The potential of sunflower as a crop for ensilage

The chemical composition and nutritive value of sunflower, cv. Armavirec, was examined at 12 stages of growth. Maximum yield of dry matter (18.2 t ha^?1) occurred at the dough seed stage. Ether extract showed a five-fold increase with the development of the seed. This increase was reflected in the gross energy value which was maximal at 19.1 MJ kg^?1 dry matter at the dough seed stage. In-vitro organic matter digestibility was highest at the onset of flowering when the estimated metabolisable energy value was 10.5 MJ kg^?1 dry matter. Throughout the sampling period the calcium to phosphorus ratios varied from 3.9-5.9:1, an imbalance which would have to be redressed on diets based largely on sunflowers. Fresh and wilted sunflowers were successfully ensiled at the flowering stage, without the use of additives. pH values of the resulting silages were 3.86 and 4.01. The silages were each fed to six cross-bred wethers and voluntary dry matter intakes were 23.9 and 26.5 g kgW^?1 for the fresh and wilted silages respectively. For the fresh silage, intakes of digestible organic matter and digestible nitrogen were 612 and 13.6 g day^?1 compared with 684 and 16.7 g day^?1 for the wilted silage. Nitrogen retention increased with increase in silage dry matter. The optimum time of cutting for yield of nutrients is at the milky ripe stage. The composition of the crop at this stage should facilitate a satisfactory preservation by ensiling. The crop provides a high yield of dry matter over about 10 weeks in late summer and could provide a valuable standby forage crop for grass in dry areas.     

Effects of enzymes in diets with varying energy levels on growth and egg production performance of Japanese quail

The present study was conducted to evaluate the effect of feed‐grade enzyme supplementation in diets with varying levels of energy on the performance of growing and laying Japanese quails. Day‐old Japanese quails, 504 in number, were subjected to six dietary treatments with six replicates at each treatment. Each replicate had 14 chicks. The dietary treatments consisted of three energy levels ie 12.15 MJ (2900 kcal), 11.30 MJ (2700 kcal) and 10.48 MJ (2500 kcal) ME kg^?1 diet and two enzyme levels (0 and 0.5 g kg^?1 diet). A metabolism trial was conducted at the fourth week of age. At the end of week 5, 10 quails (five of each sex) per treatment were sacrificed for carcass characteristics and 20 female quails from each of the six dietary groups were housed in individual laying cages and fed respective layer diet to study the laying performance and egg quality up to 20 weeks of age. Body weight gains of quails fed 12.15 MJ or 11.30 MJ ME kg^?1 diets were significantly higher (p < 0.01) than those fed diets with 10.46 MJ ME kg^?1 diet. Feed intake was significantly lower (p < 0.01) in birds that received diet with 12.15 MJ ME kg^?1 than in birds that diets containing either 11.30 or 10.46 MJ ME kg^?1 diet. Feed conversion ratio (p < 0.01) was best at 12.15, followed by 11.30 and 10.46 MJ ME kg^?1 diet. Enzyme supplementation did not improve the growth performance, feed intake or feed conversion efficiency of quails. Enzyme addition also did not influence nitrogen retention or energy or dry matter metabolizability. The carcass characteristics did not differ because of energy or enzyme supplementation. Feed intake increased significantly (p < 0.01) as the dietary energy level decreased. The egg production and quality characteristics remained almost similar in all the dietary treatments. It was concluded that the optimum dietary energy level for quail was 12.15 MJ (2900 kcal) ME kg^?1 during the growing phase and 11.30 MJ (2700 kcal) ME kg^?1 during the laying phase. Addition of feed enzymes to conventional diets containing varying levels of maize, soyabean meal, fish meal and deoiled rice bran was not beneficial to improve growth, carcass traits, egg production performance or nutrient utilization. Copyright © 2004 Society of Chemical Industry     

Protein and energy requirements for starting and finishing broiler guineafowl (Numida meleagris) in the tropics

