Acute oxalate intoxication associated to ingestion of eshnan (<Emphasis Type="Italic">Seidlitzia rosmarinus</Emphasis>) in sheep

An outbreak of acute oxalate intoxication in a sheep flock was associated to Seidlitzia rosmarinus (Chenopodiaceae) with a mortality rate of about 19%. Affected sheep showed marked azotemia and hypocalcemia. Post-mortem findings included congestion and hemorrhage in visceral organs, ruminitis frequently associated with precipitation of birefringent calcium oxalate crystals, and acute nephrosis with numerous birefringent calcium oxalate crystals in renal tubules. This is the first report of oxalate poisoning due to ingestion of S. rosmarinus in sheep.     

Linseed oil supplementation in diet for horses: Effects on palatability and digestibility

Feed palatability and in vivo apparent digestibility of nutrients were compared in horses fed concentrates in which barley was, or not, partially substituted by 8% linseed oil. According to a cross-over design, three geldings and one stallion were fed at near maintenance level hay plus low or high fat diet (50/50). The last days of each 3-months sub-periods, partial faeces collections were performed and concentrate intake rate was measured to estimate the digestibility and the palatability of the diet. The inclusion of linseed oil did not affect the palatability of the diet and increased significantly (P < 0.05) the apparent digestibility of DM (66.5 vs 64.1%), CF (83.7 vs 57.3%) and NDF (53.0 vs 50.7%) but not of CP and ADF.     

Diet composition, herbage intake and digestibility in Inner Mongolian Cashmere goats grazing on native Leymus chinensis plant communities

The botanical composition, intake and digestibility of the diet selected by Inner Mongolian Cashmere goats grazing on a native Leymus chinensis plant community were measured in two grazing periods (June and August) using the n-alkane markers. In each grazing period, 48 Inner Mongolian Cashmere goats (24 wethers and 24 does with an average live weight of 22.1 ± 1.2 kg and 19.6 ± 0.8 kg, respectively) were divided in two groups (G1: grazing group; G2: cage-fed group) of 24 animals each. Based on the observation of G1 grazing behaviour, G2 goats were fed on herbage obtained by a simulative method and were housed in metabolism cages to determine the alkane faecal recoveries. Diet composition was estimated by comparing the odd-chain n-alkane pattern (C₂₅–C₃₅) of the selected plant species with the n-alkane faecal concentrations, corrected for their incomplete faecal recovery. The alkane pair C₃₂:C₃₃ and C₃₆ alkane were used to estimate intake and diet digestibility, respectively. The results showed that the increase of herbage availability from June to August, resulted in higher (P < 0.05) DM, CP, ME, ADF and NDF intake of both wethers and does, with no evident changes in ADF and NDF intake in does., The intake of nutrients differed significantly between wethers and does in both experimental periods, except for NDF in EP1 and ME in EP2. Differences between grazing seasons and goats' sex in nutrients digestibility were not observed. Diet composition indicated seasonal differences, being Sonchus brachyotus, Artemisia frigida and Phragmites communis the main components of the diet in June. However, Suaeda corniculata, Chloris virgata, Xanthium sibiricum and Echinochloa crusgalli became the main diet components in August. Moreover, the sex affected significantly the diet choices in both grazing periods.     

Analysis of fecal nutrients and particle size in captive proboscis monkeys (Nasalis larvatus) fed seasonal dietary foliage at a Japanese zoo

One male and three female captive proboscis monkeys (Nasalis larvatus) were used as test animals to compare fecal nutrients after being fed seasonal foliage. Foliage and fecal samples were collected during three seasons (spring, summer, and winter). We analyzed crude ash (CA), ether extract (EE), crude protein (CP), neutral detergent fiber (NDF), acid detergent fiber (ADF), and acid detergent lignin (ADL). In addition to the above components, for the fecal samples, we examined total fecal nitrogen (TFN), nitrogen in fecal NDF (NDF-N), metabolic fecal nitrogen (MFN), and particle size distribution (MPS). Seasonal differences in foliage components were observed, with NDF and ADF being lowest in spring (p < 0.05). Fecal NDF and ADF also tended to be lowest in spring. Further, the distribution of fecal particle size indicated that MPS tended to increase in winter. The mean fecal NDF content (47.4%) for all three seasons measured in this study was as much as 1.3 times lower than previously reported values in free-ranging specimens. These data provide useful information that can be used to find some suitable food items for the endangered highly folivorous monkeys in captivity.     

