Ruminal Nutrient Research Articles

The presence of phytase in yeasts isolated from the gastrointestinal tract of four major carps [Labeo rohita (Hamilton, 1822), Catla catla (Hamilton, 1822), Cirrhinus mrigala (Hamilton, 1822), Hypophthalmichthys molitrix (Valenciennes, 1844)], climbing pe

Phytic acid (myo-inositol 1, 2, 3, 4, 5, 6-hexakis dihydrogen phosphate), a plant-derived anti-nutritional factor, is the major phosphorus (P) storage compound in plant feedstuffs. The presence of phytic acid restricts incorporation of various plant ingredients in formulated diets because it chelates nutritionally important minerals, proteins and amino acids, thereby rendering them biologically unavailable to the animals (Pointillart et al., 1987), including fish (Cho and Bureau, 2001), due to the lack of intestinal phytase. Phytase (myoinositol hexakisphosphate phosphohydrolase, EC 3.1.3.8) initiates the release of phosphate from phytic acid, and thus assists in the degradation of phytate compounds (Oatway et al., 2001). Phytases have a wide distribution in plants, microorganisms and some animal tissues (Vohra and Satyanarayana, 2003). Phytase produced by microbiota in the gut increases the availability of phosphorus and other important nutrients in ruminants (Selinger et al., 1996; Yanke et al., 1998) by virtue of enzymatic hydrolysis of the phytic acid. Although the specific role of the colonizing microorganisms in the gastrointestinal (GI) tract of fish is unclear, attention to identify groups of autochthonous microorganisms has been given to gain information on activities of the microbiota (Cahill, 1990). In this context, the importance of the commensal exo-enzyme producing microbiota within GI tracts of fish has been emphasized during the past decade (for review see Ray et al., 2012). Some of these recent investigations have called attention to the possibility of phytate degradation through the action of phytases produced by microbiota in the fish gut. Reports on the presence of phytase-producing microorganisms in the GI tracts of marine (Li et al., 2008; Askarian et al., 2012) and freshwater fishes (Roy et al., 2009; Khan et al., 2011; Khan and Ghosh, 2012) are available. Although most of those studies emphasized bacteria, Li et al. (2008) documented the phytase-producing marine yeast strain Kodamea ohmeri BG3 from the gut of a marine fish, Hexagrammes otakii. To our knowledge, occurrence of phytase-producing yeasts in the GI tract of freshwater fishes has yet to be evaluated, with efforts generally still in their infancy. This preliminary study therefore intended to (i) detect autochthonous phytase-producing yeasts, if any, in the GI tracts of six freshwater teleosts, (ii) screen potentially phytase-producing yeasts through in vitro quantitative phytase assay, and (iii) identify the most promising strains by 28S rDNA sequence analysis.

Chemical composition and ruminal nutrient degradability of fresh and ensiled amaranth forage

Amaranth is a crop with potential as a source of forage for ruminants that has not been well characterized. A study was conducted to determine the impact of ensiling on the nutritional quality and ruminal degradability of forage from two amaranth cultivars adapted to North America (i.e. Plainsman and D136). In particular, quantification and some microscopic characterization of oxalate found in amaranth were performed as it is an antiquality compound of concern. There were limited interactions between cultivars and ensiling for most variables. Differences in chemical composition between amaranth cultivars were also limited. Ensiling reduced non-structural carbohydrate and true protein contents. The proportion of acid detergent protein was high in fresh and ensiled forages of both cultivars (average of 177 g kg(-1) crude protein). Total oxalate content averaged 30 and 25 g kg(-1) in fresh and ensiled forages respectively. Ensiling reduced soluble oxalate content. Crystals observed in amaranth were calcium oxalate druses found mostly in idioblast cells in leaf mesophyll and parenchyma of primary and secondary veins. In situ ruminal degradability data indicated that both fresh and ensiled amaranth are highly degradable in the rumen. This study confirms that amaranth is a suitable forage for ruminant animals. Its chemical composition is comparable, for most variables, to that of other commonly used forage species.

