The genetic effects, including genetic main effects and genotype×environment (G×E) interaction effects, for oleic acid content (OAC) and linoleic acid content (LAC) at five different developmental times/stages were studied using unconditional and conditional genetic models for seed quantitative traits in diploid plants. The unconditional analysis results revealed that both OAC and LAC were simultaneously controlled by diploid embryo nuclear genes, cytoplasmic genes and diploid maternal plant nuclear genes and their G×E interaction effects. Effects on the embryo and cytoplasm were found to be more important for OAC at different developmental times while maternal effects, in combination with cytoplasmic effects, were more important for LAC at most development times. The conditional analysis revealed that the net effect from expression of maternal genes was more important for both traits at most developmental stages. The total narrow-sense heritability was high for both OAC and LAC, with general heritabilities being more visible for OAC and G×E interaction heritability being more important for LAC at most development times. The predicted genetic effects indicated that while most parents (with the exception of Youcai 601, Zhongyou 821 and Eyouchangjia) could be used for improving OAC of offspring, Double 20-4 was the most appropriate for improving LAC due to its better stability and positive values across environments at most development times.

Sunflower oil, with more than 0·9 of tocopherols in the alpha-tocopherol form, supplies more vitamin E than any other vegetable oil. Thus far, no breeding to increase vitamin E levels in sunflower seeds has been conducted. The objective of the present research was to develop sunflower lines with high and low total seed tocopherol content through evaluation and subsequent selection of a large germplasm collection (952 sunflower entries). A range of variation from 119 to 491 mg/kg was found. Selection conducted from S1 to S4 plant generations allowed the isolation of line IAST-413, with an increased tocopherol content of 467 mg/kg compared to 251 mg/kg in the control line HA89, and line IAST-522, with a reduced tocopherol content of 73 mg/kg. Another accession with potentially high tocopherol content, but completely self-incompatible, was crossed to the line HA89 followed by plant-to-row selection up to the F5 plant generation; it averaged 463 mg/kg compared to 240 mg/kg in HA89. Two field experiments carried out at Córdoba in southern Spain in 2006 and 2007 with different sowing dates confirmed that the increased tocopherol content in the selected lines was consistently expressed across environments.

Super-sweet maize (shrunken2, sh2) has a longer post-harvest life than standard sweetcorn (sugary1, su1), but is less well-adapted to cold conditions. The objective of the present work was to determine if the replacement of su1 by sh2 alters the combining abilities of sweetcorn inbreds for adaptation to early planting under cold conditions. Two diallel sets of su1 and sh2 near-isogenic inbred lines were evaluated in a cold chamber and by early field planting. For most of the traits related to adaptation, except silking date, there were significant mutant×genotype interactions and the estimates of general combining ability (GCA) of each version of the same inbred were different, probably due to epistasis. Therefore, to widen the genetic base of the super-sweet germplasm for adaptation, conversion of the earliest su1 inbreds to sh2, ignoring other characteristics such as emergence or early vigour in early planting or cold tests, is proposed.

Winter barley was sown by conventional-tillage (CT) and minimum-tillage (MT) cultivation over three seasons. Each cultivation treatment was split so that straw was incorporated into the soil during cultivation in one split, while the other did not receive straw. Aphid occurrences in autumn and incidence of barley yellow dwarf virus (BYDV) in spring were compared. Similar investigations on winter wheat were made over a further three seasons. The method of cultivation affected the number of aphids on barley and wheat plants in autumn and on wheat heads in summer; MT had fewest aphids. Soil incorporation of straw during cultivation had a similar effect. Method of cultivation affected the incidence of BYDV disease, with MT having least infection. Straw-treated cereal plots had fewer aphids and less BYDV than no-straw plots. Aphids and virus reached damaging levels only in the first barley crop. In this season, MT barley had significantly fewer aphids (48% fewer) and significantly less BYDV (71% less) than CT. Straw-treated plots within the CT system had rather similar aphid infestation and BYDV incidence as no-straw plots. Barley grown in the MT system with straw added had significantly fewer aphids (68%) than in the case when no straw was added. Overall, aphids in autumn were significantly fewer on MT relative to CT cereals in three of the six seasons and significantly fewer on straw relative to no-straw plots in two seasons. Aphids on wheat heads in summer were significantly fewer in MT relative to CT plots in one of the three seasons. Aphids on heads were also significantly fewer on straw-treated plots within each system of cultivation in two seasons, while MT wheat with straw had significantly fewer aphids/head than those without straw in one season. BYDV was lower each season in MT barley and wheat when compared with CT crops. These differences were significant for two of the three seasons in which each crop was grown. There was a lower incidence of virus in straw-treated plots than in no-straw plots. This effect was significant for one of the three seasons in which barley and wheat were grown. Plant and tiller density did not differ significantly between MT and CT barley either with or without straw incorporation. Plant density of wheat in autumn was significantly lower for straw-treated plots relative to no-straw plots in one season. Wheat head density was lower for MT relative to CT in one season, while MT with straw had significantly fewer heads than CT plots with straw in two seasons. BYDV significantly reduced grain yield only in 2001/02 when incidence of the disease was high. Grain yield in 2001/02 was 0·95 t/ha (16%) greater for MT barley, due to less BYDV, than for CT. Straw-treated CT barley outyielded no-straw plots by 0·45 t/ha, while the comparable value for the MT system was 0·3 t/ha. The combined effect of MT plus straw had a 1·24 t/ha (21%) yield advantage over CT without straw.