西藏高寒草原5种牧草养分含量及体外消化率季节变化

为掌握西藏自治区岗巴县高寒草原天然牧草养分含量及消化率季节变化规律,选取垫型蒿、高原鸢尾、藏羊茅、藏西嵩草和线叶嵩草5种牧草,分别分析8月、10月和12月各种牧草的粗蛋白质、脂肪、灰分、钙、磷和中、酸性洗涤纤维含量及干物质和纤维组分体外消化率。结果表明:5种牧草中垫型蒿的粗蛋白质含量最高(17.28%)、线叶嵩草次之(15.73%)、藏羊茅最低(3.15%),脂肪和灰分含量分别为1.31%～1.84%和2.57%～9.90%,钙含量变幅较大(0.27%～4.94%),而磷含量相对稳定(0.09%～0.23%),高原鸢尾的中、酸性洗涤纤维含量最高(84.42%和54.44%),而藏西嵩草和线叶嵩草较低;随季节变迁,粗蛋白质含量逐渐降低而纤维含量(除藏西嵩草)不断升高(P<0.05),脂肪含量无显著变化,灰分含量先升高后降低,钙含量在物种和季节间大幅变动,除线叶嵩草外磷含量逐渐降低。就体外消化率而言,藏西嵩草和线叶嵩草的干物质(71.55%、68.42%)、中性洗涤纤维(53.36%、54.45%)和酸性洗涤纤维(42.10%、45.02%)较高,垫型蒿和藏羊茅次之,高原鸢尾最低(除...     

An In vitro Evaluation of Some Unconventional Ruminant Feeds in Terms of the Organic Matter Digestibility,Energy and Microbial Biomass

In vitro organic matter apparent digestibility (IVOMAD), true digestibility (IVOMTD), metabolizable energy (ME), net energy lactation (NEL), microbial nitrogen (MN) and synthesis of microbial biomass (MBM) were estimated to predict the nutritive values of some agricultural by-products, drought-tolerant range plants and browses. The relationships between in vitro gas production (GP), and true or apparent digestibility, MN and MBM were studied utilizing an in vitro incubation technique. The values of IVOMAD, IVOMTD, ME, NEL, GP, MBM and MN varied with the studied experimental materials. The true fermentation of the outside part of Atriplex leucoclada produced a higher volume of gas than the middle or the inside parts, and this was associated with an increase in the values of IVOMAD, IVOMTD, ME and NEL. However, screening off the wood from olive cake to obtain olive cake pulp increased the IVOMAD, IVOMTD, ME, NEL and the volume of gas production from the true fermented material. One ml of gas was generated from the true degradation of 5 mg of wheat straw, Moringa oleifera, Alhagi camelorum, Eucaliptus camaldulensis and A. leucoclada, from 11 mg of Prosopsis stephaniana and olive cake pulp, and from 20 mg of olive cake or olive cake wood. The amount of MN or MBM produced from 100 mg of truly fermented organic matter depended on the kind of the fermented material and amounted to 0.7–2.9 mg or 8–34 mg, respectively. Crude fibre was negatively correlated to IVOMAD, IVOMTD, ME and NEL. Gas production was positively correlated to IVOMAD and IVOMTD but negatively correlated to MBM and MN.     

Effect of genotype on chemical composition,ruminal degradability and in vitro fermentation characteristics of maize residual plants

The objective of this study was to determine the changes to residual plant feeding value of early‐ and late‐maturing maize varieties. The influence of the cell wall carbohydrate composition, in terms of neutral and acid detergent fibre (NDF and ADF) content, NDF and dry matter (DM) degradability, and in vitro organic matter digestibility and gas production on the feeding value of a range of maize genotypes, was measured. The different genotypes were allotted into two maturity groups (MG I – early to mid‐early: S210‐S240; MG II – mid‐late to late: S 250‐S280) and harvested at four different harvest dates (depending on the DM content of the kernels). The maize varieties of MG I had lower NDF and ADF contents and higher ruminal DM degradability, in vitro digestibility and gas production and thus a higher feeding value than MG II at the same stage of physiological maturity. A strong negative relationship between NDF content and the ruminal DM degradability (r = ?0.81) was observed. The data indicate that the early‐maturing varieties permit a larger flexibility in harvesting due to a longer period of starch inclusion into the kernel whilst simultaneously maintaining a good supply of rumen‐available fibre. Conclusively, the higher feeding value of the early‐maturing varieties, based on lower NDF and high DM digestibility, permits more flexibility in the harvesting period over the later‐maturing varieties.     

