Four silage diets were prepared from tropical grass and legume mixtures and fed to intestinally fistulated sheep to determine the sites and extent of digestion of the different silage components in the digestive tract. Pangola grass (Digitaria decumbens) was ensiled either alone or with the addition, 33% (w/w), of leucaena (Leucaena leucocephala cv. Cunningham), gliricidia (Gliricidia sepium) or cowpea (Vigna unguiculata cv. Caloona). All forages were grown at the University of Queensland farm in 1985. All silages were well preserved as indicated by low pH (< 4·1), ammonia N (< 9% total N), acetic acid (< 13 g/kg dry matter (DM)) and ethanol (< 19 g/kg DM) contents, and high DM (> 290 g/kg) and lactic acid (> 41 g/kg DM) contents. The inclusion of leucaena and gliricidia significantly increased the total N content of the silages. The addition of legumes at ensiling significantly increased rumen ammonia N (pangola 59 mg N/l, legume diets 110–115 mg N/l) and the proportion of propionic acid in rumen fluid. Sheep given pangola + leucaena silages had significantly higher DM intakes (66·3 g/kg W0·75 per day) than sheep given pangola and pangola + cowpea silages (52·4 and 53·2 g/kg W0·75 per day respectively). The inclusion of gliricidia significantly depressed silage intake (43·1 g/kg W0·75 per day). There were no significant effects of diet on DM (551–609 g/kg) and organic matter (550–612 g/rkg) digestibility. Sheep given pangola + leucaena silages had higher N intakes, N balances, rates and efficiencies of microbial N synthesis and total non-ammonia N (NAN) flows to the small intestine than did sheep given the other silages. Apparent degradabilities of silage N in the rumen were similar for all diets (0·491–0·559 g N/kg N intake), but sheep given pangola + leucaena silages had lower true (corrected for endogenous N) N degradabilities (0·648 g N/kg N intake) than those given the other diets (0·751–0·775 g N/kg N intake). The values obtained in this experiment were compared with those reported for temperate grass silages, and it was concluded that whilst the digestibility of tropical grass/legume silages was low, intakes and rumen fermentation characteristics were similar to those found for temperate grass silages.

In an incomplete block 2x2x2 factorial experiment seventy-two Large White type pigs, after having been fed individually and identically up to 120 lb (54·5 kg) live weight, were fed from that weight up to 200 lb (90·9 kg) live weight maize or barley based diets (factor 1), with each diet having either a wide or a narrow calorie/protein/lysine (CPL) ratio (factor 2). The feeding was effected in individual feeders in a Danish type piggery (with six pigs per pen) with all diets offered as wet mashes and according to scales which gave two different calorie intakes (factor 3). There were, therefore, four different diets and eight different feeding treatments.

A comparison was made between an intensive system of lamb production based on Italian ryegrass RvP and one based on perennial ryegrass S. 24, over 2 years, each at three stocking rates (14, 17, 20 ewes/ha). More grass was grown in the first year than in the second when the yield of RvP was particularly reduced. The ewes and lambs ate more RvP than S. 24 but there was no difference in lamb growth rate. The lambs grew faster at the low stocking rate from 0 to 18 weeks and from 0 to slaughter than at the medium and high stocking rates, in both years. Ewe intake and lamb growth rate were higher in the second year than the first. The Masham ewes with two lambs ate significantly more grass per unit of body weight than the Finnish Landrace × Scottish Halfbred and Finnish Landrace × Scottish Blackface ewes, and their lambs grew significantly faster. It was concluded that for an intensive system of lamb production from grass, S. 24 was more suitable than RvP.

