Dioxin residues in the edible tissue of finishing pigs after dioxin feeding

The aim of this study was to determine the contamination of finishing pigs with polychlorinated dibenzodioxins and dibenzofurans (PCDD/Fs) after feeding either uncontaminated feed or feed contaminated with 0.75, 2 or 4 ng/kg toxic equivalents (TEQ; calculated by multiplying individual congener concentrations by congener-specific toxicity equivalency factors). The feed was mixed with pure substances of PCDD/Fs to get the intended contamination. Five groups of six piglets each were fed contaminated feed, one group of five piglets served as control. One group was fed contaminated feed (4 ng TEQ/kg) only for the rearing period (6 weeks), and another group for the first 8 weeks of the fattening period (4 ng TEQ/kg feed). The other groups received the contaminated feed during the 12-weeks fattening period. After slaughtering, the edible parts of the belly, loin and fore-end were collected and homogenized. The samples of group 2 and 4a were investigated uncooked as well as roasted. Fattening yield and feed conversion (kg feed/kg weight gain) of the animals of all groups were in the normal range (final weight 109.7 kg; feed conversion 2.55-2.69 kg). The PCDD/F-content in 1 kg fat of the belly, loin and fore-end in relation to the intake was between 0.016 (4 ng TEQ/kg feed for a 6-weeks rearing period) and 1.39% (fore-end; 2 ng TEQ/kg feed for 12-weeks fattening period). There was a decrease in dioxin residues after a 12-weeks period but not after a 4-weeks period of feeding an uncontaminated feed. When feed contaminated with 0.75, 2 and 4 ng TEQ/kg was given for a 12-weeks fattening period, the residue concentrations of PCDD/F-TEQ in 1 kg belly was 0.455, 1.07 and 1.55 ng, in 1 kg fore-end 0.04 ng, 0.32 ng and 0.34 ng and in 1 kg loin 0.015 ng, 0.07 ng and 0.30 ng respectively. Roasting had no influence on the dioxin-residues. The residues per g belly fat exceed the maximum limits for dioxin in food of 0.6 pg WHO-PCDD/F-TEQ/g fat (EC Recommendations 2002/201/EC), when feed containing 0.75 ng PCDD/F-TEQ/kg is given for 12 weeks. When feed containing 0.4 ng TEQ (maximum content; EC recommendations 2002/201/EC) is given for 12 weeks, approximately 0.55 pg TEQ/g fat can be expected in the food. This value is within the action level of 0.6 pg/g fat of porks. In conclusion, the results of the study allow prediction of dioxin residues in the edible tissue of pork, if the feed contamination is known and the amount of feed intake can be estimated.     

Initial research on the use of mixed corn grain and stalk silage in broiler fattening

The suitability of a corn and cob maize silage (CCM) as a component rich in energy in the fattening ration was investigated in a growth experiment with male broilers. The CCM silage with a dry matter content of 60.2% contained the following substances determining its value (per 1 kg dry matter of the feed): 102 g crude protein, 61 g crude fibre and 682 energetic feed units for chickens (EFUc). CCM silage was either fed as a component of a feed mixture consisting of 70.5% CCM silage and 29.5% protein concentrate (all values of original substance) or both components of the ration were fed to broilers separately. The protein concentrate was composed as follows (values per kg): 650 g soybean oilmeal, 110 g fishmeal, 85 g tankage from rendering plants, 55 g torula yeast, 70 g mineral mixture and 30 g of a mixture of biologically active substances. The broilers of the control group received commercial fattening feed for broilers with coarse maize meal as cereal component. The feed mixture with CCM silage and separate CCM silage were accepted readily. When CCM silage and protein concentrate were offered alternatively, the same amount of CCM silage was consumed but 8% less protein concentrate. The broilers fed with CCM silage plus protein concentrate reached 96-97% of the live weight of the control animals (1.952 g/animal, 49th day), which received conventional feed, although their net energy intake was 10% lower. This proves a more favourable net energy expenditure for the test groups fed with CCM silage.     

