Effect of Ploidy on Quality of Tall Fescue, Italian Ryegrass x Tall Fescue and Tall Fescue x Giant Fescue Hybrids

Selected quality parameters were measured for forage leaf tissuefrom a spaced-plant nursery. The genotypes used were Ky 31 tallfescue and hybrids of Italian ryegrass (Lolium multiflorum Lam.)x tall fescue (Festuca arundinacea Schreb.) and tall fescuex giant fescue [Fescue gigantea (L ) Vill.]. Hybrid ploidy rangedfrom 2n = 28 to 84 chromosomes. Forage quality was characterizedby neutral detergent fibre (NDF), acid detergent fibre (ADF),total soluble carbohydrates (TSC) nutritive value index (NVI),hemicellulose, and in vitro dry matter disappearance (DMD). Quality of tall fescue, as measured by increased DMD, was improvedby hybridization with giant fescue. Improved DMD and NVI correlatedwith lower NDF and ADF in the hybrids. A few hybrids of Italianryegrass x tall fescue (2n = 28) were higher in some qualityparameters than Ky 31. Tall fescue x giant fescue hybrids (2n= 80 to 84), as a group, had significant quality improvementover Ky 31 in higher DMD and NVI and lower NDF and ADF. Whilesome individual hybrids within each group were significantlyhigher in quality, only the 2n = 80 to 84 chromosome group wasconsistently higher than Ky 31. Prediction equations for DMD,NDF, and ADF were established based on solvent extraction withnear-infrared reflectance spectroscopy (NIRS). Linear correlationcoefficients between chemical measurement and NIRS for eachquality parameter were 0–95 or higher. Acid detergent fibre, neutral detergent fibre, dry matter disappearance, hemicellulose, nutritive value index, Festuca arundinacea, Festuca gigantea, Lolium multiflorum     

Improvement of cell wall digestibility in tall fescue by <Emphasis Type="Italic">Oryza sativa</Emphasis> SECONDARY WALL NAC DOMAIN PROTEIN2 chimeric repressor

Forage digestibility is one of the most important factors in livestock performance. As grasses grow and mature, dry matter increases but they become fibrous with secondary cell wall deposition and lignification of sclerenchyma cells, and forage quality drops. In rice (Oryza sativa), the SECONDARY WALL NAC DOMAIN PROTEIN2 fused with the modified EAR-like motif repression domain (OsSWN2-SRDX) reduces secondary cell wall thickening in sclerenchyma cells. We introduced OsSWN2-SRDX under the control of the OsSWN1 promoter into tall fescue (Festuca arundinacea Schreb.) to increase cell wall digestibility. Of 23 transgenic plants expressing OsSWN2-SRDX, nine had brittle internodes that were easily broken by bending. Their secondary cell walls were significantly thinner than those of the wild type in interfascicular fibers of internodes and in cortical fiber cells between leaf epidermal cells and vascular bundles. The dry matter digestibility increased by 11.8% in stems and by 6.8% in leaves compared with the wild type, and therefore forage quality was improved. In stem interfascicular fibers, acid detergent fiber and acid insoluble lignin were greatly reduced. Thus, the reduction of indigestible fiber composed of cellulose and lignin increased the degradability of sclerenchyma cell walls. OsSWN2-SRDX plants offer great potential in the genetic improvement of forage digestibility.     

Preference by sheep for endophyte-infected tall fescue grown adjacent to or at a distance from alfalfa

