Effect of antibiotics and Caprylohydroxamic acid on ammonia gas from chicken excreta

1. Excreta from broiler chickens, when sterilised at 121 °C for 20 min, released little ammonia gas after incubation at 33 °C for 24 h.

2. Addition of thiopeptin to fresh excreta decreased ammonia production after incubation. Caprylohydroxamic acid did not have such an effect.

3. Dietary additions (100 mg/kg) of thiopeptin or zinc bacitracin resulted in decreased ammonia gas production from incubated fresh excreta. Similar addition of caprylohydroxamic acid did not decrease ammonia production.

4. Dietary supplements of thiopeptin (2.5 mg/kg) or zinc bacitracin (20 mg/kg) resulted in somewhat decreased ammonia production from incubated fresh excreta.     

Genetic and nutritional effects on swine excreta

The objective of this study was to investigate genetic and nutritional effects on swine excreta. Two studies were used. Study I was a 3 x 2 x 2 factorial design with three genetic groups, two diets, and two sexes. Genetic groups were a maternal line (WL), paternal line (BL) and their F1 progeny. Corn-soybean meal diets with either 18 or 14% CP, differing only by substitution of soybean meal for corn, were used in both studies. Study II was a 2 x 2 factorial design with two genetic groups and two diets. High testosterone (D2) and low testosterone (D1) Duroc lines were used. Solid and liquid wastes were collected for 3 d. A total of 108 pens in Study I and 50 pens in Study II were sampled twice. Total excreta were measured and samples collected for chemical analysis of N, NH3N, P, Ca, Cu, K, Zn, and Fe. Measures were adjusted for pig weight and feed disappearance. Maternal-line pigs excreted significantly less P, Ca, Cu, Zn, and Fe than F1 or BL pigs and numerically smaller quantities of all nutrients than BL pigs. In study II, differences were found between lines ofthe same breed. Line D2 pigs had greater output of P, Ca, and Cu (P< 0.05) than D1 pigs and numerically larger quantities of all other nutrients except NH3N and Fe. Pigs fed 14% CP excreted less N, NH3N, and K (P < 0.01) in both studies and excreted significantly less P in Study I. Pigs on a 14% CP diet excreted numerically smaller amounts of all nutrients in both studies except Ca in Study II. In Study I, gilts excreted smaller (P < 0.05) amounts of all nutrients than barrows. Genetic, nutritional, and gender differences influenced waste output.     

Dietary nitrate supplementation reduces methane emission in beef cattle fed sugarcane-based diets

The objective of this study was to determine the effect of dietary nitrate on methane emission and rumen fermentation parameters in Nellore × Guzera (Bos indicus) beef cattle fed a sugarcane based diet. The experiment was conducted with 16 steers weighing 283 ± 49 kg (mean ± SD), 6 rumen cannulated and 10 intact steers, in a cross-over design. The animals were blocked according to BW and presence or absence of rumen cannula and randomly allocated to either the nitrate diet (22 g nitrate/kg DM) or the control diet made isonitrogenous by the addition of urea. The diets consisted of freshly chopped sugarcane and concentrate (60:40 on DM basis), fed as a mixed ration. A 16-d adaptation period was used to allow the rumen microbes to adapt to dietary nitrate. Methane emission was measured using the sulfur hexafluoride tracer technique. Dry matter intake (P = 0.09) tended to be less when nitrate was present in the diet compared with the control, 6.60 and 7.05 kg/d DMI, respectively. The daily methane production was reduced (P < 0.01) by 32% when steers were fed the nitrate diet (85 g/d) compared with the urea diet (125 g/d). Methane emission per kilogram DMI was 27% less (P < 0.01) on the nitrate diet (13.3 g methane/kg DMI) than on the control diet (18.2 g methane/kg DMI). Methane losses as a fraction of gross energy intake (GEI) were less (P < 0.01) on the nitrate diet (4.2% of GEI) than on the control diet (5.9% of GEI). Nitrate mitigated enteric methane production by 87% of the theoretical potential. The rumen fluid ammonia-nitrogen (NH(3)-N()) concentration was significantly greater (P < 0.05) for the nitrate diet. The total concentration of VFA was not affected (P = 0.61) by nitrate in the diet, while the proportion of acetic acid tended to be greater (P = 0.09), propionic acid less (P = 0.06) and acetate/propionate ratio tended to be greater (P = 0.06) for the nitrate diet. Dietary nitrate reduced enteric methane emission in beef cattle fed sugarcane based diet.     

