Effects of protein supplementation to steers consuming low-quality forages on greenhouse gas emissions

Providing supplements that enhance the efficiency of feed utilization can reduce methane (CH₄) emissions from ruminants. Protein supplementation is widely used to increase intake and digestion of low-quality forages, yet little is known about its impact on CH₄ emissions. British-cross steers (n = 23; initial body weight [BW] = 344 ± 33.9 kg) were used in a three-period crossover design to evaluate the effect of protein supplementation to beef cattle consuming low-quality forage on ruminal CH₄, metabolic carbon dioxide (CO₂) emissions, forage intake, and ruminal fermentation. Steers individually had ad libitum access to low-quality bluestem hay (4.6% crude protein [CP]) and were provided supplemental protein based on (dry matter basis): cottonseed meal (CSM; 0.29% of BW daily; 391 g/d CP), dried distillers grains with solubles (DDGS; 0.41% of BW daily 563 g/d CP), or none (CON). Urea was added to DDGS to match rumen degradable protein provided by CSM. Ruminal CH₄ and metabolic CO₂ fluxes were obtained 2.4 ± 0.4 times per steer daily using an automated open-circuit gas quantification system (GreenFeed emission monitoring system; C-Lock Inc., Rapid City, SD). Forage intake increased (P < 0.01) with protein supplementation; however, no difference in forage intake (P = 0.14) was observed between CSM and DDGS treatments. Flux of CO₂ (g/d) was greater (P < 0.01) for steers fed CSM and DDGS than for steers fed CON. Steers supplemented with CSM had greater (P < 0.01) CH₄ emissions (211 g/d) than DDGS (197 g/d) both of which were greater (P < 0.01) than CON (175 g/d). Methane emissions as a proportion of gross energy intake (GEI) were lowest (P < 0.01) for DDGS (7.66%), intermediate for CSM (8.46%) steers, and greatest for CON (10.53%). Steers fed DDGS also had the lowest (P < 0.01) ruminal acetate:propionate ratio (3.60), whereas CSM (4.89) was intermediate, and CON (5.64) steers were greatest. This study suggests that the common practice of supplementing protein to cattle consuming low-quality forage decreases greenhouse gas emissions per unit of GEI.     

Determination of GHG and ammonia emissions from stored dairy cattle slurry by using a floating dynamic chamber

We developed a system for measuring emissions from stored slurry by using a floating dynamic chamber. CH₄, CO₂, N₂O and NH₃ emitted from the storage tank of a dairy cattle farm in eastern Hokkaido were measured during summer 2008 (7/16–8/6), fall 2008 (10/2–10/26), spring 2009 (6/2–6/21) and winter 2009 (3/11). Average daily gas emission rates in summer, fall and spring were, respectively, 54.8, 54.2 and 34.3 g/m² for CH₄; 602, 274 and 254 g/m² for CO₂; 55.4, 68.2 and trace mg/m² for N₂O; and 0.55, 0.73 and 0.46 g/m² for NH₃. CH₄, CO₂ and NH₃ emission rates during the brief measurement period in winter were reduced to 1/4, 1/23 and 1/2, respectively, of summer emission rate levels. All gas emissions showed diurnal fluctuation and were greatest during the daytime, when the ambient temperature rose. CH₄, NH₃ and CO₂ emissions increased significantly during the daytime, and the daily emission (in grams) of each gas was positively correlated with maximum daily temperature. According to the combined spring, summer and fall measurements, the CH₄, N₂O and NH₃ annual emission factors were 1.42% (g CH₄/g volatile solids), 0.02% (g N₂O‐N/g total N) and 0.43% (g NH₃‐N/g total N), respectively.     

Feeding distillers dried grains with solubles and organic trace mineral sources to swine and the resulting effect on gaseous emissions