Investigations on potential dietetic effects of lactulose in pigs

Effects of lactulose (lac) as feed additive on chyme and feces quality in pigs (reared piglets: n = 10; fattening pigs: n = 20) were tested. Furthermore, fattening pigs were experimentally infected with Salmonella Derby (orally 2.6 × 10⁸ cfu/pig, single dose infection on 1 day) to examine potential prophylactical effects. Pigs were fed a conventional diet ad libitum (in the control group without lac, in the experimental group including lac: 28.6/26.9 g lac/kg dry matter). In piglets and fattening pigs lac intake did not alter fecal dry matter (DM) content or feces pH. Contrary to findings in human beings only small amounts of lac reached the hindgut, although higher lac concentrations were measured in ileal chyme (in piglets: 10–40 g, in fattening pigs 40–70 g lac/kg DM of chyme). Lac ingestion led neither to increased concentrations of lactic acid or volatile fatty acids (vfa) nor to reduced pH data in chyme of small intestine, but in cecum and colon contents higher vfa concentrations (significant effects in piglets) were measured. Furthermore, lac ingestion resulted in reduced ammonia levels in small and large intestine contents. But no protective effects of lac ingestion were recognized when fattening pigs were infected orally with Salmonella Derby. Due to the fact that only parts of lac reach the hindgut there are doubts, whether lac can lead to comparable dietetic effects in pigs as known from human beings (laxation, forced elimination of bacteria a.s.o.). The obtained results in pigs underline the necessity of experimental studies in the target species before substances are used and recommended for dietetic purposes in feeding of pigs.     

Possible interesting dietetic effects of lactulose as a feed additive in pig feed

In reared piglets (n = 10), fattening pigs (n = 20) and sows (n = 8) the effects of lactulose as feed additive on the quality and composition of chyme and faeces were tested to find out potential dietetic advantages of its use. The lactulose concentration in the diets varied between 27-29 g/kg dry matter in piglets and fattening pigs and 55-140 g/kg dry matter in the diet of sows. In piglets and fattening pigs the lactulose intake did not alter the dry matter content and pH in faeces; in spite of the higher concentration lactulose did not result in diarrhea in sows or adult minipigs, there was only a slight decrease in the dry matter content of faeces. In contrast to findings in human beings only traces of lactulose reached the hind gut, although higher lactulose concentrations were measured at the end of the small intestine (in piglets: 10-40 g, in fattening pigs 40-70 g lactulose per kg dry matter of chyme). The oral intake of lactulose did not increase the concentration of lactic acid or volatile fatty acids in the content of the small intestine and did not reduce the pH in the chyme, but in the contents of cecum and colon ascendens higher concentrations of volatile fatty acids were measured (in piglets: significantly higher values, in fattening pigs slightly increased concentrations). In piglets as well as in fattening pigs lactulose resulted in reduced concentrations of ammonia in the content of small and large intestine, further more the concentrations of lipopolysaccharides were increased in the colonal chyme, when pigs ingested the lactulose containing diet. Due to the fact that only small amounts of lactulose reached the hind gut there are doubts, whether lactulose has comparable dietetic effects in pigs as known from human beings (for example laxative effects, forced elimination of bacteria like salmonella). The results obtained here in pigs underline the necessity of experimental studies in the target species (including parameters of digestive physiology, chemical/microbial composition of the chyme) before substances are used and recommended for dietetic purposes in feeding practice. In spite of generally adopted similarity of the alimentary tract in pigs and human beings there are eventually some important differences within the intestine, its digestive capacity or in reactions on ingested substances leading to unexpected results.     

添加香蕉茎秆渣对育肥猪生长性能影响的研究

在育肥猪的生长过程中添加香蕉茎秆渣青贮饲料,并进行饲喂比对。结果发现,育肥猪生长状况良好,无异常反应;添加香蕉茎秆渣青贮饲料的试验组育肥猪的增重明显低于对照组,但其料肉比降低了4.73%,有效地减少了混合饲料的消耗量;经过初步核算,按照每头育肥猪每天0.50kg香蕉茎秆渣青贮饲料的添加量,每千克增重可节约精饲料成本约0.45元。     

The effect of addition of formic acid to the rations on the energy metabolism of sheep and young bulls]

Total metabolism trials were carried out with 8 fattening bulls and 4 male sheep receiving rations supplemented with formic acid. Comparative trials were performed with lucerne conservates. The following results were obtained: Formic acid supplements of up to 0.7 gm/kg liveweight per animal/day did not influence the ruminal fermentation and the digestibility of the food beyond ordinary dissimilation processes nor did they influence the energy turnover in the animals. Already in the rumen, the added HCOOH was largely broken down into CO2 and CH4. Higher levels of N retention were observed if the animals were fed fresh lucerne silage supplemented with formic acid as compared with dried green feed and the other types of silage.     

