JWSS - Journal of Water and Soil Science

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In order to increase the role of machine vision in agricultural research in Iran, especially for measuring physical attributes of seeds, a machine vision system was developed using a computer, a capture card, a video camera and a light box. All equipment was purchased from domestic markets. Computer programs were developed for hardware setup and for image processing applications. The programs perfomed tasks such as image acquisition and display, color conversion, image segmentation, object counting, and measurement of some physical attributes of the objects by analysing their images. The system was used to measure some physical attributes of pistachio nuts. The machine vision measurements were statistically compared with the measurements obtained by the conventional manual methods. The results indicated that there was generally no significant difference between the two methods. However, the time consumed by the machine vision method was far less than the time taken by manual methods. The experimental results also showed that there were many sources of error and limiting factors in using machine vision for measuring physical attributes of seeds.

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Oval fertilization and survival rates at incubation stage form the most important issues of concern in rainbow trout hatcheries in Iran. Hatchery managers tend to use the best method in fertilizing the ova in order to obtain the highest survival rates. A survey of common fertilization methods may help to determine the best one. In this study, the ova from two groups of 3-5 year-old and younger than 3 years broodstocks were fertilized employing dry and semi-dry methods in normal water and dry and semi-dry methods in fertilization solution. The experiment was carried out in a completely randomized design as a 422 factorial arrangement and with two replicates. The analysis of final results indicates that the highest survival rates of eggs and larvae were obtained in semi-dry fertilization. These rates significantly increased when fertilization solution was used (P<0.05). Moreover, the survival rates of eggs and larvae of 3-5 year-old broodstocks were higher than those of younger than 3 years. On the other hand, type and methods of fertilization showed no significant differences with degree-day (sum of heat) at developmental stage but the age of broodstocks made significant differences with degree-day from fertilization to the first hatching stage (P<0.05).

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Watermelon (Citrullus Lanatus) cv. Charleston Gray is one of the most important cultivars grown in Iran. It has some good quantitative and qualitative characteristics but unfortunately is sensitive to Blossom End rot. To solve this problem, this experiment was conducted in a factorial manner in randomized complete block design with four replications in Research Station and Laboratories of Department of Horticulture, College of Agriculture, the University of Tehran, during 1997 & 1998. In this experiment, black polyethylene mulch was used and calcium nitrate was foliar sprayed at concentrations of 0, 4, and 6 g/L. Results indicated that mulch could increase yield by 85% over two years due to weed growth suppression and conserving soil moisture for a longer time. Foliage fresh weight, number and average weight of fruits per plant and precocity were also significantly affected by black polyethylene mulch. Furthermore, mulch reduced the number and weight of fruits affected by Blossom End rot by about 13% and 12.5% (average of two years), respectively. Calcium nitrate addition during both years had no significant effect on the measured fruit characteristics nor on Blossom End rot.

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To determine the effects of salinity and boron excess in irrigation water on relative growth rate (RGR), net assimilation rate on a leaf weight basis (NAR), and leaf weight ratio (LWR) of pistachio, three pistachio rootstocks (Badami -Zarand, Sarakhs and Ghazvini) were used. Rootstocks were grown in soil in eight-liter polyethylene pots. Sodium chloride treatments were 0, 75,150 and 225 mM NaCl and boron treatments were 0, 20 and 40mg liter^-1. Treatments were applied to the one-year old pistachio rootstock seedlings in three-day intervals with irrigation water. Some plants were randomly selected and destructively harvested before (day 0) and after applying treatments (30 and 60 days after treatments started). Growth and physiological characters were then measured as follows: number of leaves, leaf area, plant height and root length, fresh and dry weights of stem, root and leaf, proline accumulation in the leaf, total chlorophyll, and leaf relative water content (RWC). Results indicated that relative growth rate decreased with time for all treatments and in all rootstocks. Salt treatment significantly reduced both RGR and NAR, whereas LWR showed no significant differences. In all rootstocks, NAR, but not LWR, was significantly correlated with RGR, indicating that NAR was an important factor underlying the salinity-induced differences in RGR among the pistachio rootstocks. Salinity did not affect leaf water potential (ψ), chlorophyll content, and Fv:Fm ratio but increased NaCl concentration and time correspondingly increased proline accumulation in leaves. In addition, Ghazvini rootstock accumulated more proline compared to other rootstocks and was more resistant to salinity treatments. Different boron treatments did not show any significant effect on growth rate nor on measured parameters after two months of exposure to treatments.