The objective of the study was to evaluate the dietary effects of distillers dried grains with solubles (DDGS) with either inorganic or organic trace mineral sources on air emissions. Three diets were compared: a corn- and soybean meal-based control diet (Con), a diet containing 20% DDGS with inorganic trace mineral sources (20In), and a diet containing 20% DDGS with organic trace mineral sources (20Org). Groups of 6 pigs were allocated randomly to 1 of 12 environmentally controlled rooms for a 98-d experiment. A total of 72 pigs were blocked into 3 light and 3 heavy BW groups to minimize BW variation. Average initial BW for the light and heavy blocks were 22.6 kg and 27.0 kg, respectively. Concentrations and airflow of NH?, H?S, N?O, CH(4), CO?, and nonmethane total hydrocarbons (NMTHC) were measured in the exhaust air from each room. Body weight gain (94 kg per pig; P = 0.36) and G:F (0.39; P = 0.79) were not different as a result of diet, although a reduced feed intake was observed in pigs offered 20Org (P < 0.05). Total daily H?S emission mass was greater (P = 0.03) in rooms where the 20In diet was offered (462.26 mg) compared with rooms where the Con (354.62 mg) and 20Org (323.10 mg) diets were offered. No dietary effect (P = 0.47) was observed when H?S emissions were adjusted for S consumption (14.38 mg of H?S emitted daily per gram of S consumed). Compared with NH? emitted on the Con diet, the daily mass of NH? emitted decreased by 7.6% when pigs were fed 20In and increased by 11.0% in rooms where the 20Org was fed (P < 0.05). On a N consumption basis, feeding swine 20In significantly reduced NH? emissions compared with 20Org and Con, whereas NH? emissions from pigs fed 20Org were significantly greater than emissions from pigs fed the Con diet (P < 0.01). The NH? emission mass from rooms offered the Con, 20In, and 20Org diets was 120.1, 109.8, and 142.8 mg/g of N consumed/d, respectively (P < 0.01). Feeding DDGS with either inorganic or organic trace mineral sources increased the daily emission masses of CH? and NMTHC (P < 0.01), but not N?O emissions. Plasma urea N (P = 0.64), albumin (P = 0.39), globulin (P = 0.75), and total bilirubin concentrations (P = 0.82) were not different between diet groups. Results demonstrated that DDGS will increase H?S, CH?, NH?, and NMTHC emissions from pigs, but organic sources of trace minerals are a promising mitigation strategy to alleviate the adverse effect of DDGS on H?S emissions.     

高寒灌丛土壤温室气体释放对添加不同形态氮素的响应

为探索不同形态氮素输入对青藏高原高寒灌丛土壤CO₂、N₂O和CH₄排放的影响,采集青藏高原东部金露梅高寒灌丛土壤,设置1个对照(CK)和3个添加不同形态氮素的处理(NH₄Cl,NH₄NO₃,KNO₃),在实验室恒温15℃下进行培养,分析了土壤CO₂、N₂O和CH₄的释放量以及土壤NH₄⁺,NO₃^-和可溶性有机碳(DOC)含量。结果表明:1)所有氮素处理抑制了高寒灌丛土壤CO₂的排放,土壤CO₂排放量与DOC浓度呈显著正相关关系;2)所有氮素处理显著增加了土壤N₂O的排放,而且以添加NO₃^--N增加的N₂O最为显著;3)高寒灌丛土壤N₂O的产生过程以反硝化作用为主;4)添加不同形态氮素对高寒灌丛土壤CH₄吸收没有显著影响。5)不同形态氮素施入后,高寒灌丛土壤温室气体全球增温潜能(GWP)顺序:KNO₃>NH₄NO₃>NH₄Cl>CK。     

Improving productive performance and mitigating harmful emissions from laying hen excreta via feeding on graded levels of corn DDGS with or without Bacillus subtilis probiotic

An experiment that included some inclusions of corn distillers dried grains with solubles (DDGS) with or without supplementation of probiotic bacteria to Hi‐sex Brown laying hen diets was conducted to evaluate the impacts on performance, egg quality, blood metabolites and nitrogen and phosphorus excretion in the manure. A total of 216 twenty‐two‐week‐old Hi‐sex Brown laying hens were randomly divided into eight treatment groups in a factorial design (4 × 2) experiment, which included four levels of DDGS (0, 50, 100 and 150 g/kg diet) plus two levels of Bacillus subtilis probiotic (0 or 1000 mg/kg diet, with a concentration of 1.5 × 108 CFU/g of dried product). The experimental period extended from 22 to 34 weeks of age. The results showed that linear increase in DDGS level up to 150 g/kg improved (p ≤ 0.01) the values of feed consumption, egg shape index and yolk colour compared to the control and other treatment groups. Inclusion of dietary DDGS up to 150 g/kg in layer diets led to a significant decrease in egg mass and a significant increase in Haugh unit score compared to other groups. In the bacillus group, the values of feed conversion, egg weight and egg mass enhanced by 6.45, 3.27 and 7.60% respectively compared with the control diet. Total protein, albumin, triglycerides, cholesterol, calcium and ammonia in serum were significantly (p ≤ 0.01) influenced by DDGS inclusion. The excreted nitrogen decreased by 8.62 and 4.31% in hens fed 50 or 100 g/kg of DDGS respectively, while excreted phosphorous decreased by 3.33, 7.22 and 10.56% in hens fed 50, 100 or 150 g/kg of DDGS respectively as compared to the control group. It could be concluded that increasing DDGS inclusion level in the diet up to 10% and the supplementation of probiotic bacteria improved the productive performance of laying hens and mitigated the harmful emissions from chicken manure; this means better production within environmentally friendly conditions.     

