Silage Type Research Articles

Nutritive Value of Sunflower Silages Ensiled with Corn or Alfalfa at Different Rate

Sunflower (Helianthus annuus L.) having shorter growing season, better cold tolerant and more drought resistant is important alternative silage plant in highlands. But it has poor silage quality. To improve the quality of sunflower silage can be mixed an appropriate amount of corn (Zea mays L.) and alfalfa (Medicago sativa L.). This research was carried out to evaluate quality characteristics of nine silage types: Sunflower, corn and alfalfa silages; plus their some mixtures silages (75% sunflower + 25% corn, 50% sunflower + 50% corn, 25% sunflower + 75% corn, 75% sunflower + 25% alfalfa, 50% sunflower + 50% alfalfa and 25% sunflower + 75% alfalfa); at two harvest stages: Beginning of flowering for sunflower and alfalfa and milk-dough stage for corn (early stage), and end of flowering stage for sunflower and alfalfa, and dough stage for corn (late stage). The experimental design was in a factorial arrangement of randomized complete block with replicated four times. Dry matter content (DM), crude protein content (CP), neutral detergent fiber content (NDF), acid detergent fiber content (ADF), silage pH and physical characteristics (PC) of silages were determined in this study. Mixing of alfalfa in NDF, ADF and CP and corn in DM, pH and PC had positively effect in sunflower silages. Late stage had positively affected DM, PC and pH for silage. Consequently, sunflower silages mixed with corn, with the condition of not being less than 50% at late stage, are recommended for farmers. Keywords: Sunflower; Corn; Alfalfa; Mixtures; Silage

Fermentation characteristics and lactic Acid bacteria succession of total mixed ration silages formulated with peach pomace.

The objective of this study was to assess the use of peach pomace in total mixed ration (TMR) silages and clarify the differences in aerobic stability between TMR and TMR silages caused by lactic acid bacteria (LAB). The TMR were prepared using peach pomace, alfalfa hay or Leymus chinensis hay, maize meal, soybean meal, cotton meal, limestone, a vitamin-mineral supplement, and salt in a ratio of 6.0:34.0:44.4:7.0:5.0:2.5:1.0:0.1 on a dry matter (DM) basis. Fermentation quality, microbial composition, and the predominant LAB were examined during ensiling and aerobic deterioration. The results indicated that the TMR silages with peach pomace were well fermented, with low pH and high lactic acid concentrations. The aerobic stability of TMR silages were significantly higher than that of TMR. Compared with TMR silages with alfalfa hay, TMR silage with Leymus chinensis hay was much more prone to deterioration. Although the dominant LAB were not identical in TMR, the same dominant species, Lactobacillus buchneri and Pediococcus acidilactici, were found in both types of TMR silages after 56 d of ensiling, and they may play an important role in the aerobic stability of TMR silages.

The effect of hybrid type and dietary proportions of corn silage on the lactation performance of high-producing dairy cows

We evaluated the effects of corn silage hybrids [control vs. brown midrib (BMR)] and the proportion of corn silage in rations on the performance of high-producing dairy cows. The chemical composition of the corn silages was similar except for lignin, which was higher in the control hybrid [3.09%, dry matter (DM) basis] compared with the BMR hybrid (2.19%). The 30-h in vitro neutral detergent fiber (NDF) digestibility was also higher (62.8% of NDF) in the BMR hybrid than in the control hybrid (52.2%). Twenty-seven Holstein cows were fed 1 of 3 diets comprising 62% forage and 38% concentrate (DM basis) containing 35% (DM basis) corn silage from the control hybrid (NLO), 35% of the BMR hybrid (BLO), or 50% of the BMR (BHI). Cows were fed the diets in a replicated 3×3 Latin square design with 28-d periods. Intake of DM was similar among treatments but milk production was greater for cows fed BLO (50.1kg/d) and BHI (51.1kg/d) than for NLO (47.9kg/d). Milk fat percentage was lower for cows fed BHI (3.37%) than for those fed BLO (3.55%) and NLO (3.56%) but yield of milk fat was similar among treatments. Yield and percentage of milk protein was higher for cows in BHI compared with NLO. The concentration of milk urea N was lower in cows fed BHI (14.0mg/dL) than in those fed NLO (14.7mg/dL) and intermediate for BLO (14.5mg/dL). The yield of 3.5% fat-corrected milk was higher in cows fed BLO (50.2kg/d) than in NLO (48.2kg/d) and was intermediate for BHI (49.8kg/d). The total-tract digestibility of dietary DM, organic matter, starch, and crude protein was lower for cows in NLO compared with the other treatments. The total-tract digestibility of NDF was highest for BHI (54.4%), intermediate for BLO (50.9%), and lowest for NLO (43.2%). We conclude that BMR corn silage can be included in rations at moderate and high proportions of a total ration, resulting in high levels of milk production.