Understanding the Effects of Forage Composition and Structure in Ruminant Nutrition

Approximately 68% of the 16 million square miles of agricultural land worldwide is used for permanent pastures for livestock production. Fortunately, ruminants can convert plant matter that is inedible or of low nutritional value for monogastrics (i.e., swine or poultry) into calorically dense products of high nutritional value. However, the process of converting poor quality plant matter into useful nutrients for ruminants is complex. This 3-page fact sheet provides an overview and understanding of how forage composition and structure affect the nutritive value and nutrient availability to ruminants. Written by Kalyn M. Waters, Nicolas DiLorenzo, and G. Cliff Lamb, and published by the UF Department of Animal Sciences, March 2013.
 http://edis.ifas.ufl.edu/an288

Effects of Feeding Corn-lablab Bean Mixture Silages on Nutrient Apparent Digestibility and Performance of Dairy Cows.

This study estimated the fermentation characteristics and nutrient value of corn-lablab bean mixture silages relative to corn silages. The effects of feeding corn-lablab bean mixture silages on nutrient apparent digestibility and milk production of dairy cows in northern China were also investigated. Three ruminally cannulated Holstein cows were used to determine the ruminal digestion kinetics and ruminal nutrient degradability of corn silage and corn-lablab bean mixture silages. Sixty lactating Holstein cows were randomly divided into two groups of 30 cows each. Two diets were formulated with a 59:41 forage: concentrate ratio. Corn silage and corn-lablab bean mixture silages constituted 39.3% of the forage in each diet, with Chinese wildrye hay constituting the remaining 60.7%. Corn-lablab bean mixture silages had higher lactic acid, acetic acid, dry matter (DM), crude protein (CP), ash, Ca, ether extract concentrations and ruminal nutrient degradability than monoculture corn silage (p<0.05). Neutral detergent fiber (NDF) and acid detergent fiber (ADF) concentrations of corn-lablab bean mixture silages were lower than those of corn silage (p<0.05). The digestibility of DM, CP, NDF, and ADF for cows fed corn-lablab bean mixture silages was higher than for those fed corn silage (p<0.05). Feeding corn-lablab bean mixture silages increased milk yield and milk protein of dairy cows when compared with feeding corn silage (p<0.05). The economic benefit for cow fed corn-lablab bean mixture silages was 8.43 yuan/day/cow higher than that for that fed corn silage. In conclusion, corn-lablab bean mixture improved the fermentation characteristics and nutrient value of silage compared with monoculture corn. In this study, feeding corn-lablab bean mixture silages increased milk yield, milk protein and nutrient apparent digestibility of dairy cows compared with corn silage in northern China.

Assessment of the cytotoxic and anti-viral potential of aqueous extracts from different parts of Acacia nilotica (Linn) Delile against Peste des petits ruminants virus

Peste des petits ruminants virus (PPRV); a negative sense single stranded RNA enveloped virus that causes Peste des petits ruminants (PPR), is dramatically affecting the health status of ruminants all around the world resulting in extensive economical losses in livestock sector. Acacia nilotica (Linn) Delile; a tannin-rich medicinal plant distributed throughout subcontinent, is traditionally used as food for ruminants and possesses anti-viral potential against different RNA viruses. In the current study, aqueous extracts from the bark, leaves and pods of A. nilotica (Linn) Delile indica were evaluated for their cytotoxicity and anti-viral activities against PPRV by adopting MTT colorimetric assay and anti-viral assay using Vero cell line. Aqueous extract from the leaves presented significantly better (P<0.05) anti-PPRV activities in comparison to pods extract. On the contrary, bark extract did not show any anti-viral activity. The data presented in the study could pave a way toward the discovery of novel anti-viral chemicals in the plants against PPRV and other viral diseases.

Effects of method of barley grain processing and source of supplemental dietary fat on duodenal nutrient flows, milk fatty acid profiles, and microbial protein synthesis in dairy cows

