In soil moderately infested with potato golden cyst-nematode, Globodera rostochiensis, nematicide treatments which lessened soil infestation when a susceptible potato crop was grown permitted a satisfactory second crop to be grown 3 years later without further treatment. In two experiments on heavily infested sandy loam on the same farm (Woburn Experimental Farm, Bedfordshire), aldicarb or oxamyl, incorporated in the seedbed in 1979 or 1980, greatly increased yields of Pentland Crown tubers and reduced the number of eggs left in the soil after harvest, but had little effect on a second crop of Pentland Crown potatoes grown 4 years later. Application of aldicarb or oxamyl to the seedbed before this second crop of potatoes increased yields and lessened nematode increase. The injection of 1,3-dichloropropene mixture (Telone II) into the soil in autumn at 224 kg/ha in one of these experiments did not enhance the nematode population control achieved by aldicarb or oxamyl alone.

The growth and yield of five cultivars of sunflower (Frankasol, Cerflor, Sunbred 246, Sokota 2057 and Sigco EX 10), sown from the end of March to the beginning of May, were studied in three experiments at Long Ashton Research Station, UK, during 1986, 1987 and 1988. The time from sowing to emergence and to maturity (as assessed by seed moisture content) was shortened by later drilling, although earlier sown crops were still ready for harvest slightly before the later sown ones. Cultivars differed in speed of development; Frankasol and Cerflor were the slowest to develop and Sigco EX 10 the fastest. Plant heights, head diameters and yields were all affected more by cultivar than by sowing date. The slower maturing cultivars produced the highest yields. Infection levels with Botrytis cinerea seemed to be related to the date of flowering, as early sown and fast developing cultivars became infected earlier. There were few benefits from early sowing and the optimum time appeared to be mid- to late April. Overall, Sunbred 246 was the most successful cultivar in these experiments, combining reasonable yields with moderately early maturity.

Growth regulators were applied to faba bean (field bean) plants in order to study hormonal control of premature reproductive abscission. Combined data from pairs of racemes sited in a consistently yielding region of the main stem indicated effects of growth regulator treatments. Decapitation increased pod numbers, but the inhibitory influence of the upper shoot could not be replaced completely by indol-3yl-acetic acid (IAA) applied to the cut stem stump. Blockage of auxin transport through the stem with the auxin-transport inhibitors 2, 3, 5-triiodobenzoic acid (TIBA) or methyl-2-chloro-9-hydroxyfluorene-9-carboxylate (CF, chlorflurenol) reduced pod numbers above the application point. The latter effects might have been indirect and due to elevated ethylene levels, since pod retention in this shoot region was decreased when sprayed with the ethylene-releasing compound 1-aminocyclopropane carboxylic acid (ACC) and increased when sprayed with ethylene-biosynthesis inhibitors 2-aminoethoxyvinyl glycine (AVG) or l-amino-2-cyclopropylcyclopropane carboxylic acid (cyclopropyl-ACC). Pod numbers were increased when the reproductive structures themselves were sprayed with IAA, gibberellic acid (GA3) or 6-benzylaminopurine (BAP), although a corresponding increase in total seed weight occurred only with the latter growth regulator. Application of BAP or abscisic acid (ABA) as root drenches showed that levels of reproductive abscission were raised or lowered with BAP treatment, depending on its concentration, and lowered with ABA treatment. It is suggested that growth regulator treatments leading to decreased ethylene production in the shoot and/or increased cytokinin and abscisic levels in the xylem sap are those most likely to reduce abscission.

Forty-one experiments were carried out in England and Wales between 1983 and 1985 to compare ammonium nitrate and urea as N top dressings for multicut silage.

The results showed that relative dry matter yields from the two fertilizers differed considerably between sites. However, compared with ammonium nitrate, there was a mean yield decrease with urea of 2% at the first cut and 5% at the second cut. Mean herbage N contents and apparent N recoveries were lower with urea than with ammonium nitrate at both the first and second cuts. It appeared, at least for first-cut dressings applied in early spring, that urea effectiveness increased with the amount of rain falling within 3 days of fertilizer application. The effect was much less obvious at the second cut.

Urea effectiveness was not markedly reduced on soils of high pH or light texture, where higher ammonia volatilization losses might have been expected.

