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Report no. 439José A. Fernández Henry Jørgensen 16.09.1999
Crina HC in feed for growing-finishing pigs
Abstract
All feed mixtures were produced at Aarhusegnens Andels Grovvareforening a.m.b.a. The feed mixtures were formulated according to the current Danish standards of nutrients. The content of the amino acids: lysine, methionine, threonine and tryptophan was calculated to be 5 per cent above the current standards. This was done in order to counteract fluctuations in the content of crude protein in the raw materials. The feed was heat treated at a minimum temperature of 81 degrees Celsius and pelleted. The raw material composition of the individual mixtures and a further description of Crina HC is shown in appendix 1 and 3, respectively. Crina HC and a marker substance (Micro Tracer) were admixed into fine wheat bran and added to the feed mixtures to group 2 and 3 in the dose of 0.5 and 1.0 per cent, respectively. The premixture containing Crina HC and Micro Tracer were produced in two batches, and the feed mixtures were produced in three batches. At each feed production each mixture was sampled for complete feed analysis including amino acids, calcium and phosphorous. Furthermore, the content of Micro Tracer in the premixture and the feed mixtures were tested, and Akzo Nobel Chemicals A/S received a feed sample from each feed production and a sample of the premixture for analysing the content of Crina HC. The test pigs were transferred to the test at an average weight of 30 kg. Each group included 119 pigs divided into 11 blocks (repeats), totalling 357 pigs in the test. Females and castrated pigs were equally distributed between the three test groups. The growing-finishing unit was arranged with pens of 10 or 11 pigs. In each block, an equal number of pigs was distributed into each pen. The pens were with fully slotted floor. In each pen there was a single space feeder (with water) and an extra nipple drinker. The pigs were fed ad libitum. The pigs were fed manually once or twice every day. Feed intake, daily weight gain, disease treatments and slaughter data were recorded. The pigs were intermediary weighted about one month after entering the test. The effect was measured on the production value as the primary parameter, stated as gross margin (GM) per place unit per year. The production value was calculated from the measured production results: weight gain, feed intake, and lean meat percentage adjusted to the same weight at entry and at slaughter and fixed prices. GM / place unit / year was calculated as:
The fixed prices were calculated from the latest 5 years’ average price (September 1st 1994 to September 1st 1999) for 30 kg MS (health status) pigs (360 DKK/pig, +/- 4.95 DKK/kg) and slaughter pigs (10.10 DKK/kg, including bonus payment). Various costs were fixed to 20 DKK and the utilization of the growing-finishing unit was fixed to 95 per cent. The feed price used was also calculated from the latest 5 years’ average price and was the same for all groups (1.28 DKK/FUp). Moreover, the production value at actual 5 weeks’ prices (week 32 -36 1999) was calculated. The average price in this period for 30 kg MS pigs was 308 DKK/pig +/- 4.36 DKK/kg, the price for finishers was 8.60 DKK/kg including bonus payment, and the feed price was 1.12 DKK/FUp. Secondary parameters were treatment of disease and mortality at pen level. Data were subjected to an analysis of variance according to the GLM procedure in SAS. The following class variables were included in the statistical model: blocks and groups. The results are shown as adjusted means for each group in the test. Statistical significant differences are stated at five per cent level adjusted for three paired comparisons by a Bonferroni t-test. Digestibility test The digestibility test was performed at the Danish Institute for Agricultural Science. The feed mixtures used were produced at Aarhusegnens Andels Grovvareforening a.m.b.a., and were the same as those used for the production test performed at the experimental station Grønhøj. The pelleted feed was grinded and added a digestibility marker (Cr2 O3, 0.5 g/kg feed). The marker was mixed with corn starch and grinded through a 0.5 mm mesh and afterwards diluted with each feed mixture, as it was mixed in the total feed amount. The feed mixtures were analysed three times for dry matter, ash, protein, HCl-fat, gross energy, starch and Cr2 O3. Further, the feed mixtures were analysed in a single analyse for amino acids, sugar substances and fibre. Seven pigs at approximately 30 kg from two litters (three and four pigs per litter, respectively) were fitted with a T-cannula at the terminal ileum. The experiment started 14 days after the fistulation. The pigs were housed in single pens during the experiment. Six pigs were fed the three feed mixtures according to a double 3x3 latin square design, i.e. all six pigs were fed all three feed mixtures, but in three different periods. The seventh fistulated pig was kept as a reserve. Each period consisted of 24 days, and at the transition from one experimental feed mixture to another, the pigs were fed a standard growing diet for three to four days. The pigs were fed three times a day at intervals of 8 hours in the collection periods. The feed was weight out in rations individually for each pig for each feeding.Water was given together with the feed in the ratio 2.5 litre water per kg feed. Digesta was collected in intervals of 8 hours in the last two days of each period. The collection of digesta was performed while the pigs were in the pens by fixing a plastic bag to the cannula at the terminal ileum. The plastic bag was changed every time that digesta appeared in the bag, and the digesta was immediately transferred to a box and frozen. Subsequently, the digesta was freeze dried and analysed for Cr2 O3, organic matter, protein, HCl-fat and gross energy. The apparent ileal digestibility (digestibility in the small intestine) was calculated as:
The results of the digestibility were subjected to an analysis of variance according to the GLM procedure in SAS. The following class variables were included in the statistical model: feed mixture, period, litter and pigs within litter. The results are shown as adjusted means for each feed mixture. Statistically significant differences are stated at five per cent level. Results and discussion Feed analyses The feed analyses showed a good concordance with the calculated content of nutrients (appendix 2). The content of Crina HC and Micro Tracer in the feed mixtures are shown in appendix 2 as well. In the premixture as well as in the feed mixtures, the analysed content of Micro Tracer showed a good concordance to the calculated content. The analysed content of Crina HC in the feed mixtures was lower than calculated, in spite of a good agreement to the calculated content of Crina HC in the premixture. The content of Crina HC in the feed mixtures variated between 42 to 94 per cent of calculated. Therefore, the results indicates, that the active substance in Crina HC was reduced during the feed production, where the feed was heat treated and pelleted. Health conditions during the production test In general, the pigs were in good health. Only one pig was treated against diarrhoea during the test. During the test period 15 pigs (4 per cent) died or were withdrawn equally between the groups due to other reasons than digestive disorders. Production results The production results are stated before and after the intermediate weighing as well as for the whole test period (table 2). The results are adjusted to same weight at entry, intermediate weighing and slaughter. The average weight at entry, intermediate weighing and delivery was 30, 60 and 102 kg, respectively. By an accident control pigs from two blocks (pens) were mixed, so that an average for the production results has been calculated for these two blocks in the control group before the statistical analyse of the results.
The production value at 5 years’ prices (September 1st 1994 to September 1st 1999) stated as gross margin per place unit per year in shown in table 3. The production value at actual 5 weeks’ prices (week 32-36 1999) is shown in table 3 as well. In the calculation of the production value at 5 weeks’ prices the gross price for Crina HC is added to the price for the control feed. The used price is shown in appendix 3 and is stated by the supplier. The price reflect the typical price for the product that the pig producer pay including the profit of the feed company.
The test showed, that addition of 75 or 150 mg Crina HC per kg feed had no statistical significant effect on the production value. Therefore, in this test it was not possible to verify the results found in an previous experiment of Crina HC in pelleted feed for growing-finishing pigs performed at the Danish Institute of Agricultural Science (DIAS) (report no 64, 1996), where a tendency for higher feed conversion ratio (p=0.07) was found by addition of 75 mg Crina HC to the feed. The lack of effect may be due to a possible inactivation of the active substances in Crina HC by heat treatment. Ileal digestibility All the six pigs included in the digestibility test remained healthy though out the test period. The daily weight gain in the whole test period (12 weeks) was 773, 771 and 768 g, respectively, when the pigs were fed control feed, 75 mg Crina HC per kg feed or 150 mg Crina HC per kg feed, respectively. The apparent ileal digestibility (digestibility in the small intestine) is shown in table 4. The level for digestibility of nutrients is in good concordance to previous experiments with corresponding feed mixture at the Danish Institute of Agricultural Science (DIAS). No statistically significant difference was found between the control mixture and the experimental mixtures in the digestibility of dry matter, organic matter, protein, fat and gross energy.
Conclusion Addition of 75 or 150 mg Crina HC per kg pelleted feed for growing-finishing pigs had no statistical significant effect on the production value or the apparent ileal digestibility of dry matter, organic matter, protein, fat and gross energy. Paeticipant Tommy Nielsen Reference Sørensen, M.T. and Larsen, A. E. 1996. Test of Crina feed additives for growing-finishing pigs. Intern Rapport nr. 64, Statens Husdyrbrugsforsøg. Appendix 1 Feed mixtures for growing-finishing pigs, ingredients in per cent
Appendix 2 Calculated and analysed content of nutrients in the feed mixtures (average of three feed productions)
Content of Crina HC and Micro Tracer in the feed mixtures (average of three feed productions)
Additional analyses of feed batches used for the digestibility test
Appendix 3 - Description of product based on company information
ppm En forkortelse af Parts per million (fx er 1 ppm er lig med 0,000001). En måleenhed som fx svarer til indhold af et stof i mg/kg af varen. i.e. "International enhed" er et udtryk for vitaminets vægtenhed. Vitamin A: 5.000 i.e. = 1 milligram retinol og for vitamin D: 200 i.e. = 5 mikrogram cholecalciferol. Toasted Toastning betyder opvarmning til 100-115 ºC i 20 minutter. En toastning reducerer indholdet af skadelige stoffer i en råvare. WHO Forkortelse af: World Health Organization. |
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