The efficacy of using exogenous enzymes cocktail on production,egg quality,egg nutrients and blood metabolites of laying hens fed distiller's dried grains with solubles

An experiment was performed using 120 Hisex Brown laying hens for evaluating the effects of different inclusion levels of corn distiller's dried grains with solubles (DDGS) as a replacement of soybean meal (SBM) with or without enzyme cocktail on performance, egg quality, egg nutrients and blood metabolites in laying hens through 22–42 weeks of age. A 4 × 2 factorial design experiment was performed including four substitution levels of DDGS (0, 250, 500 and 750 g/kg respectively) and two enzyme cocktail levels (0 and 250 mg/kg diet). The used enzyme in this study “Gallazyme” composed of xylanase, Trichoderma longibrachiatum (600 units/g), protease, Bacillus subtilis (8,000 units/g) and amylase and Bacillus amyloliquofaciens (800 units/g). The control diet showed the best feed efficiency followed by the intermediate levels of DDGS. The lowest value of feed efficiency was found in the group fed the highest level of DDGS. Enzyme addition improved feed efficiency and decreased laying rate. Increasing DDGS levels was associated with albumin and shell thickness increases. Dietary DDGS depressed all egg components except the organic matter which maximised in enzyme‐treated groups. Increasing DDGS level was accompanied by increase in yolk cholesterol and total lipids. No significant impacts were detected with enzymes supplementation on yolk lipids profile. Excepting serum calcium and phosphorous, all serum constituents increased with increasing level of DDGS. Using enzyme markedly depressed serum ammonia by 15.02% and increased calcium by 6.44% compared with enzyme‐free diets. Interaction between DDGS and enzyme was significant on most of studied parameters. It could be concluded that using enzyme cocktail in DDGS‐based diets may improve feed efficiency and egg quality, in addition to lowering blood ammonia and increasing blood calcium. It is recommended to substitute SBM by DDGS up to 500 g/kg diet.     

Nutrient content and digestibility of different batches of wheat distillers dried grains with solubles for laying hens

ABSTRACT

1. Four batches of wheat distillers dried grains with solubles (DDGS) produced by a single production plant were used to investigate variation in digestible energy (DE) and nutrient digestibility for laying hens.

2. A total of 144 Hy-Line Brown laying hens were allocated to eight treatment groups in replicates of six. Experimental diets were prepared by replacing the basal feed with either 150 g/kg or 300 g/kg of each batch of DDGS.

3. Chemical analysis of the DDGS showed variation between the different batches. Largest coefficients of variation were observed for starch (0.546) and total soluble non-starch polysaccharides (NSP; 0.276).

4. Digestible energy and the nutrient digestibility of each diet was measured using the ileal collection technique. Data were statistically analysed as a blocked 2 × 4 factorial design analysis of variance (ANOVA).

5. Variability between the different diets were observed for digestible energy and the digestibility of certain nutrients (P < 0.05).

6. The observed differences in energy utilisation and nutrient digestibility in laying hens suggested that the feeding quality of diets containing different wheat DDGS batches produced by a single production plant may still have large variation.     

Comparison of ammonia and greenhouse gas emissions during the fattening of pigs, kept either on fully slatted floor or on deep litter

