Agronomic,forage quality and economic advantages of red pea (Lathyrus cicera L.) intercropping with wheat and oat under low‐input farming

Red pea–cereal intercropping could provide animal feed with agronomic and economic advantages. The growth rate, forage yield, quality, interspecific competition and financial outcome of intercrops of red pea (Lathyrus cicera L.) with wheat (Triticum aestivum L.) and oat (Avena sativa L.) in two different seeding ratios (60:40, 80:20) were estimated. Growth rate of species was lower in the intercrops than in monocrops, especially in red pea–oat intercrops due to the strong competitive ability of oat. Red pea–oat intercrop of 60:40 produced the highest biomass (10.83 Mg/ha) and crude protein yield (1,116 kg/ha). Land equivalent ratio (LER) values were greater for the red pea with wheat (1.13) and oat 60:40 (1.09) indicating an advantage of intercropping in terms of dry‐matter (DM) yield, while red pea:oat 60:40 ranked first for LER for nitrogen yield. Aggressivity and partial actual yield loss indicated cereals as the dominant species. The highest monetary advantage index was recorded for the red pea:wheat 60:40 and the highest intercropping advantage value was recorded for the red pea:oat 80:20. In conclusion, most intercrops of red pea with wheat and oat showed significant advantages relative to their monocrops due to better DM production, resource‐use efficiency and economics under low‐input farming.     

Intercropped wheat (Triticum aestivum L.) and bean (Vicia faba L.) as a whole-crop forage: effect of harvest time on forage yield and quality

Abstract Sole crops and intercrops of wheat (Triticum aestivum L.) and bean (Vicia faba L.), at three harvest dates, representing successive growth stages, were evaluated for biomass production of whole‐crop forage and quality characteristics of crude protein (CP), neutral‐detergent fibre (NDF), acid‐detergent fibre (ADF), water‐soluble carbohydrate (WSC) concentrations and ash content. These tests were carried out for two field experiments, respectively, drilled during the spring of 1997 and autumn of 1997 on Imperial College Farm, Wye, UK. Results indicated that optimum forage yield and quality were obtained from the second to third harvest dates for the spring‐drilled experiment and the second harvest for the autumn‐drilled experiment. Wheat and bean intercrops were higher in total forage dry matter (DM) yield than either wheat or bean grown as sole crops. Field bean intercropped with wheat led to increased forage quality (CP and NDF concentrations) compared with sole wheat, and higher WSC concentrations compared with sole bean. Intercrops also enhanced weed suppression compared with sole bean. It is suggested that winter wheat–bean intercrops may have considerable potential as a moderate‐yielding, relatively high‐quality, low‐input and environmentally benign forage crop with considerable potential with regard to yield and quality and warrant further study.     

Total mixed ration silage containing elephant grass for small‐scale dairy farms

Alternatives need to be addressed for reducing losses in elephant grass (EG; Pennisetum purpureum) silages. Furthermore, smallholders lack information on the nutritional aspects of dairy farms. The aim of this study was to evaluate total mixed ration silage (TMR) combining fresh EG and concentrate ingredients, creating the following treatments: (i) EG silage (control); (ii) EG, corn and soya bean meal; (iii) EG, corn, soya bean meal and molasses; (iv) EG, citrus pulp and soya bean meal; and (v) EG, citrus pulp, soya bean meal and molasses. Five replicates of each treatment were ensiled in 15‐L plastic jars. The fermentation profile, chemical composition, microbial counts and aerobic stability were assessed. Three contrasts were tested, as follows: (i) control vs. TMR; (ii) TMR with corn vs. TMR with citrus pulp; and (iii) TMR with molasses vs. TMR without molasses. Variables were analysed through the PROC MIXED procedure of the SAS at the 5% level. The TMR had better fermentation profile, lower effluent production and longer aerobic stability compared to control. When the effect of corn was compared to citrus pulp among the TMR, silages with citrus pulp showed lower fermentation losses, non‐protein nitrogen and effluent production. The aerobic stability also improved with citrus pulp. Molasses did not affect the fermentation profile. Overall, lactic acid was the primary acid in all TMR. Nitrogen source (e.g., soya bean meal) can be used without compromising the fermentation process. TMR with citrus pulp showed better results than corn. TMR may be an alternative to optimize the use of EG on smallholdings.     

