Known genetic loci that affect metric traits may be useful in livestock improvement. Their value depends on the proportion (R) of the total additive genetic variation due to the known loci relative to the heritability of the trait concerned and on the form of selection practised. When normal selection is effective, further information on known loci can add only a little to the rate of improvement. But if normal selection is not very effective, as for characters of low heritability, or if indirect selection on relatives must be used (as for sex-limited or carcass traits) then known loci may add significantly to the rate of improvement possible.

Sampling errors in the estimated effects and in the proportion (R) may cause selection effort to be misdirected and may even lead to losses rather than gains in improvement. Such errors are most likely to occur when the heritability of the character is low.

Reports on several loci with large effects in the various farm species have been summarised, but the evidence is often inconsistent and contradictory. At present, there appear to be no loci that could be used with confidence in the improvement of economic traits in farm animals.

A Bayesian procedure was used to estimate linear reaction norms (i.e. individual G × E plots) on 297 518 litter size records of 121 104 sows, daughters of 2040 sires, recorded on 144 farms in North and Latin America, Europe, Asia and Australia. The method allowed for simultaneous estimation of all parameters involved. The analysis was carried out on three subsets, comprising (i) parity 1 records of 33 641 sows of line B, (ii) all parity records of 52 120 sows of line B and (iii) all parity records of 121 104 sows of lines A, B and A × B. Estimated heritabilities ranged from 0.09 to 0.10 (smallest to largest subset) for the intercept of the reaction norms, and were 0.15, 0.08 and 0.02 (ditto) for the slope. Estimated genetic correlations between intercept and slope were −0.09, +0.26 and +0.69 (ditto). The three subsets therefore showed a progressively lower genetic component to environmental sensitivity, and progressively less re-ranking of genotypes across the environmental (herd–year–season) range. In a genetic evaluation that does not include reaction norms in the statistical model, part of the G × E effect remains confounded with the additive genetic effect, which may lead to errors in the estimates of the additive genetic effect; the reaction norms model removes this confounding. The intercept estimates from the largest data subset show correlations with litter size estimated breeding values (EBV) from routine genetic evaluation (without reaction norms included) of 0.78 to 0.85 for sows with one to seven litter records, and 0.75 for sires. Hence, including reaction norms in genetic evaluation would increase the reliability of the EBV of young selection candidates without own performance or progeny data by considerably more than 100 × (1/0.75−1) = 33%. Reaction norm slope estimates turn out to be very demanding statistics; environmental sensitivity must therefore be classified as a ‘hard-to-measure’ trait.

In an experiment during weeks 3 to 26 of lactation, two groups of 12 cows were offered a mixed concentrate/grass silage diet containing 161 g crude protein per kg dry matter, and two similar groups a diet containing 198 g crude protein per kg dry matter. The concentrate: forage ratios and the daily metabolizable energy intakes were the same for all four groups. The cows in one of the two groups at each crude protein level had their hooves trimmed prior to parturition, the other group remaining untrimmed. The high protein diet significantly increased locomotion score (higher scores indicate poorer locomotion), the number and duration of clinical cases of lameness and outer toe length. Trimming of hooves reduced locomotion scores and the number and duration of clinical cases. Hoof growth was significantly increased by trimming. Mid-sole hardness was negatively correlated with locomotion score. At the two extremes, the low protein trimmed group had five cows lame for an average of 1·0 weeks, whereas the high protein untrimmed group had nine cows lame for an average of 4-2 weeks. Condition score and live-weight change were negatively correlated with locomotion score. There were no significant differences between treatments in milk solids yield.

Carcass and meat composition and eating quality of m. longissimus lumborum (LI) and leg joints were compared in entire male (ram), castrated male (wether) and female (ewe) Dorset Down-cross and Suffolk-cross lambs at about 20 weeks old. Rams grew faster than wethers and ewes particularly in the earlier maturing Suffolk crosses. Carcass weights ranged from 13 to 24 kg and at the mean carcass weight of 17·7 kg ram carcasses yielded larger shoulder joints. Ram carcasses were assessed visually leaner than those from the other sexes with similar conformation scores. Dorset Down carcasses tended to be fatter than Suffolk carcasses and the leanest carcasses were from Suffolk rams. Intramuscular fatness in LI was similar in all sexes. Intramuscular collagen contents were higher in ram LI than in other sexes. There were no differences in protein content, pH or colour of raw or roast LI. In assessments of eating quality of LI by triangle tests, male and female assessors differentiated twin rams and wethers equally. Category scaling showed LI from ewes to be slightly tougher than those from rams and wethers. Consumer evaluation of leg joints did not detect any differences in odour due to sex and ram meat was assessed better than that from wethers or ewes.