It is concluded that MT cereals sown at the same time as CT crops in autumn have a lower risk of aphid infestation and BYDV infection than CT crops. The soil incorporation of straw further enhances the beneficial impact of MT in reducing aphids and virus.

The aim of the present study was to use data from herds to demonstrate the degree of seasonal influence on litter size at birth in gilts compared to sow parities 2, 3–5 and older (parities ⩾6) in a conventional, open-housing system for commercial pig herds in the northeastern part of Thailand. Data were obtained during a 3-year period from July 2005 to June 2008. The data analysed included observations on 25 835 litters from 8100 sows. Total number of piglets born per litter (TB), number of piglets born alive per litter (BA), proportion of stillborn piglets per litter (SB) and proportion of mummified fetuses per litter (MF) were analysed using a general linear mixed model procedure. The influence of temperature, relative humidity and temperature-humidity index (THI) on TB, BA, MF and SB were also analysed. The meteorological data were merged with the reproductive data and the means of temperature, relative humidity and THI during 115 days before farrowing were calculated and included in the statistical models. The results revealed that sows that farrowed in the hot season had a larger TB and BA than sows that farrowed in the rainy (P<0·001) and cool seasons (P<0·001). The difference of TB and BA among seasons was more pronounced in the gilt litters than the sow litters, insofar as the gilts that farrowed in the rainy season had 0·7 TB fewer than gilts that farrowed in the hot season (P<0·001). By contrast, sows of parities 2, 3–5 and ⩾6 that farrowed in the rainy season had 0·4 (P=0·01), 0·3 (P=0·003) and 0·3 (P=0·02) TB fewer than those that farrowed in the hot season. In the first parity, MF increased from 0·022 to 0·042 when the mean temperature during gestation increased from 26 to 29°C (P<0·001). On average, a reduction of 0·8 TB and 0·7 BA were found when the humidity during gestation increased from 50 to 80% (P<0·001). The influence of THI on TB, BA and SB differed among herds. When THI increased from 71/72 to ⩾81, a decrease of 0·4 TB were observed in herd A (P<0·001) and a decrease of 0·9 TB were observed in herd B (P<0·001), but not in herds C and D (P>0·05). In conclusion, inferior litter size at birth was observed in sows that farrowed in either rainy or cool seasons. High temperature, high relative humidity and/or high THI during gestation significantly reduced the number of total piglets born per litter. The influence of season, temperature, relative humidity and/or THI on litter size at birth was more evident in the gilts than the sows. These data indicated that various strategies to reduce temperature in the open-housing system for pregnant gilts and sows in Thailand are not adequate and the proper housing of pregnant gilts should be emphasized.