The relationship between values of 85Sr concentration ratios (CRs) and exchangeable bases, expressed in absolute (mmol/kg) or relative (percentage of cation exchange capacity (CEC)) terms, was considered using the results of a glasshouse pot experiment conducted in 1989, for soils and crops of Greece. Exchangeable calcium, expressed in mmol/kg, presented, in most instances, a significant (P = 0·05–0·01) or highly significant (P < 0·01) negative correlation with the CRs of various crops or plant parts, while exchangeable calcium plus magnesium or total exchangeable bases (expressed also in mmol/kg) showed an even better correlation (higher values of r, lower variability). Expression of the amounts of exchangeable bases in relative terms further improved the correlation coefficient in each comparison. The correlations between the percentage of exchangeable (Ca + Mg) or exchangeable bases and CRs, which were always negative, were significant or highly significant for all tested crops or plant parts. The correlation between CRs and soil properties was greatest for exchangeable (Ca + Mg) expressed as a percentage of CEC (r = -0·92) and followed the order: Exchangeable (Ca + Mg) as % of CEC ≈ exchangeable bases as % of CEC ≈ exchangeable (Ca + Mg) in mmol/kg ≈ exchangeable bases in mmol/kg > exchangeable Ca as % of CEC > exchangeable Ca in mmol/kg.

Quantitative relationships between CRs of the tested crops or plant parts and exchangeable calcium plus magnesium (% of CEC) of soils are also presented.

Treatments which lowered the rate of ammonia volatilization from surface-applied cattle slurry were evaluated in three field experiments during 1989/90 at the Agricultural Research Institute of Northern Ireland. The relative effects of separation, dilution with water before application and washing with a water spray after application, on ammonia volatilization rates were compared over 4 days using ventilated enclosures. As the loss rate of ammonia during the first 4 days after application was highly correlated with the loss rate over the first 4 hours after application, the loss rate in the first 4 hours was used as a rapid method to assess the efficacy of various combinations of separation, dilution and acidification. Ammonia volatilization loss rates from treatment combinations were compared to the loss rate from whole slurry.

A 50% decrease in ammonia volatilization was achieved by separation through a 0·4 mm mesh, separation through a 10·0 mm mesh plus dilution with 86% by volume of water, or separation through a 2·0 mm mesh plus washing with 53% by volume of water.

A 75% decrease in ammonia volatilization was achieved by acidification to pH 6·5, or combinations of separation and dilution, namely separation through a 0·4 mm mesh plus 50% dilution or separation through a 5·0 mm mesh plus 100% dilution.

A 90% decrease in ammonia volatilization was achieved by acidification to pH 6·0, dilution by 50% plus acidification to pH 6·5, or separation through a 0·4 mm mesh plus acidification to pH 6·5.

The effects of separation and acidification on ammonia volatilization were cumulative. There was a highly significant inverse linear relationship between ammonia volatilization rate and volume of nitric acid used. Adding 10 M nitric acid at 1·4% by volume lowered volatilization by 75% of that from whole slurry and increased the nitrogen content of the slurry by 2 g N/l, making it a more balanced NPK fertilizer for cut swards. Because the variable value of cattle slurry is due to loss of nitrogen as ammonia and smothering of the sward with slurry solids, a combination of separation or dilution to lower sward contamination and acidification with nitric acid to lower volatilization may be the best practical option for improving cattle slurry as a fertilizer for cut grass.

Leaves of olive trees (Olea europaea L.) of eight cultivars, Manzanilla, Picual, Hojiblanca, Edremit, Conservolia, Picholine-Marroqui, Chemlali and Frantoio, were collected in different seasons and years in Córdoba, Spain. Their chemical composition and in vitro organic matter digestibility values were determined. Differences in composition and nutritive value between cultivars, years and seasons were studied in Manzanilla, Picual and Hojiblanca, the three most important local cultivars. There were significant differences both between cultivars and seasons (P < 0·05) and a non-significant difference between years.

The effect of various drying procedures (fresh, oven-dried, air-dried indoors or air-dried outdoors) on chemical composition, in vitro digestibility and in vivo digestibility in sheep was also examined. The in vivo organic matter digestibility of fresh leaves was significantly higher than that of dried leaves. No difference was found between leaves air-dried indoors and oven-dried leaves. However, leaves air-dried outdoors were significantly less digestible. Quick drying in an oven reduced the digestibility of crude protein and acid detergent fibres compared to air drying indoors. There was a significant decrease in digestibility of 11% when leaves were dried separated from the branches as compared to leaves dried on the branches.