Two experiments were conducted to determine the optimum protein and energy levels for starting and finishing guineafowls. Eighty one-day-old guinea-fowl keets were tested in groups of 20 on four starter rations (made up of four protein contents 28, 26, 24, and 22% (w/w) with corresponding energy levels 13.8, 13.4, 13.0, and 12.6MJ kg^?1 diet), for a period of 6 weeks and later changed to four finisher rations. The finisher rations were made up of four protein levels (24, 20, 16 and 12% w/w) and four corresponding energy levels (12.6, 12.2, 11.7, 11.3MJ kg^?1 diet). These were fed from 7 to 12 weeks. The result of this study indicated that the optimum protein and energy levels for starting guineafowl in the tropics were 22% (w/w) crude protein and 12.6 MJ kg^?1 ME diet while that of finishing guineafowl 16% (w/w) crude protein and 11.7MJ kg^?1 ME diet.     

Improving plantain (Musa spp. AAB) yields on smallholder farms in West and Central Africa

Plantain is an important staple in West and Central Africa, where it is predominantly grown by smallholder farmers. On-farm data are rare but yields are considered to be low. We collated actual yields in the region, reviewed regional plantain research published from 1976 to 2013, then estimated what yields would be attainable on smallholder farms if the proven, best-fit innovations were adopted. Mean actual yields reported ranged from 2.9 to 8.9 Mg ha^?1 with a mean of 5.7 Mg ha^?1 for False horn plantain and 4.5 to 10.2 Mg ha^?1 with a mean of 7.8 Mg ha^?1 for French plantain. Experiments found dealt with: cultural practices, particularly intercropping; abiotic factors such as fertiliser, mulch application and irrigation; biotic factors, predominantly sucker sanitation methods, but including three controlled yield loss studies on nematodes and black sigatoka; landrace comparisons and the introduction of improved cultivars, predominantly those exhibiting black sigatoka-tolerance. We conclude that intercropping should be retained according to farmer preference as there was no evidence of yield reductions for plantain. Boiling water treatment of suckers should be universally recommended. Inputs, whether mulch or K fertiliser up to 300 kg ha^?1, should be applied as both reduced plant losses and increased bunch mass. With the highest yielding local landrace type, on-farm yields could be increased from 7.8 Mg ha^?1 to 35.5 Mg ha^?1 with purchased inputs or to 23.7 Mg ha^?1 without purchased inputs.     

A 75% reduction in herbicide use through integration with sorghum + sunflower extracts for weed management in wheat

BACKGROUND: To reduce herbicide use by 75%, integrated use of sorghum and sunflower extracts each at 18 L ha^?1 combined with 1/4^th (75% less) of label rates of four herbicides (mesosulfuron + idosulfuron, metribuzin, phenoxaprop‐p‐ethyl and isoproturon) were investigated for the management of wild oat and canary grass, the two pernicious weeds in wheat fields worldwide. RESULTS: The results revealed that sorghum + sunflower extracts combined with 1/4^th (75% less) of label rates of herbicides inhibited dry matter production of wild oat by up to 89% and canary grass by up to 92%. The wild oat and canary grass persistence index in sorghum + sunflower extracts combined with 1/4^th (75% less) of label rates of herbicides was either lower or equal to respective label rates of herbicides, except sorghum + sunflower extract + 1/4^th phenoxaprop‐p‐ethyl. Lower herbicide rates + water extracts also produced wheat grain yield statistically equal with label rates of respective herbicides. Two treatments having water extracts + lower herbicides rates were economical and sorghum + sunflower + 1/4^th mesosulfuron + idosulfuron produced the highest (4404%) marginal rate of return. CONCLUSION: Herbicides use can be reduced by 75% through integration with sorghum + sunflower extracts without compromising yield and net benefits for cost‐effective and eco‐friendly management of wild oat and canary grass in wheat. Copyright © 2010 Society of Chemical Industry     

Technical efficiency analysis for oilseed sunflower farms: a case study in Erzurum,Turkey