Five successive batches of fattening pigs were raised, each during a four month period, on a totally concrete slatted floor in one experimental room and on straw based deep litter in another. The rooms were automatically ventilated to maintain a constant ambient temperature. Available floor space was of 0.75 m² per pig kept on the slatted floor and 1.20 m² per pig kept on the deep litter. With this last system, about 46 kg of straw were supplied per pig throughout a fattening period. The slurry pit was emptied and the litter removed after each batch. Once a month, the emissions of ammonia (NH₃), nitrous oxide (N₂O), methane (CH₄), carbon dioxide (CO₂), and water vapour (H₂O) were measured continuously for 6 consecutive days by infra-red photoacoustic detection.The performance of the animals was not significantly different according to the floor type.Gaseous emissions from pigs raised on the slatted floor and on the deep litter were, respectively, 6.2 and 13.1 g per pig per day for NH₃, 0.54 and 1.11 g per pig per day for N₂O, 16.3 and 16.0 g per pig per day for CH₄, 1.74 and 1.97 kg per pig per day for CO₂ and 2.48 and 3.70 kg per pig per day for H₂O. Except for the CH₄ emissions, all the differences were significant (P < 0.001). Thus, pig fattening on deep litter releases nearly 20% more greenhouse gases than on slatted floor, with 2.64 and 2.24 kg of CO₂-equivalents, respectively (P < 0.001). Whatever the floor type, emissions increased from the beginning to the end of the fattening periods by about 5 times for NH₃, 4 times for N₂O, 3 times for CH₄ and 2 times for CO₂ and H₂O. Correlation coefficients between CO₂-emissions and H₂O, NH₃ and CH₄ emissions were, on average for both floor types, 0.82, 0.77 and 0.74, respectively.Although rearing pigs on straw generally has a good brand image for the consumer, this rearing system produces more pollutant gases than keeping pigs on slatted floors.     

Mitigation of nitrous oxide (N2O) emission from swine wastewater treatment in an aerobic bioreactor packed with carbon fibers

Mitigation of nitrous oxide (N₂O) emission from swine wastewater treatment was demonstrated in an aerobic bioreactor packed with carbon fibers (CF reactor). The CF reactor had a demonstrated advantage in mitigating N₂O emission and avoiding NOx (NO₃ + NO₂) accumulation. The N₂O emission factor was 0.0003 g N₂O‐N/gTN‐load in the CF bioreactor compared to 0.03 gN₂O‐N/gTN‐load in an activated sludge reactor (AS reactor). N₂O and CH₄ emissions from the CF reactor were 42 g‐CO₂ eq/m³/day, while those from the AS reactor were 725 g‐CO₂ eq/m³/day. The dissolved inorganic nitrogen (DIN) in the CF reactor removed an average of 156 mg/L of the NH₄‐N, and accumulated an average of 14 mg/L of the NO₃‐N. In contrast, the DIN in the AS reactor removed an average 144 mg/L of the NH₄‐N and accumulated an average 183 mg/L of the NO₃‐N. NO₂‐N was almost undetectable in both reactors.     

Comparative Study of Nitrogen Metabolism and the Nitrogen Maintenance Requirement in Lohmann Brown Roosters and Layers

The objective of this study was to investigate the effect of dietary protein level on nitrogen retention and compare nitrogen metabolism in Lohmann Brown adult roosters and layers. The nitrogen maintenance requirement (N_m) was determined based on the nitrogen balance. Thirty Lohmann Brown adult roosters and 30 laying hens at 27 weeks of age were randomly divided into five groups of six birds per group. The birds were fed with one of five diets containing 10.46%, 11.77%, 13.79%, 16.77% or 18.29% of crude protein. Nitrogen intake, nitrogen retention and nitrogen retention efficiency were higher in roosters than in laying hens, and the average nitrogen retention rate for groups fed with CP level of 11.77%, 13.79%, 16.77% and 18.29% was improved by 9.14%. The nitrogen maintenance requirement for Lohmann Brown roosters and laying hens at 27 weeks of age were 0.4245 g/d and 0.5059 g/d, respectively, and Nm based on average body weight (BW) and metabolic body weight (BW^0.75) was 0.2364 g/kg BW and 0.2739 g/kg BW^0.75 for laying hens and 0.2754 g/kg BW and 0.3208 g/kg BW^0.75 for roosters, respectively. The regression equations for daily N gain (N_B, protein accretion) vs. daily N intake (N_I) for Lohmann Brown layers and roosters were N_B = 0.3743N_I–0.1589 (R² = 0.79) and N_B = 0.6228N_I–0.3151 (R² = 0.85), respectively. The results of this study indicate that nitrogen intake and nitrogen retention at the same dietary CP level were higher in roosters than in laying hens.     