In a comparative study which examined the effect of having access to mushroom compost in an otherwise barren environment there were three treatments and six replicates. The three treatments were (T1) control barren pen providing 0·7 m2 per pig with fully slatted floor, (T2) empty horizontal rack suspended above the pigs’ heads and (T3) mushroom compost on rack as in treatment 2. Pigs released particles of compost from the rack by nosing the metal grid from below. Almost twice as many pigs with access to mushroom compost (T3) nosed the rack (P < 0·001) and the ground below the rack (P < 0·001) as pigs which had a rack with no mushroom compost (T2). Fewer pigs with mushroom compost were involved in behaviours directed at penmates such as nosing, biting and chewing penmates than pigs in treatments 1 and 2 (P < 0·001). In addition fewer pigs in T3 were involved in feeding behaviour than in T1 and T2 (P < 0·05). Percentages of tail-bitten animals which had to be removed were 11 and 24 for T1 and T2 respectively while T3 had < 1% removed because of tail biting (P < 0·05). Apparent food intake was higher (P < 0·05) and food conversion ratio tended to be poorer in T1 (P = 0·1). It is suggested that pigs will redirect rooting behaviour towards penmates and the feeder in the absence of any rooting substrate. Adding substrate to commercial finishing pens reduces this redirection of behaviour and improves welfare by minimizing injury through tail biting.

The objective of the current study was to compare tick loads, growth and carcass characteristics of dipped and non-dipped Nguni, Bonsmara and Angus steers raised on natural pasture. One hundred 7-month-old castrated weaners were kept at the University of Fort Hare Farm for 12 months. There were 30 weaners each of Angus and Bonsmara, and 40 weaners of the Nguni breed. Half the Bonsmara, Angus and 14 Nguni weaners were dipped every fortnight. The rest were not dipped. Monthly weights and tick counts under the tail, on scrotum, belly, sternum and ears of the steers were recorded. The dipped Nguni steers had lowest (P < 0.05) tick counts, and the non-dipped Angus steers had the highest (P < 0.05) tick counts. There were more ticks (P < 0.05) during the warm wet season than during the cool dry season. Ears had the highest (P < 0.05) tick infestation. Average daily gain (ADG) was similar (P > 0.05) among the three breeds. The non-dipped Bonsmara steers had the heaviest (P < 0.05) carcasses (142 ± 5.4) while the non-dipped Nguni steers had the lightest (P < 0.05) carcasses (111 ± 4.5 kg). The non-dipped Bonsmara had the highest (P < 0.05) eye muscle area (3996 ± 120.8 mm2) while the non-dipped Angus had the smallest (P < 0.05) eye muscle area (3291 ± 210.6 mm2). The non-dipped Bonsmara also had the highest (P < 0.05) dressing percentage (53.8 ± 1.01) while the non-dipped Nguni had the lowest (P < 0.05) dressing percentage (50.3 ± 0.84). The current study has shown that while the non-dipped steers had higher (P < 0.05) tick loads than the dipped steers, their growth and carcass characteristics were similar (P > 0.05). The study has also shown that, despite being a small-framed breed, the Nguni steers had similar (P > 0.05) ADG to the large-framed Bonsmara and Angus steers. Therefore, the Nguni cattle have the potential to produce organic beef. However, a reasonable assessment of organic beef production potential of the Nguni requires an evaluation of its meat quality traits under natural pasture.

Studies of bruises, as detected on carcasses at the slaughterhouse, may provide useful information about the traumatic situations the animals endure during the pre-slaughter period. In this paper, we review scientific data on the prevalence, risk factors and estimation of the age of bruises in beef cattle. Risk factors such as animal characteristics, transport conditions, stocking density, livestock auction and handling of the animals are discussed. Investigation of the age of bruises could provide information on when in the meat chain bruises occur and, could help to pinpoint where preventive measures should be taken, from the stage of collecting the animals on the farm until slaughter. We review the methods available to assess the age of the bruises; data on human forensic research are also included. The feasibility to identify traumatic episodes during the pre-slaughter period, in order to improve animal welfare is discussed.