Effects of supplementation of Panicum maximum with four herbaceous forage legumes on performance,nutrient digestibility and nitrogen balance in West African dwarf goats

The effects of supplementing a basal diet of guineagrass (Panicum maximum cv Ntchisi) (diet 5) with Stylosanthes guianensis (diet 1), Lablab purpureus (diet 2), Aeschynomene histrix (diet 3) and Centrosema pubescens (diet 5) on West African dwarf goats were evaluated. Parameters measured were feed intake, nutrient digestibility and nitrogen balance. Voluntary intake (g/kg W0^.75/day) of dry matter (DM) 138.73, crude protein (CP) 25.86, neutral detergent fiber (NDF) (96.29) and acid detergent fiber (ADF) (65.73) of diet 1 were not significantly different (P > 0.05) from the other diets with legume supplements. The feed intake of goats on diet 5 was lower (P < 0.05), having corresponding values of DM (108.21), CP (17.33), NDF (77.68), and ADF (53.55). Weight gain (g/day) differed (P < 0.05) in goats placed on the diets. The lowest weight gain was obtained in diet 5. The digestibilities of DM, CP, ADF and acid detergent lignin (ADL) differed (P < 0.05) in diet 1–5 except for NDF digestibility. Nitrogen balance (g/kg W ^0.75/day) ranged from 0.29 in diet 5 to 0.83 in diet 2 (P < 0.05). Similarly, nitrogen retention percentage was highest in diet 2 (35.17), with the lowest value in diet 5 (20.71). It could be concluded that a diet consisting of Panicum maximum with Lablab purpureus supplementation gave the highest performance in weight gain, nitrogen digestibility and nitrogen utilization. However, any of the herbaceous legumes in this study would lead to increased productivity of ruminant livestock.     

苜蓿形态学性状与纤维含量的相关性分析

通过田间试验及纤维含量测定,研究苜蓿Medicago sativa主茎长、节间数、节间长等形态学性状与其纤维含量的关系,为在田间选择低纤维苜蓿单株提供有效地优势性状。试验结果表明：苜蓿品种（系）间,各形态学性状、中性洗涤纤维（NDF）和酸性洗涤纤维(ADF)都具有显著性差异(P＜0.05),其性状变异系数依次为节间长(29.91%)＞主枝侧枝数(22.45%)＞主枝茎粗(20.82%)＞分枝数(19.76%)＞节间数(12.57%)＞主茎长(8.87%)＞ADF(4.18%)＞NDF(3.24%),各形态学性状与NDF和ADF相关性分析表明,主茎长与NDF和ADF均呈显著的正相关,主枝侧枝数与ADF也呈显著正相关。其余形态学性状与NDF和ADF不存在显著相关性。     

Effect of Yeast Culture Supplementation on Digestibility of Varying Forage Quality in Mature Horses

Supplementation of yeast culture to equine diets has improved digestion of nutrients in some studies but not others. Improving the digestibility of lower-quality forages could be advantageous both for the producer and for the horse's health. The objective of this study was to evaluate the effect of yeast culture on digestibility of high- and low-quality forage in mature horses. Sixteen geldings (483.6 ± 25.5 kg and 6.8 ± 3.2 years), of Quarter Horse (n = 14) and Thoroughbred (n = 2) breeding, were used in a 4 × 4 Latin square design with 28-day treatment periods. Russell Bermuda grass hay of either high (13.1% crude protein (CP), 73.1% neutral detergent fiber (NDF), 35.3% acid detergent fiber (ADF), and 6.0% ash) or low (8.1% CP, 75.3% NDF, 37.6% ADF, and 4.3% ash) quality was offered at 1.35% of body weight (BW, dry matter [DM] basis). Diets consisted of high-quality forage with the addition of yeast culture (HY), high-quality forage without yeast culture (HC), low-quality forage with the addition of yeast culture (LY), and low-quality forage without yeast culture (LC). All horses were fed a commercial grain mix (12.6% CP, 25.4% NDF, 12.1% ADF, and 4.0% ash) offered at 0.45% of BW (DM basis) daily. Yeast culture was added to the grain mix during the morning feeding at a rate of 56 g per horse. Body weight was measured weekly and feed intake was adjusted accordingly. Fecal samples were obtained every 6 hours on the last 3 days of each treatment period. Horses receiving low-quality hay (LY and LC) had greater (P < .01) intake expressed as a percentage of BW compared with horses receiving high-quality hay (HY and HC). No influence of yeast culture supplementation was seen on intake of grain or forage (P < .23 and P < .62, respectively). Digestibility of DM, organic matter (OM), CP, and NDF were greater (P < .01, P < .01, P < .01, and P < .01, respectively) for the diets with high-quality forage compared with the diets with low-quality forage. Dry matter, CP, and NDF digestibilities were greater (P < .09, P < .03, and P < .05, respectively) for horses receiving LY compared with LC. Supplementation of yeast culture to mature horses improved digestibility of lower-quality Bermuda grass hay.     