Two experiments were conducted to assess preference by sheep for endophyte-infected tall fescue growing in monoculture at least 5 m away from alfalfa (fescue-middle (FM)) over endophyte-infected tall fescue growing adjacent (0.2 to 1 m; fescue–alfalfa (FA)) to alfalfa (FA), and the effect of legume scent on preference for endophyte-infected tall fescue. In Experiment 1, 10 six-month-old lambs were offered for 12 days a choice of freshly harvested FA and FM. On days 13 and 14, lambs were offered the same choice, except cages (to allow access only to scent) containing freshly harvested alfalfa were put in the feeders containing FA, whereas cages containing freshly harvested FM were included with the feeders containing FM. Forage intake was measured 1 h after feeding and at three consecutive 2-h intervals thereafter. FA contained greater (P<0.002) concentrations of the alkaloid ergovaline (360±27 ppm) and CP (8±0.4%) than FM (219±27 ppm and 6±0.4%, respectively). Lambs preferred (P<0.05) FA to FM during the 1^st hour of feeding, but the differences became smaller and disappeared in later feeding periods (P<0.005). Lambs offered FA with alfalfa scent or FM with FM scent preferred (P<0.05) FA but only on the 2^nd day. In Experiment 2, 10 six-month-old lambs were offered a choice of FM with cages (to allow access only to scent) containing freshly harvested alfalfa or FM for 8 days. During the following 4 days, FM in the cages was replaced with freshly harvested sainfoin. Preference was greater (P<0.05) for FM offered with alfalfa scent than for FM offered with FM scent only on days 4 and 8. When lambs were offered FM with alfalfa or sainfoin in cages, they preferred (P<0.05) tall fescue with sainfoin scent over fescue with alfalfa scent, but intake was variable across hours and days (P<0.001). It is concluded that (1) lambs adjusted their intake of and preference for FA and FM over successive feeding bouts within each day, likely owing to an attempt to balance intakes of nutrients and alkaloids and (2) olfactory cues influenced preference, but to a lesser extent than nutrients and alkaloids in endophyte-infected tall fescue.     

The Effects of Endophytes on Seed Production and Seed Predation of Tall Fescue and Meadow Fescue

Fungal endophytes of grasses are often included in agricultural management and in ecological studies of natural grass populations. In European agriculture and ecological studies, however, grass endophytes are largely ignored. In this study, we determined endophyte infection frequencies of 13 European cultivars and 49 wild tall fescue (Schedonorus phoenix) populations in Northern Europe. We then examined seed production and seed predation of endophyte-infected (E+) and endophyte-free (E?) tall fescue (in wild grass populations and in a field experiment) and meadow fescue (Schedonorus pratensis; in a field experiment only). Endophytes were detected in only one of the 13 cultivars. In contrast, >90% of wild tall fescue plants harbored endophytes in 45 wild populations but were absent in three inland populations in Estonia. In three wild tall fescue study sites, 17%, 22%, and 56% of the seeds were preyed upon by the cocksfoot moth. Endophyte infection did not affect seed mass of tall fescue in the field experiment. However, seed predation was lower in E+ than E? grasses in the two tall fescue populations with higher predation rates. For meadow fescue, the mean number of seeds from E+ plants was higher than E? plants, but E? and E+ seeds had equal rates of predation by the moth. Our results suggest that the effects of grass endophytes on seed production and cocksfoot moth seed predation vary considerably among grass species, and the effects may depend on herbivore pressure and other environmental conditions.     

Fiber digestibility in juvenile Galapagos tortoises (Geochelone nigra) and implications for the development of captive animals

Digestive strategies have been recognized to be a key factor for healthy growth in juvenile Galapagos giant tortoises (Geochelone nigra). The aim of present study was to investigate digestive coefficients with special regard to fiber fractions. Four captive bred Galapagos giant tortoises 4–5 years of age were fed a controlled diet for 32 days. The diet consisted of 77% hay, 15% tortoise pellets, and 8% apples on a dry matter basis. On a dry matter basis diet analysis showed: 95.7% organic matter, 11.3% crude protein, 20.5% crude fiber, 22.6% acid detergent fiber, 5.0% acid detergent lignin, and 17.6% cellulose. Based on total fecal collection during 7 days average dry matter digestibilities were calculated: 65% for dry matter, 67% for organic matter, 63% for crude protein, 55% for crude fiber, 49% for acid detergent fiber, 41% for acid detergent lignin, 54% for cellulose. An increase in crude fiber content resulted in a reduced digestibility in comparative evaluations of data for different tortoise species, and in a comparison of tortoises and mammalian hindgut fermenters. Compared to some mammalian hindgut‐fermenting herbivore species (domestic horses, Asian elephants, Indian rhinoceroses) on a diet of hay and concentrates, the juvenile Galapagos giant tortoises showed a digestion of similar efficiency. If a reduction in dietary digestibility is warranted in juvenile Galapagos giant tortoises, it is concluded that dietary fiber levels should be increased and it is proposed that crude fiber levels of 30–40% on a dry matter basis should be achieved. Zoo Biol 24:185–191, 2005. © 2005 Wiley‐Liss, Inc.     