The objective of this study was to determine the interactive effects of barley grain processing and source of supplemental fat on ruminal nutrient digestion, duodenal nutrient flow, microbial protein synthesis, and milk fatty acid (FA) profiles in dairy cows. Four Holstein cows (656±28kg of BW; 80±12d in milk) fitted with permanent ruminal and duodenal cannulas were used in a 4×4 Latin square design with a 2×2 factorial arrangement of experimental treatments, in which barley was either dry-rolled (DRB) or pelleted (PB) and supplemented with full-fat canola seed (canola) or full-fat flaxseed (flaxseed). Cows fed DRB consumed 1.8 to 3.5kg/d more dry matter compared with those fed PB. Mean ruminal pH was lower and the duration (min/d) and area (pH × min) of total ruminal acidosis (RA; ruminal pH <5.8), mild RA (5.8 >ruminal pH >5.5), and severe RA (5.5 >ruminal pH >5.2), and the duration of acute RA (ruminal pH <5.2) were greater in cows fed PB compared with those fed DRB. Milk yield was unaffected by diet. Milk fat content and yield were greater in cows fed DRB than in cows fed PB. Cows fed PB had greater duodenal flows of C18:1 trans, C18:1 cis, C18:2 trans-9,trans-12, C18:2 trans-9,cis-12, C18:2 trans-11,cis-15, and C18:2 trans-10,cis-12 compared with those fed DRB. Duodenal flows of C18:1 cis, C18:1 trans, total C18:1, C18:2n6, C18:2 cis-9,trans-11, C18:2 trans-10,cis-12, C18:2 trans-11,trans-13, total conjugated linoleic acid (CLA), and C18:3n3 were greater in cows fed flaxseed compared with those fed canola. Milk concentrations of C18:3n3 and total CLA tended to be greater in cows fed PB compared with those fed DRB. When compared with cows fed canola, milk concentrations of C18:2 trans-11,cis-15, C18:2 cis-9,trans-11, C18:2 trans-11,trans-13, total CLA, and C18:3n3 were greater in cows fed flaxseed. Ruminal digestion of neutral detergent fiber and acid detergent fiber was greater in cows fed DRB compared with those fed PB. Duodenal flow of ammonia-N tended to be greater in cows fed PB compared with those fed DRB. Duodenal flow of nonammonia nonmicrobial N was greater in cows fed flaxseed compared with those fed canola; however, barley grain processing did not affect duodenal nonammonia nonmicrobial N flow. Duodenal flow of microbial nonammonia N and microbial efficiency were not affected by diet. In summary, barley grain processing and source of fat altered ruminal FA biohydrogenation, and this was reflected in changes in duodenal FA flow and milk FA profiles; however, ruminal microbial protein synthesis was unaltered.

Nutritive evaluation and acceptability of two aquatic weeds (Eichhornia crassipes and Acroceras zizanioides) by West African dwarf goats

Aquatic weeds are plants which grow and reproduce in rivers, streams, brooks, swamps and dams without agronomic care. They have potentials as forage for ruminants. The chemical composition, forage acceptability, secondary metabolites and N- balance of Eichhornia crassipes (EC) and Acroceras zizanioides (AZ) were studied using West African Dwarf goats. The effect of rainy and dry seasons in EC was not noticed for dry matter, crude protein, ether extract, crude fibre and ash. Crude protein content was highest (14.40%) in the leaf but least (7.04%) in the stem and this was contrary for crude fibre. Fresh EC and AZ were richer in crude protein (11.80 and 23.60%) respectively, but lower in dry matter (7.70 and 18.72%) than the dried form. AZ contained more crude protein (23.6%) and was more preferred in the fresh and dried forms by goats than any of the presented form of EC. The two water weeds contained tannin, phenol and saponin at non-toxic levels. Dry matter intake (DMI) increased at 20 and 40% supplementation than grass alone, but decreased with 100% AZ. N-balance and N-retention by goats was positive in AZ composed forages, but negative for AZ alone. The results revealed that EC and AZ are potential sources of nutrients for ruminants. Key words: Aquatic plant, chemical composition, forage acceptability, secondary metabolites, nitrogen balance.

Characterization and Identification of Gut-Associated Phytase-Producing Bacteria in Some Freshwater Fish Cultured in Ponds