Effects of dietary fibre level and body weight of pigs on nutrient digestibility and available energy in high‐fibre diet based on wheat bran or sunflower meal

The objectives of this study were (a) to investigate the effect of body weight (BW) on available energy in fibre‐rich diets containing two NDF levels; and (b) to evaluate the effect of fibre type and NDF level on AA digestibility. In Exp. 1, barrows (24 at 33.4 ± 1.1 kg; 24 at 86.8 ± 3.3 kg) were randomly allotted to 4 diets containing a high protein basal (HPB), a low protein basal (LPB), 70% HPB + 30% wheat bran (WB) (HPB‐WB) and 70% LPB + 30% sunflower meal (SFM) (LPB‐SFM). In Exp. 2, barrows (24 at 33.5 ± 1.8 kg; 24 at 87.0 ± 3.8 kg) were randomly allotted to 4 diets containing no SFM with 12% NDF (SFM0LF), no SFM with 16% NDF (SFM0HF), 24% SFM with 12% NDF (SFM24LF) and 24% SFM with 16% NDF (SFM24HF). In Exp. 3, twelve barrows (35.5 ± 3.4 kg) fitted with T‐cannulas were allotted to two 6 × 4 Youden square design with 6 diets (4 same diets as in Exp. 2 and 2 nitrogen‐free diets). The concentration of DE, ME and ATTD of GE, CP, NDF and ADF in diets was greater (p < .01) when fed to 90 kg pigs compared with 30 kg pigs. The ME in ingredients was not affected by BW. The ATTD of NDF was negatively correlated with the CF (r = ?.98; p < .01), ADF (r = ?.99; p < .01) and ADL content (r = ?.96; p < .01). The ME of diets was negatively correlated with the ATTD of CF (r = ?.98; p < .01). The addition of SFM increased the standardized ileal digestibility (SID) of Met (p < .05). In conclusion, diets rich in fibre had different nutritional values at different pig weight stages. The AA digestibility depends mainly on chemical composition of diets.     

Comparison of Tifton 85 and Coastal bermudagrasses for yield, nutrient traits, intake, and digestion by growing beef steers.

A study was undertaken to compare Tifton 85 (T85) and Coastal (CBG) bermudagrasses for effects of cultivar and age at harvest on yields of DM and digestible DM, in vitro digestion, nutrient content, cell wall composition, in situ digestion kinetics, and feed intake and digestion by growing beef steers. In Exp. 1, T85 and CBG forages staged for growth in May or July of 1993 were harvested at 3, 4, 5, 6, 7, and 8 wk from subplots. Tifton 85 bermudagrass had 7.1% greater DM yield, 18.2% higher (P < .05) digestible DM yield, and 7.1% greater IVDMD than CBG, and, after 5 wk of forage growth, IVDMD of both T85 and CBG decreased with increased age at harvest (P < .05). In Exp. 2, T85 and CBG forages staged for growth in July 1997 were harvested at 2, 3, 4, 5, 6, and 7 wk from subplots. Even though T85 had higher concentrations of NDF and ADF than CBG, T85 had 34.1% higher DM yield, 47.9% higher digestible DM, 55.0% higher digestible NDF, 91.7% higher digestible ADF, greater IVDMD, in vitro NDF and ADF disappearances, and higher in situ DM and NDF digestion (P < .05). Coastal bermudagrass had higher concentrations of lignin and lower concentrations of total neutral sugars, arabinose, glucose, and xylose than T85 (P < .05). In vitro digestibilities of DM, NDF, and ADF were lower and concentrations of ADF and lignin were greater for 7- vs 6-wk harvests of both T85 and CBG (P < .05). In Exp. 3, T85 and CBG forages staged for growth in July 1997 were harvested as hay at 3, 5, and 7 wk from .8-ha pastures and fed to 36 individually penned growing beef steers (initial BW = 244 kg) to quantify ad libitum intake without supplementation. Tifton 85 bermudagrass had lower concentrations of lignin and ether-linked ferulic acid and greater concentrations of NDF, ADF, hemicellulose, and cellulose than CBG (P < .05). Steers fed T85 had higher (P < .05) digestion of DM, OM, NDF, ADF, hemicellulose, and cellulose than steers fed CBG. Digestion of NDF, ADF, hemicellulose, and cellulose decreased (P < .05) with increased age at harvest for both cultivars. In conclusion, T85 produced more DM and had more digestible nutrients in vitro, in situ, and in vivo than CBG, and 3 and 5 wk of growth would be recommended ages to harvest either cultivar.     