Leaf economics spectrum–productivity relationships in intensively grazed pastures depend on dominant species identity

Plant functional traits are thought to drive variation in primary productivity. However, there is a lack of work examining how dominant species identity affects trait–productivity relationships. The productivity of 12 pasture mixtures was determined in a 3‐year field experiment. The mixtures were based on either the winter‐active ryegrass (Lolium perenne) or winter‐dormant tall fescue (Festuca arundinacea). Different mixtures were obtained by adding forb, legume, and grass species that differ in key leaf economics spectrum (LES) traits to the basic two‐species dominant grass–white clover (Trifolium repens) mixtures. We tested for correlations between community‐weighted mean (CWM) trait values, functional diversity, and productivity across all plots and within those based on either ryegrass or tall fescue. The winter‐dormant forb species (chicory and plantain) had leaf traits consistent with high relative growth rates both per unit leaf area (high leaf thickness) and per unit leaf dry weight (low leaf dry matter content). Together, the two forb species achieved reasonable abundance when grown with either base grass (means of 36% and 53% of total biomass, respectively, with ryegrass tall fescue), but they competed much more strongly with tall fescue than with ryegrass. Consequently, they had a net negative impact on productivity when grown with tall fescue, and a net positive effect when grown with ryegrass. Strongly significant relationships between productivity and CWM values for LES traits were observed across ryegrass‐based mixtures, but not across tall fescue‐based mixtures. Functional diversity did not have a significant positive effect on productivity for any of the traits. The results show dominant species identity can strongly modify trait–productivity relationships in intensively grazed pastures. This was due to differences in the intensity of competition between dominant species and additional species, suggesting that resource‐use complementarity is a necessary prerequisite for trait–productivity relationships.     

Sows’ preferences for different forage mixtures offered as fresh or dry forage in relation to botanical and chemical composition

Providing forage to feed-restricted pregnant sows may improve their welfare by reducing their high feeding motivation. The aim of this study was to determine sows’ preferences for four forage mixtures cultivated in Canada. Forage mixtures were compared when offered either fresh or dry. The four forage mixtures were composed of different proportions and species of legumes (alfalfa (Alf) or red clover (Clo)) and grasses (tall fescue (F) and/or timothy (T)): (1) Alf-F, (2) Alf-F-T, (3) Clo-T and (4) Clo-F-T. Voluntary intake was measured, and preference tests were carried out for two experiments: one in spring for fresh forages ( n = 8) and the other in autumn for hays ( n = 8) with different sows housed in individual pens and fed a concentrated diet meeting their nutritional requirements for maintenance and foetal growth. Voluntary intake was measured by offering each forage mixture separately (one forage mixture/day) during 90 min according to a 4 × 4 Latin square design replicated four times. During preference tests, all six combinations of two forage mixtures were offered once (one combination/day) for 45 min to each sow. Individual forage intake was measured, and feeding behaviour was observed. Forages were analysed for botanical and chemical composition. Difference in voluntary intake among the four forage mixtures was determined using a variance analysis followed by Tukey tests for post hoc comparisons. In preference tests, differences between the two forage mixtures offered were determined using a paired Student’s t test, and the most ingested forage mixture was considered the preferred one. Results from both experiments revealed clear preferences for some forage mixtures when offered either fresh or dry. Forage mixtures with a greater proportion of legumes (AlfT and CloT) were preferred over forage mixtures with a higher proportion of grasses (AlfFT and CloFT). The AlfFT and CloFT forage mixtures contained at least 30% of fescue; therefore, the greater preference for the AlfT and CloT forage mixtures could also be due to the absence of fescue. Sows preferred forages with low DM and NDF concentrations and high CP and non-structural carbohydrates concentrations. Based on results from previous studies, the preferences seen in the present study are most likely due to the greater proportion of legumes, although an effect of tall fescue in preference cannot be excluded. Therefore, offering forages with a high proportion of legumes would be a good strategy to maximise both fresh and dry forage intake in pregnant sows.     