BACKGROUND: The main purpose of this study was to examine the technical efficiency of farms producing sunflower in Erzurum, Turkey and to identify factors that might be causing inefficiency. Stochastic frontier analysis was used to measure technical efficiency. One hundred and seventeen randomly selected farms were interviewed for farm‐level data in the 2004–2005 production period. RESULTS: Results revealed that the mean technical efficiency for the sunflower farms, estimated by the stochastic production frontier, is 64%. At full technical efficiency, on average, the farmers could reduce their inputs by around 56% without reducing their sunflower production, simply by improving technical efficiency. In the inefficiency model the parameter estimates showed that older farmers, higher level of farmer's education, more experienced farmers, larger farm size and higher information score resulted in lower technical inefficiency, while bigger family size and more credit usage resulted in higher technical inefficiency. CONCLUSION: This study proposes strategies such as providing better extension services and farmer‐training programmes, including more educated people in sunflower farming and also expanding the sunflower‐growing area through provision of adequate facilities in order to increase technical efficiency. Copyright © 2010 Society of Chemical Industry     

Energy use in soy-bean meat analog manufacture: A comparison with beef

Beef cattle production in the USA required 2200 to 16 000 kcal kg^?1 of product and a further 500 kcal kg^?1 to process into meat. A typical US production total is 8700 kcal kg^?1 at an energy intensity of 1100 × 10³ kcal ha^?1 of land employed. Typical US soy-bean production has an energy subsidy of 950 kcal kg^?1 at an energy intensity of 1500 × 10³ kcal ha^?1. Soy-bean processing typically requires 710 kcal kg^?1 for solvent extraction, 1300 kcal kg^?1 for refining and hydrogenation of oil and 760 kcal kg^?1 for assembly into a meat analog product. A dried egg albumin binder for the analog, with 40 000 kcal kg^?1 energy subsidy, comprises almost half the total subsidy of 2700 kcal kg^?1 to a model analog, though comprising only 3% of the ingredient total. A soy-bean isolate based analog would usually require a total of 5200 kcal kg^?1. Other land use, input and by-product considerations make beef appear more favourable than the straightforward comparison with the analogs might indicate.     

Short‐duration cassava genotypes for crop diversification in the humid tropics: growth dynamics,biomass, yield and quality

BACKGROUND: Short‐duration (6–7 months) cassava provides opportunities to smallholder farmers for effective utilisation of resources such as land, moisture and nutrients as well as diversification of enterprise and income. The variation in biomass production and partitioning, seasonal course of growth indices, yield, quality and nutrient uptake of ten short‐duration/early‐bulking genotypes of cassava and their impact on nutrient contents in soil in a lowland situation akin to rice fallow were examined in this study. RESULTS: Triploid 2–18 gave the highest yield (38.34 t ha^?1), followed by triploid 4‐2, Sree Vijaya, Sree Jaya and Vellayani Hraswa, which were on a par (30–32 t ha^?1). Vellayani Hraswa, Sree Vijaya and triploid 4‐2 had significantly higher tuberous root dry matter content (370–380 mg g^?1) and fairly higher starch content (270–280 mg g^?1). All genotypes except triploid 4‐2, triploid 2–18 and H‐165 had low cyanogen content (29.2–43.8 µg g^?1), well within the tolerable limit. Tuberous root dry matter and total dry matter production, crop growth rate, tuberous root bulking rate and harvest index at the last phase, number of tuberous roots, mean weight of tuberous roots and nutrient uptake showed significant positive correlations with tuberous root yield. Principal component analysis also showed a similar trend. CONCLUSION: The diploids Sree Vijaya, Sree Jaya, Vellayani Hraswa and Kalpaka are ideal for cultivation in rice fallow for food use owing to their high yield, good cooking quality and low cyanogen content. The triploids are better suited for industrial use owing to their high tuberous root dry biomass production. Copyright © 2009 Society of Chemical Industry     

The interaction between threonine and avilamycin on piglet performance and diet digestibility post weaning