Joint research on the precise determination of the energy and protein requirements of fattening pigs. 7. The effect of various energy levels on the performance and feed expenditure of fattening pigs

Scientific feeding experiments were carried out with 7 male castrated pigs of the genetic origin land race pig X large white with the test animals fed individually and the rations containing approximately the same amounts of protein, amino acids, minerals and vitamins but varied amounts of energy. Energy intake was adjusted to three levels: 100%, 85% and 70% of semi-ad-libitum intake (group 1 = 100%). With regard to protein supply there was a subdivision into 30-60 and 60-100 kg live weight. In addition to this, the digestibility of the feed mixture used and the N-balance were determined in both fattening periods. Having reached 100 kg live weight, the animals were slaughtered and a number of slaughtering parameters was determined. The average daily live weight gain in the three test groups was 749, 664 and 540 g over the whole fattening period. The feed expenditure was 3.7, 3.9 and 4.3 kg mixed feed per kg live weight gain so that, with regard to live weight performance and feed expenditure the group with the highest energy supply showed the best results. The level of energy supply had a remarkable influence on the composition of weight gain; thus the amount of fat in the carcass of the animals of groups 3 was by 1.8 kg and 2.5 kg resp. lower than of the animals in groups 2 and 1.     

小麦全株青贮饲料饲喂育肥猪效果研究

为探讨小麦全株青贮饲料的饲喂方法,以汶鑫黑猪和三元（杜×长×大）杂交猪为研究对象,通过饲养对比试验,证明小麦全株青贮饲料在中国地方猪和进口三元猪上应用的可行性。选择体重相近的汶鑫黑猪120头,分别饲喂基础日粮和用14%的小麦全株青贮饲料替代基础日粮,测定平均日采食量和平均日增重;同时,选取体重相近（60±0.16 kg）的三元（杜×长×大）猪24头,随机分为2个处理,每个处理3个重复,每个重复4头猪。试验分2个阶段,育肥前期（60~90 kg）和育肥后期（90 kg至出栏）。对照组,连续2个阶段均饲喂基础日粮,参考NRC（1998）育肥猪营养需要供给;试验组,2个阶段分别用20%和40%小麦全株青贮饲料等量替换基础组日粮。测定生猪的生产性能、屠宰性能、器官重量和肉的品质。研究结果表明汶鑫黑猪对小麦全株青贮饲料的接受度较高,不影响采食量,试验组生猪的结束重比对照组增加5.8%;添加20%小麦全株青贮饲料饲喂育肥猪阶段,对照组平均日增重和平均日采食量极显著高于试验组（P<0.01）,而试验组料重比极显著高于对照组（P<0.01）;添加40%小麦全株青贮饲料饲喂育肥猪阶段,对照组平均日增重、平均日采食量和料重比极显著高于试验组（P<0.01）,屠宰性能、肉品质低于试验组。由此证明,利用小麦全株青贮饲料饲喂汶鑫黑猪,既可以保持其优良品质,又可以节约养殖成本;饲喂添加40%小麦全株青贮饲料组生猪的生产性能高于添加20%小麦全株青贮饲料试验组,日粮中添加小麦全株青贮饲料增加了育肥猪胃和小肠的容积,提高了胴体性能和猪肉品质。     

Vitamin A requirement of growing swine. 2. Effect of the vitamin A supply on the vitamin A concentrations in the liver and plasma of piglets and fattening swine

In 9 experiments the vitamin A content of the livers of 64 newborn (still births and deaths up to 48 h p.p.) and 69 weaned piglets, 122 growers and 110 fattening pigs was investigated after slaughtering or autopsy. Liver samples were taken from 78 growers by means of biopsy after latarotomy. A fluorometric analysis of the plasma vitamin A level was made. At the time of birth the vitamin A content of the piglet livers was less than 100 IU/g and did not show any differences between the experiments. At the time of weaning, however, the livers of piglets from large-scale production showed a three times higher content (175 IU/g liver) in comparison to those from traditional production. Highly significant linear relations were established between the vitamin A content of the feed and the liver. According to these, a liver content of vitamin A of approximately equal to 30 IU/g is ensured by approximately equal to 2,000 IU in weaning piglets and by approximately equal to 800 IU vitamin A/kg feed in fattening pigs. The vitamin A activity of the beta-carotene in weaners was ascertained as less than 100 IU/mg. The plasma vitamin A level indicated the vitamin A status only in the range of deficient supply. A different plasma content could not be detected between 1,000 and 4,000 IU vitamin A/kg feed. According to this, a semilogarithmic relation was calculated according to the model of a saturation curve between the vitamin A content of the plasma and the liver. The threshold value for the decrease of the plasma level under 45 IU vitamin A/dl is 35 IU/g liver. Due to the low definiteness measure (B = 0.52) the relation cannot be applied to the individual animal. A contamination of 1,000 mg nitrite/kg feed had a low, and in the course of the experiment decreasing, influence on the vitamin A content of plasma and liver.     