In vivo and in situ measurements of the digestive characteristics of sainfoin in comparison with lucerne fed to sheep as fresh forages at two growth stages and as hay

In vivo and in situ digestive characteristics of sainfoin (Onobrychis viciifolia L., a tannin-rich forage) and lucerne (Medicago sativa L., a tannin-free forage) were compared to evaluate the effects of condensed tannins (CT) and growth stage (vegetative v. early flowering) in experiment 1. In experiment 2, the hays of the two forages, harvested at early flowering, were compared. Ingestibility, organic matter digestibility (OMD) and nitrogen (N) retention were measured in sheep fed sainfoin and lucerne fresh forages and hays. The loss of dry matter (DM) and N from polyester bags suspended in the rumen, abomasum and small intestine was also measured using rumen fistulated sheep and other intestine fistulated sheep. Nitrogen content was lower in sainfoin than in lucerne. Content of CT in sainfoin decreased with growth stage (3.5 to 2.5 g CT/kg DM) and was lower for sainfoin hay (0.6 g CT/kg DM). Ingestibility and OMD did not differ between fresh-fed forage species. Total N tract digestibility in vivo was much lower for sainfoin than for lucerne fresh forages (mean value 0.540 v. 0.721, P < 0.001) and for sainfoin hay than lucerne hay (0.464 v. 0.683, P < 0.001). In both species, N digestibility was not altered by growth stage. The rumen degradation of N was lower in sainfoin than in lucerne, resulting in a lower proportion of N intake excreted in urine. The intestinal digestibility of sainfoin was also lower than that of lucerne, resulting in a higher N excretion in faeces. Hence the efficiency of N utilisation by sheep (ENr) was similar (mean value 0.205 and 0.199 g N retained/g N intake for fresh sainfoin and lucerne, respectively). The coefficient of N retention by the animal was higher for sainfoin at the vegetative stage than for all the other forages. Nitrogen degradability in the rumen determined by the nylon bag technique (DegN) was lower for sainfoin than for lucerne when forages were studied both fresh (mean value 0.608 and 0.818, respectively) and as hays (0.631 and 0.767). The efficiency of forage N digestion (ENd) was higher for sainfoin at the vegetative stage. Compared with lucerne, sainfoin greatly increased the in situ estimate of forage N escaping the rumen but decreased its intestinal digestibility.     