Background. Phytase produced by gut bacteria increases the availability of phosphorus and other important nutrients in ruminants by virtue of enzymatic hydrolysis of the phytic acid, an antinutritional factor present in the majority of plant feedstuffs. This topic, however, has been insufficiently investigated in fish. This study was intended: to evaluate the presence of phytase-producing autochthonous bacteria in the gastrointestinal (GI) tracts of 14 freshwater teleost fishes; and to identify the most promising phytase-producing strains by phenotypic characterization and 16S rDNA. Materials and methods. The GI tracts were removed and divided into proximal (PI) and distal (DI) intestine. Homogenates of intestinal segments were spread onto sterilized tryptone soya agar and modified phytase screening media (MPSM) plates to determine autochthonous culturable heterotrophic and phytase-producing microbiota, respectively. Data were presented as log viable counts (LVC) g-1 intestine. Out of 95 phytase-producing isolates, primarily selected 32 isolates were studied for phytase-assay using MPSM broth. Promising phytase-producing isolates were evaluated for other exo-enzymes (amylase, cellulase, protease, lipase) using 4 selective media. Two most promising phytase-producing isolates were identified by phenotypic characterization and 16S rDNA. Results. Population of heterotrophic bacteria was highest (LVC = 8.29 g-1 intestine) in the DI of Gudusia chapra followed by DI of Hypophthalmichthys molitrix (LVC = 6.82 g-1 intestine). However, more than log 4 reduction of the phytase-producing bacteria was observed compared to heterotrophic bacteria. Phytase-producing microbiota was highest in the PI of G. chapra (LVC = 3.95 g-1 intestine) followed by PI of Labeo calbasu (LVC = 3.78 g-1 intestine). The strain LB1.4 isolated from DI of Labeo bata showed highest phytase activity (2.33 &#177; 0.006 U &#183; mL&#8211;1) followed by the strain GC1.2 (2.19 &#177; 0.018 U &#183; mL&#8211;1) isolated from PI of G. chapra. Both isolates were efficient in producing other exo-enzymes. Phenotypic characterization and nucleotide homology analysis revealed that the isolates LB1.4 and GC1.2 were similar to Bacillus subtilis and Bacillus atrophaeus, respectively. Conclusion. Autochthonous phytate degrading bacteria were present in the GI tract of fish that might endow ecological advantages to overcome the anti-nutritional effects of plant phytate.

The influence of herbage mass and supplementary feeding on nutrient flows and animal performance in grazing, lactating ewes

SUMMARYThe present paper examines the effect of the type of supplement given to grazing ewes in early lactation on the performance of ewes and lambs on temperate sown pastures. Lactating ewes grazed perennial ryegrass pastures at either low- or high-herbage masses, between days 8 and 96 of lactation. On the low-herbage mass treatments, ewes were either unsupplemented or received either an energy supplement (sugarbeet pulp) or a protein supplement (1:1 sugarbeet pulp:formaldehyde-treated soyabean meal) between days 8 and 50 of lactation. The provision of supplements or the higher herbage mass led to increases in live weight (LW) and body condition score of ewes during days 8–50 of lactation, while unsupplemented ewes on the low-herbage mass treatment lost LW and had lower body condition scores. After supplementation finished, previously supplemented ewes or those grazing the higher herbage mass lost LW and condition, while unsupplemented ewes grazing the low-herbage mass gained both LW and condition. Non-treatment factors such as ewe dentition score significantly affected ewe and lamb LW gains. Regression analyses indicated that lamb LW gains between days 8 and 50 of lactation were 40–60 g/d greater in lambs from supplemented ewes or ewes grazing the higher herbage mass cf. unsupplemented ewes. Overall, there was no difference in the response of ewes or lambs to the type of supplement. Milk yields were estimated in a subset of ewes (replicate 4). Ewes on the high-herbage mass treatment or those supplemented with protein had higher milk yields than those on the low-herbage mass treatment or those given the energy supplement. Supplemented ewes in this replicate had higher metabolizable energy intakes (MEIs). Measurements of digesta flow in a further subset of ewes indicated that both supplements resulted in greater ruminal and post-ruminal supplies of energy and protein than in the unsupplemented ewes at the lower herbage mass, but differences in ruminal and post-ruminal nutrient provision between the supplements were less than had been intended. It is suggested that this is the reason for there being no statistical difference in the performance of ewes and lambs in response to the type of supplement.

Evaluation of Moringa oleifera, Gliricidia sepium and Leucaena leucocephala - based multinutrient blocks as feed supplements for sheep in South Western Nigeria

Moringa oleifera has not found much use as human food and feed for ruminants compared to other known fodder trees in South- Western Nigeria. Feed blocks were made using 30% Moringa oleifera, Gliricidia sepium and Leucaena leucocephala leaf meals to supplement basal diets of guinea grass – cassava peels mixture for small ruminants. The diets were fed to 32 West African Dwarf rams with average weight of 11.2+ 0.6 kg in a completely randomized design and body weight gain, linear body measurements, physiological parameters, nitrogen retention and haematological indices were measured. The basal diets and feed blocks contained 8.14g 100g -1