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Knowledge of the spatial dependency of soil properties, sensitive to grazing systems, is important from an ecosystem protection point of view. In the current study, geostatistical methods and fractal concepts have been used in order to characterize the impact of long-term grazing exclusion on the spatial variability of some soil chemical parameters including organic matter, total nitrogen, available phosphorous, and available potassium in both ungrazed and grazed sites located in Sabzkuh region, Chaharmahal Bakhtiari Province. The spatial pattern of different variables was studied using variogram. The results indicate that spatial variability of soil parameters depends upon grazing history. The variogram of organic matter in grazed areas shows a linear behavior without reaching the sill variance while organic matter in the ungrazed area established a strong spatial structure. Moreover, available phosphorous in the grazed area had pure nugget variation. Variograms of total nitrogen and available potassium in both grazed and ungrazed areas showed spatial structure approximated by spherical model. However, the range of variograms in exclusion sites was twice that of the grazed area. The results of applying the fractal theory show that soil properties have fractional behavior since increasing the scale of study reveals more details. Moreover, calculated fractal dimension values from variograms of different variables were close to 2.0 although this index was usually greater in the grazed area than in the exclusion sites. The calculated fractal dimensions can be used as a proper indicator of describing the pattern of spatial variability and its complexity.

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Yield is a quantitative trait and improving grain yield through direct selection is time-consuming. Indirect selection consisting of selection indices is more promising. A field experiment was conducted during 1999-2000 growing season in two experimental locations (Kooshkak and Badjgah) of College of Agriculture, Shiraz University, Shiraz. Thirteen corn hybrids were used in a randomized complete block design with three replications in each location. Thirty-five traits were measured in five developmental stages (stem elongation, tasseling, blister, hard dough and physiological maturity) and combined analysis of variance and covariance were conducted. Finally, 12 traits were selected for constructing selection indices via path analysis. Two optimum selection indices were used in this experiment. In both selection indices, different combinations of traits applied as linear function (multivariate linear model) and coefficients of traits in combinations were calculated. The coefficient of indices were obtained from: b=P^-1Ga, where b is the vector of index coefficients, P^-1 is the inverse of phenotypical variance and covariance matrix, G is the matrix of genotypical variance and covariance and a is the column vector of traits heritability. In the first index, heritability of traits with the same sign was used as economic values. Selection index including grain yield and net assimilation rate in the second stage (NAR₂) was the best. In the second index, the sign of genotypic correlation with yield was given to economic values. Finally, selection index including grain yield and NAR₂ was the best, too. In both selection indices, correlation of selection indices with genotypic value was equal to 1. This was 14% higher than the first index including yield alone. In both selection indices, physiological indices including net assimilation, crop growth, and relative growth rates were the most important traits comprising the best selection indices.

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In a pot experiment, the growth (Dry matter) responses of 18 rapeseed varieties to three levels of NaCl salinity induced by 1.2, 6, and 12 dS.m^-1 were investigated using a factorial experiment with a randomized complete block design in 3 replications. The results indicated that salinity reduced total dry matter, Na concentration, K/Na ratio, ion selectivity of K versus Na, and leaf water potential while it increased K concentration. However, the leaf water potential of the plants had the highest and a significantly negative correlation with total dry matter accumulation. Therefore, it seemed that leaf water content of the plants could explain the tolerance or sensitivity responses to salinity. The rapeseed varieties were accordingly ranked into different groups. The varieties viz, Alice, Fonax, DP.94.8 and Licord were classified as saline tolerant group, and varieties such as Okapi, Akamar and Eurol as saline sensitive group. The remaining eight rapeseed varieties were moderately tolerant. Moreover, the response of rapeseed varieties viz. Consul, VDH8003-98 and Orient were different such that the above explanation could not be applied to them. Therefore, halophytic strategies for these three varieties might be worth further investigation.