Analysis of Noxious Gas Pollution in Horse Stable Air

The aim of this study was to determine quantitative and qualitative occurrence of noxious gas compounds in the stable, depending on the time of the day (4:00 AM, 12:00, 8:00 PM), the height (20 cm, 150 cm), and the place (boxes, aisle) from which the samples were collected. Seven compounds were analyzed (NH₃, SO₂, COS, HCN, CH₄, NO₂, and CO). For analyzing stable air, a mobile gas analyzer was used. The time of day was a significant differential factor (P < .01) for concentrations of NH₃, COS, and CH₄. The highest concentrations of CH₄, COS, NO₂, NH_3, and CO appeared at 4:00. For the rest of the studied compounds (SO₂, HCN, CO) differences were not statistically significant, but there was a tendency for the highest concentrations at 12:00. The concentrations of gas compounds depending on height did not differ significantly from each other, but there was a tendency for higher concentrations of NH₃, SO₂, CH₄, and CO at 150 cm and for HCN at 20 cm. COS and NO₂ remained constant at both heights in boxes. The places where the samples were collected was a significant differential factor (P < .01) for NH₃ and SO₂. For the rest of the studied compounds the differences were not statistically significant. It can be concluded that many noxious compounds may appear without being noticed, and that is why it is necessary to provide stables with efficient air exchange throughout the day.     

Effects of selected feed additives on the performance of laying hens given a diet rich in maize dried distiller's grains with solubles (DDGS)

1. A total of 192 ISA Brown hens were given diets containing a high concentration of maize dried distiller's grains with solubles (DDGS) and the effect of selected feed additives on laying performance and egg quality was determined.

2. Birds were allocated to 8 treatment groups with 12 replicates (cages) of two hens and were given, from week 26 to 55, iso-caloric and iso-nitrogenous experimental diets with or without a high concentration of DDGS (200 g/kg). The diet containing DDGS was not supplemented or supplemented with enzymes (xylanase and phytase), sodium butyrate, probiotic bacteria (Lactobacillus salivarius) and a mixture of herbal extracts (Taraxaci siccum, Urticae siccum and Salviae siccum), inulin or chitosan.

3. The inclusion of DDGS in the diet had no effect on number of eggs produced, total egg mass, mean egg weight, feed intake or feed conversion ratio. Egg and eggshell quality parameters were also unaffected by dietary DDGS. The yolk colour score (points in Roche scale) was significantly increased by DDGS inclusion. DDGS in the diet caused some changes in the yolk lipid profile that were rather unfavourable from a dietary perspective (an increase of cholesterol content, and PUFA n-6/PUFA n-3 ratio).

4. During the experimental period (26–55 weeks of age) supplementation of the diet containing a high concentration of DDGS with enzymes, inulin as well as chitosan, increased number of eggs produced and daily egg mass. In older hens (50 weeks of age) inulin positively affected eggshell quality parameters, i.e. shell percentage, thickness and density. Diet supplementation with herb extracts, inulin or chitosan, decreased the content of cholesterol in yolks.

5. The results of this study suggest that DDGS may be incorporated up to a concentration of 200 g/kg in the diet of laying hens without any negative effects on egg performance. Moreover, supplementation of xylanase and phytase, as well as inulin and chitosan, can positively affect the performance of layers given diets with a high concentration of DDGS.     

Tolerance and safety evaluation of sodium sulfate:A subchronic study in laying hens

Sodium sulfate (Na₂SO₄) is a readily available chlorine-free source of sodium, which could be used to reduce sodium chloride to maintain the ratio between chlorine and sodium in poultry diets. Dietary supplementation with excessive levels of Na₂SO₄ might be detrimental to bird''s health and performance. A subchronic study was carried out to investigate the potential adverse effects of an accidental oversupply of Na₂SO₄ in the diets of laying hens. Four hundred and fifty 21-week-old Hy-Line White layers were randomly assigned to 5 treatments with 6 replicates. The birds were fed diets supplemented with 0 (control), 0.3%, 0.6%, 1.5%, and 3.0% Na₂SO₄ for 8 weeks. Laying performance, egg quality parameters, clinical blood parameters, histopathology, intestinal barrier functions, and intestinal microflora composition were measured. No clinical signs of intoxication or mortality were observed during the experimental period. The results of this study showed that the optimal levels of Na₂SO₄ (0.3% to 0.6%) significantly improved the laying rates, average daily egg mass, and eggshell quality of hens compared to the control (P < 0.05). However, 3.0% Na₂SO₄ produced negative effects on laying performance, eggshell quality, blood biochemistry, and particularly on liver and kidney pathology, and intestinal morphology and barrier functions compared with the controls. Although minor changes were observed in clinical blood parameters of hens receiving 1.5% Na₂SO₄, these were not considered to be of toxicological significance due to the absence of any organ pathological changes in hens. In conclusion, our results indicated that a Na₂SO₄ concentration of 1.5% was non-deleterious to laying hens after a daily administration for 56 d, namely that dietary supplementation of up to 5 times the maximum recommended dose is safely tolerated by laying hens.     