Intercropping of orchardgrass and alfalfa improves soil fertility,forage yield,feeding values and land use efficiency while limiting ruminal greenhouse gas emissions

Intercropping has been a globally accepted practice for forage production, however, consideration of multiple performance criteria for intercropping including forage production, feed use efficiency and ruminal greenhouse gas emissions needs to be further investigated. A two-year field study was conducted to evaluate forage dry matter (DM) yield, nutritive value, feeding values and land-use efficiency as well as ruminal carbon dioxide (CO₂) and methane (CH₄) emissions of intercropped orchardgrass (Dactylis glomerata) and alfalfa (Medicago sativa) sown in five intercropping ratios (100:0, 75:25, 50:50, 25:75, and 0:100, based on seed weight) and three nitrogen (N) fertilizer levels (0, 50, and 100 kg ha⁻¹). Increasing alfalfa proportion and N fertilizer level increased soil nutrients and the two-year total DM yield. Intercropping increased both land and nitrogen use efficiency (NUE) compared with monocultures. Greater NUE was obtained when N fertilizer was applied at 50 kg ha⁻¹, compared with 100 kg ha⁻¹. Increasing the proportion of alfalfa in intercrops increased the crude protein yield and rumen undegraded protein yield. Harvested forage intercrops were incubated with ruminal fluid for 48 h. Degraded DM yield, CO₂ and CH₄ emissions increased with increasing alfalfa proportion in intercrops. Overall, the 75:25 of orchardgrass-alfalfa intercrops was recommended as the best compromise between high forage productivity, superior feed use efficiency and low ruminal greenhouse gas emissions through complementary effects. The results indicate that the appropriate N fertilization level would be 50 kg ha⁻¹ for acquiring higher nitrogen use efficiency and forage productivity.     

The productivity of oats and berseem clover intercrops. II. Effects of cutting date and density of oats on annual forage yield

Annual forage yields of intercrops of berseem clover (Trifolium alexandrinum L.) and oats (Avena sativa L.), as affected by timing of initial harvest and sowing rate of oats, were investigated. Berseem clover was intercropped with oats at 0, 30, 60, 90 and 240 plants m^?2 of oats in 1999 and 2000 in Alberta, Canada. Cutting date treatments involved initial harvest at 10‐d intervals between 35 and 88 d after planting (DAP), and one or two subsequent harvests of regrowth. Total intercrop dry‐matter (DM) yield averaged 12·9–13·3 t ha^?1 with proportions of 0·21–0·43 of berseem clover in the forage. Treatments with an initial cut at the silage stage of oats (76 DAP in 1999, 88 DAP in 2000, at about soft‐dough stage of oats) had greater yields of oats, lower yields of berseem clover, and lower proportions of berseem clover in total annual yields than treatments with an earlier initial cut. Total crude protein (CP) yield was greater with an initial cut at 65–66 DAP than with a silage‐stage initial cut. With an initial cut at 35 DAP (before stem elongation of oats) or after 65 DAP (after heading of oats), yield potential of oats was sometimes reduced compared with silage‐stage treatments, but this was balanced by a greater yield of berseem clover. The impact of harvest timing on total yield decreased as the proportion of berseem clover in the intercrops increased. With decreasing density of oats, DM yield of first‐cut intercrops and total DM yield of oats decreased, while regrowth and total DM yields of berseem clover increased. Intercrops with oats at 60 plants m^?2 had equal or greater total DM and CP yields than intercrops with 240 plants m^?2 of oats. For intercrops with oats at 60 plants m^?2, with initial cuts at 65–66, 75–76, or 88 DAP, yields of regrowths were 0·30–0·35, 0·16–0·26 and 0·09 of the total yield respectively. Oats–berseem clover intercrops showed potential to manipulate the pattern of annual forage yield and to provide flexibility of harvest without reducing annual yields.     