As demand for animal products, such as meat and milk, increases, and concern over environmental impact grows, mechanistic models can be useful tools to better represent and understand ruminant systems and evaluate mitigation options to reduce greenhouse gas emissions without compromising productivity. The objectives of the present study were to describe the representation of processes for growth and enteric methane (CH4) production in AusBeef, a whole-animal, dynamic, mechanistic model for beef production; evaluate AusBeef for its ability to predict daily methane production (DMP, g/day), gross energy intake (GEI, MJ/day) and methane yield (MJ CH4/MJ GEI) using an independent data set; and to compare AusBeef estimates to those from the empirical equations featured in the current National Academies of Sciences, Engineering and Medicine (NASEM, 2016) beef cattle requirements for growth and the Ruminant Nutrition System (RNS), a dynamic, mechanistic model of Tedeschi & Fox, 2016. AusBeef incorporates a unique fermentation stoichiometry that represents four microbial groups: protozoa, amylolytic bacteria, cellulolytic bacteria and lactate-utilizing bacteria. AusBeef also accounts for the effects of ruminal pH on microbial degradation of feed particles. Methane emissions are calculated from net ruminal hydrogen balance, which is defined as the difference between inputs from fermentation and outputs due to microbial use and biohydrogenation. AusBeef performed similarly to the NASEM empirical model in terms of prediction accuracy and error decomposition, and with less root mean square predicted error (RMSPE) than the RNS mechanistic model when expressed as a percentage of the observed mean (RMSPE, %), and the majority of error was non-systematic. For DMP, RMSPE for AusBeef, NASEM and RNS were 24·0, 19·8 and 50·0 g/day for the full data set (n = 35); 25·6, 18·2 and 56·2 g/day for forage diets (n = 19); and 21·8, 21·5 and 41·5 g/day for mixed diets (n = 16), respectively. Concordance correlation coefficients (CCC) were highest for GEI, with all models having CCC > 0·66, and higher CCC for forage diets than mixed, while CCC were lowest for MY, particularly forage diets. Systematic error increased for all models on forage diets, largely due to an increase in error due to mean bias, and while all models performed well for mixed diets, further refinements are required to improve the prediction of CH4 on forage diets.

Winter rapeseed was introduced into Greece a decade ago to provide oil for biodiesel. To identify agronomic traits affecting yield and quality, three hybrids and an inbred line were tested over two seasons (2005–2006 and 2006–2007) and four locations, in central and northern Greece, varying in pedo-climatic conditions. The large variations in seed yield, quality and agronomic traits were largely ascribed to location; in contrast, cultivar accounted for ⩽0·010 of the variation for many traits. Below 40°N, rapeseed is a risky crop; short season, high temperatures and low rainfall during reproductive growth diminished seed yield and oil content, increased oleic and erucic acid and minimized linolenic acid. A hybrid, Exact, with tall stature and large seeds was adaptive to such conditions. The most productive location had dense stands with tall plants bearing numerous pods on the main raceme. At the site with the coldest winter, plant density (PD) was lowest (ca. 30 plants/m2) but rapeseed compensated by producing large seeds, with high oil content and harvest index (HI). A biplot revealed that the hybrid Excalibur, outperforming the other cultivars for oil content in six out of eight trials, produced the highest and most stable oil yield. Combined data showed that seed yield and oil yield were positively correlated with PD, seed size and HI and negatively to the number of pods on branches and per plant. Large seeds had high seed oil content. Oleic acid was negatively correlated to linolenic acid concentration. High temperatures and low rainfall favoured oleic acid, which was positively associated with seed number per pod.

Six compounds which show juvenile-hormone-like (JH) activity (TH6040, JH-25, Altosid, Altozar, ZR-777 and ZR-619) were tested on larvae of Culex pipiens. The reproduction potential of the females obtained during two successive generations was not affected greatly, but there was a decline in pupation rate with some compounds. There seemed to be a direct relationship between the size of females of this species and treatment with JH compounds tested in the present investigation, since treatment with concentrations to inhibit the emergence of 10% or 50% of adults caused significant changes in the width of head, wing dimensions or length of hind legs.

The present paper develops a mixture regression model that allows for distributional flexibility in modelling the likelihood of a semi-continuous outcome that takes on zero value with positive probability while continuous on the positive half of the real line. A multivariate extension is also developed that builds on past multivariate models by systematically capturing the relationship between continuous and semi-continuous variables, while allowing for the semi-continuous variable to be characterized by a mixture model. The flexibility associated with this model provides potential applications in many production system studies. The empirical model is shown to provide a more accurate measure of mortality rates in cattle feedlots, both independently and within a system including other performance and health factors.

A liquid chromatography mass spectrometry method for determination of clothianidin in brown rice, straw, rice hull, paddy water and paddy sediment was developed and residue levels were determined in the different components. The limit of quantification was set at 0·01 mg/kg for the matrices studied. Clothianidin degradation in straw, paddy water and soil was studied, and clothianidin residues in brown rice, straw, hull and paddy soil were determined. Concurrent recoveries were between 85·6 and 92·5%, with relative standard deviations ranging from 1·3 to 6·8% at three fortification levels between 0·01 and 5·0 mg/kg. The half-lives in straw, paddy water and paddy sediment were found to be 1·9–4·9, 4·1–5·0 and 4·9–6·3 days, respectively. The maximum residues in brown rice, straw, hull and paddy soil samples were 0·38, 1·88, 1·38 and 0·14 mg/kg, respectively.