The effects of olive (MONO) or sunflower (POLY) oil-enriched (30 g/kg) diets with either a basal (10 mg/kg food) or supplemented (200 mg/kg) level of a-tocopheryl acetate on some measures of production, fatty acid composition of animal tissues and susceptibility to oxidation of rabbit meat and membrane extracts have been studied. MONO diet produced higher levels of C18:1 in animal tissues. Animals that received POLY diet had a higher level of C18:2 in perirenal and neutral fraction of intramuscular fat and higher levels of C18:2, C20:4, C22:4 and C22:5 in phospholipid, reaching a higher overall unsaturation (P = 0·001). Muscle samples from rabbits given the POLY diet were more susceptible to lipid oxidation (P = 0·0001). Differences in membrane lipid oxidation, between groups followed a similar pattern to that of meat. Diets rich in C18:2 resulted in increases in concentration of pentanal (P < 0·001), hexanal (P = 0·0001) and total volatile aldehydes (P = 0·0001) in meat as monitored by headspace gas liquid chromatography. Dietary supplementation with α-tocopheryl acetate reduced the overall concentration of volatile aldehydes (P < 0·05), particularly hexanal (P < 0·05). Dietary administration of monounsaturated fatty acids not only reduces membrane and meat lipid oxidation but also modifies the relative proportion of volatile aldehydes generated upon heating, with a specific decrease in those generally related to rancidity and off-flavour of meats.

Robustness in farm animals was defined by Knap as ‘the ability to combine a high production potential with resilience to stressors, allowing for unproblematic expression of a high production potential in a wide variety of environmental conditions’. The importance of robustness-related traits in breeding objectives is progressively increasing towards the production of animals with a high production level in a wide range of climatic conditions and production systems, together with a high level of animal welfare. Current strategies to increase robustness include selection for ‘functional traits’, such as skeletal and cardiovascular integrity, disease resistance and mortality in various stages. It is also possible to use global evaluation of sensitivity to the environment (e.g. reaction norm analysis or canalization), but these techniques are difficult to implement in practice. The hypothalamic–pituitary–adrenocortical (HPA) axis is the most important stress-responsive neuroendocrine system. Cortisol (or corticosterone) released by the adrenal cortices exerts a large range of effects on metabolism, the immune system, inflammatory processes and brain function, for example. Large individual variations have been described in the HPA axis activity with important physiopathological consequences. In terms of animal production, higher cortisol levels have negative effects on growth rate and feed efficiency and increase the fat/lean ratio of carcasses. On the contrary, cortisol has positive effects on traits related to robustness and adaptation. For instance, newborn survival was shown to be directly related to plasma cortisol levels at birth, resistance to bacteria and parasites are increased in animals selected for a higher HPA axis response to stress, and tolerance to heat stress is better in those animals that are able to mount a strong stress response. Intense selection for lean tissue growth during the last decades has concomitantly reduced cortisol production, which may be responsible for the negative effects of selection on piglet survival. One strategy to improve robustness is to select animals with higher HPA axis activity. Several sources of genetic polymorphism have been described in the HPA axis. Hormone production by the adrenal cortices under stimulation by adrenocorticotropin hormone is a major source of individual differences. Several candidate genes have been identified by genomic studies and are currently under investigation. Bioavailability of hormones as well as receptor and post-receptor mechanisms are also subject to individual variation. Integration of these different sources of genetic variability will allow the development of a model for marker-assisted selection to improve animal robustness without negative side effects on production traits.

Bacteria attached to the rumen epithelium (or epimural community) are not well characterised and their role in rumen functioning is not totally understood. There is just one published report of a clone library from one cow that suggests that this epimural community differs from the bacteria associated with the rumen digestive contents. However, this time-consuming approach is not adapted for examining microbial population changes in groups of animals. In in vivo studies, when samples from several animals have to be analysed simultaneously, a simpler technique has to be used. In this study, a genetic fingerprinting technique, polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE), was used to characterise the structure of the bacterial population attached to the rumen epithelium. This community was compared with that present in the solid and liquid phases of rumen content under two contrasting diets. Rumen samples were obtained from four forage-fed and four high-concentrate-fed (80 : 20, wheat grain : hay) 5-month-old lambs. After slaughter, samples from five epithelial sites and the solid and liquid digesta phases were taken for DNA extraction and analysis. Bacterial communities were profiled by PCR-DGGE using bacterial-specific 16S rDNA primers. Analysis of the fingerprint revealed that the epithelial community differed from those of rumen content in both diets. As expected, the nature of the feed influenced the bacterial communities from the solid and liquid rumen phases but no diet effect was observed in the rumen epithelial profiles suggesting a strong host effect on this bacterial population. Additionally, no differences were observed among the five epithelial sampling sites taken from each animal. The profile of the bacterial population attached to the rumen epithelium presented a high inter-animal variation, whether this difference has an influence in the function of this community remains to be determined.

