Gasol-treated barley for pigs

Moistbarley (GB) preserved with Gasol additive (containing formaldehyde, acetic acid, isobutyric acid and lignosulphonates)was evaluated as pig feed. A digestibility trial was conducted as a 3 x 3 Latin square, in which dried barley (DB) was replaced with GB at two levels, 50 and 100 Vo. The performance and carcase properties were examined in a feeding trial with 48 growing pigs fed on either DB or GB supplemented with protein concentrate. Gasol barley showed no signs of deterioration during storage (DM 79 Vo, average application level 1.0 Vo). The lysine content was lower in GB than in DB, 2.3 vs. 3.9 g/16 g N and sulphuric amino acids and threonine were also lower. GB had lower digestibilities for OM, CP and NFE: 78.9, 68.8 and 86.9 Vo vs. 82.0, 75.6 and 88.6 in DB (P > 0.05). The amino acid digestibilities of the GB averaged 88 Vo of the values of the DB diet (P > 0.05). The estimated feed values for GB and DB were, respectively 1.05 and 1.09 FU/kg DM and 85 and 86 g DCP/FU. On the GB diet, the pigs gained significantly less (P < 0.01) than on the DB diet (589 vs. 703 g/d) and FCE was poorer, 3.46 vs. 2.89 kg DM/kg gain (P < 0.01). The firmness of the fat and colour of the lean were inferior in the pigs fed on GB (P > 0.05). The results showed that Gasol is unsuitable for preserving grain intended for pig feed if the grain is uncontaminated, but moulded barley can be treated with Gasol to reduce the detrimental effects of the fungal


Introduction
Organic acids and formaldehyde inhibit microbial growth on high-moisture grains, which allows the grains to be stored aero- bically and thus offers an alternative to the conventional drying process.When highmoisture barley treated with organic acids was fed to growing pigs and compared with a dried barley ration with the same dry matter con- tent, its feeding value was reported to be the same (Alaviuhkola 1973, Cole et al. 1975,  1980, Pringle et al. 1983) or a little less (Thomke and Tiden 1973).»GASOL» is a new grain preservative developed for use in ruminant feeding by Farmos-Group Ltd.
Gasol solution contains 15 % formaldehyde and acetic acid, isobutyric acid and lignosul- phonates.It has given promising results when used against the fungus Fusarium graminearum and has reduced the detrimental effects of the toxin zearaleone produced by this fungus (Kallela and Saastamoinen 1982).
The objective of this study was to determine the feeding value of Gasol-preserved highmoisture barley for growing pigs, as measured by the nutrient digestibilities, pig performance and carcase properties.

Materials and methods
Barley var.Porno was harvested and part of it was dehydrated in a warm air dryer, the remainder being preserved with Gasol liquid.The level of application of Gasol was chosen according to the moisture content of the Before storing the dry matter of the barley averaged 75 %.According to visual inspection, the preserved barley showed no signs of spoiling.The barley was milled in a hammer mill, using a 3 mm sieve.
The digestibility and balance trial was car- ried out with three castrated Landrace pigs weighing 35-67 kg.The total collection meth- od was used and the experiment was designed as a 3 x 3 Latin square, in which dried bar- ley was replaced with Gasol preserved barley at two levels, 50 and 100 %.The diets were enriched with 15 % of skim milk powder, a mineral mixture, 40 g/d, and a vitamin mix- ture, 15 g/d.The crude protein content of the diets was 16.5 % of DM.The daily rations in the different periods were 2.0, 2.2 and 2.6 kg/d (average intake 98.8 g DM/kg W 0 75 ).
The transition period between diets was four days and the standardization and collection periods were both six days.The details of the procedures of feeding and faeces collection are described by NAsi (1982).
In the feeding experiment, 48 pigs were allocated to two groups, of which one was fed with dry barley (DB) and the other received Gasol preserved barley (GB).The two groups received the same daily amount of protein concentrate, composed of fish meal 40 %, soybean meal 25 % and mineral and vitamin mixture 35 °7o.The DCP content of the pro- tein concentrate mixture was 36.7 °7o, and the supplementation level was 10 % of the airdried feed.The two groups were intended to receive an equal amount of barley dry matter daily.The dry matter content of the dehydrated barley averaged 86.6 and that of the Gasol barley 79.0 %.There was sufficient Gasol barley to feed 16 pig for the whole ex- perimental period.
The chemical analyses of the feeds and faeces were performed according to the offi- cial procedures.Amino acids were determined with a Technicon TSM autoanalyzer after hydrolysis of 20 hours in 6 N HCI.The vola- tile fatty acids of Gasol barley were deter- mined by gas-liquid chromatography.