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Russian Wheat Aphid (RWA) is a serious pest of wheat, barely and other small grains in cereal-producing regions of the world. The use of resistant cultivars is an effective management strategy to control this pest. In this study, 15 lines and 13 cultivars of durum and bread wheats along with two resistant and susceptible controls were used to evaluate their reaction to RWA under greenhouse conditions, using completely randomized design with four replications. Three seedlings at each plot were considered as an experimental unit. Five aphid nymphs (4-5 ages) were placed on each plant at 1-2 leaf stage. Leaf rolling and leaf chlorosis percentages were measured 21 days after infesting and used to screen the genotypes. Despite the relatively high linear correlation between two resistance components, leaf rolling and leaf chlorosis, estimated as 80%, analysis of variance indicated significant differences among genotypes. Eight durum lines DW9, DW14, DW4, DW2, DW7, DW8, DW12 and DW3 and one bread wheat cultivar (Azadi) were significantly more resistant than the resistant control (Halt). One durum line (DW13) and two bread wheat cultivars (Shiroodi and M-75-7) had higher leaf rolling and leaf chlorosis than the susceptible control (Sholeh). So they were selected as the most susceptible to the biotype of D. noxia. under study. Orthogonal comparison showed that durum lines were more resistant than bread wheat cultivars. These results were confirmed by Cluster Analysis based on leaf rolling and leaf chlorosis.

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Despite its economic importance, not much information exists on growth and productivity of durum wheat in Iran and Isfahan. In order to evaluate growth, grain yield, and attributes in three durum wheat genotypes, Osta/Gata, Dipper-6, and PI40100, with five planting densities of 200, 275, 350, 425 and 500 seeds/m², a four-replicate RCBD field study with a spilt-plot layout was carried out in winter 2000 to spring 2001 at Lavark Research Farm, College of Agriculture, Isfahan University of Technology. Genotypes were the main-plots and planting densities, the sub-plots. Each plot contained six rows, spaced 25cm apart, each 6m in length. While Osta/Gata produced a greater spikes/m², 1000-grain weight and grain yield, PI40100 indicated a greater height, leaf area index (LAI) and biological yield, and Dipper-6 produced a larger number of grains per spike and harvest index, compared to the other two genotypes. Increasing plant density led to an increase in LAI, spikes/m², grain yield, biological yield and harvest index but a decrease in grains/spike and 1000-grain weight. Grain yield was positively correlated with spikes/m², grains/spike and 1000-grain weight, despite negative correlations with LAI and plant height. It may be concluded that with environmental conditions such as those encountered in Isfahan in 2000-2001, Osta/Gata can be planted at approximately 425 seeds/m², if an acceptable grain yield is to be achieved.

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To evaluate the effect of broiler growth rate and feed intake on development of the inflammatory response‚ commercial broiler diets were fed to 275 day–old chicks of the modern 2000 strain and 1957 random-bred strain. Half of the chicks had free access to feed while others were restricted. Twelve birds from each strain and group pens were removed‚ weighed, and housed in individual cages by their original feeding programs on 0‚ 7‚ 14, and 28 days. Three feed-restricted and three ad libitum birds from each strain were injected with 1-3 ml of 100 μg/ml solution of Salmonella typhimurium lipopolysaccharide on days 6‚ 13‚ 27‚ and 41, and 3 birds of each group were not injected‚ serving as controls. All birds were weighed and the liver‚ breast muscle‚ thymus gastro intestinal tract and bursa were removed on the day after injection. The thymocytes of the control birds were subjected to an interleukin–1 responsiveness assay. The 1957 strain birds were more severely affected by an inflammatory challenge going almost completely off feed‚ but the 2000 strain birds experienced a more drastic decline in growth rate after injection. Thymocytes of ad libitum birds were more sensitive to IL-1 than the restricted birds in week 4 (P=0.056). Interleukin-1 stimulated thymocytes of 2000 birds more effectively than the 1957 strain ones. In conclusion‚ the broiler inflammatory response was affected by growth rate and feed intake.