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Diets formulated with protein sources presenting different resistance to ruminal degradation were compared by evaluating ruminal parameters, production and microbial efficiency and nutrients flow to the omasum in goats. Eight rumen cannulated non-lactating, non-pregnant goats were distributed in a 4 × 4 Latin square design with two replicates. Treatments consisted of four diets where different sources of plant protein accounted for the major protein source named soybean meal, source of higher ruminal degradability, and three other sources of higher resistance of degradation: roasted soybean, corn gluten meal, and cottonseed cake. Amounts of rumen protein were similar among rations; however, flows of dry matter, protein and non-fiber carbohydrate to omasum were higher for diets with protein source with reduced rumen degradation rate. Higher values of rumen ammonia were obtained by using ration with soybean meal as major source of protein. Higher values of pH were obtained for rations with roasted soybean e cottonseed cake. Regarding kinetic of transit, similar values were found among rations. Diets with protein sources presenting reduced ruminal degradation increase nutrients flow to the omasum in goats and alter digestive parameters such as pH and ammonia without compromising bacteria growth and efficiency, which grants their use for dairy goats with similar efficiency to rations using more degradable sources of protein.

Short chain fatty acids (propionic and hexanoic) decrease Staphylococcus aureus internalization into bovine mammary epithelial cells and modulate antimicrobial peptide expression

Short chain fatty acids (SCFAs) are critical nutrients for ruminants and are mainly obtained from bacterial fermentation of carbohydrates. In addition to their nutrimental function, SCFAs have antimicrobial and anti-inflammatory properties, as well as immunomodulatory roles. It has been reported that sodium butyrate reduces Staphylococcus aureus internalization into bovine mammary epithelial cells (bMEC) and modulates antimicrobial peptide mRNA expression. Nevertheless, it has not been evaluated if sodium propionate (NaP) and sodium hexanoate (NaH) have similar actions. Since they are present in milk, the aim of this study was to determinate the effect of both SCFAs on S. aureus internalization into bMEC and to evaluate their effects on modulation of innate immunity elements. Our data showed that both SCFAs (0.25–5mM) did not affect S. aureus growth and bMEC viability. By gentamicin protection assay (MOI 30:1) we showed that NaP and NaH reduced bacterial internalization into bMEC, which ranged 27–55% and 39–65%, respectively, in relation to non treated controls. Also, both SCFAs up-regulate tracheal antimicrobial peptide (TAP) mRNA expression; however, bovine neutrophil β-defensin 5 (BNBD5) mRNA expression was not modified or was down-regulated. In addition, TAP and BNBD5 expression was up-regulated by S. aureus. Finally, the decrease in bacterial internalization under SCFA treatments is not related to nitric oxide production. In conclusion, NaP and NaH decrease S. aureus internalization into bMEC and modulate TAP gene expression, which may be related to the reduction in bacterial internalization.

NUTRITIVE VALUE OF GREEN MASS AND HAY FROM THE DIVČIBARE REGION

With the aim of forming a complete observation of the botanical composition and nutritive value of pasture and meadow hay from the Divcibare region, which is a typically hilly-mountain area in Serbia, investigations were designed to evaluate the quality of pasture and hay (chemical composition and energy value), as well as the losses which are results of drying pasture. Twelve samples of grass were taken from three different altitudes and after mowing, samples of hay were also taken from the same meadow. In a conventional chemical analysis (Weende) the chemical composition of grass and hay were determined. On the basic of this analysis nutritive values were calculated. Pasture and hay from the Divcibare region have a satisfying chemical composition, they can be used as a forage base and a source of nutrients for ruminants, predominantly, lowproducing livestock. The difference in content of proteins among samples from some localities might be bound with the content of fabaceae. The increase fibre content with the proportional decrease content of protein had a negative influence on the nutritive value in the samples of grass and hay. The Net Energy Lactation (NEL) of hay from the investigated region is near the lower limit reported as average for pasture and meadow hay. Significant higher nutritive values of green mass, calculated on dry matter (NEL 8.35 MJ/kg, SV 0.78 SJ/kg) when compared to the nutritive value of hay (NEL 8.12 MJ/kg, SV 0.74 SJ/kg) show that losses are results of haymaking. Nutrients losses during drying are in correlation with losses of proteins, lipids and mineral matter, but there is an increase in fiber. The change in chemical composition due to the described losses during drying and the negative influence on organic matter digestibility, led to a reduction in the energy value of the investigated samples.