The objective of the current study was to develop, validate and describe a decision support system (DSS) to evaluate cull dairy cow finishing strategies. The DSS was developed within a Microsoft Excel framework. The purpose of a DSS is to assist the process of making accurate and repeatable calculations, assisting the decision on which cull cow finishing strategy is most profitable under individual farm circumstances. The model was based on data from two evaluation experiments including eight finishing strategies in total: ad libitum grass silage (GS); GS+3 kg concentrate (GS+3); GS+6 kg concentrate (GS+6); GS+9 kg concentrate (GS+9); ad libitum grass silage prior to ad libitum spring grass (GS+G); 0·75 grass silage and 0·25 straw prior to ad libitum spring grass (GS+S) and finally grass silage plus 6 kg concentrate dry matter (DM)/cow/day and milked twice daily prior to ad libitum spring grass (EXTLAC). Stochastic budgeting was included in the model to account for variability in key input and output variables on the overall profitability of various finishing strategies. The stochastic input and output variables included in the model were initial carcass value, feed strategy, concentrate cost and final carcass value. Net profit per cow was selected as the output distribution. The mean net profit per cow with the GS, GS+3, GS+6, GS+9, GS+G, GS+S and EXTLAC was €85·3, €73·7, €95·6, €58·5, €158·8 and €186·8 and €283·0, respectively. Profitability for the EXTLAC strategy was stochastically dominant to all other strategies evaluated meaning a higher level of profit and a lower level of risk is associated with the EXTLAC strategy. The optimal strategy of cull cow beef production depends greatly on the prevailing economic environment, purchase and sale price, milk price, feed costs, housing and labour.

In vitro gas production (GP) of substrate incubated with cow rumen liquor is commonly used to evaluate feed nutritional quality; GP is correlated with organic matter digestibility and metabolizable energy content. The hypothesis tested was that GP differs among liquors of ruminant species and is dependent on the natural dietary intake of the donors. Measurements were of 24 h GP of seven browse species using rumen liquor from a large (cow) and small (sheep) grazer and from a small intermediate feeder (goat). Mean GP for browse with goat liquor (7±2·4 ml per 200 mg substrate) was significantly (P=0·019) higher than that with cow liquor (5±1·9 ml), and GP with sheep liquor (6±1·1 ml) was intermediate, not significantly different from the cow liquor (P=0·197) and the goat liquor (P=0·061). There was a significant correlation in the ranking of the browses between goat and sheep (P=0·013) liquor using a Mantel test with 9999 permutations, which indicated a similar ranking of browses when using rumen liquor of either of these small ruminants. There were trends between both cow and sheep (P=0·096) and cow and goat (P=0·092) liquors. It was concluded that the dietary habits of ruminant species donors may affect in vitro nutritional studies when using rumen liquor.

The present study investigated the effects of maternal plasma iodine concentration on twin- and triplet-born lamb plasma thyroid hormone concentrations, rectal temperature and maximal heat production. On pregnancy day 68 (P68), 16 twin- and 14 triplet-bearing ewes were randomly chosen from ewes that were injected intramuscularly with 1·5 ml of iodized peanut oil and ewes that were not. Selected ewes were grazed on ad libitum pasture from P68 until parturition. After parturition, lamb blood samples were collected within 5 min of birth and at 3, 12 and 24–36 h after birth. Lamb rectal temperatures were measured within 5 min of birth and at 1, 3 and 12 h after birth. Lamb body weight, crown–rump length and thoracic-girth circumference were recorded at 3 h of age, and the capability of the lamb to produce heat at 24–36 h of age was measured using indirect open-circuit calorimetry. Maternal iodine supplementation successfully increased plasma iodine concentrations of twin- and triplet-bearing ewes throughout pregnancy, but had no effect on the rectal temperature, thyroid hormone concentration and maximal heat production of twin- or triplet-born lambs. Compared with twin-born lambs, triplet-born lambs had lower birth weights, rectal temperatures and plasma T4 and T3 concentrations within 5 min of birth. Overall, under the conditions of the present study, maternal iodine supplementation offered no benefit in improving lamb heat production.