黄颡鱼对四种动物性蛋白原料在不同制粒工艺下的表观消化率研究

实验以三氧化二铬(Cr₂O₃)为外源指示剂,采用“70%基础饲料+30%实验原料”的方法配制实验饲料,测定了初始体质量为(28.68±0.49) g的黄颡鱼(Peltobagrus fulvidraco)对国产鱼粉、进口鱼粉、进口鸡肉粉和脱脂黄粉虫粉在膨化制粒和非膨化制粒两种工艺下的干物质、粗蛋白、粗脂肪和氨基酸表观消化率。结果显示,在非膨化制粒工艺下,黄颡鱼对进口鸡肉粉的干物质表观消化率显著高于另外3种原料(P<0.05),黄颡鱼对黄粉虫粉蛋白消化率最低(P<0.05),黄颡鱼对进口鸡肉粉脂肪表观消化率显著高于国产鱼粉和进口鱼粉(P<0.05); 在膨化制粒工艺下,进口鸡肉粉的干物质表观消化率显著低于另外3种原料(P<0.05),国产鱼粉和进口鱼粉的粗蛋白质消化率达94%以上,显著高于另外两种原料(P<0.05),但进口鸡肉粉的脂肪表观消化率显著低于其他原料(P<0.05)。在非膨化制粒工艺和膨化制粒工艺下国产鱼粉、进口鱼粉和黄粉虫粉的干物质表观消化率无显著性差异,但在非膨化制粒工艺下进口鸡肉粉的干物质表观消化率显著高于膨化制粒工艺(P<0.05)。对于国产鱼粉、进口鱼粉和黄粉虫粉而言,非膨化制粒工艺的蛋白消化率显著低于膨化制粒工艺(P<0.05),而鸡肉粉则相反。膨化加工工艺进口鱼粉的脂肪表观消化率显著高于非膨化加工工艺(P<0.05),而膨化加工工艺的黄粉虫脂肪表观消化率显著低于非膨化加工工艺(P<0.05)。氨基酸的消化率结果与粗蛋白的表观消化率变化趋势基本一致。由此可知,对于黄颡鱼饲料,国产鱼粉和进口鱼粉是最佳的蛋白质来源,进口鸡肉粉和黄粉虫亦可以作为其优质的蛋白质来源。对于进口鱼粉、国产鱼粉和黄粉虫粉,膨化制粒工艺更有利于黄颡鱼对其干物质、蛋白、脂肪和氨基酸等营养元素的消化利用,而对于进口鸡肉粉,非膨化制粒工艺更有利于黄颡鱼对营养元素的消化利用。     

Understanding medusahead low intake and palatability through in vitro digestibility and fermentation kinetics

The low intake of medusahead grass (Taeniatherum caput-medusae ssp. asperum) by sheep is attributed to the high silica content of the plant and its negative impact on digestibility, making this weed a successful competitor in grazed plant communities. The goals of this study were to determine the influence of (1) plant maturity stage (from late vegetative stage to beginning of senescence and thatch), (2) particle size (1, 5, 10 and 20 mm), and (3) high-quality feeds (alfalfa hay and a high-energy concentrate) on fermentation kinetics and apparent digestibility of medusahead relative to palatable feeds (alfalfa and tall fescue hays, and high-energy concentrates). In vitro gas production was estimated and apparent digestible organic matter (DOM) of the substrates was assessed after incubation. Medusahead from late vegetative to senescence stage had greater DOM (65% to 71%; P<0.05) than alfalfa hay (53%), similar to tall fescue hay (67%; P>0.05), and lower than the high-energy concentrates assayed (77% to 79%; P<0.05). Fermentation kinetics showed slow fermentation rates for medusahead relative to alfalfa (P<0.05), and a decline in fermentation rates with plant maturity (P<0.05). Fermentation rates of the substrates were reduced with particle sizes ⩾5 mm (P<0.05), and apparent DOM for medusahead declined as particle size increased, a relationship not found for alfalfa or tall fescue hays (P<0.05). No effects (P>0.05) on digestibility parameters were observed by the addition of high-quality feeds to medusahead. Slow fermentation kinetics and a significant inhibitory effect of particle size on apparent digestibility of organic matter contribute to explain the low use of medusahead by sheep. Such inhibitory effect may also underlie the lack of positive associative effects observed during the study.     

Mixing sainfoin and lucerne to improve the feed value of legumes fed to sheep by the effect of condensed tannins