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The population parameters of sweet potato white fly, Bemisia tabaci (Genn.) (Hom.: Aleyrodidae), which is an important pest of cotton fields, were studied during 2001. The infected leaves containing nymphs and pupae were collected from Darab, Qom, Saveh, Gonbad, Gorgan, Varamin, Garmsar, Orsoiieh (Kerman), and Shooshtar cotton fields. Experiments were conducted in a growth chamber under 24±.2^ºC, 55%±3RH and 16:8 (L:D) photoperiod on cotton, a Gossypium hirsutum L. (Varamin 76 variety). The newly emerged populations of each locality were released into a large cage set on cotton plants separately. Population parameters of 40 mated females were calculated for each local population. Intrinsic rates of increase (r) for Darab, Qom, Saveh, Gonbad, Gorgan, Varamin, Garmsar, Orsoiieh and Shooshtar were 0.0401, 0.0719, 0.0750, 0.0602, .0682, 0.0774, 0.0876, 0.0751 and 0.0988, respectively. Doubling times (DT) were 17.26, 9.63, 9.24, 11.51, 10.16, 8.94, 7.91, 9.22 and 7.083 days, respectively, and mean generation times (T_c) were calculated to be 28.72, 28.9, 28.74, 28.3, 28.68, 27.53, 29.12, 28.21 and 26.84 days, respectively. Other population parameters such as finite rate of increase (λ), intrinsic birth rate (b), intrinsic death rate (d), and stable age distribution were also calculated. The results revealed that there were significant differences between population parameters in local populations. The parameter (r) was the least in Darab and the greatest in Shooshtar populations.

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Traditional paddy dryer systems in Iran cause considerable losses in rice production due to non-uniform drying. In order to decrease the amount of kernel fissuring and to increase the drying rate, fluidized bed method was applied in this study for rough rice drying at temperatures higher than normal. An experimental dryer was used for drying the samples. The drying experiments were set up to find kernel fissuring percentage and the drying times under three conditions: fixed, minimum, and full fluidized bed conditions at temperatures of 40, 60 and 80^oC. Results showed that the amount of kernel fissuring, at minimum fluidization compared to fixed bed condition, decreased 57%, 68% and 75% at temperatures of 40, 60 and 80^oC, respectively. This reduction at full fluidization compared to fixed bed condition, at the above temperatures, was 40%, 54% and 65%. The minimum fluidization method took the lowest and the fixed bed method took the highest drying time. It was concluded that the minimum fluidization drying method had the lowest fissuring and drying times at all experimental temperatures.

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The vast pastures and agricultural development plans for dry farming and irrigated farming in Khuzestan Province depend on rain. This requires availability of annual precipitation prediction models to be used in the management decision-making process. In this research, the long-term daily precipitation data from 15 rain gauge stations in the study area were collected for study and a relationship between the early fall season precipitations of 42.5 mm (t_42.5) and the annual precipitation was obtained. The results showed that the relationship was an inverse one such that the later the fall precipitation occurred, the greater the annual precipitation would be. To increase the coefficient of determination in the models, climatic variables such as Persian Gulf sea surface temperature and geographical characteristics (longitude, latitude, altitude, and long term mean annual precipitation) were used. Except for the long term mean annual precipitation and altitude, other variables did not increase the coefficient of determination. The final simple model found is as follows: P_a=184.787-1.891t_42.5+0.855P_m , R²=0.704 where, P_a is the annual precipitation, t_42.5 is the time from beginning of fall season for 42.5 mm of precipitation, and P_m is the long term mean annual precipitation.