Effects were studied on food intake and diet apparent digestibility of giving to goats once daily a basal diet rich in tannin from inclusion of leaves of Quercus calliprinos either supplemented with a high carbohydrate or a high protein food. Also interactions with polyethylene glycol (PEG) were investigated. The results of the present work confirmed our presumption that the content of tannin in some Mediterranean browse is so high that it may negatively affect the utilization of protein in supplementary foods. Neutralizing the tannins with once-daily provision of PEG proved to be an effective means of preventing the negative effect. Providing 10 g/day PEG to goats given Quercus calliprinos leaves ad libitum and supplemented with 300 g/day concentrates containing 160 g crude protein per kg DM increased digestible crude protein intake by 50 g/day. When the concentrate food was given to goats, leaf dry-matter intake decreased significantly (from 664 to 565 g/day) and the goats lost weight rapidly. Therefore, supplementing tannin-rich leaves with concentrate food is recommended only if done in combination with PEG. High protein supplementation increased leaf (from 664 to 844 g/day) and digestible protein intakes (from 4·8 to 92·3 g/day) but a considerable portion of the protein supplementation was wasted due to interaction with tannins. PEG may allow economies in the use of such high-cost foods due to the greater efficiency of protein utilization (digestible crude protein intake increased from 92·3 to 122 g/day) of the supplementary food and to increased intake and protein utilization of the basal leaf diet (from 844 to 1023 g/day).

Automatic milking systems (AMS), one of the earliest precision livestock farming developments, have revolutionized dairy farming around the world. While robots control the milking process, there have also been numerous changes to how the whole farm system is managed. Milking is no longer performed in defined sessions; rather, the cow can now choose when to be milked in AMS, allowing milking to be distributed throughout a 24 h period. Despite this ability, there has been little attention given to milking robot utilization across 24 h. In order to formulate relevant research questions and improve farm AMS management there is a need to determine the current knowledge gaps regarding the distribution of robot utilization. Feed, animal and management factors and their interplay on levels of milking robot utilization across 24 h for both indoor and pasture-based systems are here reviewed. The impact of the timing, type and quantity of feed offered and their interaction with the distance of feed from the parlour; herd social dynamics, climate and various other management factors on robot utilization through 24 h are provided. This novel review draws together both the opportunities and challenges that exist for farm management to use these factors to improved system efficiency and those that exist for further research.

The overall assessment of animal welfare is a multicriterion evaluation problem that needs a constructive strategy to compound information produced by many measures. The construction depends on specific features such as the concept of welfare, the measures used and the way data are collected. Welfare is multidimensional and one dimension probably cannot fully compensate for another one (e.g. good health cannot fully compensate for behavioural deprivation). Welfare measures may vary in precision, relevance and their relative contribution to an overall welfare assessment. The data collected are often expressed on ordinal scales, which limits the use of weighted sums to aggregate them. A sequential aggregation is proposed in the Welfare Quality® project, first from measures to welfare criteria (corresponding to dimensions with pre-set objectives) and then to an overall welfare assessment, using rules determined at each level depending on the nature and number of variables to be considered and the level of compensation to be permitted. Scientific evidence and expert opinion are used to refine the model, and stakeholders’ approval of general principles is sought. This approach could potentially be extended to other problems in agriculture such as the overall assessment of the sustainability of production systems.

Two hundred and forty pigs of 56 ± 3 days of age were used to investigate the effects of sex (barrows; gilts), boar sire (DD, Danish Duroc; ND × LW, Dutch Duroc × Large White ; P × LW, Pietrain × Large White) and slaughter age (160; 175 days) on performance and carcass and meat quality. Treatments were arranged factorially (2 × 3 × 2) and there were four replicates (five pigs per replicate) per treatment. The female line was Landrace × Large White in all cases. Barrows had greater daily food intake (P <0·001) and average daily gain (P <0·01) and had poorer food conversion ratio (P <0·001) than gilts. Carcasses from castrates were fatter and had a lower yield of trimmed lean cuts than carcasses from females (P <0·001). Longissimus muscle from barrows had more intramuscular fat and higher a* value than muscle from gilts (P <0·05). Pigs from DD sire line grew faster (P <0·05) and had a better food conversion ratio (P <0·001) than pigs from the other two lines. Dressing proportion and backfat thickness were greatest for P × LW sired pigs (P <0·01) and proportion of trimmed lean cuts was greater for DD and P × LW than for ND × LW sired pigs (P <0·01). Longissimus muscle from DD sired pigs had less protein (P <0·01) and more intramuscular fat (P <0·001) than muscle from the remaining lines. Longissimus muscle from P × LW line had more intense colour than muscle from DD and ND × LW lines (P <0·01). Pigs slaughtered at 175 days had poorer food conversion ratio (P <0·01) and less trimmed primal cut proportion (P <0·001) than pigs slaughtered at 160 days. Also, increasing the age at slaughter increased intramuscular fat content (P <0·01), a* value (P <0·001) and colour intensity of the muscle (P <0·01). Danish Duroc boars are a good alternative to ND × LW or P × LW boars for production of heavy pigs whether the crossbreds are sacrificed at 160 or 175 days. Also, an increase in age at slaughter impairs growth efficiency and yield of lean cuts but improves some aspects of meat quality, which might be of interest in the production of heavy pigs destined for the dry-cured product industry.