The effect of nutritional and fermentational characteristics of grass and legume silages on feed intake, growth performance and blood indices of lambs

The objective of this study was to determine the effects of feeding silage made from different plant species to lambs. The experimental materials comprised 24 Kamieniec rams weaned at 70 days of age, allocated into one of three groups, and offered ad libitum three types of silage: red clover silage (RC), alfalfa silage (ALF), grass silage (GR). All lambs also received 0.5kg ground barley per animal per day and 12.5g mineral–vitamin premix per animal per day. The animals were kept in individual pens throughout a 60-day experimental period. The growth rate and selected blood biochemical indices of lambs were determined. On day 60, the greatest (34.7kg) and the least (31.8kg) body weights of lambs were from groups ALF and GR, respectively (P≤0.01). The difference between groups RC and GR was also significant. The nutritional regime had no effect on blood parameters, whereas lambs fed legume silages were characterized by increased blood glucose levels, decreased total blood protein levels (P≤0.05) and greater urea concentrations (P≤0.01), compared with lambs receiving grass silage. Lambs offered legume silages showed better growth performance, in comparison with those offered grass silage, which resulted from greater intake and supply of metabolizable energy and protein from alfalfa silage, and more effective utilization of nutrients contained in red clover silage.

Effects of utilization of local food by-products as total mixed ration silage materials on fermentation quality and intake, digestibility, rumen condition and nitrogen availability in sheep.

Four wethers were used in a 4 × 4 Latin square design experiment to evaluate in vivo digestibility of total mixed ration (TMR) silage with food by-products for dairy cows, and the ruminal condition and nitrogen (N) balance were examined. Five by-products (i.e. potato waste, noodle waste, soybean curd residue, soy sauce cake and green tea waste) were obtained. Four types of TMR silage were used: control (C) containing roughage and commercial concentrate, T1:20% and T1:40% containing the five by-products replacing 20% and 40% of the commercial concentrate on a dry matter (DM) basis, respectively, and T2:40% containing three by-products (potato waste, noodle waste and soybean curd residue) replacing 40% of the commercial concentrate on a DM basis. The ingredients were mixed and preserved in oil drum silos for 4 months. The TMR silages showed 4.02-4.44% and 1.75-2.19% for pH and lactic acid contents, respectively. The digestibility of DM and neutral detergent fiber, and total digestible nutrient content were higher (P < 0.05) for T2:40% feeding than for C feeding. Urinary nitrogen excretion tended to be lower (P = 0.07) for T2:40% than for C. The results suggested 40% replacing of commercial concentrate by using the three food by-products can be most suitable for TMR silage.

Effect of total mixed ration composition and daily grazing pattern on milk production, composition and fatty acids profile of dairy cows.

The possibilities of using high quality pastures in conjunction with total mixed ration (TMR) during the grazing season have been examined. An experiment with sixteen Holstein cows blocked and randomly assigned to four treatments in a factorial arrangement was conducted in order to evaluate the influence of grazing time of day (day or night) and type of silage (maize or Italian ryegrass) included in the TMR of dairy cows grazing 12h daily on milk yield, composition and fatty acid profile. The silage type had no effect on the dry matter intake, milk yield and fat and protein proportions. However, cows grazing during the night ate more grass than cows grazing during the day (8·53 vs. 5·65kg DM/d; P<0·05). No differences were seen between grazing-time with respect to milk production, fat and protein contents. However, the proportion of polyunsaturated fatty acid was higher in milk of dairy cows grazing at night-time than grazing at day-time, especially 18:2n-6 (2·37 vs. 2·12g/100g FA respectively, P<0·05) and 18:2cis9trans11 (2·08 vs. 1·74g/100g FA respectively, P<0·05).

Bacterial communities in alfalfa and corn silages produced in large‐scale stack and bunker silos in China

AbstractAlfalfa silage (Al) and corn silage (Cs) samples were collected from two large‐scale farms in China; one of these farms used stack silos and the other used bunker silos for silage production. Three samples were collected from the upper and lower layers of each silo. Thus, six samples were examined for each of Al‐stack, Al‐bunker, Cs‐stack, and Cs‐bunker. Bacterial community was determined by denaturing gradient gel electrophoresis (DGGE). Lactic acid was the main fermentation product in Al‐stack, Cs‐stack and Cs‐bunker, whereas acetic acid and butyric acid were predominant in Al‐bunker. Pediococcus pentosaceus and Clostridium sp. were common to four silage types. Lactobacillus acetotolerans and Lactobacillus pontis were detected specifically in Cs, whereas the lactic acid bacteria identified in Al were regarded as those usually found in silage. Differences between stack and bunker silos were apparent in Al with regard to fermentation products and DGGE band patterns. Differences between the upper and lower layers were observed in the fermentation products in Cs regardless of silo type, whereas variations in the DGGE band patterns of Cs‐stack were detected.