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In Iran, about 75% of national rice production is supplied in Gilan and Mazandaran proviences which have the highest amount of precipitation. Seasonal prediction of rainfall induces significant improvement on yield production and on preventing climate hazardz over these feritle areas. Canonical correlation analysis (CCA) model was carried out evaluates the possibility of the prediction of winter rainfall according to the states of ENSO events. The time series of (southern oscilation index (SOI) and SST (sea surface temperature) over Nino's area (Nino's SST) are used as the predictors, and precipitation in Bandar Anzali and Noushahr are used as the predictands. Emperical orthogonal functions (EOF) were applied for reducing the number of original predictors variables to fewer presumably essential orthogonal variables. Four modes of variations (EOF1, EOF2, EOF3, EOF4) which account for about 92% of total variance in predictors field were retained and the others were considered as noise. Based on the retained EOFs and precipitation time series, the canonical correlation analysis (CCA) was carried out to predict winter precipitation in Noushahr and Bandar Anzali. The results indicated that the predictors considered account for about 45% of total variance in the rainfall time series. The correlation coefficents between the simulated and observed time series were significant at 5% significant level. For 70% of events the anomalies of observed and simulated values have the same sign indicating the ability of the model for reasonable prediction of above or below normal values of precipitation. For rainfall prediction, the role of Nino's SST (Nino4 in particular) was found to be around 10% more influential than SOI. .

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An approach for regional low flow frequency analysis is to use multiple regression techniques for obtaining relationships between low flows with specific return periods and catchments characteristics. In this paper, this method has been used. After single-site frequency analysis for 20 stream gauging stations, homogeneity test was performed. Regional relationships between low flows with return periods 2 , 5 , 10, and 20 years and catchments characteristics were derived. For this purpose, catchment area, mean elevation, minimum elevation, shape factor, main channel length, length of main chanel from catchment centroid to outlet, forest area, mean annual rainfall, and mean catchment slope as model inputs were examined and cachment area, mean elevation, and mean catchment slope entered to the models. Finally, the mean relative error of models for different return period, 2, 5, 10, and 20 years, was computed 41.1, 41.3, 45.0, 47.2 percent, respectively that in comparison with other studies, it displays smaller errors.

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Experiments were conducted during 1996-1997 in Nough of Rafsanjan to evaluate double pollination on fruit set and development of pistachio nut. In the first experiment, Owhadi cultivar was pollinated by a combination of pollen from Beneh (P. mutica F&M), Atlantica (P. atlantica Desf) and Soltani (P.vera L.). In the second experiment, Owhadi cultivar was pollinated by pollen from Beneh, Atlantica and Khinjuk (P. Khinjuk). The results showed that in the double pollination experiment, the nut, kernel and fruit set were affected more by the first pollen than by the second one. Pollen from the wild pistachio species reduced kernel weight, number of split nuts but increased percentage of the deformity and blank nuts in Owhadi. It was concluded that the effectiveness of the first pollen on fruit set, nut and kernel development was independent of the second one. The pollen of P. vera proved to be the best pollen source for pistachio cultivars.

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Germination of strawberry seeds from self- and cross pollination of 4 commercial cultivars were evaluated under mist and in vitro cultures. The study was conducted in McGill University in Quebec, Canada, during 1994 and 1995. Self-pollination of Chambly and Redcoat cvs., and cross pollination of Oka × Chambly as well as Redcoat × Veestar and their reciprocals were used. At maturity, fruits were harvested and their seeds were separated. A sample of each seed lot was grown in greenhouse under mist condition and in vitro using MS medium. In the latter, both intact and cut seeds were used. Germination index (containing germination velocity and rate) was used as a criterion for germination evaluation. The results showed that there was no sign of germination in intact seeds 40 days after cultivation on MS medium however, cut seeds containing plantlets started germination 2 days after cultivation and obtained 90 percent of the germination after one week of culturing on the medium. Germination of seeds under mist condition began 15 days after sowing and showed a minimum of 55 to 87 percent in different genotypes till the end of the experiment period (60 days). Germination index (GI) under this condition ranged from 15.4 to 26.1. GI comparison of seeds under in vitro and mist conditions indicates a lower germination rate in different genotypes under mist condition. This study also showed that the rate of germination in strawberry seeds could range from 0 to 100 percent depending on genotype and type of treatment used. The best treatment for a synchronized and rapid germination was found to be using cut seeds containing the plantlets on MS medium.