Efficacy of urease inhibitor to reduce ammonia emission from poultry houses

As the poultry industry has grown, so have concerns about the environmental management aspects of these industries, including air and water quality. Poultry operations continue to expand and are large contributors to farm income. There is increased concern related to ammonia emission from poultry operations. Various abatement methods, including dietary manipulation, chemical amendment of litter, and improvement in ventilation system management have been used to control ammonia concentrations from livestock facilities, but these methods are perceived to be too expensive, to impair bird growth, or to add to pollution in some other form. Alternative strategies include reduction of ammonia emissions by arresting N in the litter. An alternative approach to decrease ammonia emissions in poultry facilities is to block the enzyme activity in the litter because ammonia is the by-product of a 5-step enzymatic degradation of uric acid. Our preliminary study with layer feces, which were allowed to accumulate on a layer of broiler litter, indicated that a commercially available urease inhibitor resulted in a significant reduction in equilibrium ammonia concentration over time. Based on the results of the preliminary experiment, further studies were conducted to study the effect of the urease inhibitor on broiler litter and layer feces directly. The results showed that the urease inhibitor did not have any effect on equilibrium ammonia concentration when applied to drier broiler litter. The reduced moisture content in the broiler litter may have inhibited urease inhibitor activity. With layer feces, urease inhibitor reduced equilibrium ammonia concentration. The effect of the first application lasted for 1 wk, after which the equilibrium ammonia concentration in the treated trays rebounded to exceed that of the control trays. Upon a second application of urease inhibitor, the effect lasted for 14 d. The difference in the effect of the urease inhibitor on equilibrium ammonia concentration upon first and second application could have been influenced by a change in manure characteristics over time. Layer manure is a dynamic environment with continued change; therefore, more research is warranted in the area of stored layer manure.     

Effect of aluminum chloride and dietary phytase on relative ammonia losses from swine manure

Ammonia (NH3) losses from swine manure contribute to odor problems, decrease animal productivity, and increase the risk of acid rain deposition. This study was conducted to determine whether aluminum chloride (AlCl3) or dietary manipulation with phytase could decrease relative NH3 losses from swine manure. Twenty-four pens of nursery pigs were used in two trials, and the pigs were fed normal or phytase-supplemented (500 IU/kg) diets. Aluminum chloride was added to manure pits (1.9 x 1.2 x 0.5 m) under each pen at 0, 0.25, 0.50, or 0.75% (vol:vol) of final manure volume. Manure pH and NH3 losses (measured by relative NH3 flux) were determined twice weekly. The addition of AlCl3 at 0.75% decreased (P < 0.05) manure pH from 7.48 to 6.69. Phytase decreased (P < 0.05) manure pH to 7.07 compared with 7.12 in the normal diet manure. Aluminum chloride administered at 0.75% without phytase reduced (P < 0.05) relative NH3 losses 52% for the entire 6-wk period. Relative NH3 losses were decreased (P < 0.05) from 109 mg of NH3/(m2 x h) in pens containing pigs fed the normal diet without AlCl3 to 81 mg of NH3/(m2 x h) in pens housing pigs administered the phytase diet, a 26% reduction. When the phytase diet and 0.75% AlCl3 additions were used in combination, relative NH3 losses were reduced (P < 0.05) by 60% compared with pens of pigs fed the control diet without AlCl3. Decreases in manure pH were likely responsible for the observed reduction in NH3 losses. Multiple regression was performed with relative rates of NH3 losses as the dependent variable and rate of AlCl3 addition, diet, and manure pH as independent variables. The model was tested using a stepwise regression (P < 0.001), and results indicated that the most important factors determining NH3 losses were manure pH and diet. However, the contribution of AlCl3 cannot be discounted. When manure pH was regressed against AlCl3 and dietary phytase, AlCl3 levels accounted for 64% of the variation in manure pH (P < 0.001). Dietary manipulation with phytase and application of AlCl3 to manure are promising management practices for the reduction of NH3 from swine facilities.     