Replacing corn silage with different forage millet silage cultivars: Effects on milk yield, nutrient digestion, and ruminal fermentation of lactating dairy cows

This study investigated the effects of dietary replacement of corn silage (CS) with 2 cultivars of forage millet silages [i.e., regular millet (RM) and sweet millet (SM)] on milk production, apparent total-tract digestibility, and ruminal fermentation characteristics of dairy cows. Fifteen lactating Holstein cows were used in a replicated 3×3 Latin square experiment and fed (ad libitum) a high-forage total mixed ration (68:32 forage:concentrate ratio). Dietary treatments included CS (control), RM, and SM diets. Experimental silages constituted 37% of each diet DM. Three ruminally fistulated cows were used to determine the effect of dietary treatments on ruminal fermentation and total-tract nutrient utilization. Relative to CS, RM and SM silages contained 36% more crude protein, 66% more neutral detergent fiber (NDF), and 88% more acid detergent fiber. Cows fed CS consumed more dry matter (DM; 24.4 vs. 22.7kg/d) and starch (5.7 vs. 3.7kg/d), but less NDF (7.9 vs. 8.7kg/d) than cows fed RM or SM. However, DM, starch and NDF intakes were not different between forage millet silage types. Feeding RM relative to CS reduced milk yield (32.7 vs. 35.2kg/d), energy-corrected milk (35.8 vs. 38.0kg/d) and SCM (32.7 vs. 35.3kg/d). However, cows fed SM had similar milk, energy-corrected milk, and solids-corrected milk yields than cows fed CS or RM. Milk efficiency was not affected by dietary treatments. Milk protein concentration was greatest for cows fed CS, intermediate for cows fed SM, and lowest for cows fed RM. Milk concentration of solids-not-fat was lesser, whereas milk urea nitrogen was greater for cows fed RM than for those fed CS. However, millet silage type had no effect on milk solids-not-fat and milk urea nitrogen levels. Concentrations of milk fat, lactose and total solids were not affected by silage type. Ruminal pH and ruminal NH3-N were greater for cows fed RM and SM than for cows fed CS. Total-tract digestibility of DM (average=67.9%), NDF (average=53.9%), crude protein (average=63.3%), and gross energy (average=67.9%) were not influenced by dietary treatments. It was concluded that cows fed CS performed better than those fed RM or SM likely due to the higher starch and lower NDF intakes. However, no major differences were noted between the 2 forage millet silage cultivars.

Anaerobic co-digestion of sugar beet tops silage and dairy cow manure under thermophilic condition

The effects of co-digesting different proportions of sugar beet tops (SBT) silage (40, 60, 80 and, 100 %, wet weight basis) with cow manure and duration of storage of two types of SBT silage (silage I: storage time of 120 days and silage II: storage time of 210 days) on digester performance in terms of biogas production and volatile solids (VS) reduction were investigated. The highest methane (CH4) yields were obtained at the 40 % proportion treatments and were 0.422 and 0.377 l/g VS for silage I and II, respectively. The digestion systems failed at 80 and 100 % proportions of silage I and 100 % proportion of silage II. Furthermore, 40 % proportion treatments presented highest VS reductions among manure-silage mixtures (57.0 % for silage I and 57.4 % for silage II) while the control treatment (manure only) had the highest VS reduction (65.0 %) among all the treatments. Based on the results, the 40 % proportion of SBT silage was most efficient for methane production. Comparison of digester performance at 40 and 60 % proportions showed that no remarkable differences were observed between silage I and II, indicating that duration of storage of SBT did not have any appreciable effect on digester performance.

Assessing the efficiency of switchgrass different cultural practices for pellet production

Switchgrass is a perennial crop producing high amounts of biomass for good quality pellet production. The objective of this study is to examine the efficiency of different cultural practices of switchgrass for pellet production under field conditions for four different N-fertilization (0, 80, 160 and 240kgha−1) and two different irrigation levels (0 and 250mm), in two soils in central Greece with rather different moisture status over the period 2009–2012. Moreover, comparison between three harvest methods (two different types of bales and silage) was made. The results derived from this study revealed that the bale at 22kg is the harvesting practice with the highest costs while there was reduction of efficiency scores when nitrogen levels increased. At both environments the efficiency scores followed the same trend, confirming that low levels of nitrogen fertilization enhance the economic competitiveness of switchgrass production. Palamas site is the area where switchgrass for pellet production had positive income ranging from 400 to 1600€ha−1, while Velestino site had always negative. Therefore, places like Velestino with non-aquic soil should be avoided for switchgrass. These data suggest that growing switchgrass for solid biofuel production as energy crop is a worthwhile decision only in areas with a moderately shallow groundwater table (aquic soil) or maybe in high precipitation regions.