The aim of this study was to investigate whether the use of sainfoin-based condensed tannins (CT) enhances feed value when given with tannin-free legumes (lucerne) to sheep. The experiments were conducted with fresh sainfoin and lucerne harvested at two stages (vegetative stage as compared with early flowering) in the first growth cycle. Fresh sainfoin and lucerne forages were combined in ratios of 100 : 0, 75 : 25, 25 : 75 and 0 : 100 (denoted S100, S75, S25 and S0, respectively). Voluntary intake, organic matter digestibility (OMD) and nitrogen (N) retention were measured in sheep fed the different sainfoin and lucerne mixtures. Loss of dry matter (DM) and N from polyester bags suspended in the rumen, abomasum and small intestine (SI) was also measured using rumen-fistulated sheep and intestinally fistulated sheep. The CT content in sainfoin (S100) decreased with increasing percentage of lucerne in the mixture (mean value from 58 g/kg DM for S100 to 18 g/kg DM for S25) and with growth stage (S100: 64 to 52 g/kg DM). OMD did not differ between different sainfoin/lucerne mixture ratios. Sainfoin and lucerne had an associative effect (significant quadratic contrast) on voluntary intake, N intake, total-tract N digestibility, N in faeces and urine (g/g N intake) and N retained (g/g N intake). Compared with lucerne mixtures (S0 and S25), high-sainfoin-content mixtures (S100 and S75) increased the in situ estimates of forage N escaping from the rumen (from 0.162, 0.188 for S0 and S25 to 0.257, 0.287 for S75 and S100) but decreased forage N intestinal digestibility (from 0.496, 0.446 for S0 and S25 to 0.469, 0.335 for S75 and S100). The amount of forage N disappearing from the bags in the SI (per g forage N) was the highest for high-sainfoin mixtures (from 0.082, 0.108 for S100 and S75 to 0.056, 0.058 for S25 and S0, P < 0.001). Rumen juice total N (tN) and ammonia N (NH3-N) values were the lowest in the high-sainfoin diet (mean tN 0.166 mg/g in S100 as compared with 0.514 mg/g in S0; mean NH3-N 0.104 mg/g in S100 as compared with 0.333 mg/g in S0, P < 0.001).     

麦瑞加拉鲮幼鱼对12种原料表观消化率的比较研究

试验以麦瑞加拉鲮（Cirrhinus mrigala）幼鱼（3.88±0.06）g为试验对象,研究其对国产鱼粉、白鱼粉、花生粕、白酒糟、鸡肉粉、米糠、棉粕、菜粕、豆粕、玉米蛋白粉、玉米酒糟和羽毛粉的干物质、粗蛋白、粗脂肪、总能、磷、钙、镁、锌、铜、铁和锰的表观消化率。结果表明:12种试验原料的干物质、粗蛋白质、粗脂肪、总能、磷、钙、镁、锌、铜、铁和锰的表观消化率范围分别为24.93%-85.68%、50.02%-97.40%、51.89%-94.02%、39.18%-96.39%、9.72%-87.37%、3.47%-25.92%、26.11%-88.25%、12.63%-66.35%、41.33%-104.86%、10.69%-91.84%、4.42%-85.49%。其中包括干物质、粗蛋白和总能在内的主要营养物质的表观消化率以国产鱼粉和白鱼粉最高。除鱼粉外的其他原料中,干物质以花生粕、豆粕和玉米蛋白粉最高;粗蛋白以花生粕最高;粗脂肪以米糠和花生粕最高;总能以花生粕和鸡肉粉最高;白酒糟的干物质、粗蛋白、粗脂肪、总能的消化率最低。在矿物质元素表观消化率中,羽毛粉的磷、铜、铁和锰的表观消化率最高;米糠的锌表观消化率最高;钙的表观消化率以白鱼粉、豆粕和羽毛粉最高;镁的表观消化率以豆粕、羽毛粉和玉米酒糟最高;鸡肉粉的磷、钙、镁和铁表观消化率最低;花生粕和棉粕中锌的表观消化率最低;菜粕中铜的表观消化率最低;白酒糟中锰的表观消化率最低。因此,花生粕、豆粕和玉米蛋白粉是麦瑞加拉鲮幼鱼配合饲料中较优质的蛋白源,可进一步开发用于适量替代饲料中的鱼粉;米糠可作为较好的能量饲料;羽毛粉可作为饲料中较好的矿物质元素来源;白酒糟对麦瑞加拉鲮幼鱼而言营养价值最差。     

Effects of fibre on digestibility and passage time in callithricidae

The effects of fibre in a pelleted diet on food intake, digestibility of crude fibre, dry matter and energy, on passage time and consistency of faeces were studied in 2 species of Callithricidae, Callithrix jacchus and Saguinus fuscicollis. Coarse cellulose, microcellulose, wheat bran and shrimp meal (chitin = crude fibre) were tested in diets containing 2,4 and 6% total crude fibre, respectively. Digestibility and passage time were determined by inclusion of 0.5% Cr2O3 in the diet. Both celluloses had little influence on the digestibility of energy and dry matter. Digestibility of crude fibre was very low. Wheat bran led to evident depression of energy and dry matter digestibility. High digestibility of crude fibre occurred at the higher levels of inclusion in the diet. Shrimp meal was highly digested with little influence on digestibility of energy and dry matter, indicating considerable degradation of chitin. Wheat bran showed a marked effect, while microcellulose had no effect on passage time, consistency and volume of faeces.     