欧洲国家猪舍氨气排放现状及控制方法

最近10年来,欧洲大部分国家养猪业都有所增加,氨气的大量排放造成了环境污染。猪舍氨的排放可从以下几方面控制：1）减少粪尿混合物中的尿素和氨的浓度。2）降低粪尿混合物的温度。3）减小发散面积。4）降低粪尿混合物的pH。猪舍建筑设计与营养调控结合减少氨的排放量是目前较为有效的方法。降低饲粮中蛋白质的含量、加入非淀粉多聚糖和加入酸化后的盐代替碳酸钙,是当前在营养调控方面减少氨排放的主要方法。     

Reduced diet crude protein level, benzoic acid and inulin reduced ammonia, but failed to influence odour emission from finishing pigs

Intensified pig production is associated with odour and ammonia emissions causing nuisance and environmental concerns. The aim of four experiments was to investigate the effect of different dietary interventions on odour and ammonia emissions from finishing pigs. In exp. 1, diet crude protein levels of 16% and 14% were compared. In exps. 2 and 3, the effect of adding 1% and 3% benzoic acid, respectively, to the diets was studied. In exp. 4, inclusion of 15% inulin in the diet was investigated. All experiments were carried out in two identical climate chambers with three pens. There were 12 pigs per pen in total 36 pigs per chamber. Each dietary treatment was repeated two times. The temperature, ventilation rate and concentrations of NH₃ in the exhaust air were measured every hour. Odour concentration was measured in samples of the exhaust air by olfactometry. Reduced diet crude protein, the addition of 3% benzoic acid and inclusion of 15% inulin reduced ammonia emission by 30%, 57% and 34%, respectively. It was not possible to influence odour emission in any of the experiments.     

Odour and ammonia emission from pig manure as affected by dietary crude protein level

The objective of this study was to determine the effects of dietary crude protein (CP) level on odour emission, odour intensity, odour hedonic tone, ammonia and greenhouse gaseous emission from pig manure, and on fresh faeces and manure characteristics. An experiment was conducted with finishing pigs (n = 12) in a randomized complete block arrangement with 2 treatments of 12 and 15% dietary CP in six blocks. The 2 diets were supplemented with essential AA up to the level of the animal's requirement. Pigs with an initial body weight (BW) of 57.7 ± 0.7 kg were penned individually in partly slatted floor pens. Faeces and urine of each pig accumulated in separate manure pits under the slatted floor. In the 3rd week of the collection period, fresh faeces were collected for identifying fresh faeces characteristics and for assessing dry matter, organic matter, nitrogen (N), fat and non-starch polysaccharides digestibility using Cr₂O₃ as a marker. In the 6th week of the collection period, air samples were collected directly from each manure pit: one for odour, one for ammonia concentration and one for greenhouse gases. Afterwards the manure was mixed and a representative sample was taken for manure characteristic analysis. Odour samples were analyzed for odour concentration and for hedonic tone and odour intensity. Manure samples were analyzed for volatile fatty acids (VFA), indolic, phenolic, sulphurous compounds, ammonium and total N concentrations and pH. Reducing dietary CP level from 15 to 12% did not affect odour emission, odour intensity and odour hedonic tone and greenhouse gaseous concentration (CH₄, CO₂ and N₂O) (P > 0.05) of odorous air above the manure pit. Reduced dietary CP level decreased manure pH (P < 0.001), total N (P < 0.001) and ammonium (P < 0.001) concentrations and ammonia emission from pig manure (P = 0.03). In addition, total VFA, acetic, propionic, iso-butanoic and iso-pentanoic acids, phenol, 4-ethyl phenol and carbon disulfide concentrations in manure were decreased by reducing dietary CP level (P < 0.05). We conclude that reducing dietary CP from 15 to 12% did not reduce odour emission and greenhouse gaseous concentration; however, ammonia emission was significantly reduced.     