A 3 × 2 factorial experimental design was used to investigate the interaction between threonine level (8.6, 10.5 or 12.1 g kg^?1) and an antimicrobial growth promoter (0 or 60 mg kg^?1 avilamycin) in piglet starter diets. Three hundred and sixty weaned piglets (24 d of age; 5.9 kg live weight) were blocked on the basis of live weight and assigned to one of six dietary treatments. The treatments were (1) 8.6 g kg^?1 threonine and avilamycin, (2) 10.5 g kg^?1 threonine and avilamycin, (3) 12.1 g kg^?1 threonine and avilamycin, (4) 8.6 g kg^?1 threonine and no avilamycin, (5) 10.5 g kg^?1 threonine and no avilamycin and (6) 12.1 g kg^?1 threonine and no avilamycin. The diets were formulated to have identical concentrations of digestible energy (16 MJ kg^?1) and total lysine (16 g kg^?1). There was no interaction between threonine and avilamycin in any performance variable measured. Neither the level of threonine nor the inclusion of avilamycin in the diet had any effect on feed intake, average daily gain or food conversion ratio. There was a significant interaction between threonine level and avilamycin inclusion in the apparent digestibility of dry matter, organic matter, nitrogen, ash, neutral detergent fibre and gross energy and also digestible energy content. In the absence of avilamycin, there was a linear increase in nutrient digestibility to increased threonine levels in the diet. However, in the presence of avilamycin there was a quadratic response to increased threonine levels. In conclusion, optimum piglet performance was achieved at a threonine level of 8.6 g kg^?1 and there was no advantage to avilamycin inclusion under current conditions. Copyright © 2005 Society of Chemical Industry     

Regional distribution of nitrogen fertilizer use and N-saving potential for improvement of food production and nitrogen use efficiency in China

BACKGROUND: An apparently large disparity still exists between developed and developing countries in historical trends of the amounts of nitrogen (N) fertilizers consumed, and the same situation holds true in China. The situation of either N overuse or underuse has become one of the major limiting factors in agricultural production and economic development in China. The issue of food security in N‐poor regions has been given the greatest attention internationally. Balanced and appropriate use of N fertilizer for enriching soil fertility is an effective step in preventing soil degradation, ensuring food security, and further contributing to poverty alleviation and rural economic development in the N‐poor regions. RESULTS: Based on the China Statistical Yearbook (2007), there could be scope for improvement of N use efficiency (NUE) in N‐rich regions by reducing N fertilizer input to an optimal level (≤180 kg N ha^?1), and also potential for increasing yield in the N‐poor regions by further increasing N fertilizer supply (up to 116 kg N ha^?1). For the N‐rich regions, the average estimated potential of N saving and NUE increase could be about 15% and 23%, respectively, while for the N‐poor regions the average estimated potential for yield increase could be 21% on a regional scale, when N input is increased by 13%. CONCLUSION: The study suggests that to achieve the goals of regional yield improvement, it is necessary to readjust and optimize regional distribution of N fertilizer use between the N‐poor and N‐rich regions in China, in combination with other nutrient management practices. Copyright © 2011 Society of Chemical Industry     

Aflatoxins in sunflower and safflower seeds from Iran

Aflatoxin content of 173 sunflower and safflower seeds was determined by HPLC with immunoaffinity column (IAC) clean-up and fluorometric detection. Aflatoxin B₁ contamination was found in 111 samples: in 8 of the sunflower seed samples (16%) at a mean level of 40.68?ng?g^?1 and in 103 safflower seed samples (83.7%) at a mean level of 2.81?±?0.44?ng?g^?1. In 5 sunflower seed samples and 1 safflower seed sample, aflatoxin B₁ levels were higher than the maximum levels of AFB₁ under Iran regulations (5?ng?g^?1). Aflatoxin B₁ levels in 5 sunflower and 2 safflower seed samples were higher than the European Union maximum limit (2?ng?g^?1).     