Wheat was grown in rotation with three different crops, namely wheat, chickpea and lentil, and with a fallow, in three consecutive seasons beginning in 1992 in NW Syria. Two rates of N fertilizer (0 and 30 kg N ha−1) were superimposed on these four rotations, giving eight treatments which were replicated three times in each season. 15N-labelled fertilizer was applied to microplots within the fertilized plots at sowing when unlabelled fertilizer was broadcast on the rest of the plot.

Yields of grain and dry matter were generally greatest when wheat followed a fallow, and least in the continuous wheat rotation; this was significant in 1993 and 1994. Applications of N fertilizer had no effect on productivity in 1992, but in the other two seasons grain yields were increased by 550 kg ha−1, on average. Depending on the season, between 8 and 26% of the 15N-labelled fertilizer was recovered in the shoot dry matter, while between 18 and 54% of the fertilizer remained as N in the soil at harvest, mostly in the 0–20 cm soil layer. More than half the fertilizer in the crop at harvest had been taken up by the end of March, although by March the plants were only c. 10% of their mass at harvest. Conversely, <35% of the soil-derived N in the crop at harvest had generally been taken up by March. This temporal difference in the pools of N utilized by the crop was attributed to the drying of the soil surface layers where most of the N fertilizer remained. Approximately 50% of the 15N-labelled fertilizer was unaccounted for in the crop and 0–40 cm soil layer at harvest.

The yield benefit of growing wheat in rotation with a fallow or either grain legume rather than continuously, ranged from nothing to the equivalent of a fertilizer application of at least 30 kg N ha−1 to continuous wheat, depending upon the season and the previous crop. Only in the season where the residual effect of the rotation on wheat yields was greatest (1993) did the preceding grain legume crop or fallow appear to contribute between 10 and 20 kg N ha−1 to the wheat crop. Otherwise they contributed no N at harvest. While a fallow may increase the availability of water to the succeeding wheat crop, the benefit from the preceding grain legumes may lie in their effect on the soil physical structure or on the increased availability of other limiting nutrients rather than additional N.

Under experimentally controlled nutritional levels, using Hereford, Hereford x Dairy Shorthorn, Dairy Shorthorn and Friesian breed-types, 288 animals were studied for age of eruption of the four pairs of front permanent teeth. Standard deviations are similar to those of other reports on Bos taunts. Breed differences were negligible and there is no evidence of heterosis. Lower nutritional levels delayed and higher levels advanced eruption. This effect had a maximum difference of 72 days if the differential nutrition was applied in calfhood. Differential nutrition later produced a smaller effect. It is concluded that in practice, the age of teeth eruption cannot be used to determine accurately the previous nutritional status of individual animals.

Male and female (Suffolk × (Finnish Landraee × Dorset Horn)) lambs were used in three experiments to examine the replacement of milk by undried and dried fish protein hydrolysates (FPH), a mixture of lard and coconut fat, and partially hydrolysed starch (Protamyl 110). The animals received the experimental diets from 1 week of age in Expts 1 and 2, and from 4 weeks of age in Expt 3. They were given the diets in eight equal feeds (i.e. every 3 h) from an automated teat bar system. The level of feeding was 1·046 MJ/kg0−76/day. Experiments 1 and 2 lasted for 35 days, during which live-weight gain and food conversion ratios were recorded and at the end the digestibility of N, dry matter and starch was determined. Experiment 3 consisted of three small digestibility trials.

In Expt 1, the replacement of milk protein with undried FPH and of milk fat with lard plus coconut fat had no significant effects on live-weight gain, food conversion ratio or nutrient digestibility. Somewhat lower gains for the lambs given the FPH than those given milk protein were observed during the first 15 days of the experiment. Apparent digestibility of milk protein and milk fat was 95 and 99% while that of PFH and lard plus coconut fat was 94 and 96% respectively. The replacement of milk fat with lard and coconut fat caused some reduction in live-weight gains and nutrient digestibility. Lactose was completely replaced by protamyl both in diets based on milk protein or FPH with no effect on live-weight gains or food conversion ratio.

Apparent digestibility of fish protein was not affected by the drying process. Fat digestibility of diets containing undried or dried FPH ranged from 46 to 98% according to the type of emulsifier used. The results are discussed in relation to published data concerning the problems associated with the use of fish protein in milk replacers.

1. A spring top-dressing of 0·5 cwt.nitrogen/acre was applied to winter wheat as urea or ammonium nitrate in a single spray at 30 gal./acre or as solid fertilizer applied to the soil. A weed-killer, 2,4-dichlorophenoxyacetic acid, was applied in the nitrogen spray or separately in spray to plots that received solid fertilizer.