Characteristics of ammonia and carbon dioxide releases from layer hen manure

1.?Ammonia (NH₃) is an important gaseous pollutant generated from manure in commercial poultry farms and has been an environmental, ecological, and health concern. Poultry manure also releases carbon dioxide (CO₂), which is a greenhouse gas and is often used as a tracer gas to calculate building ventilation.

2.?A 38-d laboratory study was conducted to evaluate the characteristics of NH₃ and CO₂ releases from layer hen manure using 4 manure reactors (122 cm tall, 38 cm internal diameter), which were initially filled with 66 cm deep manure followed by weekly additions of 5 cm to simulate manure accumulation in commercial layer houses.

3.?The average daily mean (ADM) NH₃ and CO₂ release fluxes for the 4 reactors during the entire study were 161?5 ± 21?1 µg/s.m² (ADM ± 95% confidence interval) and 10?0 ± 0?3 mg/s.m², respectively. The daily mean NH₃ and CO₂ releases in individual reactors varied from 35?2 to 679?1 µg/s.m² and from 6?6 to 20?5 mg/s.m², respectively.

4.?The ADM NH₃ release flux was within the range of those obtained in 4 high-rise layer houses by Liang et al. (2005 Liang, Y, Xin, H, Wheeler, EF, Gates, RS, Li, H, Zajaczkowski, JS, Topper, PA, Casey, KD, Behrends, BR, Burnham, DJ and Zajaczkowski, FJ. 2005. Ammonia emissions from US laying hen houses in Iowa and Pennsylvania. Transactions of the ASAE, 48: 1927–1941. [Crossref] [Google Scholar], Transactions of the ASAE, 48). However, the CO₂ release flux in this study was about 10 to 13 times as high as the data reported by Liang et al. (2005 Liang, Y, Xin, H, Wheeler, EF, Gates, RS, Li, H, Zajaczkowski, JS, Topper, PA, Casey, KD, Behrends, BR, Burnham, DJ and Zajaczkowski, FJ. 2005. Ammonia emissions from US laying hen houses in Iowa and Pennsylvania. Transactions of the ASAE, 48: 1927–1941. [Crossref] [Google Scholar]). Fresh manure had greater NH₃ release potential than the manure in the reactors under continuous ventilation. Manure with higher contents of moisture, total nitrogen, and ammonium in the 4th weekly addition induced 11 times higher NH₃ and 75% higher CO₂ releases immediately after manure addition compared with pre-addition releases.     

Reduction of Ammonia Emissions from Stored Laying Hen Manure Through Topical Application of Zeolite,Al+ Clear,Ferix-3, or Poultry Litter Treatment

Practical means to decrease aerial emissions will enhance the ability of the US egg industry to improve environmental stewardship while continuing to provide consumers safe and affordable eggs. Ammonia emissions from manure-belt laying hen houses have been shown to be less than 10% of the emissions from high-rise counterparts where manure is stored in-house for a year. However, on-farm manure storage for manure-belt houses also emits NH₃, which is a part of the total farm emissions. Nevertheless, treating manure in storage sheds to decrease NH₃ emissions may be more readily implemented than treatment inside the layer houses because of potential bird health concerns and possible detrimental effects of the treatment on the housing equipment. The laboratory-scale experiments reported here examined the efficacy of 4 commercially available treatment agents, topically applied to laying hen manure at 3 different dosages, in decreasing NH₃ emissions from the manure storage. The treatment agents included zeolite, 2 forms of Al⁺ Clear (aluminum sulfate, 48.5% liquid and granular), Ferix-3 (ferric sulfate), and Poultry Litter Treatment (PLT, sodium bisulfate). All the tested agents showed appreciable NH₃ emission reduction of 33 to 94%. In all cases, the greatest application dosage provided little additional NH₃ reduction as compared with the medium dosage (P > 0.70). Comparison among the dry granular Al⁺ Clear, Ferix-3, and PLT in reduction of NH₃ emission over a 7-d manure storage period showed no significant difference when the agents were applied at 0.5 kg/m² of manure surface area (P = 0.40) but greater reduction for Al⁺ Clear (92 ± 3%) and Ferix-3 (90 ± 1%) as compared with PLT (81 ± 2%) when applied at 1.0 kg/m² (P < 0.01). Further field verification tests of the laboratory-scale findings are warranted.     