Weed management in upland rice in sub-Saharan Africa: impact on labor and crop productivity

Rice is one of the most important crops for food security in sub-Saharan Africa (SSA). There exists, however, a widening gap between its regional demand and supply. Competition from weeds is typically one of the major biophysical constraints in upland rice, frequently leading to significant yield losses and sometimes to complete crop failure, thereby threatening the food security of subsistence farmers. However, weed management practices that are currently employed to avoid such losses are associated with high weeding labor demands. This study examined the relationships between weeding times per farm, average time per hectare per weeding and rice yields of upland rice farmers in SSA, with the objective of estimating the impact of weeds on rural households’ economies in SSA reliant on upland rice production systems. To this end, we analyzed survey data collected from 992 farmers in four countries (Cameroon, Democratic Republic of Congo, Togo and Uganda). The counterfactual outcomes framework of modern evaluation theory was used to estimate the Average Treatment Effect (ATE) of the number of times a farm is weeded on weeding labor efficiency, as measured by the average number of hours spent per hectare at each weeding, and on crop productivity expressed as rice grain yield per hectare. A single weeding required 173 h per hectare, while weeding twice required 130 h per hectare per weeding (259 h per hectare in total) and weeding three times required 125 h per hectare per weeding (376 h per hectare in total). Correspondingly, a single weeding was associated with an average rice yield of 1.2 t ha^?1, weeding twice yielded 1.7 t ha^?1 and weeding three times yielded 2.2 t ha^?1. Compared to the situation where the farm is weeded only once and controlling for other factors, the model estimated yield gains of a second weeding to be 0.33 t ha^?1 and a third weeding to result in a gain of 0.51 t ha^?1. The estimated labor gains were respectively 64.2 and 68.1 h per hectare per weeding for a second and a third weeding. We conclude that weeding an upland rice crop more than once in SSA increases weeding labor efficiency by about 37 % and rice productivity by more than 27 %. Rather than motivating farmers to increase their labor inputs for manual weeding, however, we propose that more research and development funds should be devoted to developing, testing and promoting locally adapted strategies of labor-saving weed management in rice in sub-Saharan Africa. This will result in a significant contribution to regional food security and poverty alleviation.     

A lysimeter study of nitrate leaching, optimum fertilisation rate and growth responses of corn (Zea mays L.) following soil amendment with water-saving super-absorbent polymer

BACKGROUND: Nitrate leaching and the resulting groundwater contamination from intensive cereal production has become a major concern for long‐term farmland efficiency and environmental sustainability in northern China. The aim of this study was to evaluate a water‐saving super‐absorbent polymer (SAP) for minimising NO₃^? leaching from soil and optimising corn growth and yield. Thirty‐six undisturbed soil lysimeters were installed in a field lysimeter facility in drought‐affected northern China to study the growth and yield characteristics of summer corn (Zea mays L.) as well as the amount of NO₃–leaching losses under different fertiliser (standard, medium or 75% and low, or 50% of conventional fertilisation rate) and SAP (control, 0; level‐1, 15 kg ha^?1 and level‐2, 30 kg ha^?1) treatments. RESULTS: Corn yield fell by 19.7% under medium and 37.7% under low fertilisation; the application of SAP increased yield significantly by 44.4% on level‐1 and 80.3% on level‐2. Similarly, plant height, leaf area, number of grains as well as protein, soluble sugar and starch contents in the grain also increased with SAP treatment. Application of SAP at 30 kg ha^?1 plus half of conventional fertilisation can reduce maximum (64.1%) nitrate leaching losses from soil. CONCLUSIONS: Application of SAP at 30 kg ha^?1 plus only half the amount of conventional fertiliser rate (150 kg urea, and 50 kg each of superphosphate and potassium sulfate) would be a more appropriate practice both for minimising nitrate leaching and sustainable corn production under the arid and semiarid conditions of northern China. Copyright © 2011 Society of Chemical Industry     

The chemical composition and true metabolisable energy content of cassava root meal imported into Northern Ireland

The chemical composition and true metabolisable energy (TME) content of 10 samples of cassava root meal imported into Northern Ireland were measured. There were no major significant differences in the chemical composition of the native and pelleted cassava. Traces of HCN were found in all the samples and the four mycotoxins for which examinations were carried out were absent. The true metabolisable energy content of the meal was 13.46 MJ kg^?1 as fed, i.e. 15.13 MJ kg^?1 in the dry matter.     