Growth,yield and nitrogen performance of faba bean intercrops with oat and triticale at varying seeding ratios

Intercropping of grain legumes with cereals may offer several advantages over sole crops for forage production and is commonly used, particularly in low‐input agriculture. Faba bean (Vicia faba L.), oat (Avena sativa L.) and triticale (×Triticosecale Wittmack) sole crops as well as the intercrops of faba bean with each of the above cereals, in three seeding ratios (75:25, 50:50 and 25:75), were compared for dry‐matter (DM) yield, nitrogen (N) concentration, chlorophyll content, growth rate and plant height in a 2‐year field experiment. Triticale sole crop and faba bean intercrops with triticale provided higher DM yield than faba bean sole crop and the intercrops of faba bean with oat. Growth rates of faba bean, oat and triticale in mixtures were lower than those in sole crops. Faba bean plants were taller in the intercrops than in the sole crop at 3 weeks after tillering (WAT), whereas at 6 WAT, the trend was different as faba bean plants in the sole crop were taller than in the intercrops. N concentration was higher for the cereals when faba bean was included in the mixture. Crude protein (CP) concentration was the highest in faba bean sole crop followed by the faba bean intercrops with oat. However, triticale sole crop and faba bean mixtures with triticale provided higher CP yield than all other crops because of their highest DM yield. Thus, mixtures of faba beans with triticale could be a promising alternative for increased forage production because of their capacity for high DM and protein yields.     

Effect of soya bean oil supplementation and forage type on methane production and fibre digestibility using the in vitro gas production system

We aimed to evaluate the effect of soya bean oil (SBO) supplementation with different forages on in vitro gas production kinetics, methane (CH₄) emissions and potentially digestible neutral detergent fibre (pdNDF) digestibility (IVpdNDFD). Samples of whole‐crop maize silage (MS; Zea mays), sugarcane (SC; Saccharum sp.), perennial ryegrass (RG; Lolium perenne), guinea grass (GG; Panicum maximum) and palisadegrass (PG; Brachiaria brizantha) were incubated with three concentrations of SBO (0, 30 and 60 g/kg of dry matter). The interaction between forage species and SBO inclusion affected molar proportion of acetate, acetate‐to‐propionate ratio, asymptotic gas and IVpdNDFD. Acetate‐to‐propionate ratio numerically decreased from 3.56 to 3.44 and 3.77 to 3.56 for MS and SC respectively. Soya bean oil inclusion at 60 g/kg DM decreased 21.2% and 12.9% of IVpdNDFD for MS and SC respectively. Soya bean oil increase did not affect IVpdNDFD for RG, GG and PG. Soya bean oil inclusion decreased quadratically the asymptotic gas (294–265 ml/g OM) for MS and increased linearly (275–283 ml/g OM) for GG. Lower and greater CH₄ production was observed for RG and SC respectively. Methane production decreased quadratically by SBO increase. Soya bean oil inclusion linearly decreased CH₄ concentration in total gas at 48 hr of incubation from 133 to 128 ml/L. In conclusion, MS and SC are more sensitive to adverse effects of SBO supplementation from 30 to 60 g/kg DM on rumen fermentation when compared to RG, GG and PG.     