In a glasshouse pot experiment in Athens, Greece in 1989, 85Sr to calcium observed ratios (OR) based on the values of exchangeable Ca instead of soil Ca (ORexCa), were determined for crops or plant parts grown in eight soils widely differing in their physical and chemical properties. Compared to the values of concentration ratio (CRs) the values of ORexCa did not show as wide variation with the soil type. They were relatively constant and usually not related to soil properties. The ORexCa values were essentially the same as OR values for the non-calcareous soils and much smaller than the OR values for calcareous soils, considering as soil Ca in the calculation of OR, the sum exchangeable, watersoluble and CaCO3 Ca.

The values of 85Sr/Ca + Mg observed ratios (ORexCaMg) were just as good as the ORexCa values, while those of 85Sr/Ca + Mg + K + Na (ORex bases) showed more variation.

Highly significant (P <0·01) correlations were observed between the fractions of the observed ratios ORexCa, ORexCaMg and ORex bases, for each crop or plant part tested.

Combinations of treatments of cattle slurry, which have previously been shown to have lowered ammonia volatilization by 75% of that from whole slurry, were compared in a field experiment with perennial ryegrass at the Agricultural Research Institute, Hillsborough in 1990. Whole slurry and slurries obtained by separation through screens with mesh sizes of 5·0, 3·0, 1·1 and 0·4mm were acidified with 1·4% by volume of 10M nitric acid. Slurries separated through 5·0 and 0·4 mm meshes were diluted 100% and 50% respectively by volume with water and amended with calcium nitrate to supply the same amount of nitrogen as the nitric acid. All slurry combinations were surface-applied at 100 kg (NH4+-N + NO3−-N)/ha to different plots on three occasions during the growing season. Volatilization of ammonia was measured on adjacent plots using ventilated enclosures. By comparison with inorganic fertilizer treatments, assessments were made of the efficiency of slurry nitrogen for herbage production, the fertilizer value of phosphorus, potassium and sulphur in the slurry, and the effects of slurry on silage quality.

The mean ammonia volatilization over all applications of acidified slurries was 17% of that from whole slurry. The two separation plus dilution treatments, however, only lowered volatilization to about half of that from whole slurry. Within separation plus acidification treatments, the trend was for dry matter yield and nitrogen offtake to increase as mesh size decreased down to 1.1 mm. For slurries separated through 5·0 and 0·4 mm meshes, the effect of the additional dilution treatment on dry matter yield and nitrogen offtake was similar to the effect of acidification. Efficiency of nitrogen offtake over all three cuts, relative to inorganic fertilizer nitrogen, was 54% for acidified whole slurry and 88% for slurry separated through a 1·1 mm mesh and acidified. Denitrification in nitric-acid amended slurries and sward contamination from slurry solids may have been responsible for lowering nitrogen efficiency.

Chemical analyses of herbage showed that the concentrations of phosphorus, potassium and sulphur from the slurry treatments were comparable to those in herbage receiving the recommended rates of inorganic fertilizers and were sufficient for optimum yield. Slurry application had a detrimental effect on the fermentation quality of the ensiled herbage. Chemical analyses indicated that fermentations from two slurry treatments at the first cut and all slurry treatments at the third cut were poorer than those on treatments receiving the equivalent rate of inorganic fertilizer nitrogen.

Field trials at the University of Nottingham, UK, in 1979 and 1980 investigated the effect of moisture stress on the growth and yield of the leafless dried pea Filby. In the absence of drought, the crop photosynthetic area was increased and maturity delayed. Seed yield was increased by the production of a greater number of reproductive nodes and a reduced abortion of flowers and pods.

In the second season, two sowing dates were also tested. Later sowing reduced the seed yield under the high and low moisture treatments by 14 and 33% respectively, due to an increased abortion of flowers and pods. The high moisture treatment reduced the water use efficiency (WUE) in this season and WUE was lower for the later sown crops, but there was no effect on WUE in the previous season.

The seed yield and water use of pot-grown leafless peas were lower than were those of a nearisogenic line of leafed peas. Moisture stress reduced the yield of both phenotypes but the effect on the leafless pea was greater. Moisture stress imposed at flowering reduced yields more than it did at pod filling and there was an additive effect of moisture stress at both times.