The current study investigated the effects of dam weight and nutrition during gestation on the reproductive performance of female primiparous offspring at 2 years of age. Four hundred and fifty heavy (H) (mean±s.e.m.: 60·8 kg±0·18) and 450 light (L) (42·5 kg±0·17) dams were randomly allocated to ad libitum (A) or maintenance (M) nutritional regimens from day 21 until day 140 of pregnancy, under pastoral grazing conditions. One week prior to lambing, all dams and their lambs were provided with ad libitum feeding through to weaning. After weaning, female progeny were managed and fed to requirements as one group. At 2 years of age, the oestrous cycles of the female offspring (n=207) were synchronized and the offspring were naturally mated. Ewes were scanned for pregnancy by ultrasound at day 70 of pregnancy. Within 24 h of birth, lambs were weighed and body dimensions were measured. Lambs were also weighed at day 24 (L24) and weaning. No effects of dam nutrition or dam weight were found (P>0·10) on the reproductive performance of the ewe offspring. Lambs of M-grand-dams were heavier at birth (P=0·024) and weaning (P=0·031) than lambs of A-grand-dams. Twin lambs of H-grand-dams were heavier at birth (P=0·014) than twin lambs of L-grand-dams; however, grand-dam weight had no effect (P>0·10) on lamb weaning weight. In summary, dam weight had no effect on reproductive performance of the female offspring, with only a minor effect on the weight of grand-offspring. Thus, being born to a larger dam has no advantages over being born to a smaller dam, in terms of number of lambs born and weight of lambs at birth and weaning. Grand-dam maintenance nutrition had no effect on reproductive performance although it increased lamb birth and weaning weight and lamb growth rates of the grand-offspring. Therefore, this indicates that ewes born to dams fed at maintenance during pregnancy have an advantage over A-ewes in physiological stressful situations including pregnancy or lactation.

In order to assess the diet of lactating ewes fed at pasture and the relationship of diet quality to pasture characteristics and milk production (MP), 12 lactating ewes were monitored during five lactation cycles (LCs). Individual faecal samples were collected three times per LC and scanned using a Foss NIRSystem 6500 monochromator. The organic matter digestibility (OMD), organic matter intake (OMI), digestible OMI (DOMI) and the chemical composition of the herbage ingested, i.e. the crude protein (CP) content of the herbage ingested (CPi) and the acid detergent fibre and lignin contents of the herbage ingested (ADFi and ADLi), were determined. The MP of the ewes and the pasture characteristics were measured and their relationships with diet quality were analysed.

OMI and DOMI were higher during the first and the fourth LC (P<0·01). OMD and CPi were higher during the second and the fifth LC (P<0·01). MP varied with OMI (P<0·01) and with DOMI (MP=0·1362×DOMI0·53, R2=0·40, P<0·001), whereas it was negatively correlated with OMD (r=−0·46, P<0·001). OMD and CPi were both positively correlated with the CP content of the pasture (r=0·25, P<0·03; r=0·50, P<0·001), whereas the ADFi was negatively correlated with CP content (r=−0·48, P<0·01). The variation in OMI, DOMI and MP, on the one hand, and OMD and CPi, on the other, throughout the different LCs illustrates the importance of measuring several parameters when evaluating diets at pasture.

The objective of the present study was to evaluate the effects of betaine supplementation on rumen fermentation, lactation performance and plasma characteristics in dairy cows. Twenty multiparous Holstein dairy cows (597±11·8 kg body weight (BW), 88±4·5 days in milk (DIM) and average daily milk production of 26·3±0·5 kg/cow) were used in a replicated 4×4 Latin square experiment. The treatments were: control (without betaine), low-betaine (LB), medium-betaine (MB) and high-betaine (HB) with 0, 50, 100 and 150 g supplemental anhydrous betaine/cow/day, respectively. Betaine was hand-mixed into the top one-third of the daily ration at feeding. Experimental periods were 30 days with 15 days of adaptation and 15 days of sampling. Dry matter (DM) intake was not affected with increasing the betaine supplementation. There were linear increases in milk yield and fat-corrected milk yield (corrected to 40 g fat/kg) and a linear and quadratic increase in milk fat concentration with increasing the betaine supplementation, whereas the proportion and yield of milk protein and lactose, and feed efficiency, were not affected. Ruminal pH and ammonia N linearly decreased, whereas total volatile fatty acid (VFA) concentration linearly and quadratically increased with increasing the betaine supplementation. The ratio of acetate to propionate (A:P) linearly increased from 3·06 to 3·53 as betaine supplementation increased. Digestibility of DM linearly increased, whereas digestibilities of organic matter (OM), crude protein (CP), neutral detergent fibre (NDF) and acid detergent fibre (ADF) in the total tract were quadratically increased with increasing the betaine supplementation. Plasma concentrations of non-esterified fatty acids (NEFA) and β-hydroxybutyrate (BHBA) were lower for betaine supplementation than for control, and were linearly decreased by betaine supplementation. The results indicate that supplementation of mid-lactation dairy cow diets with betaine increased milk yield through increased feed digestion. Betaine supplementation may benefit lactation performance when methionine supply is limiting.