Joint research on the precise determination of the energy and protein requirements of fattening pigs. 4. The effect of the energy level on the fattening of Camborough-type hybrid swine

Scientific feeding experiments were carried out with 5 castrated male pigs and 4 female animals of the genetic origin "Camborough" in the live weight range between 30 and 100 kg with a subdivision at 60 kg. In each test group the animals were fed individually and received rations with approximately equal contents of protein, amino acids, minerals and vitamins but different energy contents. Energy intake was adjusted to 3 levels of 100%, 85% and 70% of semi-ad-libitum intake. Apart from that, the digestibility of the feed mixtures used in the 2 fattening periods was determined. Having reached a live weight of 100 kg, 7 representative animals per group were slaughtered and a number of slaughtering parameters were registered. In all three test groups the daily live weight gain over the complete fattening period was very high (846, 819 and 778 g). Though the weight gain in group 3 with 70% of the energy supply of group 1 is significantly lower than in the other two groups, it is, however, only 70 g lower than in group 1. Consequently, the feed expenditure (2.6 kg mixed feed per kg live weight gain) in group 3 is by 20% lower than in group 1, in which the feed expenditure is 3.2 kg mixed feed per kg live weight gain. There were no significant differences on the weight gain performances and the registered carcass parameters between sows and castrated male pigs. Observed deviating tendencies are discussed.(ABSTRACT TRUNCATED AT 250 WORDS)     

Vitamin A requirement of growing swine. 1. Effect of vitamin A supply on growth of piglets and fattening swine

For the purpose of ascertaining the vitamin A requirement seven experiments with 303 pigs in the live weight range between 6.5 and 114 kg were made. In three experiments under in practice conditions we checked the standard vitamin A supplement to the mixed feed with 1,732 pigs (live weight range between 8.5 and 110 kg). The supplement to vitamin-A-free rations and to those poor in or free of carotene amounted to between 0 and 8,000 IU/kg feed. Above that, between 0 and 16 mg beta-carotene and 1,000 mg nitrite/kg feed were supplemented. As long as the vitamin A store in the liver during weaning amounted to greater than 50 IU and greater than 100 IU/g at the beginning of fattening, feed intake, live weight growth and feed expenditure were not influenced by the supplement of vitamin and provitamin resp. The supplement of 250 IU resulted in the same weight growth from weaning to the end of fattening as that of 4,000 IU. Nitrite supplement had a negative effect at 250 IU, at 500 IU vitamin A consumption and weight growth tended to be only insignificantly lower. The methaemoglobin content decreasing in the course of the experiment reflects the adaptation of the pigs to the nitrite load. The consumption and growth depression caused by vitamin A deficiency could be observed from the 7th week of the experiment when casein-swelling starch rations were fed, but from the 13th week of the experiment only when cereal-soybean oilmeal rations were fed. The weight of liver, spleen, kidneys, heart and brain was not influenced by vitamin A supply. The same applies to the body composition and retention with the exception of two deficiency piglets, which contained less fat in the empty body than the control animals.     

Immunostimulatory effect of dietary oregano etheric oils on lymphocytes from growth-retarded, low-weight growing-finishing pigs and productivity