Effect of feeding silages from different plant raw materials on the profile of fatty acids, cholesterol, and vitamins A and E in lamb meat

Recently, the quality of lamb meat has been regarded with attention to the content of intramuscular fat, and its fatty acid profile. These indicators are determined by the feed administered to the animals. Apparently, the type of silage used in animal nutrition may be important. The objective of this study was to determine the effect of feeding lambs with silages produced from different plant species on selected meat quality traits. The experiment was conducted on 24 ram lambs, divided into 3 equal groups fed with red clover silage, alfalfa silage, and grass silage, respectively. After 60 days of fattening, the lambs were slaughtered. Samples collected from musculus longissimus lumborum were assayed for: contents of intramuscular fat, cholesterol, the vitamins retinol and α-tocopherol, and the fatty acid profile of intramuscular fat. The meat of lambs fed red clover silage was characterized by a higher content of fat compared to lambs receiving grass silage (P ≤ 0.05). The concentration of vitamin E in the group fed grass silage was the highest and differed significantly (P ≤ 0.01) compared to the group fed alfalfa silage. Intramuscular fat of lambs fed red clover silage contained more polyunsaturated fatty acids n-3 and was characterized by a lower ratio of polyunsaturated fatty acids n-6:n-3 compared to the lambs fed grass silage. The concentration of conjugated linoleic acid was higher in lambs fed grass silage compared to fat of lambs from the other groups (P ≤ 0.05). Feeding lambs with silages produced from various plant species had a positive effect on traits characterizing the health quality of meat. Until now, only a few studies have been conducted in this species; this is the first such comprehensive study in sheep.

The use of Lactobacillus species as starter cultures for enhancing the quality of sugar cane silage

Sugar cane (Saccharum spp.) is a forage crop widely used in animal feed because of its high dry matter (DM) production (25 to 40t/ha) and high energy concentration. The ensiling of sugar cane often incurs problems with the growth of yeasts, which leads to high losses of DM throughout the fermentative process. The selection of specific inoculants for sugar cane silage can improve the quality of the silage. The present study aimed to select strains of lactic acid bacteria (LAB) isolated from sugar cane silage and to assess their effects when used as additives on the same type of silage. The LAB strains were inoculated into sugar cane broth to evaluate their production of metabolites. The selected strains produced higher concentrations of acetic and propionic acids and resulted in better silage characteristics, such as low yeast population, lower ethanol content, and lesser DM loss. These data confirmed that facultative heterofermentative strains are not good candidates for sugar cane silage inoculation and may even worsen the quality of the silage fermentation by increasing DM losses throughout the process. Lactobacillus hilgardii strains UFLA SIL51 and UFLA SIL52 resulted in silage with the best characteristics in relation to DM loss, low ethanol content, higher LAB population, and low butyric acid content. Strains UFLA SIL51 and SIL52 are recommended as starter cultures for sugar cane silage.

Colour of fat, and colour, fatty acid composition and sensory characteristics of muscle from heifers offered alternative forages to grass silage in a finishing ration

The effect of type of silage offered to beef heifers during the finishing period on aspects of beef quality was determined. In two experiments, a diet based on grass silage (GS) was compared with a diet based on maize silage (MS) or whole-crop wheat silage (WCW). Compared to the GS-based diet, increasing the amount of MS linearly increased fat whiteness while the increase in fat whiteness due to WCW was dependent on the stage of crop maturity at harvesting. There was no effect of diet on muscle colour or on muscle pH measured at 48h post-mortem, drip loss, taste panel traits after 14days ageing or shear force values at 2, 7 or 14days ageing. The alternative silages decreased the n−3 polyunsaturated fatty acid proportion and increased the linoleic:linolenic acid ratio in intramuscular lipid. It is concluded that type of silage affects fat colour and fatty acid composition of muscle but not the other muscle characteristics examined.