Improving ruminal degradability and energetic values of bamboo shoot shell using chemical treatments

This study evaluated effects of different treatments on nutritive value of bamboo shoot shell (BSS). Five treatments were sun‐drying (control), ammoniation (5%/dry matter (DM) urea), Ca(OH)₂ (4%/DM calcium hydroxide), NaOH (4%/DM sodium hydroxide), and AHP (4%/DM sodium hydroxide plus 1%/DM hydrogen peroxide). The results showed that chemical composition of BSS was greatly changed by chemicals (P < 0.01) except acid‐detergent lignin. All chemical treatments significantly reduced neutral detergent fiber (NDF) content except AHP (P < 0.01), and obviously increased acid detergent fiber (ADF) content (P < 0.01) except ammoniation. The predicted organic matter digestibility, metabolizable energy and net energy for lactation of BSS were greatly increased by chemical treatments (P < 0.01), the highest for ammoniation, followed by Ca(OH)₂, NaOH and AHP. Ammoniation had higher (P = 0.03) ammonia‐N concentration than the other four treatments. There were significant differences among all treatments on total volatile fatty acids (P = 0.03), propionate (P = 0.01), butyrate concentration (P < 0.01) and C₂/C₃ ratio (P = 0.02). Chemical treatments greatly improved effective degradability (ED) of DM (P < 0.01) and ED of NDF (P = 0.06) and ADF (P = 0.07) numerically. Ammoniation got a higher ED of crude protein than control. In conclusion, all chemical treatments greatly improved nutritive value of BSS with highest value obtained from ammoniation, followed by strong alkalization, alkaline hydrogen peroxide and modest alkalization.     

Effect of exogenous fibrolytic enzyme on ruminal fermentation and digestibility of alfalfa and rye-grass hay fed to lambs

This experiment was carried out to study the effect of a directly fed exogenous fibrolytic enzyme on intake and digestion of DM, OM, protein, NDF, ADF, and hemicellulose of alfalfa and ryegrass hay by sheep. Four diets were randomly assigned to four ruminally cannulated lambs using a 4 x 4 Latin square design, repeated in time, with a factorial arrangement (2 x 2) of diets: 1) alfalfa hay; 2) alfalfa hay + exogenous fibrolytic enzymes (enzyme); 3) ryegrass hay; and 4) ryegrass hay + enzyme. Lambs consumed more DM and OM from alfalfa than from ryegrass hay (P < 0.001). The ADF intake was not different between the hays, but NDF intake was lower for alfalfa (P < 0.001). For both hays, the enzyme increased intake of DM (P < 0.01), as well as OM and CP (P < 0.05); however, NDF and ADF intake were not changed. Alfalfa hay had higher apparent digestibility of DM, OM, and CP (P < 0.001), but lower digestibility for NDF, ADF, and hemicellulose. The enzyme increased apparent digestibility of CP, hemicellulose (P < 0.05), and NDF (P < 0.10) for alfalfa. Also, for both hays, the enzyme improved N balance because lambs retained more N (P < 0.05). The enzyme increased (P < 0.05) total VFA concentration (3 and 6 h) for both hays. Results from this trial indicate that directly fed exogenous fibrolytic enzymes may change ruminal fermentation, intake, and digestibility of forages with different nutritive value.     