Silage quality and preservation of Urtica cannabina ensiled alone and with additive treatment

Urtica cannabina (U. cannabina), a member of the Urticaceae family, is widely distributed throughout the temperate regions of the world and can be used as a nutritious feed for animals through the winter period. To provide high‐quality forage all year‐round, we treated freshly harvested U. cannabina without additives (control), but with corn flour (CF) (5:1 w/w), molasses (2, 4, and 8% fresh weight), or LalsiL Dry (LD) inoculant (5, 10 and 20 mg kg^?1 of fresh weight). We then assessed the chemical composition, in vitro digestibility and fermentative parameters of the products after 0, 3, 5, 15, 20 and 60 d of ensiling. The results showed that: (i) U. cannabina had large quantities of protein and some essential minerals, including calcium, potassium, sodium, zinc, copper and manganese, and was particularly rich in magnesium and iron. (ii) U. cannabina can be preserved as a highly nutritious silage. No additive treatment or the LD inoculant treatments produced badly preserved silages. The 2% molasses treatment produced badly preserved silage, but 4–8% molasses produced well‐preserved silages. The CF treatment also produced well‐preserved silage. We recommend the application rates of molasses at 4–8% of fresh weight or 5:1 CF to improve U. cannabina silage.     

The influence of the system of silage harvesting and feeding and the use of protected protein on milk production

The study compared two systems of silage harvesting, direct-cutting flail harvesting (flail-direct) or pre-cutting, followed by wilting and collection by a meter-chop harvester (precision-wilted). Each silage was self or easy fed to dairy cows. In addition, the response to protected soya bean meal included in the supplementary concentrate was also examined. Approximately 400 t of each of the two silages were produced from the same swards under good weather conditions with formic acid applied as an additive. The resulting silages were well preserved and had mean particle lengths of 43 and 29-mm, and D-values of 0-74 and 0-71 for the flail-direct and precision-wilted silages, respectively. During a 159-d feeding period commencing on 5 November, the silages were offered to 88 British Friesian cows in a 2³ factorial design, continuous feeding experiment. The cows calved during the experiment and had a mean calving date of 18 January. The feeding treatments involved both silage types, two systems of silage feeding (self and easy) and two sources of protein in the supplementary concentrate given after calving (soya bean or 100 g kg^-1 protected soya bean). No concentrates were offered pre-calving and all animals were given 7.6 kg d^-1 concentrates post-calving. There were no significant interactions between the system of silage harvesting and feeding. Animals on the precision-wilted silage consumed 14% more silage dry matter (10.9 vs. 9.6 kg DM d^-1) over the total period and by the end of the experiment were producing 7% less milk per day (25.4 vs. 27.2 kg). However, the responses in the output of total milk constituents (fat and protein) were lower than those obtained in milk yield. Animals offered silage by self feeding had similar dry matter intakes, but produced marginally less milk than those easy-fed. Ration digestibility and nitrogen utilization data, obtained from a concurrent change-over design experiment, suggested that the energy from the precision-wilted silage was less efficiently utilized for milk production. There was no significant response in either milk yield or composition to the inclusion of protected soya bean in the supplement.     

Effect of pearl millet silage ammoniated with urea on lamb production and metabolic performance

The objective of this study was to determine the effect of diets containing pearl millet silage ammoniated with urea on the intake, digestibility, production performance, and nitrogen metabolism of lambs. Thirty‐two uncastrated mixed‐breed lambs at 4 to 5 months of age, with an average initial body weight of 17.39 ± 2.16 kg, were distributed into four treatments in a randomized block experimental design with eight replicates. Experimental diets consisted of pearl millet silage ammoniated with urea during ensiling at the levels of 0, 20, 40, and 60 g/kg dry matter (DM). Increasing urea levels in the pearl millet silage led to a linear decrease (p < .05) in the intakes of DM, organic matter, and total digestible nutrients by the lambs. Total and average daily weight gains decreased linearly (p < .05) with the addition of urea to the silage. Intake and digestibility of crude protein, nitrogen intake, urine urea nitrogen, plasma urea nitrogen, microbial synthesis, and microbial efficiency had a quadratic response (p < .05) to the urea levels in the silage. Pearl millet silage ammoniated with urea reduces dry‐matter intake and daily weight gain in lambs. Urea is not recommended for use in the ensiling of pearl millet.     