Phosphorus (P) cycling and losses in irrigated, sheep-grazed pastures receiving superphosphate (SP) applications for 35 years at annual rates of 0, 188 and 376 kg/ha were studied using a massbalance approach which accounted both for P inputs to and outputs from the soil-plant-animal system. Total recoveries of applied P in the soil-plant-animal systems in the 188 and 376 kg SP/ha treatments were 94 and 83% respectively. Approximately 52–53% of the applied P was recovered in the soil within the major plant rooting zone (0–300 mm soil depth). These data suggest that P leaching losses from SP fertilizer, plant litter, root residue and sheep faeces were unlikely to occur beyond the major plant rooting zone. However, the transfer of excretal P to stock camps and the transport of P from SP fertilizer, plant litter and sheep faeces via the irrigation water along the border from the top to the bottom of the irrigated border strip accounted for less than 6% of the applied P. Superphosphate applications resulted in the accumulation of both soil inorganic and organic P fractions to a depth of 225 mm. The accumulation of soil inorganic P was most pronounced when SP was applied annually at the rate of 376 kg/ha, which was in excess of pasture P requirements.

A field experiment compared the effects of urea, surface-applied either as a solid or liquid, at a rate of 100 kg N/ha, on ammonia volatilization from an established perennial ryegrass sward on three separate occasions during 1990 at the Agricultural Research Institute, Hillsborough, Northern Ireland. Total NH3 loss over 10 days from prilled urea for each of the three study periods was equivalent to 3.4, 9.1 and 4.4% of N applied. On two occasions, applying urea as a liquid significantly increased NH3 loss compared to prills, whereas on the third occasion there was no significant effect. Increasing the spray volume from 80 to 640 ml/m2 had no significant effect on NH3 volatilization.

Surface application of urea as a liquid compared to the prilled form did not lower NH3 volatilization and therefore is not a strategy that would improve the efficiency of urea as a nitrogen source for temperate grassland.

Twelve yearling Droughtmaster heifers were grazed on a tropical grass/legume pasture in north-east Australia for 1 year in four paddocks, each of 4 ha. One paddock was fertilized annually with 10 kg P/ha (treatment HPF). The other three paddocks had low soil P and low pasture P status. In one of the low soil P paddocks, P was added to the drinking water (treatment HPS) but no supplement was provided in the other two paddocks (treatments LP1 and LP2). In February, May and August 1989, the P kinetics of the heifers were monitored following oral administration of ruminal chromic oxide capsules and i/v injection of 32P. At the same times, oesophageal-fistulated steers were grazed in the paddocks to obtain extrusa samples to estimate the P content and digestibility of selected forage.

The liveweight gain per heifer was higher in the HP treatments (196 kg) than in the LP treatments (152 kg). The intake, absorption and excretion of P were closely related but the faecal excretion of P relative to P intake was less in heifers with than without P supplement. The P intakes of the LP heifers were about half the quantities recommended in the nutrient feeding standards for the observed food intakes and weight gains. The coefficients of P absorption in the LP heifers in May and August were high (> 0·8) and did not decrease with age or liveweight. The coefficients of P absorption of heifers given supplementary P were as high as those for LP heifers, but those of heifers on the fertilized pasture were significantly lower in May and August. The endogenous faecal excretion of P was related to P intake but more closely to dry matter intake and plasma inorganic P together. The reasons for the difference between observed P intakes of LP heifers and recommended requirements are discussed in relation to the assessment of P requirements of grazing cattle. The results from this experiment suggest that recommended P requirements are higher than necessary to sustain the measured liveweight gains of cattle on grass/legume pastures in the tropics.

Four Friesian bulls with ruminal and duodenal cannulae were used in a 4 × 4 Latin square experiment to study the effects of lactic acid (LA) on rumen fermentation and microbial protein synthesis. On a dry matter (DM) basis (g/kg), the basal diet comprised grass silage (700), barley (240) and rapeseed meal (60) and it was given at the rate of 7·1 kg DM/day. LA was infused continuously into the rumen at the rates of 0 (L0), 40 (L40), 80 (L80) or 120 (L120) g/kg basal diet DM.