2. Uptake of nitrogen by the crop from solid fertilizer was about twice that from fertilizers applied in sprays. Solid fertilizer increased yield slightly more than did sprays.

3. Ammonium nitrate and urea had the same effects, both when applied in sprays and when applied as solid to the soil.

4. 2,4-D decreased the amount of weed slightly, but had no effect on yield of wheat.

5. The interactions between weed-killer and method of applying nitrogen were small; the response to nitrogen in dry weight of straw, including weeds, in one experiment, and of shoots in another experiment, was decreased by 2,4-D when nitrogen was applied in spray but not when it was applied as solid fertilizer.

A very serious effort to modernize irrigation systems is being made in Spain, to reduce water and energy losses in an environmentally sustainable way. This is expensive and it is important that the new irrigation systems work properly over a long period. The systems have been designed taking into account historical evapotranspiration (ET) averages during the months of maximum demand, as well as the crop-specific ET values (Kc coefficients) of typical crops. However, the increase in ET rates due to global warming could mean that the capacity of these new and expensive irrigation systems to fulfil the crop water requirements may be exceeded in the near future. However, the expected increase in CO2 concentration could diminish crop transpiration rates for similar water demands from the atmosphere, thereby reducing irrigation requirements. A methodology was developed in order to estimate crop water requirements under climate change conditions. The reliability of a new irrigation system designed in Valladolid, Northern Spain was tested. The regionalized climate change scenarios for Valladolid, provided by the National Institute of Meteorology, were used for the periods 2011–40, 2041–70 and 2071–2100 and the A2 and B2 emission scenarios were considered using the ECHAM and coupled general circulation model (CGCM) global circulation models. A historical series of daily meteorological data for Valladolid was used to generate statistical ET distributions through the LARS-WG generator. Simulations considered each of the above periods, global circulation models (GCM) and emission scenarios. Furthermore, the Kc of the typical irrigated crops of the zone (maize, potato and sugar beet) were reduced for each period, GCM and emission scenario according to the relationships between CO2 concentrations and transpiration obtained by Kruijt et al. (2008). The results indicated that, on average, historical ET rates provide a sufficiently robust indicator to enable estimations of the crop ET in the future, particularly considering the CO2 effect in reducing crop transpiration. However, ET variability is significantly increased after 2040, especially for the A2 emission scenario. The results show that ET variability rather than global increase is the most serious risk that current irrigation systems must face in the near future in Northern Spain, as consequence of climate change. Such variability should be included in irrigation designs.

Analyses of yields for 12 sets of test-crosses of inbred lines of winter beans are given.

Since the introduction of silos and associated techniques of ensilage production in the late 1870's, maize has been the principal silage crop in the United States. Many British authorities agree that maize is a ‘splendid silage crop, highly nutritious, heavy yielding and easy to cut and handle’ (Bond, 1948, see also Watson & Smith, 1956; Woodman & Amos, 1944) but, nevertheless, it is very rarely grown in Britain for silage. In this country, as in most countries of Western Europe, the predominant aim of maize cultivation has been to produce succulent green fodder for direct feeding to animals during time of drought and consequent grass shortage. The acreage grown in England is small, but in Western Germany in 1955 there were about 100,000 acres of fodder maize (Becker, 1956), while in France, in 1954, the acreage exceeded 500,000 (Desroches, 1955). Recently in Western Europe considerable interest has been shown in the possibilities of maize as a silage crop, and within the past few years preliminary results have been reported from Holland (Becker, 1956; Anon. 1954, 1955); Denmark (Bagge & Hansen, 1956); Belgium (Lacroix, 1955; Ledent, 1955); Germany (Jungehulsing, 1955; Schell, 1954); France (Desroches, 1955), and Switzerland (Bachmann, 1952).

The current study investigated the effects of supplementing rumen-protected choline (RPC) on metabolic profile, selected liver constituents and transcript levels of selected enzymes, transcription factors and nuclear receptors involved in mammary lipid metabolism in dairy goats. Eight healthy lactating goats were studied: four received no choline supplementation (CTR group) and four received 4 g RPC chloride/day (RPC group). The treatment was administered individually starting 4 weeks before expected kidding and continuing for 4 weeks after parturition. In the first month of lactation, milk yield and composition were measured weekly. On days 7, 14, 21 and 27 of lactation, blood samples were collected and analysed for glucose, β-hydroxybutyrate, non-esterified fatty acids and cholesterol. On day 28 of lactation, samples of liver and mammary gland tissue were obtained. Liver tissue was analysed for total lipid and DNA content; mammary tissue was analysed for transcripts of lipoprotein lipase (LPL), fatty acid synthase (FAS), sterol regulatory binding proteins 1 and 2, peroxisome proliferator-activated receptor γ and liver X receptor α. Milk yield was very similar in the two groups, but RPC goats had lower (P<0·05) plasma β-hydroxybutyrate. The total lipid content of liver was unaffected (P=0·890), but the total lipid/DNA ratio was lower (both P<0·05) in RPC than CTR animals. Choline had no effect on the expression of the mammary gland transcripts involved in lipid metabolism. The current plasma and liver data indicate that choline has a positive effect on liver lipid metabolism, whereas it appears to have little effect on transcript levels in mammary gland of various proteins involved in lipid metabolism. Nevertheless, the current results were obtained from a limited number of animals, and choline requirement and function in lactating dairy ruminants deserve further investigation.