Effect of nitrogen application rate on the content and composition of oil,essential oil and minerals in black cumin (Nigella sativa L.) seeds

A field experiment was conducted to study the effect of nitrogen fertility level on the content and composition of oil, essential oil and minerals in black cumin (Nigella sativa L.) seeds. Sixty‐three‐day‐old plants were supplied with varying levels of N, i.e., 0, 30, 60, and 90 kg N ha^?1 soil. The fixed oil content of the seeds ranged from 32.7% to 37.8% and it remained almost unchanged at the two higher external N regimes, i.e., 60 and 90 kg N ha^?1, but at 30 kg N ha^?1 the oil content increased significantly. Of the saturated fatty acids analyzed, palmitic acid increased slightly at all external N levels, but in contrast stearic acid decreased considerably at 60 kg N ha^?1. Of the unsaturated fatty acids of fixed oil, the predominant fatty acid was linoleic acid (18:2) followed by oleic acid (18:1). Linoleic acid and dihomolinoleic acid (20:2) showed no change in their amounts at varying levels of N. In contrast, a marked reduction in α‐linolenic acid (18:3) was found at the two higher N regimes, i.e., 60 and 90 kg N ha^?1. Seed essential oil content did not vary with the change in applied N level. The major component of essential oil of black cumin seed was found to be p‐cymene, which showed an increase at 30 kg N ha^?1, whereas no change in the levels of α‐pinene or β‐pinene was observed at varying levels of N. K, P, Na, Fe, Mn, and Ni were found to be predominant elements in the seeds. Ca, Mg, Cu, and Cr were present in low amounts, but Zn was present in moderate quantity. Increasing N rate did not affect the content of K, P, Ca, Mg, or Cr in the cumin seeds. In contrast, a consistent decrease in seed Mn, Zn, and Ni was observed with increase in external N level. Increasing N level had a marked effect on some of the components of black seed oil. Copyright © 2006 Society of Chemical Industry     

The effect of fertilizer nitrogen input to grass-clover swards and calving date on the productivity of pasture-based dairy production

The objective of this systems-scale study was to investigate grazing season timeframes on pasture and milk production and on milk processability of dairy systems with compact spring-calving dairy cows grazing white clover (Trifolium repens L.) based grassland. Fifty-four primiparous and multiparous Holstein-Friesian dairy cows were used in a one-factor study with 3 systems (n = 18) and repeated over 2 yr (2008/09 and 2009/10). The 3 systems were: early spring calving with annual fertilizer N input of 100 kg·ha^?1 applied in spring (ES100N; 2.1 cows·ha^?1; grazing February to November), early spring calving without fertilizer N (ES0N; 1.6 cows·ha^?1; grazing February to November) and late spring calving without fertilizer N (LS0N; 1.53 cows·ha^?1; grazing April to January). Annual pasture production was affected by an interaction between grazing system and year: Mean annual pasture yields for 2008 and 2009 were ES100N; 10.35 and 9.88, ES0N; 8.88 and 8.63, LS0N; 9.18 and 10.31 t of dry matter (DM)·ha^?1 (SEM 0.39). LS0N had higher pasture DM yield in 2009 due to higher clover DM production and biological N fixation compared with the other systems. Clover stolon and root mass in the following February was correlated with stolon and root mass in the previous November with 64% of stolon mass present on LS0N in February (R² = 0.84). There were no detectable differences in per-lactation milk yield (6,335 kg·cow^?1), fat, protein and lactose yields (271, 226, 297 kg·cow^?1, respectively), cow liveweight (585 kg) or body condition score (3.02). Although winter grazing favored subsequent clover DM production, biological N fixation and pasture DM production, delaying calving date in spring and extending lactation into the following winter led to inefficient use of this pasture by the grazing herd and lowered the quality of late-lactation milk for processing purposes. Hence, a mean calving date in mid- to late-February is recommended for zero-fertilizer N input clover-based grassland.     