The present study was designed to evaluate the possible effect of dietary oregano etheric oils as non-specific immunostimulating agents in growth-retarded, low-weight growing-finishing pigs. Forty-nine growth-retarded (> 10% under average weight in a group) growing-finishing pigs of the same age were assigned to two groups and treated as follows: Group 1 (n = 25): the animals weighed 58.2 +/- 2.4 kg and were fed until slaughter ad libitum with a commercial fattening diet supplemented with 3000 ppm commercial oregano feed additive (Oregpig Pecs, Hungary). Oregpig is dried leaf and flower of Origanum vulgare, enriched with 500 g/kg cold-pressed essential oils of the leaf and flower of Origanum vulgare. Analysis of Oregpig: 60 g carvacrol and 55 g thymol/kilogram. Group 2 (n = 24): the animals weighed 57.9 +/- 2.6 kg and were fed until slaughter with the same diet without Oregpig supplementation. Oregpig-receiving pigs showed a significantly (P < 0.05) better average daily gain and feed conversion rate than the non-treated animals (Oregpig group 788.1 +/- 31.3 g, control animals 709.3 +/- 42.2 g; 2.96, vs. 3.08, respectively). Mortality was significantly (P < 0.001) higher in the non-treated animals (Oregpig group, 1 animal = 4%; control, 8 animals = 33.3%). The proportion of CD4, CD8, MHC class II antigen, and non-T/non-B cells in peripheral blood lymphocytes was significantly higher in the Oregpig-receiving pigs than in the control animals. The proportion of CD4+ CD8+ double-positive T lymphocytes in peripheral blood and mesenteric lymph nodes was higher in the Oregpig-receiving pigs than in the control animals. Implication: Dietary oregano improves growth in growth-retarded growing-finishing pigs and has non-specific immunostimulatory effects on porcine immune cells.     

Effects of essential oils from fennel (Foeniculi aetheroleum) and caraway (Carvi aetheroleum) in pigs

The ban of antibiotics as a feed additive requires alternatives to stabilize the health and performance particularly of the young animals. Essential oils obtained from fennel seed (Foeniculi aetheroleum) and caraway seed (Carvi aetheroleum) were tested in diets for weaned piglets in comparison with either a diet without feed additive or with a combination of formic acid and copper (positive control). Four groups of sixteen piglets (live weight 7 kg, age 26 days) received diets without (1) or with supplements of 7.5 g formic acid + 160 mg Cu/kg (2), 100 mg fennel oil/kg (3) or 100 mg caraway oil/kg (4) during 3 weeks after weaning. In the subsequent 4 weeks, all piglets were fed a diet without these additions. Fennel oil contained almost 2/3 anethol, approximately 1/5 fenchon and the remaining part consisting of alpha + beta-pinen, limonen (p-mentha-1,8-dien) and estragol. In the caraway oil, half of the contents was represented by limonen and the other half by carvon. There were no piglet losses and only few cases of diarrhoea. The combination of formic acid and copper increased feed consumption by 27% and daily weight gain by 25%. There were no differences in the performance between the group fed fennel oil and the control without additives. Piglets fed caraway oil tended to consume less feed and to gain approximately 10% less. In feed choice experiments, pigs consumed the same two diets from two troughs with 50% of total feed amount, as expected. The diets containing fennel or caraway oils were consumed at less than 50%. If the diet contained 100 mg fennel oil/kg, the decrease of percentual feed intake was significant. The results of the feeding experiment and of the feed choice experiment question the classification of fennel and caraway oils as flavour additives or as 'appetite promoters' in diets for weaned piglets.     

皇竹草与玉米秸秆青贮料饲喂肉牛的对比试验

利用皇竹草和抽穗期玉米秸秆青贮料作为能繁母牛、育肥牛的主要青粗饲料开展对比试验。通过120 d饲喂对比试验,饲喂2种不同饲料的能繁母牛受胎率分别为70.37%和76.92%,说明皇竹草和抽穗期玉米秸秆青贮料饲养能繁母牛对其受胎率无明显影响（P〉0.05）;育肥牛的日增重分别为1294 g/d和1320 g/d,表明利用皇竹草和抽穗期玉米秸秆青贮料育肥肉牛,其生长速度无明显差异（P〉0.05）。由于皇竹草在低海拔喀斯特山区易于种植,生长期长,产量高,易于加工和青贮,是低海拔喀斯特山区解决肉牛产业发展中青粗饲料来源的有效途径,适宜大面积推广应用。     

Effect of the Stellamune Mycoplasma vaccine on growth, energy conversion, death, and medication use in fattening pigs on a pig farm chronically infected with Mycoplasma hyopneumoniae