국내 조사료용 볏짚의 수확 전 작물포 및 수확 후 저장에 따른 곰팡이독소 오염 실태 연구

본 연구는 국내 생산 볏짚의 곰팡이독소 오염 실태를 파악하기 위하여 벼의 생육 단계별, 볏짚의 보관 형태별 및 곤포사일리지의 지역별 오염을 조사하였다. 수확하기 전 논에서 생장 중인 비에서 곰팡이독소 및 곰팡이 오염이 확인되었다. 벼의 생장 초기에는 deoxynivalenol(<TEX>$297{\mu}g/kg$</TEX>) 이 발견되었고, 중기에는 ochratoxin A(<TEX>$1.8{\mu}g/kg$</TEX>) 및 deoxynivalenol(<TEX>$264{\mu}g/kg$</TEX>) 이 오염되어 있었다. 그리고 수확시기에는 deoxynivalenol(<TEX>$190{\mu}g/kg$</TEX>) 및 zearalenone (<TEX>$168{\mu}g/kg$</TEX>) 이 오염되어 있었다. 그리고 곰팡이 오염은 생장 초기에는 <TEX>$10^{3-4}$</TEX> cfu/g 그리고 생장 중기와 수확시기에는 <TEX>$10^{4-5}$</TEX> cfu/g 이었다. 오염된 곰팡이로는 Fusarium sp., Fusarium proliferatum, Penicillium sp., Gibberella sp., Gibberella zeae, Mucor circinelloides, Aspergillus oryzae 등 다양한 종류가 발견되었다. 사료용 볏짚의 통 볏짚단, 사각 볏짚단 및 곤포사일지 등 저장 방법에 따른 오염원 mycotoxin을 조사하였을 때 zearalenone, deoxynivalenol 및 ochratoxins A가 검출되었다. 통 볏짚단의 곰팡이독소 오염도는 23% 이었고, 사각 볏짚단과 곤포사일지지는 각각 38%가 오염되어 있었다. 그리고 105점의 볏짚 곤포사일리지에서 곰팡이독소를 분석하였을 때 46%의 샘플에서 곰팡이독소가 발견되었고, 지역적으로는 경기, 강원, 충청, 영남 및 호남지역에서 각각 48, 33, 40, 50 및 57%의 샘플이 오염되어 있었다. 2가지의 곰팡이독소(zearalenone, deoxynivalenol)가 발견된 충청지역을 제외한 모든 지역의 볏짚 곤포사일리지에서 3가지의 곰팡이독소(zearalenone, deoxynivalenol, ochratoxins A)가 발견되었다. Ochratoxins A의 오염 수준은 전체적으로 <TEX>$2.6{\mu}g/kg$</TEX>으로 충청지역에서는 발견되지 않았지만 호남지역은 <TEX>$3.0{\mu}g/kg$</TEX>으로 다른 지역보다 높았다. Deoxynivalenol의 오염 수준은 전체적으로 <TEX>$413{\mu}g/kg$</TEX>으로 충청지역이 <TEX>$800{\mu}g/kg$</TEX>로 가장 높았고, 다른 지역은 <TEX>$246{\mu}g/kg$</TEX>에서 <TEX>$433{\mu}g/kg$</TEX>의 수준으로 발견되었다. 그리고 zearalenone은 전체적으로 <TEX>$338{\mu}g/kg$</TEX>으로 경기지역이 <TEX>$168{\mu}g/kg$</TEX>로 다른 지역보다 낮았고, 강원과 호남지역이 각각 <TEX>$467{\mu}g/kg$</TEX>과 <TEX>$442{\mu}g/kg$</TEX>으로 높았다. 이상의 연구 결과는 볏짚은 수확하기 전 벼의 생장 기간에도 곰팡이독소 및 곰팡이 오염에 노출되어 있으며, 볏짚의 보관 형태 및 지역에 상관없이 곰팡이독소의 오염이 발생할 수 있음을 명확히 시사한다. 따라서 안전하고 질 좋은 조사료를 확보하기 위해서는 이들 곰팡이독소 관련 더 구체적 연구와 대책관련 탐구가 지속적으로 이루어져야 할 것으로 사료된다. The studies were conducted to investigate real condition of mycotoxin contamination in the fields before harvest and by the storages of rice straw used as roughage in Korea. It was found mycotoxin contamination before harvest of rice straw that the rice plants were detected deoxynivalenol at the initial growth, ochratoxin A and deoxynivalenol at the middle growth, and deoxynivalenol and zearalenone at the harvest periods in the fields. Also, the rice plants were contaminated by various fungi such as Fusarium sp., Fusarium proliferatum, Penicillium sp., Gibberella sp., Gibberella zeae, Mucor circinelloides and Aspergillus oryzae. The levels of fungal contamination were <TEX>$10^{3-4}$</TEX> cfu/g at the initial growth, and <TEX>$10^{4-5}$</TEX> cfu/g at the middle growth and harvest periods. All storage types of rice straw were contaminated with zearalenone, deoxynivalenol and ochratoxins A. The samples of rice straw contaminating mycotoxins were account for 3% in bundle rice straw, and 38% in both types of square rice straw and rice round bale silage, respectively. When 105 samples of rice bale silage were analyzed for mycotoxins depending on the regional area, mycotoxin contamination was found in 46% of total samples in Korea. Regional contaminations of mycotoxins were respectively 48, 33, 40, 50 and 57% of samples in Gyeonggi, Gangwon, Chungcheng, Yeongnam and Honam area. Rice round bale silage was contaminated by three kinds of mycotoxins (zearalenone, deoxynivalenol and ochratoxinsA) in the all of area without Chungcheong area where was contaminated zearalenone and deoxynivalenol. Ochratoxins A, deoxynivalenol and zearalenone were respectively determinated with the average levels of 2.6, 413 and <TEX>$338{\mu}g/kg$</TEX> in rice round bale silage for the overall area, even if it was some difference depending on each regional area. Therefore, the above results clearly show that the rice straws were exposed to the contamination by mycotoxin and mycotoxigenic fungi before harvest in the fields, and mycotoxin contamination was not dependent on the regional area or the storage types such as bundle rice straw, square rice straw and rice round bale silage.