The molar proportion of propionate in the rumen volatile fatty acids (VFA) increased linearly (P < 0.001) and that of acetate, isovalerate, caproate (P < 0.01) and isobutyrate (P < 005) decreased linearly with an increasing rate of LA infusion. At the same time there was a linear decrease (P < 0.05) in the number of rumen protozoa. When the metabolic fate of infused LA was calculated on a molar basis, 0.21 of lactic acid was converted to acetate, 0·52 to propionate and 0.27 to butyrate.

Infusion of LA into the rumen had no effect on the site or extent of the digestion of basal diet organic matter (OM) and neutral detergent fibre (NDF). LA diets tended to have a lower microbial N flow at the duodenum (71·4 v. 85·8 g N/day) and lower synthetic efficiency in the rumen (14·4 v. 20.4 g N/kg OM apparently fermented) when compared with the control diet. The ratio of duodenal non-ammonia N to N intake was highest with the control diet and lowest with L40, the effect of the LA rate being quadratic (P < 0·05). The results suggest that propionate was the main end-product of lactic acid fermentation in the rumen with the grass silage based diet. Lactic acid had no value as an energy source for microbial protein synthesis.

Sulphur (S) cycling and losses in irrigated, sheep-grazed pastures receiving annual superphosphate (SP) applications for 35 years at rates of 0, 188 and 376 kg/ha were studied using a mass-balance approach which accounted both for S inputs to and outputs from the soil-plant-animal system. Total recoveries of applied S in the 188 and 376 kg SP/ha treatments were estimated to be 35·2 and 21·2% respectively. Over 65·0% of the applied S was not recovered, and this was attributed to leaching losses beyond the major rooting zone (0–300 mm), lateral S transfer by irrigation water and cxcretal S transfer to stock camps. The lower S recovery in the 376 compared with the 188 kg/ha per year treatment was probably due to a higher accumulation of soil phosphorus (P), which might have competed with sulphate (SO42-) for adsorption sites on soil colloids. Superphosphate applications resulted in the accumulation of soil organic S (S0) fractions (hydriodic acid-reducible and carbonbonded S) to a soil depth of 300 mm in both camp and non-camp areas. However, an increase in SP applications from 188 to 376 kg/ha per year did not lead to a further accumulation of soil S0 fractions. Approximately 50% of this additional S input was estimated to be leached beyond the 300 mm depth. The presence of soil So fractions at 300 mm soil depth, especially in camp areas, suggests that leaching occurred, involving not only SO42- but also So fractions from soil, plant litter, root residues and animal excreta, as the soil had a low SO42- retention capacity. These leaching losses may limit the ability of soil S reserves to sustain adequate S for pasture production when S fertilizer application is withheld.

Four swamp buffaloes (Bubalus bubalis) and four crossbred Bos indicus x B. taurus cattle, fistulated at the rumen and abomasum or duodenum, were offered rice straw with mineral supplements in two experiments. In Expt 1, the straw was supplemented with 5% of leaf of Leucaena leucocephala, and in Expt 2 with either urea or urea with sunflower meal and rice grain. Intake of supplements of urea or urea/sunflower/rice respectively was 935 and 681 g/kg offered in buffaloes and 566 and 789 in cattle.

Buffaloes ruminated longer than cattle (Expt 1, 635 v. 452 min/day; Expt 2, 626 v. 466 min/day, P < 0·01). In Expt 1, voluntary intake and frequency of ‘A’ sequence forestomach contractions of both species was not affected by species, but buffaloes had a greater (P < 0·05) contraction force in the rumen and omasum, lower rate of ‘B’ sequence rumen contractions, and faster (P < 0·001) rate of gastrointestinal passage than cattle. In Expt 2, voluntary intake of both species was similar, and addition of concentrates did not affect voluntary roughage consumption, nor in situ rate of digestion of rice straw. Rate and predicted extent of digestion of dietary materials did not differ between species in Expt 1, despite lower concentrations of ammonia in rumen fluid in cattle than buffaloes; however in Expt 2, the rate of digestion of rice straw was higher (p < 0·05) and predicted extent of digestion was 14–20% (P < 0·05) lower in buffaloes. Digestibility of cell wall constituents was lower (P < 0·05) in buffaloes than in cattle in both experiments, but in Expt 2, provision of concentrates reduced (P < 0·01) the proportion of digestible cell wall constituents digested in the forestomach of buffaloes, but not of cattle.