The effect of Stellamune Mycoplasma vaccine, administered to piglets aged 2-15 days and then 13-15 days later, on daily weight gain, energy conversion, and use of medication was examined in fattening pigs on a chronically Mycoplasma hyopneumoniae infected pig farm. Half of the piglets were vaccinated and the other half acted as controls. In the study design, half of the pens in the fattening unit were allocated to vaccinated pigs; the other half to non-vaccinated pigs, pen was the experimental unit. In the fattening pens sows and castrated boars were separated. The study consisted of a total of 37 pens with vaccinated, and 37 pens with non-vaccinated pigs in 12 different compartments within the pig herd. In the finishing period, mean growth performance and mean energy conversion (EV/kg) of vaccinated animals was 65 grams/day higher and 0.07 EV/kg lower than in control pigs. Furthermore, the incidence of individual curative medication against respiratory problems was more than 4 times higher in control pigs than in vaccinated pigs. There was a tendency for a higher number of group medications against respiratory problems in control pigs than in vaccinated pigs. It is concluded that, in this herd, vaccination against M. hyopneumoniae was successful from an economic point of view.     

Joint research on the precise determination of the energy and protein requirements of fattening pigs. 5. The effect of the crude protein concentration in the isocaloric diet on the fattening performance of swine of the Bulgarian Landrace

Live weight development and feed expenditure on 3 levels of crude protein supply and with isocaloric rations were investigated in scientific feeding experiments with 7 castrated male pigs each of the Bulgarian land race in the live weight range between 30 and 100 kg with a subdivision at 60 kg. The crude protein concentrations in the rations for the 3 groups were 17%, 15% and 13% in the first fattening period and 15% 13% and 11% in the second fattening period. In the two fattening periods the digestibility of the feed mixtures used was ascertained in experiments. The daily live weight gain in the three groups over the whole fattening period reached a high level of performance (836 g, 778 g and 757 g). The feed expenditure values were 3.3, 3.7 and 3.7 kg mixed feed (88% dry matter) per kg live weight gain. The highest protein supply resulted in the best weight gain performance and the lowest feed expenditure.     

The effect of continuous in-feed medication with thiophanate on Ascaris suum and Oesophagostomum spp. egg output in young pigs

The full potential of anthelmintics now available for single dose treatment is not achieved because the devising system for worm control in piglets/weaners is not efficiently applicable in practice. Therefore an in-feed medication programme for growing young pigs, allowing only one feed lot to be handled by the farmer, was tested in two studies. Study A Feed containing 0.0225% thiophanate was continuously fed almost ad lib. to piglets from birth right up to about 25 kg body weight when ready for fattening. This control measure effectively prevented A. suum and Oesophagostomum from becoming established during the whole pre-fattening period, thus allowing "worm-free" weaners to be produced. -33% of animals receiving unmedicated feed harboured mature Oesophagostomum already at an age of 63 days when first examined. Three out of 97 unmedicated pigs were then A. suum egg-count positive. At the same time all medicated pigs, except one with a low Oesophagostomum egg output, were egg-count negative. All medicated were still egg-count negative at 23-29 days after the withdrawal of the feed. About 30% of unmedicated pigs were then shedding eggs of A. suum and Oesophagostomum respectively. At 45-49 days after the withdrawal of the medicated feed 8% of previously medicated pigs and 43% of unmedicated pigs were A. suum egg-count positive. The corresponding figures for Oesophagostomum egg-count positive pigs were 6% and 40% respectively. The acquisition of worm infections by previously medicated pigs most probably was made in the fattening unit after the withdrawal of the thiophanate medicated feed. Study B In this study it was further substantiated that in-feed medication of pigs with thiophanate prevents A. suum from becoming established. All treated pigs were A. suum egg-count negative at Day 43 and 46 after the withdrawal of the medicated feed whereas about 62% of untreated control pigs were shedding A. suum eggs at the same time. This finding justify the proposal that the in-feed medication performed prevented larval migration. Furthermore it was shown that the in-feed medication must proceed right up to the transfer of piglets to the fattening unit in order to achieve its full potential. Farrowing pens may be heavily contaminated with infective Oesophagostomum larvae at the end of the pre-fattening period resulting in sudden and heavy nodular worm infections after the withdrawal of the medicated feed.     