Competition and yield in intercrops of maize and sunflower for biogas

Maize (Zea mays L.) is widely used for the production of biogas, but intercrops of maize and sunflower (Helianthus annuus L.) might improve yield as well as the environmental compatibility of biofuel production. We conducted a field study planting both crops in pure stands and intercrops in three intercropping ratios (maize:sunflower with 33:67, 67:33 and 50:50 ratio) at two nitrogen application rates (no fertilizer and 85 kg N/ha as organic fertilizer plus 85 kg N/ha as mineral fertilizer) to determine the competition between the two species and the advantage of intercropping systems at two sites differing in water supply during 2007 and 2009. Dry matter yield of maize and sunflower in mono- and intercropping systems were significantly affected by intercropping ratio, nitrogen fertilizer rate and environments. Sunflower was more competitive than maize especially in intercrops with 67% sunflower. Intercropped sunflower had a higher relative crowding coefficient (K = 1.39) than intercropped maize (0.86). Intercropping with 67% maize had the highest land equivalent ratio (1.11) and relative methane yield advantages (0.94) in one environment and showed high yield stability. It is concluded that the maize component should be dominant (>50%) for intercropping. In regions with more rainfall during the growing season, maize-sunflower intercrops required a sufficient N supply to realize a yield advantage.     

Effect of applications of organic solid cattle manure on Hungarian vetch and barley intercropping mixtures grown on soils of different depths

Sloping fields on soils of shallow depth to tillage are commonly left uncultivated in many parts of the world. This study was conducted to compare the effects on morphological traits, dry‐matter (DM) yield, legume ratio (LR), crude protein content (CP), crude protein yield (CP yield) and mineral concentrations (N, P, K, S, Ca, Cu, Fe, Mg, Mn, Na, B and Zn) of Hungarian vetch (Vicia pannonica Crantz.) and barley (Hordeum vulgare L.) grown in intercropping mixtures in response to three rates of organic solid cattle manure application (M₀: 0, M₁: 10, M₂: 20 t ha^?1). Experimentation was conducted on soils of two different soil depths [shallow (8–12 cm; low‐medium erosion risk) and normal soil depth (18–22 cm; no erosion risk)] on a sloping field in the 2006–2007 and 2007–2008 growing seasons at Gumushane, Turkey. Herbage harvested on the shallow depth area had 22–73% less DM yield, 14–72% less CP yield, 6–9% greater CP content and generally higher minerals contents than herbage from the normal soil depth area. Cattle manure applications increased DM yield by about 23%, increased CP content and CP yield, and also increased the contents of most minerals in herbage of the intercropping mixtures, relative to the control, averaged over the two soil depths. It is suggested that, for areas with shallow soil depths that are prone to erosion, plant cover should be used for forage production, and that fertilization with solid cattle manure at 20 t ha^?1 can support production of quality forage of acceptable DM yield.     

Responses to shade and subsequent recovery of soya bean in maize-soya bean relay strip intercropping

In relay intercropping systems, late-planted crops often grow under the shade of the canopy of early-planted tall crops and then transfer to full sunlight after the harvest of the early-planted crops. In order to know the effects of recovery growth of the late-planted soya bean in maize–soya bean relay intercropping, a field experiment was carried out to observe architectural, morphological, physiological and anatomical traits of soya bean plants related to shade and subsequent removal in intercropping before and after maize harvest, respectively. During shade period, soya bean biomass was severely reduced, and stem elongation was stimulated. Typical features of shade grown leaves were found, such as lower LMA (leaf mass per unit area), thinner thickness, higher chlorophyll content, lower chlorophyll a:b ratio. Whole-plant leaf area analysis found that soya bean increased leaf area ratio by adjusting leaf morphology rather than by dry mass allocation. After maize harvest, leaf area and leaf mass increased rapidly, contributing to compensation growth in intercropped soya bean. Meanwhile, physiological and anatomical traits of leaf went back to similar levels as grown in sole cropping. However, stem morphological traits were irreversible after removal of shade. Finally, no difference on seed weight per plant of soya bean was observed between relay intercropping and sole cropping. Based on these findings, we speculated the recovery growth might be the direct determining factor on pod formation in soya bean, and improvement on the capacity of recovery growth could increase yield of relay intercropped soya bean.     