Nutritive value of papyrus (Cyperus papyrus,Cyperaceae), a tropical emergent macrophyte

Papyrus (Cyperus papyrus, Cyperaceae) covers large areas in tropical African wetlands. Analysis of its nutritive value has revealed that crude protein is higher in umbels than culms. Ruminai dry matter digestibility of papyrus is, however, higher in culms than umbels. Both the crude protein and ruminai dry matter digestibility decrease with increasing age of the plant. Values for crude protein and ruminai dry matter digestibility are similar to those reported for the range grasses that constitute the greatest percentage of forage in East Africa. In general, papyrus has some grazing potential and could be used as fodder especially in the dry season when other forage is scarce and of low nutritive value.     

Determination of polyphenol and crude nutrient content and nutrient digestibility of dried and ensiled white and red grape pomace cultivars

The present study aimed to determine the nutrient and energy content of fresh and ensiled grape pomace (GP) from different grape varieties originating from Germany, and to estimate the feed value of dried white, dried red and ensiled white GP by calculating nutrient digestibility and the content of metabolisable energy (ME) and net energy lactation (NEL) measured in sheep as a ruminant model. GP from red cultivars had higher contents of organic matter (OM), crude protein (CP), ether extract (EE), crude fibre (CF), total phenolic contents (TPC) and ME, whereas the concentrations of ash and sugar were lower than from white cultivars. Compared with untreated GP, ensiled GP had increased concentrations of CP (+19%), ether extract (EE; +23%) and CF (+12%) and a higher ME content (+7%) and markedly decreased concentrations of sugar (?99.6%) and TPC (?48%). The concentrations of dry matter, OM and ash were not different between ensiled and fresh GP. Compared with dried GP, ensiled GP had a higher nutrient digestibility (OM, +32%; CP, +43%; CF, +46%; neutral detergent fibre [NDF], +54%; acid detergent fibre [ADF], +69%) and higher energy values (ME, +16%; NEL, +19%). The digestibility of OM, CP, EE and CF and the energy content were higher for dried red than for dried white GP, whereas the digestibility of NDF_OM and ADF_OM was lower for dried red than dried white GP. In conclusion, the results show that both red and white GP are suitable dietary sources for enrichment with TPC. Furthermore, compared with drying ensiling of GP improves the feeding value of GP and is a good possibility of preserving the seasonally produced by-product of winemaking for ruminant feeding.     

Microsite conditions influence nutritive value characteristics of a tall fescue cultivar devoid of,or infected with a native,or a novel non-ergogenic endophyte

Tall fescue [Lolium arundinaceum, Schreb., S.J. Darbysh.] productivity and persistence often benefits from association with Neotyphodium coenophialum [Morgan-Jones and Gams], Glenn, Bacon, and Hanlin) endophyte. The influence of novel, non-ergogenic endophytes on nutritive value is unclear, especially when simultaneous stresses (e.g., defoliation and shading) are imposed on the association. We conducted a field experiment using Jesup tall fescue that had either a native or novel non-ergogenic fungal endophyte (AR542; referred to as MaxQ?), or that was endophyte free. Dry matter production and nutritive value including crude protein (CP), non-structural carbohydrates (TNC), ergo- and loline alkaloids, and phenolics were determined for plants stockpiled or clipped repeatedly in sites differing in the amount of light. Productivity varied less among sites when plants were infected with a native endophyte compared to novel or no endophyte. The trend suggests that native endophyte contributed to resilience of the host in this experiment. Leaf dry matter content was affected by host–endophyte association interacting with light availability suggesting differences in leaf composition could occur. Herbage CP increased, whereas TNC decreased with increasing shade. The concentration of loline alkaloids, irrespective of host–endophyte association, tended to increase in leaves with decreasing light availability and could be related to the relatively greater N concentrations in shade-grown leaves. Phenolics decreased in leaves, but increased in stembases as light availability decreased. The combination of increased loline alkaloids in leaves and phenolics in stembases, suggests that shade-grown tall fescue might have some competitive advantage based on the known anti-herbivory attributes of loline alkaloids and phenolic compounds.     

