparing” effect of these differing silage additives, whilst producing a constant yield of milk constituents.

Five silages with a range of fermentation characteristics were produced by ensiling first regrowth herbage either untreated (C) or treated with four differing silage additives including: an inoculant of lactic acid bacteria (I); an inoculant of lactic acid bacteria plus enzymes (I+E); formic acid applied at 2.54 litres/t grass (FA) and antimicrobial carboxylic acids applied at 5.95 litres/t grass (CA).

Maxgrass (BP Chemicals Ltd), a product containing ammonium hexamethanoate, ammonium hexapropionate and carboxylic acids, has been claimed to restrict the extent of WSC fermentation in herbage during ensiling. This has been shown to result in increased DM intake and subsequent animal performance (Kennedy 1990). The objective of the present experiment was to further investigate the effects of this treatment of grass at ensiling and in particular to examine the interaction of the responses with levels of concentrate supplementation when offered to finishing beef cattle. Evaluation parameters included an assessment of additive effect on silage intake, animal performance and carcass characteristics.

Approximately 70 tonnes of primary growth grass was ensiled from 22-24 May 1990 into each of eight concrete covered, walled silos (4 per treatment). Grass was treated with Maxgrass (6 l/t) or left untreated. Seventy-two Continental cattle (460 kg) were blocked into groups of 9 according to liveweight and allocated at random to either untreated or Maxgrass treated silage supplemented with 0, 1.5, 3.0 or 4.5 kg/day of a 15% CP proprietary beef concentrate or slaughtered.

Epiphytic LAB, e.g., lactobacilli, lactococci, enterococci, pediococci, streptococci, and leuconostocs, play a major role in silage fermentation. Their numbers and populations have become a concern in predicting the adequacy of silage fermentation and in determining whether or not to apply a bacterial inoculant (Bolsen et al, 1989). Epiphytic LAB counts are usually low and variable on silage crops (Lin et al, 1991), and increases in the LAB counts usually occur coincident to the chopping process. Only limited information is available concerning the succession of epiphytic LAB species during the ensiling period of alfalfa (Medicago sativaL.) and maize (Zea mays L.), the two major silage crops in North America. The present studies investigated the epiphytic LAB succession during the pre-ensiling and ensiling periods for two cuttings of alfalfa, each harvested at three stages of maturity, and three whole-plant maize hybrids.

A second-year stand of alfalfa was harvested at the 2nd and 4th cuttings and at the late-bud, 10% bloom, and 50% bloom stages of maturity within each cutting in 1989. Following mowing, the alfalfa was wilted in the windrow for 5 to 6 hours prior to precision chopping.