δ13C as a marker to study digesta passage kinetics in ruminants: a combined in vivo and in vitro study

The aim of the current study was to explore the use of the tracer 13C as an internal marker to assess feed fraction-specific digesta passage kinetics through the digestive tract of dairy cows. Knowledge on feed-specific fractional passage rates is essential to improve estimations on the extent of rumen degradation and microbial protein efficiency; however, this information is largely lacking. An in vivo and in vitro experiment was conducted with grass silages (Lolium perenne L.) that were enriched with 13C by growing the grass under elevated 13CO2 conditions. In a crossover design, two dairy cows received pulse doses of two 13C-enriched grass silages and chromium-mordanted neutral detergent fibre (Cr-NDF) into the rumen. The two 13C-enriched grass silages used differed in digestibility and were grown under identical field conditions as the bulk silages fed to the animals. Faecal excretion patterns of 13C-enriched dry matter (13C-DM), neutral detergent fibre (13C-NDF) and Cr-NDF were established, and a nonlinear multicompartmental model was used to determine their rumen passage kinetics. In addition, the 13C-enriched silages were incubated in rumen liquid in an in vitro batch culture system at different time intervals to determine the effect of fermentation on 13C-enrichment in the residue. The in vitro study showed that the 13C : 12C ratios in DM and NDF residues remained stable from 24 h of incubation onwards. In addition, in vitro fractional degradation rates for 12C in the DM and NDF did not differ from those of 13C, indicating that fermentative degradation does not affect the 13C : 12C ratio in the DM nor in the NDF fraction of the residue. Model fits to the faecal excretion curves showed a significant difference in fractional rumen passage rates between Cr-NDF, 13C-DM and 13C-NDF (P ⩽ 0.025). Silage type had no clear effect on rumen passage kinetics (P ⩾ 0.081). Moreover, it showed that peak enrichments for 13C-DM and 13C-NDF in faeces were reached at 30.7 and 41.7 h post dosing, respectively. This is well after the time (24 h) when the 13C : 12C ratios of the in vitro unfermented residues have reached stable enrichment level. Fractional rate constants for particle passage from the rumen are estimated from the descending slope of faecal excretion curves. The present study shows that the decline in 13C : 12C ratio after peak enrichment is not affected by fermentative degradation and therefore can be used to assess feed component-specific fractional passage rates.

Effect of silage botanical composition on ruminal biohydrogenation and transfer of fatty acids to milk in dairy cows