Swamp buffaloes (Bubalus bubalis) and crossbred cattle (B. indicus x B. taurus) were offered two forages in two experiments. In Expt 1, four animals of each species were offered mature Rhodes grass hay (Chloris gayana) with a mineral supplement or with a supplement of minerals and urea (17·6 gN/d). In Expt 2, another group of four buffaloes and four cattle were offered mature spear grass hay( Heteropogon contortus) with mineral supplementation at intervals of 3 h. Four levels of urea (0, 5, 21 and 97 g/day) and 35S-sulphate were continuously infused in four periods.

Rhodes grass was consumed in greater amounts by cattle, whereas buffaloes ate more spear grass. Urea supplements increased intake of Rhodes grass by 12% in buffaloes and 22% in cattle, and of spear grass by 34% in buffaloes and 41 % in cattle. Digestibility of cell wall constituents and acid-detergent fibre of spear grass was lower (P < 0·05) in buffaloes than in cattle (417 v. 499; 471 v. 560 g/kg respectively). In Expt 2, dry matter digestibility progressively increased (P < 0·05) from 364 to 408 g/kg with increased urea infusion. Rumen dry matter pool increased by 11–21 % on infusion of 97 g urea/day, compared with no urea. Digestion of ground forages incubated in situ in the rumen was depressed below rumen ammonia levels of 30–60 mg N/l, while digestion of cotton thread was depressed below 60–80 mg N/l (Expt 1) or 150–200 mg N/l (Expt 2).

Patterns of N content in cotton thread suggested that more microbes attached in buffaloes and there was subsequently faster detachment than in cattle, particularly with increased urea infusion.

Dorper sheep are raised in extreme desert areas. Body mass loss and body fluid shifts were measured in Dorper rams denied water for 4 days and offered only wheat straw. The rams lost 16·3% body mass, 22·0% total body water volume, 35·1 % extracellular fluid volume and 41·7% plasma volume. On first drinking following dehydration, Dorpers were able to consume 19·7% of their dehydrated body mass and 100·3 % of their body mass loss. It was concluded that Dorpers can survive in harsh deserts through their ability to withstand dehydration and quickly replenish body mass losses when water becomes available.

Varied quantities of concentrate supplement were fed to three groups of pregnant West African Dwarf (WAD) goats at different gestational periods, while forage was provided ad libitum throughout pregnancy. One group (A) was fed on concentrate at the rate of 50 g/kg metabolic weight (W0·75) per day throughout pregnancy, a second group (B) was offered concentrate from Days 61 to 120, and 121 to term at the rate of 50 g and 25 g/kg metabolic weight per day, respectively, and a third group (C) was provided with concentrate from Days 61 to 120 and 121 to term at the rate of 25 g and 50 g/kg metabolic weight per day, respectively.

Results showed that there were no abortions, although two animals from group A had dystocia (difficult birth). There was no significant difference between the mean birthweight and neonatal growth rates of kids from groups A and B. The mean birthweight and neonatal growth rates of the kids from group C were significantly (P < 0·01) lower than those of groups A and B. There was no significant (P >0·05) difference between the mean udder circumference of animals in group C and those in groups A and B. All the neonatal deaths were recorded among the kids in group C. It is concluded that for economic animal production although it may not be necessary to feed pregnant WAD goats on high concentrate rations throughout the gestational period, they should not be underfed between Days 61 and 120 of pregnancy.

Using [14C]urea, the rates of urea synthesis in the body, excretion in the urine and degradation in the rumen and gut were compared in 20-month-old Kedah-Kelantan cattle and swamp buffaloes at the Universiti Pertanian Malaysia, Malaysia in 1987. The animals were fed rice straw or straw plus molasses.

The buffaloes were heavier than the cattle and had higher straw and nitrogen intakes, although these intakes did not differ significantly when compared on the basis of metabolic liveweight (W0·75).

Rumen pH in the buffaloes was lower, whereas ammonia and total volatile fatty acid (VFA) concentrations were higher than in the cattle. Total VFA concentration was lower when the diet contained molasses. Rumen bicarbonate kinetics did not differ significantly between species or diets.

There were no significant differences between species in plasma urea concentration, or urea synthesis rate per W0·75, or endogenous urea movement into the rumen per W0·75.

The buffaloes consumed more water and discharged twice as much urine as the cattle, but nevertheless excreted less urea per W0·75, and a larger fraction of their endogenously produced urea entered the gut. Movement of urea into the rumen per W0·75 was lower when the diet contained molasses.