Comparative analyses of estimated and calorimetrically determined energy balance in high-yielding dairy cows

Our aim was to compare the energy balance estimated (EBest) according to equations published by various energy feeding systems (German Society for Nutrition Physiology, French National Institute for Agricultural Research, and US National Research Council) and the EB calculated by use of calorimetrically measured heat production (EBhp) of 20 high-yielding (≥10,000 kg/305 d) German Holstein cows at ?4 (pregnant, nonlactating) and 2 wk (early lactation) relative to parturition. In addition to heat production, feed and water intake, physical activity (including standing-lying behavior), body weight, body condition score, body temperature, plasma concentrations of fatty acids and β-hydroxybutyrate, milk yield, and milk composition were measured to characterize the metabolic status. The EBhp was balanced [2.74 ± 4.09 MJ of metabolizable energy (ME)/d; ±standard error] before calving, but strongly negative (?84.7 ± 7.48 MJ of ME/d) at wk 2 of lactation. At both time points, EBhp and EBest differed significantly. On average, the equations overestimated the antepartum EB by 33 MJ of ME/d and underestimated the postpartum negative EB by 67 MJ of ME/d, respectively. Because the same ME intake and energy-corrected milk values were used for calculation of EBest and EBhp in our study, we considered that the factors (0.488 to 0.534 MJ of ME/kg^0.75) currently used to calculate the ME requirements for maintenance probably underestimate the needs of high-yielding dairy cows, particularly during early lactation. In accord, heat production values determined under standard conditions of thermoneutrality and locomotion restriction amounted to 0.76 ± 0.02 MJ of ME/kg^0.75 (4 wk antepartum) and 1.02 ± 0.02 MJ of ME/kg^0.75 (2 wk postpartum), respectively. The expected positive correlation between EBhp and DMI was observed in pregnant cows only; however, a bias of 26 MJ of ME/d between mean actual energy intake and ME intake predicted according to German Society for Nutrition Physiology was found in cows at wk 4 antepartum. At both investigated time points, mobilization of tissue energy reserves (reflected by plasma fatty acid concentration) was related to EBhp. In early lactating cows, metabolic body weight (kg^0.75) and the percentage of milk fat showed the strongest correlation (correlation coefficient = ?0.70 and ?0.73) to EBhp. Our findings must be taken into account when experimental data are interpreted because the true energy status might be significantly overestimated when EBest is used.     

Validating the current amino acid and energy requirements of coloured broiler chickens

Background: Coloured broilers are gaining popularity in the Indian subcontinent. However, very scanty reports are available on their dietary requirements for amino acid (AA) and energy. An experiment was conducted involving three levels of amino acids (115, 100 and 85% AA level of the NRC), at three levels of energy (13.40, 12.55 and 11.72 MJ kg^?1 diet) for 0–28 days of age. Results: Body weight gain and feed conversion ratio (FCR) in the 115% AA group was better than those fed diets with 100 and 85% AA. Dietary energy levels did not influence body weight gain up to 14 days of age but thereafter it was higher (P < 0.01) in birds offered the 13.40 MJ ME kg^?1 diet. The exponential regression equation had better curve fitting for daily body weight gain over daily AA intake and the power regression model for FCR. Nitrogen retention was higher in birds offered the diets with 115 and 100% AA than 85% AA, although nitrogen retention was not affected by dietary energy level. Thymus weight (P < 0.036) and in vivo response to PHA‐P (P < 0.006) was significantly higher in birds offered the 85% AA diet. Dietary energy levels had no effect on the immune response of the birds. Weight of gizzard, proven‐triculus and small intestine was higher in birds offered the 85% AA diet. Conclusion: Body weight of coloured broilers may be optimised by feeding higher level of AA and immune response can be optimised by feeding 12.55 kJ ME kg^?1 diet and 15% lower level of AA as suggested by the US National Research Council. Copyright © 2007 Society of Chemical Industry     