Limits to food intake and fiber utilization in the prairie vole,Microtus ochrogaster: effects of food quality and energy need

We fed prairie voles (Microtus ochrogaster) rat chow diluted with variable amounts of -cellulose to determine 1) how much fiber the voles could tolerate in their diet; 2) changes in food intake and digestibility of dry matter and of fiber; 3) the extent to which voles utilized fiber as an energy source; and 4) whether any of these variables differed between groups of animals maintained at 5 or 22°C. Fiber content of the diets ranged from 20 to 84%. Animals held at 5°C maintained body mass through a diet containing 69% fiber, while animals held at 22°C maintained body mass through the 84% fiber diet. Dry matter intake increased with fiber level from 9.3 to 15.0 g·day^-1 for animals at 5°C and from 5.6 to 14.0 g·day^-1 for animals at 22°C; intake on the highest fiber diet eaten by either group was not different. Dry matter digestibility decreased significantly as the fiber in the diets increased, but was not affected by temperature treatments. Digestible dry matter intake for each group remained constant regardless of diet quality, but on each diet digestible dry matter intake for animals at 5°C was significantly higher than that of the animals held at 22°C. Digestibility of the fiber portion of the experimental diets remained constant as food quality decreased, so the percent of daily energy need met by fiber utilization increased with higher food intake. On the lowest quality diet each group tolerated, fiber digestion provided approximately 42 and 68% of the energy needs of voles at 5 and 22°C, respectively.Abbreviations BM body mass - BMR basal metabolic rate - DE digestible energy - DM dry matter - DMD dry matter digestibility - DDMI digestible dry matter intake - MR metabolic rate - NDF neutral detergent fiber (=cell walls) - NDS neutral detergent solubles (=cell solubles) - SEM standard error of mean - T _a ambient temperature     

Feed intake and milk production in dairy cows fed different grass and legume species: a meta-analysis

The aim of this meta-analysis was to compare feed intake, milk production, milk composition and organic matter (OM) digestibility in dairy cows fed different grass and legume species. Data from the literature was collected and different data sets were made to compare families (grasses v. legumes, Data set 1), different legume species and grass family (Data set 2), and different grass and legume species (Data set 3+4). The first three data sets included diets where single species or family were fed as the sole forage, whereas the approach in the last data set differed by taking the proportion of single species in the forage part into account allowing diets consisting of both grasses and legumes to be included. The grass species included were perennial ryegrass, annual ryegrass, orchardgrass, timothy, meadow fescue, tall fescue and festulolium, and the legume species included were white clover, red clover, lucerne and birdsfoot trefoil. Overall, dry matter intake (DMI) and milk production were 1.3 and 1.6 kg/day higher, respectively, whereas milk protein and milk fat concentration were 0.5 and 1.4 g/kg lower, respectively, for legume-based diets compared with grass-based diets. When comparing individual legume species with grasses, only red clover resulted in a lower milk protein concentration than grasses. Cows fed white clover and birdsfoot trefoil yielded more milk than cows fed red clover and lucerne, probably caused by a higher OM digestibility of white clover and activity of condensed tannins in birdsfoot trefoil. None of the included grass species differed in DMI, milk production, milk composition or OM digestibility, indicating that different grass species have the same value for milk production, if OM digestibility is comparable. However, the comparison of different grass species relied on few observations, indicating that knowledge regarding feed intake and milk production potential of different grass species is scarce in the literature. In conclusion, different species within family similar in OM digestibility resulted in comparable DMI and milk production, but legumes increased both DMI and milk yield compared with grasses.