Ruminal biohydrogenation and transfer of fatty acids (FA) to milk were determined for 4 silages with different botanical compositions using 4 multiparous Norwegian Red dairy cows [(mean ± SD) 118±40.9d in milk, 22.5±2.72kg of milk/d, 631±3.3kg of body weight, 3.3±0.40 points on body condition score at the start of the experiment] fitted with rumen cannulas. Treatments consisted of 4 experimental silages: a mix of the first and third cut of organically managed short-term grassland with timothy (Phleum pratense L.) and red clover (Trifolium pratense L.; 2 yr old; ORG-SG); organically managed long-term grassland with a high proportion of unsown species (6 yr old; ORG-LG); conventionally managed ley with perennial ryegrass (Lolium perenne L.; CON-PR); and conventionally managed ley with timothy (CON-TI). The herbages were cut, wilted, and preserved with additive in round bales and fed at 0.90 of ad libitum intake. A barley (Hordeum vulgare L.) concentrate constituted 300g/kg of dry matter of the total feed offered. A Latin square design (4×4) with 3-wk periods and the last week in each period used for sampling was implemented. Omasal flows of FA were measured using Yb acetate, Cr-EDTA, and the indigestible neutral detergent fiber fraction as indigestible markers. The composition of FA was analyzed in feed, omasal digesta, and milk. Compared with ORG-LG, ORG-SG had a higher herbage proportion of red clover (0.36 vs. 0.01) and lower proportions of timothy (0.42 vs. 0.18), smooth meadowgrass (Poa pratensis L.), meadow fescue (Festuca pratensis Huds.), white clover (Trifolium repens L.), dandelion (Taraxacum spp.), and creeping buttercup (Ranunculus repens L.). The silages were well preserved. The concentration of neutral detergent fiber was higher and the concentration of Kjeldahl-N was lower for CON-TI than for the other silages. Silage type had no effect on dry matter intake, but milk yield was lower for CON-TI than for the other silages. Apparent biohydrogenation of C18:3n-3 was lower for ORG-SG (932g/kg) than for ORG-LG (956g/kg), CON-PR (959g/kg), and CON-TI (958g/kg). Compared with the grass-based silages, ORG-SG and ORG-LG resulted in higher omasal flows of C18:1 trans FA and higher milk fat proportions of C18:1 trans FA and C18:2 cis-9,trans-11. Apparent recovery of C18:3n-3 in milk was higher for ORG-SG (61g/kg) than for ORG-LG (33g/kg), CON-PR (34g/kg), and CON-TI (38g/kg), and milk fat proportion of C18:3n-3 was higher for ORG-SG than for CON-TI. Milk fat proportions of C16:0 were lower for ORG-SG and ORG-LG compared with those for CON-PR and CON-TI. It was concluded that high proportions of red clover and other dicotyledons in the silages affected ruminal biohydrogenation and increased milk fat proportions of beneficial FA.

Silagem de híbridos de sorgo associado a percentagens de concentrado no desempenho de novilhos

Avaliou-se o desempenho de novilhos alimentados em confinamento com silagem de híbridos de sorgo forrageiro e de duplo propósito associado a níveis de concentrado. Foram utilizados 60 novilhos, com idade inicial de 20 meses e peso corporal inicial de 322,45±5,58kg, distribuídos inteiramente ao acaso, nos seguintes tratamentos: três porcentagens de concentrado e dois tipos de silagem de sorgo. Foi verificada interação tipo de silagem versus porcentagem concentrado para consumo de matéria seca e ganho de peso médio diário, os quais aumentaram com o aumento de concentrado na dieta com silagem de sorgo forrageiro, mas não com silagem de sorgo duplo propósito. Os novilhos alimentados com silagem de sorgo forrageiro consumiram menos energia digestível (27,89Mcal/dia-1) que aqueles alimentados com silagem de sorgo duplo propósito (31,42Mcal/dia-1). A conversão alimentar média não foi alterada pelo tipo de silagem utilizada. O aumento da porcentagem de concentrado em dietas com volumoso de menor qualidade aumenta a eficiência biológica de bovinos confinados.

Tamanho de partícula do volumoso e freqüência de alimentação sobre o metabolismo energético e protéico em ovinos, considerando dietas com elevada participação de concentrado

Objetivo-se avaliar o efeito diferente de tamanhos de partículas do volumoso e a frequência de alimentação sobre o metabolismo dos animais. Oito carneiros com peso vivo médio de 52,5kg foram distribuídos em esquema fatorial 2x4, de modo a corresponder a duas frequências de alimentação e quatro tamanhos (2mm; 5mm; 10mm e 25mm), em delineamento em blocos ao acaso. Foi utilizado o feno de Tifton-85 (Cynodon spp.) como volumoso e concentrado comercial, o que impôs um ajuste na relação volumoso:concentrado, que assim ficou quantificada: 25:75%. O trabalho de respirometria foi conduzido em câmara respirométrica, tipo circuito aberto, para pequenos ruminantes. Foram determinados os teores de oxigênio, gás carbônico e metano. Na urina, foi determinado o teor de nitrogênio. A partir desses parâmetros, foi determinada a produção de calor (PC). O nitrogênio retido representou 36,0% do Nitrogênio (N) ingerido (g/dia) e 46,8% do N absorvido (g/dia). A produção média de CH4 foi de 1,45L/UTM/dia. A PC foi cerca de 40,0% da energia bruta ingerida. A energia metabolizável foi 73,2% da Energia bruta ingerida e a energia líquida apresentou valor médio de 1.807,35kcal/dia. Não houve efeito dos tamanhos de partícula e da frequência sobre o balanço de nitrogênio e o metabolismo energético.