Perennial forage grasses, from breeding to healthy ruminant feed

Temperate forage grasses are the main components of grasslands occupying 40.5 % of the world?s terrestrial area and 30-40% of European agricultural area. They cover the land, providing a habitat and a source of food for domestic livestock, thus ensuring a supply of livestock products, with contributes to rural agricultural and economic development. Grasses are a natural food for ruminants. Rich in fibre, they provide the bulk necessary for good rumen function. Eaten at a sufficiently young stage, they are highly digestible and contain lot of energy. At this stage they also have high mineral and protein contents that cover a large part of animals? requirements. Grasslands usually produce the majority of the forage ingested by ruminant animals during grazing season. During winter housing grass hay and silage are often major parts of the staple diets. There are many improved grass genotypes in Serbia that share main characteristics: high yield and quality of dry matter within a target group of environments and in particular agricultural context. Beyond this common breeding goal there are vast of forage breeding programs as varied as the species upon which they are based and the breeders who develop and implement them. The intensification of forage production and utilization, especially during the second half of the twentieth century, led to a drastic reduction in the number of grass species in sown mixtures, as well as in permanent grasslands. Only a small number of species mainly the ryegrasses, timothy, cocksfoot and fescues are highly suited to intensive management. Moreover, in Europe from 1980 onwards, many forage systems were deintensified and wild or hardly selected species became more important in grasslands. Therefore, it is evident that importance of perennial grasses as animal feed will be increased in the future.

Potential of Sarson Saag Waste-a Cannery Waste as Ruminant Feed

The nutritional worth of Sarson Saag Waste (SSW), a cannery waste, was assessed in comparison with conventional complete diet as a total mixed ration (TMR), and a conventional green fodder, Avena sativa. Each diet was offered ad libitum, supplemented with mineral mixture and common salt, to 4 male murrah buffaloes. The control TMR was made iso-nitrogenous to SSW. Simultaneously, each diet was offered to 3 rumen fistulated male buffaloes for assessing the biochemical changes in the rumen. The nutrient digestibility of unconventional SSW was comparable to that of conventional green fodder-A. sativa but significantly (p<0.05) higher than that of control TMR. The tri-chloro acetic acid (TCA) precipitable-N in the strained rumen liquor of animals fed SSW was considerably higher than that of animals fed A.sativa. The urinary excretion of total purine derivatives was comparable in animals fed SSW and conventional green fodder but significantly (p<0.05) higher than those fed conventional control TMR. The significantly (p<0.05) lower purine nitrogen index (PNI) in animals fed control TMR resulted in significantly (p<0.05) lower microbial protein synthesis than that in animals fed SSW and conventional green fodder. The N-excretion as per cent of nitrogen intake was significantly (p<0.05) lower in animals fed SSW as compared to either of the conventional feeds tested, resulting in significantly (p<0.05) higher N- retention and apparent biological value. SSW supplemented with mineral mixture could serve as an excellent source of nutrients for ruminants. (Asian-Aust. J. Anim. Sci. 2005. Vol 18, No. 4 : 479-482)

Effect of Molasses, Corn Meal, or a Combination of Molasses plus Corn Meal on Ruminal Fermentation of Orchardgrass Pasture During Continuous Culture Fermentation

Although molasses is being used by dairy farmers, particularly certified organic dairies, as a lower cost energy alternative to corn, little research currently exists evaluating the effects of molasses as the sole supplement on the ruminal fermentation of grazing dairy cows. This study evaluated the effects of pasture supplementation with molasses, corn meal, or a combination of molasses and corn meal, on ruminal nutrient digestibility and bacterial N synthesis in continuous culture fermenters. Experimental treatments were 1) orchardgrass (Dactylis glomerata L.) pasture only (control; 70 g DM/d); 2) molasses plus orchardgrass pasture (MOL; 3.5 g DM/d of molasses plus 66.5 g DM/d of pasture); 3) corn meal plus orchardgrass pasture (CM; 4.9 g DM/d of corn meal plus 65.1 g DM/d of pasture); and 4) molasses plus corn meal plus orchardgrass pasture (MOL + CM; 3.5 g DM/d of molasses plus 4.9 g DM/d of corn meal plus 61.6 g DM/d of pasture). Treatment did not affect (P > 0.05) apparent DM, OM, and NDF digestibility values; true DM and OM digestibility values; molar proportions of VFA; or acetate-to-propionate ratio. Mean ruminal pH tended (P = 0.071) to be greater for MOL. Maximum ruminal pH was greatest (P 0.05). At low levels of inclusion, molasses showed results similar to corn meal in improving ruminal fermentation and N utilization, with both supplements showing only minimal improvement compared with a pasture-only diet.