Calcium content in the diet can affect egg quality and production in aged birds. Calcium pidolate is a new form of calcium supplementation in poultry diets, which favours the absorption of this mineral. The current study was conducted to evaluate the effect of dietary calcium pidolate concentration in the diets of aged laying Japanese quails. A total of 120 female quails (27 weeks old) were assigned to four treatment groups, each with six replicates of five quails per pen. In the 10-week trial, quail diets were supplemented with calcium pidolate at four concentrations (0, 0.25, 0.50 and 1.00 g/kg), providing 25.1, 25.4, 25.8 and 26.5 g/kg calcium, respectively. As a result of this study, body weight, feed intake and feed conversion ratio did not change with the concentration of calcium pidolate (P > 0.05). In contrast, albumen and yolk index decreased as calcium pidolate level increased (P < 0.05). Moreover, calcium pidolate at a concentration of 0.50 g/kg resulted in the greatest egg production, eggshell breaking strength and eggshell thickness (P < 0.05), while above these levels the factors studied were negatively affected. According to these results, the optimal concentration of calcium pidolate in the diets of aged laying quails was 0.50 g/kg.

The partitioning of above ground nitrogen (N) in chickpea (Cicer arietinum), lentil (Lens culinaris), lupin (Lupinus angustifolius) and pea (Pisum sativum) at crop maturity was investigated. The plants were grown at different plant populations and sowing depths in 1998/99 and 1999/2000 in Canterbury, New Zealand. In all four legumes the N concentration was highest in seed (29–36 mg/g N) followed by senescent leaves. The lowest N concentration was in stems. Lupin had the highest seed N yield at 16·82 and 19·29 g/m2 followed by chickpea at 10·26 and 13·10 g/m2, in 1998/99 and 1999/2000, respectively. Lentil had the lowest N concentrations and yield. The distribution of N to all legume plant parts increased as population increased up to twice the optimum and 400 plants/m2 in 1998/99 and 1999/2000, respectively. Over all plant populations, the nitrogen harvest index (NHI) was stable in each of the four species across the two seasons. However, the NHI changed with changes in plant population and sowing depth. The N accumulation efficiency (EN) was highest in lentil at 0·024 and 0·027 g N/g DM and lowest in chickpea at 0·018 and 0·021 g N/g DM in 1998/99 and 1999/2000, respectively. The NHI and the crop harvest index (CHI) were correlated and both were strongly associated with seed yield. Thus, NHI might be useful as a selection criterion to improve seed yield in grain legumes.

Tapioca flour, sometimes referred to as manioc meal, is now a comparatively well-known feeding stuff. Its value as a food for pigs has been tested in several recent farm feeding trials in this country and on the Continent (1, 2, 3), and, as a consequence, its merit, when used in partial replacement of barley or maize, is now generally recognised. Sago pith meal, on the other hand, has not hitherto been used in pigfeeding in this country, and no information respecting its composition and feeding value is available.

In the course of an experiment designed to study the effects of calcium and phosphorus supplementation on the performance of Scottish Blackface hill ewes, with particular reference to the premature loss of permanent incisor teeth (Gunn, 1969), blood samples were taken from 40 ewes on ten occasions per year over a 4-year period. These were drawn equally from a control and three treatment groups. The control group followed the existing pattern of ewe management on the farm in question by utilizing improved pastures in the spring and early summer, and the treatment groups were a calcium dosed group (12 g calcium carbonate) and a phosphorus dosed group (13 g monosodium phosphate), both of which received the same management, and an undosed group run permanently on the hill. Details of the management and feeding are given in a previous paper (Gunn, 1969). It is sufficient to say here that mineral dosing took place three times per week between mid-February and the end of May and no minerals except salt were added to the concentrated ration fed to all groups at the rate of 10 oz (283 g)/head/day from mid-February to early May. Lambing commenced at about the end of the first week in April.