Results and discussion
The chemical composition of the experimental feeds is presented in Table 1.The Gasol-treated barley contained acetic acid 1.97 g and isobutyric acid 2.82 g/kg, which were residues from the preservative.The lactic acid content was 0.56 g/kg, indicating slight fer- mentation during storage.The GB showed no visible spoilage and smelled fresh.Its NH 3 -N content was found to be quite low, 0.04 g/kg.The lysine content was reduced during stor- age to 2.3 g/16 g N, as against 3.3 g in dried barley.The GB also had lower contents of sulphur amino acids (3.9 vs 3.4), threonine (3.7 vs 3.5) and arginine (4.4 vs 3.7).Protein treated with formaldehyde has been shown to  (Just)  14.27 13.72 NE, FU/kg DM (Just)  1.14 1.09 DCP, Vo in DM 8.10 6.86 DCP, g/FU 86 85 have a reduced content of lysine (Hove and Lohrey 1976, Kowalczyk and Otwinowska  1983).The content of a-tocoferol and a- tocotienol was lower in GB than in DB (4 mg/kg vs 45 mg/kg).
The apparent nutrient digestibilities were lower in GB than in DB: by 3.1 % units for organic matter, 6.8 % units for crude protein and 1.7 % units for NFE (Table 1).The dif- ferences were not statistically significant (P > 0.05).The digestibility of starch was complete and similar in both grains (99.7 % vs 99.5 %).In GB the pepsin HCI solubility of crude protein was lower and the water- soluble fraction of total nitrogen was greatly reduced (Table 1).Experiments with pigs, rats and chicks have indicated that treatment with formaldehyde reduces the digestibility of protein (Thomas et al. 1979, Spears et al. 1980,  Kowaczyk and Otwinowska 1983).However, treatment of soybean meal with low levels of formaldehyde, 0,3 -0.4 %, did not affect the performance of rats and chicks (Hove and Lohrey 1976, Spears et al. 1980).Formaldehyde treatment reduces protein degradability by rumen microbes and improves nitrogen utilization and performance in ruminants, but high concentrations reduce the digestibility of total protein (Kaufmann and Topping 1982,   Kowaltczyk et al. 1982).Huhtanen (1984)  found that the degradation rates of DM, crude protein and starch determined by the nylon bag technique were lower in GB than in pro- pionic acid barley.The degradation of crude protein in 9 hours was 46.6 % for GB and 76.4 % for PAB.
The feed values calculated for DB and GB are presented in Table 1.In DB the net energy value was 3.7 % higher and that for metab- olizable energy 3.9 % higher than in GB.
The nitrogen balance measurements are shown in Table 2. Nitrogen retention was on average 5.9 % lower in pigs fed on GB than in pigs fed on DB.Nitrogen utilization, mea- sured as percentage retention of absorbed nitrogen, was also lower on a GB diet (differences not significant, P > 0.05).This indicates poorer balance of the amino acids ab-sorbed from the intestinal tract.Loss of lysine occurred during storage.The lysine intake on the GB diet averaged 14.2 and on DB 17.2 g/d.The values for threonine and S-amino acids were 12.9, 12.9 and 11.5 and 12.1 g/d, respectively.
Estimates of the average digestibilities of in- dividual amino acids on the different diets are presented in Table 2.The apparent faecal di- gestibilities of amino acids on the GB diet averaged 89 % of the values found on a DB diet.The differences were not significant (P > 0.05).Lysine, for example was less digestible by 9.5 % units on GB diet, which means that the mean daily amount of lysine absorbed was only 8.9 g compared with 12.5 g on the DB diet.
In the growth trial the pigs on the GB diet gained 16 % slower (589 vs 703 g/d) than the pigs on the DB diet (P < 0.01).The differ- ence in feed conversion efficiency was 20 °7o (P < 0.01).The decreased leanness of the carcases of the pigs in the GB group shows the inferior quality of the protein (Table 3).The protein level was rather low (120 g DCP/ FU) in respect to get information of the effect of the preservation on the protein quality.Growing pigs of the lean type require 13 °7o DCP in their diet (Salo et ai.1982).
As regards the carcase characteristics, the firmness of the fat and colour of the lean were inferior in the animals of the GB group to those in the control group.
The results in both the digestibility and balance and the growth trials showed that  (Göfo values)  57 54 NS Gasol solution is not promising as a preservative for grain intended for use in pig feed- ing.If the grain is moulded, however, the detrimental effects of the toxin zearaleone can be diminished by using Gasol (Kallela and   Saastamoinen 1982).When grain treated in this way is used in pig feeding the quality of the protein should be improved, e.g. by supplementation with synthetic lysine and vitamin E.

Table 1 .
Chemical composition and nutrient digestibilities of dried barley and Gasol preserved barley fed to pigs and estimated feed values.

Table 2 .
Nitrogen balance, protein utilization and amino acid apparent digestibilities of diets in which dried barley (DB) was replaced with Gasol preserved barley (GB).

Table 3 .
Performance and carcase properties of pigs fed on dried or Gasol preserved barley.