Influence of cultivation site and fertilisation on the properties of condensed tannins and in vitro ruminal nutrient degradation of Calliandra calothyrsus, Flemingia macrophylla and Leucaena leucocephala

Samples obtained from two planting experiments with tropical shrub legumes rich in condensed tannins (CT) ( Calliandra calothyrsus, Flemingia macrophylla, Leucaena leucocephala) were analysed in detail for CT concentration, composition and properties, as well as for in vitro degradability. The factors evaluated included cultivation site (fertile mollisol with pH 7.8 and bimodal rainfall vs. infertile oxisol with pH 5.0, high Al saturation and unimodal rainfall) and different levels of mineral fertilisation. In vitro ruminal degradability, CT concentration and properties were affected by cultivation site or fertiliser application or both. In Calliandra and Flemingia, the CT concentration showed a trend ( P < 0.1) to be higher at the site with the infertile soil. This was consistent with the increased ( P < 0.001) astringency of CT extracts found in Calliandra when plants were cultivated at this site. In Flemingia, however, astringency was reduced ( P < 0.001) on the infertile soil. There were certain effects of the cultivation site on the anthocyanidin profile of CT from Calliandra and Flemingia, but these were relatively small and could not explain the differences in astringency observed between sites. Fertilisation did not affect ( P > 0.05) total CT concentration in Calliandra and Flemingia but clearly increased ( P < 0.01) astringency of the CT extracts. This suggests that not only CT concentration but also properties of CT may be affected by cultivation site and fertilisation. Leucaena did not grow on the infertile soil and site effects could therefore not be evaluated in this species. Fertilisation did not affect ( P > 0.05) CT concentration and astringency of CT extracts of Leucaena but reduced ( P < 0.05) the cyanidin proportion in CT. Cultivation site affected several variables describing fermentation dynamics. Foliage of the legumes grown on the infertile soil exhibited lower ( P < 0.05) gas production rates. Dry matter degradation was lower ( P < 0.001) and the proportion of dietary N remaining undegraded after in vitro incubation was higher ( P < 0.001) when Calliandra was grown on the infertile compared to the fertile soil. The present results indicate that the cultivation site may affect the feeding value of CT-containing legumes. Fertilisation could not compensate the negative effects of the cultivation site on CT properties and ruminal nutrient degradation. Selecting appropriate cultivation sites (with higher soil fertility) may contribute to improve the feeding value of certain tanniniferous tropical shrub legumes.

A nutrition mathematical model to account for dietary supply and requirements of energy and other nutrients for domesticated small ruminants: The development and evaluation of the Small Ruminant Nutrition System

A mechanistic model that predicts nutrient requirements and biological values of feeds for sheep (Cornell Net Carbohydrate and Protein System; CNCPS-S) was expanded to include goats and the name was changed to the Small Ruminant Nutrition System (SRNS). The SRNS uses animal and environmental factors to predict metabolisable energy (ME) and protein, and Ca and P requirements. Requirements for goats in the SRNS are predicted based on the equations developed for CNCPS-S, modified to account for specific requirements of goats, including maintenance, lactation, and pregnancy requirements, and body reserves. Feed biological values are predicted based on carbohydrate and protein fractions and their ruminal fermentation rates, forage, concentrate and liquid passage rates, and microbial growth. For sheep, the SRNS accurately predicted gains and losses of shrunk body weight (SBW) of adult sheep ( n = 15; mean bias (MB) = 5.8 g/d and root mean square error of prediction (RMSPE) = 30 g/d; and r 2 = 0.73) when diets were not deficient in ruminal nitrogen. Several evaluations indicated the SRNS had MB varying from 2.4 to 18 g/d, RMSPE varying from 21.4 to 41 g/d, and r 2 varying from 0.70 to 0.84 when predicting average daily gain (ADG) of growing lambs. For goats, the evaluation for lactating does indicated that predictions of ME intake ( n = 21; MB = 0.04 Mcal/d; RMSEP = 0.24 Mcal/d; and r 2 = 0.99) and energy balance ( n = 21; MB = 0.075 Mcal/d; RMSEP = 0.20 Mcal/d; and r 2 = 0.87) were adequate. Similarly, the SRNS accurately predicted ADG of kids ( n = 31; MB = −6.4 g/d; RMSEP = 32.5 g/d; and r 2 = 0.85). In conclusion, the SRNS can accurately predict, ADG of growing lambs, and changes in SBW of mature sheep and ME intake and the energy balance of lactating and non-lactating adult goats and the ADG of kids of dairy, meat, and indigenous breeds. The SRNS model is available at http://nutritionmodels.tamu.edu.