Nutrient profile and availability of co-products from bioethanol processing

Bioethanol production in North America has led to the production of considerable quantities of different co‐products. Variation in nutrient profiles as well as nutrient availability among these co‐products may lead to the formulation of imbalanced diets that may adversely affect animal performance. This study aimed to compare three types of dried distiller’s grains with solubles [100% wheat DDGS (WDDGS); DDGS blend1 (BDDGS1, corn to wheat ratio 30:70); DDGS blend2 (BDDGS2, corn to wheat ratio 50:50)] and their different batches within DDGS type with regard to: (i) protein and carbohydrate sub‐fractions based on Cornell Net Carbohydrate and Protein System (CNCPS); (ii) calculated energy values; and (iii) rumen degradation of dry matter (DDM), organic matter (DOM), crude protein (DCP), neutral detergent fibre (DNDF) and starch (Dstarch) at 36 and 72 h of ruminal incubations. Wheat DDGS had a lower intermediately (PB2, 136.4 vs. 187.4 g/kg DM) and a higher slowly degradable true protein (PB3, 142.2 vs.105.3 g/kg DM) than BDDGS1, but similar to those of BDDGS2. Sugar (CA4) was higher, whereas starch (PB1) and digestible fibre (PB3) were lower in WDDGS than in BDDGS1 and BDDGS2. All carbohydrate sub‐fractions determined differed significantly between the two batches of BDDGS2. The BDDGS2 had the highest calculated energy values (TDN, DE_3×, ME_3×, NEL_3×, NE_m and NE_g) among the three DDGS types. The energy values were slightly different between the batches of the three DDGS types. At all incubation times, wheat DDGS had a significantly higher (p < 0.05) DDM, DOM, DCP and DNDF than both DDGS blends. Differences were observed between different batches within DDGS types with regard to in situ rumen degradation of DM, OM, CP, NDF and starch. In conclusion, differences were observed in protein and carbohydrate sub‐fractions and in situ ruminal degradation of DM, OM, CP, NDF and starch among the three DDGS types and different batches within DDGS type. This indicates that the nutrients supplied to ruminants may not only differ among different types of DDGS but it may also differ among different batches within DDGS type.     

饲粮铬对产蛋鸡产蛋性能、蛋品质及血清生化特性的影响

本试验研究不同铬源和铬水平对注射禽流感疫苗高产蛋鸡产蛋性能、蛋品质及血清生化特性的影响。选用23周龄罗曼褐产蛋鸡189只,产蛋高峰期注射禽流感H5N1灭活疫苗,按2×5因子的完全随机设计随机分为9个处理组,每个处理7个重复,2种铬源为三氯化铬(CrCl3)和吡啶甲酸铬(Cr-Pic),5个添加铬水平为0、0.4、0.8、1.6mg/kg和3.2mg/kg,试验期42d。结果表明:铬源对料蛋比有显著影响,CrCl3组显著低于Cr-Pic组(P0.10);铬水平对产蛋率、产蛋量、料蛋比、软破蛋率有显著影响(P0.10)。添加CrCl3和Cr-Pic均可提高注射禽流感疫苗高产蛋鸡产蛋性能和蛋壳质量,若以经济效应计算,以添加0.8mg/kgCrCl3为最佳。     

Effect of amount and source of manganese and/or phytase supplementation on productive and reproductive performance and some physiological traits of dual purpose cross-bred hens in the tropics

1.?The effect of different amounts of added manganese (Mn) (0, 10, 20 and 40 mg/kg) in inorganic and organic form and phytase (0 and 300 U) was investigated on productive, reproductive and haematological traits on 480 hens and 60 cocks (Inchas breeds) divided into 12 groups: 10 and 20 Mn × 0 and 300 phytase × 2 Mn sources (8 groups), two negative controls (0 Mn × 2 levels of phytase) and two positive controls (40 Mn × 2 Mn sources).

2.?Phytase supplementation increased laying rate by 1·1% and egg weight by 0·4 g.

3.?Manganese supplementation at 10 mg/kg over dietary sources improved hatchability, at 20 mg/kg decreased death embryos and abnormality as those of hens supplemented with 40 mg/kg Mn. Inorganic Mn at 10 mg/kg significantly increased egg mass compared to the organic form. Inorganic Mn was more efficient in decreasing abnormal chicks than organic Mn. Phytase supplementation significantly increased hatchability of fertile eggs and decreased the number of abnormal chicks of groups fed on diets unsupplemented with Mn and those supplemented with 10 mg/kg Mn.