不同加工方式苜蓿干草在肉羊瘤胃内的降解及对消化代谢的影响

选用12只安装有永久性瘤胃瘘管的1.5岁杂交一代(无角陶赛特×小尾寒羊)肉用羯羊,随机分成3组,研究日粮中不同加工方式(整株、颗粒、草粉)苜蓿干草在瘤胃内的降解及其对肉羊消化代谢的影响。试验结果表明:苜蓿干草经粉碎及颗粒处理后,DM、CP、NDF在瘤胃内的降解率较整株组有显著提高(P<0.05),但ADF降解率未有明显变化(P>0.05)。不同加工方式(整株、颗粒、草粉)苜蓿干草对DM、OM、NDF、ADF表观消化率没有影响(P>0.05),但加工成颗粒及粉料使氮的利用率显著提高(P<0.05)。3种不同加工方式下DM、OM、NDF、ADF表观消化率分别高达71.74%～72.18%、73.67%～74.22%、66.69%～68.48%、45.64%～52.41%。     

Nutritive value of selected grasses in North Sumatra, Indonesia

The nutritive values of seven native grass species collected in North Sumatra, Indonesia, during dry and rainy seasons were evaluated. The chemical composition, in vitro dry matter digestibility (IVDMD), in vitro organic matter digestibility (IVOMD), in vitro crude protein digestibility (IVCPD), macro mineral concentrations of calcium, phosphorus and magnesium, in vitro gas production profile and metabolizable energy (ME) content of the grasses varied greatly among species and seasons. The crude protein content ranged from 6.6 (Andropogon gayanus) to 16.2% dry matter (Cynodon plectostachyus) in the rainy season, with a significant (P < 0.05) reduction in the dry season. Data on the fiber fraction showed that the grasses contained more neutral detergent fiber (NDF) and acid detergent fiber (ADF) in the dry season and it significantly (P < 0.05) decreased in the rainy season, except for Panicum maximum and Pennisetum purpureum for NDF content and C. plectostachyus, P. maximum and Brachiaria decumbens for ADF content. Data on the mineral concentration showed that C. plectostachyus in the dry and rainy seasons had a higher calcium content than those of other species. The overall means of the seven grasses for IVDMD, IVOMD and IVCPD were significantly higher (P < 0.05) in the rainy season than in the dry season. The in vitro gas production and ME concentration were numerically higher in the rainy season than in the dry season. In conclusion, the nutritive value of the observed grasses in North Sumatra was relatively higher during the rainy season compared with the dry season. Among the species of grass, P. purpureum and C. plectostachyus had a higher nutritive value in both the dry and rainy seasons.     

不同蛋白和中性洗涤纤维水平对瘤胃发酵、消化和微生物蛋白合成的影响

以3头装有瘤胃瘘管的干奶牛作为瘤胃液供体,用体外培养法研究不同日粮蛋白和中性洗涤纤维(NDF)水平对瘤胃发酵、消化和微生物蛋白合成的影响。采用2×3双因子完全随机设计,粗蛋白水平14%、16%和18%,NDF水平为32%和36%。体外发酵后2、4、6、12、24 h取瘤胃液测定pH、NH3-N浓度和微生物蛋白含量,发酵结束后测定饲料中干物质(DM)、NDF和酸性洗涤纤维(ADF)消化率。结果表明:随着蛋白水平升高,瘤胃发酵pH有增加趋势(P=0.079),显著提高NDF和ADF消化率和细菌蛋白合成量(P<0.05),但不影响DM消化率和原虫蛋白的合成量(P>0.05);日粮中NDF水平显著影响瘤胃pH、NH3-N浓度和ADF消化率(P<0.05),但不影响DM和NDF消化率以及微生物蛋白的合成量(P>0.05)。本试验条件下,日粮中16%CP和32%NDF组可在一定程度上促进瘤胃发酵,提高纤维消化率以及微生物蛋白的合成量。     

An <Emphasis Type="Italic">in vitro</Emphasis> nutritive evaluation and rumen fermentation kinetics of <Emphasis Type="Italic">Sesbania aculeate</Emphasis> as affected by harvest time and cutting regimen