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The possibility of using a steel plant by-product (converter sludge) as an iron fertilizer was investigated. This compound consists of 64% Fe oxides. Considerable amounts of elements such as Ca, Si, Mn, P, and K are also present in the sludge. To study the converter sludge, an incubation experiment was carried out on three calcareous soils. Treatments were 0, 4, and 8 percent of converter sludge mixed with soils plus mixtures of 4% converter sludge with elemental sulfur, thiobacillus inoculum and sulfuric acid. Soil samples (400 g) were kept at field capacity and room temperature in capped, aerated plastic containers for two months. Sub-samples were taken at 1, 10, 30, and 60 days of incubation and analyzed for Fe, Mn, Zn, P, and K contents as well as EC and pH. Results showed that converter sludge increased significantly extractable Fe proportional to the rate of sludge used. Sulfuric acid application increased Fe availability significantly, but the availability of this nutrient generally decreased with the incubation time. Application of the sludge also increased the pH slightly at the beginning of incubation. Elemental sulfur and sulfuric acid application increased Fe and Mn availability significantly. Application of the sludge without and with elemental sulfur and sulfuric acid slightly increased availability of P. The results of this study revealed that converter sludge might be used as an iron fertilizer. However, further investigation in greenhouse and field experiments is needed.

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An experiment was carried out to determine the effect of substituting alfalfa hay (Medicago sativa) with Gundelia tournefortii hay (a range forage in Fars Province) in the ration of fattening lambs. Alfalfa hay was substituted with Gundelia tournefortii harvested at the final stages of flowering at various ratios (0, 25, 50, 75, and 100% dry matter basis) in the ration of fattening lambs. The rations (iso-nitrogenous and iso-energetic) were pelleted and each ration was fed for 75 days to 12 Shirazi Grey ram lambs with an average age of 136 days. The lambs were slaughtered and their feedlot performance and carcass characteristics were measured. Substituting alfalfa hay with Gundelia tournefortii hay did not significantly affect the mean daily weight gain, feed consumption, feed conversion ratio, dressing percentage, internal fat weight, carcass meat content, or meat DM and CP contents (p>0.05). However, backfat depth was significantly different among various rations (p<0.01). At present costs, the inclusion of Gundelia tournefortii in the ration of fattening lambs seemed to be cost-effective the cost of one kg DM of ration was 1266, 1155, 1050, 924, and 787 Rials for rations 1 to 5, respectively.

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In order to determine the effects of using macaroni wastes instead of barley on dry matter intake (DMI), milk yield and composition, and nutrient digestibility, eight lactating Holstein cows (4 primiparous and 4 multiparous) in midlactation were used in a 44 Latin square design. The experimental periods were 21 d with 16 d for adjustment and 5 d for data collection. Treatments included a control diet (1) and diets 2, 3, and 4 containing 15, 30, and 45% macaroni wastes, respectively, which were fed three times a day as total mixed rations. During the last 5 days of each period, feed and fecal samples were taken for determination of DMI and apparent digestibilities and milk samples for fat, protein, lactose, and solids no fat (SNF). During the last day of collection period, urine samples were collected 3 and 5 h postfeeding for pH determination. The results showed no significant differences among experimental traits in either primiparous or multiparous, and across all cows. Milk yield and efficiency of feed conversion were nonsignificantly higher for diets 2, 3, and 4 compared with control cows. Compared to the control diet, DMI, fat, protein and SNF percentages did not significantly decrease in diets 3 and 4. From the results of this expriment, it may be concluded that replacing barley with macaroni wastes up to 45 percent could increase energy intake without any adverse effects on milk production and composition or on metabolic function in midlactating dairy cows.