Dietary calcium and phosphorus levels for growing swine from 18 to 57 kilograms body weight

A randomized complete block design experiment was conducted using 408 crossbred pigs to evaluate the effects of six dietary Ca/P levels for growing swine (18 to 57 kg). Total dietary P levels ranged from .40 to .90% in .1% intervals with Ca concurrently increased at a 1.3:1 ratio in a 16% protein corn-soybean meal diet. Dicalcium phosphate and limestone were the source of inorganic Ca and P. For the overall trial, daily gain and feed intake improved as dietary Ca/P increased to an approximate level of .65/.50%. An inverse relationship occurred between serum Ca and P, with serum Ca declining and P increasing at the lower mineral levels. Femur, humerus, rib, metatarsal and metacarpal ash content increased quadratically (P less than .01) as dietary Ca/P increased with suggested dietary breakpoint inflections of .90% Ca and .70% P at 40 kg, and at .72/.55% levels at 57 kg body weight. Percentage ash of the head portion of the bone was lower than the shaft section. Bone shaft thickness and bending moments for metatarsals and metacarpals increased as dietary Ca/P levels increased, with higher values and higher dietary inflection points at 57 than at 40 kg body weight. Bone length was not influenced by dietary Ca/P level, but fat-free dried bone weight was, resulting in higher total bone ash and organic weight as Ca/P level increased.     

Zinc-amino acid complexes for swine

Two experiments were conducted to determine the effect of sources of dietary zinc on gain, feed conversion and blood and bone traits of swine. In the first experiment 96 pigs were used in a 28-d study. The pigs were fed diets with no supplemental Zn or with either 9 or 12 ppm supplemental Zn from zinc sulfate (ZnSO4), zinc methionine (ZnMet) or zinc methionine with picolinic acid (ZnMet w/PA), each with or without 5% added corn oil. There were differences (P less than .05) in average daily gain (ADG) and average daily feed intake (ADFI) between the pigs fed the two organic Zn sources, with those fed ZnMet w/PA showing the better gains and feed conversion. However, neither organic Zn source resulted in pig performance that was different from either the diet with no supplemental Zn or the diets supplemented with Zn from ZnSO4. In the second experiment the same dietary Zn sources and treatments were fed as in Exp. 1 except that corn oil was deleted as a variable. No differences in ADG, ADFI, feed/gain (F/G) or in changes in serum Zn or Cu were observed among treatments during either the 21-d nursery or the 56-d growing periods. During the subsequent 56-d finishing period ADG and ADFI were greater (P less than .01) for pigs fed the Zn-supplemented diets than for those fed the diets without supplemental Zn. There were no differences among treatments in F/G during the finishing period. Zn content of bone ash was lower (P less than .01) in the non-Zn-supplemented pigs. These data suggest that the Zn sources used are of similar biological value and do not support the theory that picolinic acid aids Zn absorption.     

Dietary L-carnitine suppresses mitochondrial branched-chain keto acid dehydrogenase activity and enhances protein accretion and carcass characteristics of swine.