The nitrogen content of potato (Solanum tuberosum L.) tubers in relation to nitrogen application—the effect on amino acid composition and yields

The effect of nitrogen application on the nitrogen content and yield of amino acids from potato tubers was studied in one experiment in 1983 and two in 1984. Increasing fertiliser N over the range 0–250 kg ha^?1 raised tuber nitrogen concentrations from 0.68–0.81 to 1.27–1.49% DM. Applying half the fertiliser on the seedbed and half at tuber initiation did not increase tuber nitrogen concentrations compared with a single broadcast application at planting. Increasing tuber nitrogen concentrations had little effect upon the proportion recovered in amides or the different amino acids. Yields of some nutritionally essential amino acids were, therefore, substantially increased up to a maximum of 256 kg ha^?1 in 1982 and 308 and 384 kg ha^?1 in 1984 at the highest fertiliser level. These yields were significantly higher (P<0.01) than those found with the nitrogen application rate optimal for tuber dry matter production (213, 195 and 331 kg N ha^?1, respectively) in the same experiments. Methionine and cystine were the limiting essential amino acids. As the amount of each amino acid contained in a unit weight of fresh tuber increased with nitrogen supply, application of more nitrogen than is needed for maximal tuber dry matter production increased protein yields without decreasing the nutritional quality.     

The influence of fibre level and fat supplementation in expander‐processed diets on grower–finisher pig performance

Seventy‐two entire male pigs (40.4 ± 1.0 kg) were used to study the effects of increasing crude fibre (CF) level in the diet and maintaining the digestible energy (DE) content of the diet by increasing dietary fat inclusion on pig performance and nutrient digestibility in a 3 × 2 factorial experiment. Productive performance and nutrient digestibility were determined in individually fed pigs offered expander‐processed pelleted diets ad libitum containing three levels of CF (50, 60 and 70 g kg^?1) and two levels of fat supplementation (25 and 50 g kg^?1) until slaughter at 100 kg. All diets were expander processed at 105 °C for 5 s at 35 bar pressure having been previously conditioned at 85 °C for 5 s. All diets were formulated to have similar concentrations of digestible energy (13.5 MJ kg^?1) and lysine (10 g kg^?1) and the fat source was a 60:40 blend of tallow and palm oil. The increase in dietary CF level decreased (P < 0.05) the apparent digestibility of crude protein, organic matter (OM) and energy, while the inclusion of 50 g kg^?1 fat decreased (P < 0.01) OM and energy digestibility. The inclusion of 50 g kg^?1 fat in the diet increased (P < 0.01) ether extract digestibility at the 50 and 60 g kg^?1 CF levels; however, fat inclusion had no effect at the 70 g kg^?1 CF level. There was no CF × fat interaction in any growth criteria. The inclusion of 50 g kg^?1 fat in the diet significantly reduced (P < 0.05) feed intake (2.28 versus 2.43 kg day^?1, SEM 0.039), average daily gain (ADG; 0.877 versus 0.927 kg day^?1, SEM 0.017) and DE conversion ratio (36.1 versus 35.0 MJ kg^?1, SEM 0.40). The increase in dietary CF level decreased (linear, P < 0.05) feed intake (2.45 versus 2.32 versus 2.29 kg day^?1, SEM 0.040), ADG (0.940 versus 0.896 versus 0.872 kg day^?1, SEM 0.021) and kill‐out proportion (740 versus 741 versus 730 g kg^?1, SEM 3.6). In conclusion, increasing both the CF level and supplementary fat inclusion rate had a negative effect on pig growth performance and nutrient digestibility. © 2002 Society of Chemical Industry