Evaluating pea and barley cultivars for complementarity in intercropping at different levels of soil N availability

Two field experiments were carried out on a temperate sandy loam using six pea (Pisum sativum L.) and five spring barley (Hordeum vulgare L.) cultivars to determine cultivar complementarity in the intercrop for grain yield, dry matter production and nitrogen (N) acquisition. Crops were grown with or without the supply of 40 or 50 kg N ha⁻¹ in the two experiments. Cultivars were grown as sole crops (SC) and as mixed intercrops (IC) using a replacement design (50:50). The land equivalent ratio (LER), which is defined as the relative land area under SC that is required to produce the yields achieved in intercropping, were used to compare cultivar performance in intercropping relative to sole cropping.Barley was the stronger competitor in the intercrops and as a result barley grain yield and nitrogen uptake in IC were similar to SC. The per plant pea grain production and aboveground N accumulation in IC were reduced to less than half compared to SC pea plants due to competitive interactions.Application of N caused a dynamic change in the intercrop composition. Competition from barley increased with N application and the pea contribution to the combined intercrop grain yield decreased. The LER values showed that in the intercrop plant growth resources were used on average 20% more efficient without N application and 5–10% more efficient with N application.The choice of pea cultivar in the intercrop influenced the intercrop performance to a larger degree than the choice of barley cultivar. Furthermore, pea cultivar×cropping systems interactions was observed, indicating that cultivars performed differently in sole and intercrops. An indeterminate pea cultivar competed strongly with barley causing a greater proportion of peas in the intercrop yield, but caused a reduced N uptake and yield of barley. Determinate peas with normal leaves caused the highest degree of complementary use of N sources by allowing barley to exploit the soil N sources efficiently, while they contribute with fixed N₂. However, difference in performance among cultivars was observed. Using the indeterminate pea cultivar combined IC grain yield was in general lower than the greatest sole crop yield and vice versa for the determinate pea cultivars. Up to 22% (LER=1.22) greater combined IC grain yield was observed in several mixtures using determinate pea cultivars.From the present study, it is was concluded that there is a need for breeding suitable pea cultivars for intercropping purposes, since cultivars bred for sole cropping may not be the types, which are the most suitable for intercropping. For optimized N-use in pea–barley intercrops it is concluded that important traits for the intercropped pea are: (1) determinate growth, (2) a medium competitive root system for soil inorganic N and other nutrients during early growth, (3) high light absorption capacity by peas growing underneath the canopy of the higher barley component and (4) early establishment of symbiotic N₂ fixation to support a high growth rate during early growth stages.Fertilized pea–barley intercrops gave a 15% higher net income than fertilized barley sole cropping and is regarded as a better safeguard for the farmer’s earnings compared to pea sole cropping known for variable yields and poor competitive ability towards weeds.     

Characteristics of baled silage made from first and second harvests of wilted and severely wilted forages