The nutritive value of Sesbania aculeate harvested after 60 and 120 days of planting and subjected to two cutting regimen (15 or 30 cm length) was evaluated by determination of the crude protein (CP), crude fibre (CF), buffer soluble nitrogen (BS-N), buffer soluble non-protein nitrogen (BS-NPN) and cell wall constituents (neutral-detergent fibre; NDF, acid-detergent fibre; ADF and lignin). In vitro digestible organic matter (IVDOM), metabolizable energy (ME), microbial nitrogen (MN) and biomass (MBM) production were also estimated in the experimental plant samples after their incubation with rumen fluid for 96 h in the absence or presence of polyethylene glycol (PEG, 6000) at a ratio of 2:1 PEG:substrate. Fermentation characteristics (initial gas production; a, gas production during incubation; b, potential gas production; a+b, fractional rate of gas production; c) were assessed using an in vitro incubation technique with rumen fluid. There was a significant (P < 0.05) effect of harvest time on all studied nutritive parameters and fermentation characteristics. The early harvest plant samples (after 60 days of planting) gave significantly higher values of IVOMD, ME, CP, BS-N, BS-NPN, MN, MBM and fractional rate of gas production and lower values of CF and cell wall constituents than the late harvest. Crude protein, BS-N, BS-NBN, IVOMD and ME were negatively correlated with CF and cell wall constituents. Metabolisable energy and IVOMD were positively correlated with CP, BS-N and BS-NPN. Cutting treatments significantly affected the CP, CF, BS-N, BS-NPN, NDF, ADF, IVDOM, ME, potential gas production and b values. There was no significant (P > 0.05) effect of added PEG on IVDOM, ME, MN, MBM, fermentation characteristics and gas production over 96 h. The greatest proportion of gas production occurred between 6 and 24 h of incubation. The fractional rate of gas production from 100 mg substrate was higher (0.046 mL/h) for the plant samples harvested at early stage and cut at 30 cm length than harvested at late stage (0.018 mL/h). C values were negatively correlated with lignin concentrations. The amount of MN and MBM produced from 100 mg substrate amounted to 1.29 mg and 14.95 mg at early maturity stage and 0.68 mg and 7.89 mg at late stage, respectively. Microbial nitrogen and MBM production were negatively correlated with CF, cell wall constituents and gas production but positively correlated with CP, BS-N and BS-NPN.     

BOVINE ENZOOTIC HAEMATURIA IN QUEENSLAND

Bovine enzootic haematuria was diagnosed in Queensland in coastal areas in association with bracken fern (Pteridium esculentum) on 3 properties or with mulga fern or rock fern (Cheilanthes sieberi) on 4 properties, and in inland areas in association with C. sieberi on 3 properties. In the absence of bracken fern, long-term ingestion of C. sieberi is suggested as a cause of bovine enzootic haematuria. Haemangiomas, haemangiosarcomas, transitional cell carcinomas, papillomas, fibromas and an adenoma were detected in the urinary bladders of 19 affected cattle and were accompanied by chronic cystitis.     

Prediction of Forage Energy Content by Near Infrared Reflectance Spectroscopy and Summative Equations

In livestock nutrition, summative models (SM) are displacing empirical models as a preferred method to predict energy content of forages. The objective of this study was to determine the effect of using near infrared reflectance spectroscopy (NIRS) to determine nutrient subcomponents required of SM on overall ability to predict energy content of corn and legume-grass silages. Corn (n = 90) and legume-grass (n = 70) silages were collected and analyzed for CP, ADF CP, NDF, NDF CP, in vitro (IV) digestible (d) NDF, ash, and fat by standard laboratory techniques. Samples were scanned on a Model 6500 NIRS, and calibration equations were developed for each nutrient. The TDN contents of corn and legume-grass silages were then estimated using a SM, where the model nutrients were determined by laboratory or NIRS methods. The predicted TDN content of corn and legume-grass silages was compared to IV d OM to assess overall utility. The NIRS calibrations were adequate (R² > 0.90) for CP and NDF for both corn and legume-grass silages with standard errors of calibration (SEC) < 0.55 for CP and < 1.09 for NDF. Near infrared calibrations for ADF CP, NDF CP, fat, and ash were less accurate in both corn and legume-grass silages with R² < 0.75. Calibrations for IV d NDF in corn and legume-grass silages had R² = 0.87 and 0.79, respectively, but possible co-dependency with NDF is speculated. The relationship between corn and legume-grass silage SM TDN and IV d OM was excellent when model nutrients were determined by laboratory procedures. The TDN estimates when NIRS was used to determine all SM nutrients were superior to older empirical models, but SM TDN estimates using NIRS-determined nutrients were less accurate as compared with SM TDN prediction when model nutrients were determined by laboratory procedures. In particular, using NIRS to predict IV d NDF and ash for use in SM lead to the greatest challenge in TDN prediction in both corn and legume-grass silages.