A trial was conducted to biochemically explain the decreased lipid deposition and increased protein accretion observed in pigs fed carnitine. Our hypothesis was that an increase in the ratio of acetyl CoA:CoA-SH produced by stimulation of fatty acid oxidation by supplemental L-carnitine may decrease branched-chain alpha-keto acid dehydrogenase activity and increase pyruvate carboxylase activity. Such changes could reduce oxidative loss of branched-chain amino acids and provide more carbons for amino acid biosynthesis. Yorkshire gilts (n = 36; 12 per treatment) were fed a control diet or diets containing either 50 or 125 ppm of added L-carnitine during growth from 56 to 120 kg. After slaughter, the semitendinosus muscle and liver were collected for isolation of mitochondria and hepatocytes. Increasing dietary L-carnitine did not influence growth performance (P > 0.10) but linearly decreased (P < 0.05) 10th rib backfat thickness and increased (linear, P < 0.05) percentages of lean and muscle. The rates of [1-(14)G]palmitate oxidation in isolated hepatocytes and isolated mitochondria, and incorporation of [35S]methionine into the acid insoluble fraction of isolated hepatocytes were increased (linear, P < 0.01) in pigs fed L-carnitine. Flux through branched-chain alpha-keto acid dehydrogenase linearly decreased (P < 0.01) in isolated liver and muscle mitochondria with increasing dietary carnitine. Flux through pyruvate carboxylase was increased (linear, P < 0.01) in isolated mitochondria from liver of pigs fed carnitine, and assays with particle-free extracts indicated that the amount of mitochondrial pyruvate carboxylase was tripled by feeding carnitine (linear, P < 0.01). The association of increased protein accretion and reduced backfat thickness with greater rates of palmitate oxidation, more rapid flux through pyruvate carboxylase, and reduced flux through branched-chain alpha-keto acid dehydrogenase suggests pigs fed carnitine are more able to use fat for energy, divert carbon toward synthesis of amino acids, and spare branched-chain amino acids for protein synthesis.     

Dietary L-arginine supplementation reduces lipid accretion by regulating fatty acid metabolism in Nile tilapia(Oreochromis niloticus)

Background: Excessive white fat accumulation in humans and other animals is associated with the development of multiple metabolic diseases. It is unknown whether dietary L-arginine supplementation reduces lipid deposition in high fat diet-fed Nile tilapia(Oreochromis niloticus).Results: In the present study, we found that dietary supplementation with 1% or 2% arginine decreased the deposition and concentration of fats in the liver;the concentrations of triglycerides, low-density lipoprotein, total cholesterol, and high-density lipoprotein in the serum;and the diameter of adipocytes in intraperitoneal adipose tissue. Compared with the un-supplementation control group, the hepatic activities of alanine aminotransferase,aspartate aminotransferase, and lactate dehydrogenase, and hepatic concentration of malondialdehyde were reduced but these for catalase and superoxide dismutase were enhanced by dietary supplementation with 2% arginine. Arginine supplementation reduced the total amounts of monounsaturated fatty acids, while increasing the total amounts of n-3 and n-6 polyunsaturated fatty acids in the liver. These effects of arginine were associated with reductions in mRNA levels for genes related to lipogenesis(sterol regulatory element-binding protein-1, acetyl-CoA carboxylase α, stearoyl-CoA desaturase, and fatty acid synthase) but increases in mRNA levels for genes involved in fatty acid β-oxidation(carnitine palmitoyltransferase 1α and peroxisome proliferator-activated receptor α). In addition, hepatic mRNA levels for Δ4 fatty acyl desaturase 2 and elongase 5 of very long-chain fatty acids were enhanced by arginine supplementation.Conclusion: These results revealed that dietary L-arginine supplementation to tilapia reduced high fat diet-induced fat deposition and fatty acid composition in the liver by regulating the expression of genes for lipid metabolism.     

猪营养中的脂肪酸平衡

猪日粮中的脂肪除了供能以外,其脂肪酸组成与平衡也是当前关注的热点。其中饱和脂肪酸与不饱和脂肪酸的平衡、n-6多不饱和脂肪酸与n-3多不饱和脂肪酸的平衡是其中最为重要的两个方面。建立规范的脂肪酸模式,开发功能性的脂肪酸产品,将是今后脂肪营养发展的方向。     

Dietary folic acid addition reduces abdominal fat deposition mediated by alterations in gut microbiota and SCFA production in broilers

Intensive selective breeding for high growth rate and body weight cause excess abdominal fat in broilers.Gut microbiota and folic acid were reported to regulate lipid metabolism. A total of 210 one-day-old broilers were divided into the control(folic acid at 1.3 mg/kg) and folic acid groups(folic acid at13 mg/kg) to illustrate the effects of folic acid on growth performance, abdominal fat deposition, and gut microbiota, and the experiment lasted 28 d. Results revealed that dietary folic acid add...