Vacas lactantes alimentadas com silagem de cana-de-açúcar com e sem aditivo bacteriano: consumo, digestibilidade, produção e composição do leite

A ensilagem de cana-de-açúcar é uma ferramenta que pode ser utilizada para atender a deficiência de alimento em períodos seco do ano, e a adição de aditivos microbianos na ensilagem pode melhorar o perfil fermentativo e, consequentemente, seu valor alimentício. O objetivo com o presente trabalho foi avaliar o efeito da utilização da cana-de-açúcar fresca ou conservada, sob a forma de silagem, com ou sem aditivo microbiano, bem como verificar a influência da queima da cana em dietas de vacas lactantes sobre o consumo e digestibilidade aparente dos nutrientes, produção e composição do leite. Os animais foram distribuídos em um quadrado latino 5 x 5 para avaliar os efeitos da cana fresca e da silagem de cana sem Lactobacillus buchneri (SCSI); cana com L. buchneri (SCCI); cana queimada sem L. buchneri (SCQSI); cana queimada com L. buchneri (SCQCI). Vacas alimentadas com cana fresca apresentaram maiores consumo de matéria seca e carboidratos não fibrosos, quando comparada com as silagens. A queima da cana e a conservação na forma de silagem, com ou sem aditivo microbiano, não alterou os consumos de matéria orgânica, proteína bruta, extrato etéreo, fibra em detergente neutro, fibra em detergente ácido, carboidratos totais, assim como, não influenciou a digestibilidade dos nutrientes dos animais. Ao alimentar vaca com silagem de cana sem aditivo bacteriano, observou-se menor produção de leite e de proteína bruta, quando comparado com as silagens queimadas com ou sem aditivo e cana fresca. Recomenda-se a utilização de cana fresca por proporcionar aos animais melhor desempenho produtivo.

Milk production, nitrogen balance, and fiber digestibility prediction of corn, whole plant grain sorghum, and forage sorghum silages in the dairy cow

Total mixed rations containing corn (CS), whole plant grain sorghum (WPGS), or forage sorghum (FS) silages were fed to 6 primiparous Italian Friesian cows to determine the effects on lactation performance, nutrient digestibility, and N balance. Furthermore, the relationship between in vivo total-tract neutral detergent fiber (NDF) digestibility (ttNDFD) and the ttNDFD derived by the Cornell Net Carbohydrate and Protein System (CNCPS) model was assessed. Cows were assigned to 1 of 3 diets in a replicated 3×3 Latin square with 28-d periods. The experimental treatment was silage type and 3 different silages were included in the diets. The diets were formulated to be iso-NDF. Accordingly, each diet was formulated to contain 41.5% CS silage, 36.7% WPGS silage, or 28.0% FS silage, on a DM basis. Starch content was balanced by adding the appropriate amount of corn meal. Separate collection of total urine and feces was performed. Dietary forages were analyzed for in vitro NDF digestibility (6 and 24h of incubation) to predict fiber digestion rate with 2 NDF pools (digestible and indigestible). Rumen digestibility of the potentially digestible NDF pool was predicted using CNCPS version 6.1, using the in vitro forage fiber digestion rate. The ttNDFD was predicted assuming that intestinal digestibility of the NDF amount escaping rumen digestion was 20%, according to the CNCPS model. Dry matter intake was decreased by approximately 1.8kg/d in cows fed the FS diet compared with the other diets, probably for the greater particle size of FS diet. Hence, milk yield (kg/d) was lowest for FS (23.6), intermediate for WPGS (24.6), and highest for the CS diet (25.4). Milk urea N (mg/dL) was highest for FS (12.9), intermediate for WPGS (11.9), and lowest for CS (10.7) diet. In vivo ttNDFD (%) was 51.4 (CS), 48.6 (WPGS), and 54.1 (FS); this was probably due to a higher retention time of FS diet in the rumen rather than to a better quality of the FS silage, as confirmed by in situ and in vitro results. Urinary N excretion (% N intake) was highest for FS (31.8), intermediate for WPGS (29.3), and lowest for the CS (27.5) diet. The predicted ttNDFD (37.7, 36.3, and 39.5% for CS, WPGS, and FS, respectively) were lower than the in vivo results. Providing an adequate starch supplementation, whole plant grain sorghum silage can replace corn silage in dairy cows TMR. Forage sorghum silage had rumen NDF digestibility comparable to the other silages; however, it had a negative effect on dry matter intake and milk production, probably due to an inadequate effect of processing.