First and second harvests of lucerne (Medicago sativa L.), perennial ryegrass (Lolium perenne L.) and a lucerne–perennial ryegrass mixture [80 or 144 g kg^?1 dry matter (DM) of ryegrass] at the first and second harvests were cut and conditioned, wilted to 500 or 700 g DM kg^?1 then baled and stretch‐wrapped for silage on the same dates. Lucerne bales were denser (411 kg m^?3) than bales of perennial ryegrass (331 kg m^?3) (P < 0·05). After an 8‐month storage period, silage made from high DM‐content forage had a higher concentration of neutral‐detergent fibre (NDF) and was less digestible than that made from low DM‐content forage. Daily DM intakes by beef steers, when the silages of the second harvest were fed ad libitum, were 31·2, 31·2 and 22·3 g kg^?1 live weight for lucerne, lucerne–perennial ryegrass mixture and perennial ryegrass silages, respectively (P < 0·01), when the herbage had been wilted to 500 g kg^?1. In vivo digestibility of NDF in the lucerne–perennial ryegrass mixture silage (0·587) was significantly lower than that of perennial ryegrass silage (0·763) but higher than lucerne silage (0·518). Higher intakes of baled lucerne silage tended to offset its lower digestibility values. Lucerne–perennial ryegrass mixture silage had a higher DM and NDF digestibility than lucerne silage, indicating perhaps the presence of associative effects.     

Silage and milk production: a comparison between soya, groundnut and single-cell protein as silage supplements

Grass silage made in May from S24 perennial ryegrass was offered ad libitum to twelve Ayrshire cows in a 12-week feeding experiment. The silage had a DM concentration of 217 g kg ^-1, contained 147 g crude protein per kg DM and had a D-value of 64·6. In addition each cow consumed 1 kg hay per d plus concentrate supplements of dried sugar-beet pulp with (A) soya bean meal, (B)‘Pruteen’, a single-cell protein (C) groundnut cake. The three concentrate supplements each contained 250 g crude protein per kg DM and were offered at the rate of 2·9 kg per 10 kg milk. The daily intakes of silage DM were 8·38, 7·94 and 7·49 kg on treatments A, B and C, respectively, with the extreme values being significantly different. The mean daily yields of milk on treatments A and B were both 16·2 kg per cow, and were significantly higher than the yield of 15·2 kg per cow on treatment C. The fat and lactose contents of the milk on the three treatments were not significantly different, but the CP content on treatment C was significantly lower than that on the other treatments. It is concluded that soya bean meal and‘Pruteen’were superior to groundnut cake as a protein supplement in a silage-based ration.     

Proteolysis and in situ ruminal degradation of lucerne ensiled with Cistus ladanifer tannins

The effects of ensiling lucerne with graded inclusion of Cistus ladanifer condensed tannins (CT) on in silo fermentative parameters, in vitro organic matter digestibility (IVOMD) and on in situ rumen degradability of dry matter (DM) and crude protein (CP) were studied. Lucerne forage ( Medicago sativa subsp. sativa ) was sprayed with different solutions of C. ladanifer CT extract in 60 ml of water in order for dose 0 (control), 40 (L40), 80 (L80) and 120 (L120) g of CT per kg of lucerne DM and was ensiled in lab‐scale silos. After 35 days, the silages were analysed for chemical composition, and the in situ ruminal degradability was determined in rams. The inclusion of CT in the silages caused an important dose‐dependent reduction in soluble‐N, NH₃‐N and a large increase in true protein content and N bound with neutral detergent fibre (NDF‐N), which indicates an effective proteolysis reduction during ensiling. Also, the rumen undegradable protein (RUP) increased linearly (P < 0.01) with CT inclusion. However, a linear decrease (P < 0.02) of 5%, 13% and 22% of IVOMD was observed for the silages L40, L80 and L120 respectively. The results obtained suggest that C. ladanifer CT can be used as silage additives to reduce proteolysis of high‐protein forages during ensiling. A level of CT of 40 g/kg DM seems to be the best compromise between the gains achieved by the protection of CP degradation in silo and in the rumen and the losses associated with the depression of the digestion and absorption.     