Isolation and identification of bioactive compounds responsible for the anti-bacterial efficacy of Lotus corniculatus var. São Gabriel.

Lotus corniculatus (Fabaceae) is considered a forage plant utilized as food for ruminants in the south of Brazil. This herb is also actually used to treat intestinal infection in these animals. In our experiments, we evaluated the anti-bacterial activity of crude extract from L. corniculatus var. Sao Gabriel were assayed against Gram-positive and Gram-negative bacterium. The crude extracted did not show any anti-bacterial activity, but the hexane fraction did on Bacillus cereus (MIC=100 μg/mL) and on Enterococcus faecalis, Listeria monocytogenes, Staphylococcus aureus, Staphylococcus epidermidis, Acinetobacter calcoaceticus, and Providencia alcalifaciens (MIC=600, 800 or 1000 μg/mL). The Ethyl acetate fraction (AcOEt) also showed important anti-bacterial activity on Bacillus cereus, E. faecalis, and Acinetobacter calcoaceticus (MIC=800 μg/mL). The oleanolic acid isolated from hexane fraction showed the same effect on Staphylococcus aureus methycillin-resistant (MIC=100 μg/mL), L. monocytogenes (MIC=25 μg/mL), and Bacillus cereus (MIC=25 μg/mL). Further, Kaempferitrin isolated from ethyl acetate fraction has also shown anti-bacterial activity on Shighella flexinerii (MIC=100 μg/mL), Salmonella typhimurium (MIC=100 μg/mL), A. calcoaceticus (MIC=100 μg/mL), E. faecalis (MIC=3.9 μg/mL), and Bacillus cereus (MIC=8.5 μg/mL). This study suggests that L. corniculatus var. Sao Gabriel have potential pharmacological property for a new anti-bacterial drug development. Key words: Anti-bacterial activity, Kaempferitrin, Lotus corniculatus, Oleanolic acid, β-sitosterol.

The effect of roughage and urea solution infusion levels on ruminal NH3-N concentration and nutrient digestibility in beef cattle and swamp buffaloes.

Four, fistulated, male crossbred cattle and swamp buffaloes were randomly assigned in a 2 x 2 factorial arrangement in a 4 x 4 Latin square design. There were four combination dietary treatments; T1) UTS as a roughage and urea infusion at 50 g/h/d (50U), T2) UTS as a roughage and urea infusion at 100 g/h/d (100U), T3) CH as a roughage and urea infusion at 50 g/h/d (50U) and T4) CH as a roughage and urea infusion at 100 g/h/d (100U). Rumen fluid and blood were collected at 0, 0.5, 1, 1.5, 2, 3, 4 and 6 h-post feeding and then analyzed for total bacteria and protozoal, NH3-N, VFA and BUN, respectively. It was found that TDMI in buffoloes fed with UTS as a roughage source with both urea solution infusion were highest (P<0.05). While, digestibility of OM was higher in cattle fed with UTS as a roughage and urea solution infusion in both levels, CP, NDF and ADF digestibility were affected by type of roughage (P<0.05). With regards to digestible nutrient intake, the values of OM, CP, NDF and ADF (kg/d) were significantly different among treatments (P<0.05). Higher levels of ruminal pH were found in buffaloes fed with CH as a roughage and urea infusion in both levels (P<0.05). NH3-N concentrations were higher (P<0.05) in buffaloes fed with CH as a roughage and urea in fusion at 100 g/h/d (34.3 mg%) and lower in cattle fed with both roughage sources and urea infusion at 50 g/h/d (20.0 and 23.5 mg%, respectively). TVFA was affected by type of roughage (P<0.05) and urea infusion at 100 g/h/d. Proportion of C2, C3 and C4 were significantly different (P<0.05) among treatments.