4.?Mn supplementation at 10 mg/kg over dietary sources significantly improved sperm mass motility and decreased abnormal sperm. Phytase significantly decreased lymphocyte cells and plasma AST.

5.?Mn supplementation of the control diet (containing only 16 mg/kg from raw materials) with 20 mg/kg of Mn from either organic or inorganic source is adequate to support egg production traits, egg quality, reproductive traits and economic efficiency of dual purpose cross-bred hens; however, phytase supplementation may reduce the required Mn supplementation to 10 mg/kg.     

Influence of Aguamiel (Agave atrovirens) as a Natural Feed Additive on Cecal Fermentation Kinetics of Some Forage Species in Horse Feeding

This study aimed to evaluate the effect of different dose levels of aguamiel (Agave atrovirens) on in vitro cecal gas, methane (CH₄), and carbon dioxide (CO₂) productions of five forage species (Avena sativa [hay]), Moringa oleifera, Caesalpinia coriacea, Salix babylonica, and Eichhornia crassipes using inocula from the horse. The forage samples were incubated with three doses of aguamiel: 0, 34, and 68 μg of aguamiel/g dry matter (DM) of substrate. Cecal inocula were collected from four adult female Criolla horses (3–4 years of age and weighing 300 ± 15.0 kg) grazed on native grasses for about 8 hours without supplementation. Forage type affected (P < .001) cecal asymptotic, rate and lag time of gas, CH₄ and CO₂ productions (mL/g DM), pH and DM degradability. Aguamiel dose had linear and quadratic effects (P < .05) on the asymptotic and rate of CH₄ productions and rate and lag time of CO₂ productions (mL/g DM). Forage type × aguamiel dose interactions were significant (P < .05) for asymptotic, rate and lag time of gas, and CH₄ and CO₂ productions (mL/g DM). Forage species effects were pronounced (P < .05) on CH₄ and CO₂ productions (mL/g incubated and degraded DM) and proportional CH₄ production at all hours of incubation, except for CO₂ production (mL/g incubated DM). Aguamiel dose affected (P < .05) CO₂ production (mL/g incubated DM) and proportional CO₂ production at the incubated hours. Forage type × aguamiel dose interactions were observed (P < .05) for CO₂ production (mL/g incubated DM) and proportional CO₂ production at the incubated hours but had no impact on CH₄ production. It is concluded that addition of aguamiel to five forage species affected fermentation kinetics of gas production resulting in different in vitro cecal gas, CH₄ and CO₂ productions from these substrates.     

Influence of protein fermentation and carbohydrate source on in vitro methane production

Incubations were carried out with batch cultures of ruminal micro‐organisms from sheep to analyse the influence of the N source on in vitro CH₄ production. The two substrates were mixtures of maize starch and cellulose in proportions of 75:25 and 25:75 (STAR and CEL substrates, respectively), and the three nitrogen (N) sources were ammonia (NH₄Cl), casein (CA) and isolated soya bean protein (SP). Five isonitrogenous treatments were made by replacing non‐protein‐N (NPN) with CA or SP at levels of 0 (NPN), 50 (CA50 and SP50, respectively) and 100% (CA100 and SP100) of total N. All N treatments were applied at a rate of 35 mg of N/g of substrate organic matter and incubations lasted 16.5 h. With both proteins, N source × substrate interactions (p = 0.065 to 0.002) were detected for CH₄ production and CH₄/total VFA ratio. The increases in CH₄ production observed by replacing the NPN with protein‐N were higher (p < 0.05) for STAR than for CEL substrate, but the opposite was observed for the increases in volatile fatty acid (VFA) production. As a consequence, replacing the NPN by increased levels of CA or SP led to linear increases (p < 0.05) in CH₄/total VFA ratio with STAR, whereas CH₄/total VFA ratio tended (p < 0.10) to be decreased with CEL substrate. Increasing the amount of both proteins decreased linearly (p < 0.05) ammonia‐N concentrations, which may indicate an incorporation of amino acids and peptides into microbial protein without being first deaminated into ammonia‐N. In incubations with the tested N sources as the only substrate, the fermentation of 1 mg of CA or SP produced 1.24 and 0.60 μmol of CH₄ respectively. The results indicate the generation of CH₄ from protein fermentation, and that the response of CH₄ production to protein‐N supply may differ with the basal substrate.