Yield,nutritive value and silage fermentation of kura clover‐reed canarygrass and lucerne herbages in northern USA

Excellent winter hardiness, persistence and nutritive value of both kura clover (Trifolium ambiguum M. Bieb.) and reed canarygrass (Phalaris arundinacea L.) suggest that intercropping these species could substitute for lucerne (Medicago sativa L.). The dry matter (DM) yield and nutritive value of herbage, and silage characteristics of kura clover‐reed canarygrass (KC‐RCG) herbage, were compared to those of lucerne over two growth cycles near Arlington, WI, USA. First and second growths of lucerne and KC‐RCG herbage were sampled four times at 1‐week intervals and ensiled for 100 d. Yield of DM of the KC‐RCG was 0·23–0·57 greater than that of lucerne on sampling dates in the first growth cycle, with no differences in DM yield in the second growth cycle. The pH of lucerne silage was lower than that of KC‐RCG silage in the first growth, and the opposite occurred in second growth, which was attributed to maturity differences and the proportion of kura clover in the mixture. Lactate concentration was lower in KC‐RCG than lucerne silages in both growth cycles. The lucerne and KC‐RCG silages had similar in vitro DM digestibility except for the final sampling date in the first growth cycle when neutral‐detergent fibre concentration of KC‐RCG herbage exceeded 550 g kg^?1 DM. Crude protein concentration was greater in lucerne silage than in KC‐RCG silage in both growth cycles. Overall, differences in nutritive value and silage fermentation between the two herbages were minimal across growth cycles. These results suggest that a KC‐RCG sward is a viable alternative to lucerne in northern environments of the USA where lucerne production may be limited by winter injury or edaphic factors.     

The effects of the inclusion of either maize silage, fermented whole crop wheat or ure-treated whole crop wheat in a diet based on a high-quality grass silage on the performance of dairy cows

Sixteen multiparous Holstein/Friesian cows were used to examine the effect on food intake and milk production of replacing 40% of the dry matter (DM) of first cut perennial ryegrass silage (G) with either maize silage (M), fermented (F) or urea-treated (U) wheat whole crop silage. In addition to the forage mixtures, the animals received 5.25 kg DM d ^?1 of a standard concentrate and 1.75 kg DM d ^?1 of soya bean meal. The experiment consisted of four periods, each of 4 weeks duration, in a Latin square design. The grass silage used was of high quality with an estimated metabolizable energy (ME) content of 11.4 MJ kg ^?1 DM and in vitro digestibility of 748 g kg ^?1 DM. DM intake was significantly increased (s.e.d. = 0.364, P < 0.01) with the inclusion of M, F and U. The resulting total DM intakes were 17.6, 18.4, 19.2 and 20.1 kg d ^?1 for treatments G, M, F and U respectively. None of the animal production variables was significantly affected by the treatments. Milk yield was 27.4, 26.4, 27.1 and 26.9 kg d ^?1 for treatments G, M, F and U respectively. Milk fat content was 48.9, 46.9, 49.0 and 48.1 g kg ^?1, and milk protein content was 34.1, 33.6, 34.0 and 34.3 g kg ^?1 for treatments G, M, F and U respectively. The results show that partly (40%) replacing a high-quality grass silage with forage maize, fermented whole crop wheat or urea-treated whole crop wheat will increase DM intake in dairy cows but is not accompanied by an increase in animal performance and therefore will result in decreased efficiency of forage DM utilization.     

Effects of crop mixtures on chocolate spot development on faba bean grown in mediterranean climates

Chocolate spot incited by Botrytis fabae is a serious faba bean disease of worldwide distribution. The increasing interest in sustainable tools for disease control, together with the lack of sufficient levels of genetic resistance triggered our interest in the use of intercropping as a tool for the management of this disease. The effect of intercropping on chocolate spot severity was studied in field experiments performed in Egypt, the Palestinian Territories, Spain and Tunisia, in which a susceptible faba bean cultivar was grown as a monocrop or with two mixed species intercrops of either barley, oat, triticale, wheat, pea or common vetch, or with three mixed species intercrops of wheat and berseem clover. Chocolate spot was significantly reduced when faba bean was intercropped with cereals, but not when intercropped with legumes. Suppressive effects can be ascribed to a combination of host biomass reduction, altered microclimate and physical barriers to spore dispersal.