The effect of diets supplemented with fish broth and fish oil on the health of weaners

The aim of this study was to determine the effect of fish-based feed materials, as a source of readily available protein contained in fish broth and essential polyunsaturated fatty acids (PUFAs) found in fish oil, on the health of piglets and rearing results. The experiment was conducted on a commercial pig fattening farm. The study involved a total of 80 weaners with an approximate body weight of 15 kg. The experiment was carried out over a period of 40 days. Feed samples were subjected to laboratory analyses. Blood samples were collected from experimental group animals to determine serum biochemical and immunological parameters. The body weight gains of weaners, mortality rates and average feed intake per animal were calculated for the entire experimental period. The addition of fish broth and fish oil significantly improved the n3:n6 fatty acid ratio in diets. The presence of EPA and DHA in the experimental diet could have had a positive health effect on piglets, comparable with that exerted by therapeutic doses of zinc often administered to pigs of this age group. During the experiment, feed conversion ratio (FCR) gain was considerably reduced in the experimental group, with similar daily gains in the control and experimental group.     

茶树油制剂(颗粒剂)对保育猪生长性能的影响

试验旨在探究茶树油饲料添加剂(颗粒型)对保育猪生长性能的影响。试验动物选取小保育猪50头和大保育猪36头,小保育猪分为5组,每组10头,对照组饲喂基础饲料,试验组饲喂基础饲料中分别添加50 mg/kg、100 mg/kg、200 mg/kg、400 mg/kg茶树油的试验饲料。大保育猪分为6组,每组6头,对照组饲喂基础饲料,试验组饲喂基础饲料中分别添加500 mg/kg、1000 mg/kg、2000 mg/kg、4000 mg/kg、6000 mg/kg茶树油的试验饲料,试验期为60 d。结果表明,在小保育阶段,添加50 mg/kg茶树油饲料添加剂组在增重方面显著高于对照组(P<0.05);在大保育阶段,添加500 mg/kg茶树油添加剂组的试验组猪只增重最高,料重比最低;但是在大保育猪,添加茶树油添加剂的量达到6000 mg/kg时,料重比最高,并且显著低于对照组(P<0.05),说明在保育猪的不同阶段添加适量的茶树油饲料添加剂,可提高猪只的生长性能,降低料重比。     

外源生物制剂对玉米秸秆和马铃薯渣混贮品质及瘤胃降解率的影响

【目的】 试验旨在研究外源生物制剂对玉米秸秆与马铃薯渣混贮饲料发酵品质、营养价值及72 h瘤胃降解率的影响, 筛选高效饲用生物制剂, 探索实用的玉米秸秆饲料转化技术。【方法】 以粮饲兼用型玉米品种原单32秸秆和克新1号马铃薯渣为试验材料, 以3∶1比例混合青贮。采用完全随机试验设计, 共15个处理, 分别采用酶制剂(CE₁、CE₂、CE₃和CE₄)、菌制剂(LAB)及酶菌复合处理(MCL₁、MCL₂、MCL₃、MCL₄、MCL₅、MCL₆、MCL₇、MCL₈和MCL₉), 并设置不添加任何酶菌制剂的对照组(CK)。青贮发酵60 d之后, 对混贮饲料青贮质量指标及瘤胃降解率进行测定。【结果】 混贮饲料各处理及对照感官评定均达到了优级; 酶处理组和酶菌处理组混贮饲料乳酸、乙酸含量均显著高于菌处理组及对照(P<0.05), 其中MCL₂和MCL₄处理组乳酸含量最高, 分别为2.82%和2.77%;与对照相比, 各处理组混贮饲料纤维素、中性洗涤纤维(NDF)及酸性洗涤纤维(ADF)含量均显著降低(P < 0.05), 其中MCL₂处理最低, 分别为22.86%、53.43%、33.99%;1 g/3 kg纤维素酶添加处理组(CE₁、MCL₂、MCL₆、MCL₇)纤维素72 h瘤胃降解率均显著高于其他处理组(P<0.05)。【结论】 酶、菌及菌酶协同作用不同程度促进玉米秸秆与马铃薯渣混贮饲料发酵, 改善混贮饲料营养价值, 提高反刍动物瘤胃对营养物质的降解效率, 综合玉米秸秆发酵品质、营养成分及养分瘤胃降解率: 酶菌复合处理>酶处理>菌处理, 其中MCL₂处理组(木聚糖酶1 g/3 kg、果胶酶1 g/3 kg、β-葡聚糖酶1 g/3 kg、乳杆菌3 g/3 kg、纤维素酶1 g/3 kg)效果最佳; 纤维素酶降低玉米秸秆混贮饲料纤维素、ADF、NDF含量, 最适纤维素酶添加量为1 g/3 kg。