The larger the mature size of a mammal, the longer tends to be the time it takes to mature. In an attempt to quantify this relationship, Brody's (1945) studies on post-natal growth and Weinbach's (1941) study on pre-natal growth are re-examined. Both these authors described growth by attributing to each species a live-weight scaling parameter, an age scaling parameter, and a parameter for age origin. By examining the interrelations of these six pre- and post-natal growth parameters, a general empirical relationship between mature weight and time taken to mature is obtained. The time a species takes to reach any particular degree of maturity, that is any fraction of its mature weight, tends to be directly proportional to its mature weight raised to the 0·27th power. This result is in general agreement with previous theoretical work and with results on the time required to reach adult weight.

The simplest way to make use of this general relation is considered. When age measured from an origin at or near conception is divided by the 0·27th power of mature weight, then on this modified scale, the age at which a species reaches a given degree of maturity has an expectation independent of mature weight. This age scale has been called metabolic age, since it amalgamates the properties of Brody's physiological age and Kleiber's metabolic turnover time. The most useful working form, however, is the logarithm of metabolic age which is approximately normally distributed with constant variance at all degrees of maturity. Equations are derived giving the expected metabolic age of a species at any degree of maturity in the range covered by Brody's and Weinbach's growth curves. Metabolic age thus appears to furnish a one-parameter representation of comparative mammalian growth.

The introduction of legumes in grass-based swards provides some economic and agronomic advantages, often allowing an increase in the performance of grazing ruminants. The aim of this study was to obtain a better quantification of the nutritional benefits to dairy cows after introducing white clover into swards of perennial ryegrass (PRG), using two ages of regrowth. Four treatments were studied in a 2 ✕ 2 factorial design with two sward types and two ages of regrowth. The swards were either a pure perennial ryegrass sward with nitrogen (N) fertilization, or a perennial ryegrass/white clover mixture (GC) with no N fertilization. The regrowth ages were 19 and 35 days (treatments: PRG19, PRG35, GC19 and GC35). The proportion of clover in the GC swards was on average 420 g/kg dry matter (DM). Twelve late-lactation Holstein cows, fistulated at the rumen and duodenum, were used according to a 4 ✕ 4 Latin-square design with four 11-day periods. The pasture was strip-grazed with 12 kg DM per cow of herbage above 5 cm offered daily in all the treatments.

The effects of sward type and regrowth age were often additive, in particular for herbage intake and milk yield. Herbage organic matter (OM) intake, duodenal non-ammonia N (NAN) flow and milk yields were higher on the GC swards and lower on the older regrowths. Finally, the performance of the cows was similar on the PRG19 and GC35 treatments. The OM digestibility of the selected herbage as well as the duodenal nitrogen flux per kg digestible OM intake was not affected by the sward type. Ruminal fermentations were more intense with mixed swards and the youngest regrowths. The daily grazing time and the daily pattern of grazing activities were modified by the type of sward and by regrowth age. The average OM intake rate was higher on the GC swards than on the PRG swards. In this study, the nutritional advantage of introducing white clover into swards of perennial ryegrass was related to an increase in herbage intake and not to any improvement in the nutritive value of the sward.

Although vitamin E has been known as an essential nutrient for almost 80 years, we are far from a complete understanding of all the aspects related to bioavailability and its effects on health and milk quality in dairy cows. Vitamin E is a generic descriptor for two families of lipid-soluble compounds, the tocopherols and the tocotrienols, of which α-tocopherol has the highest biological activity. Commercially available α-tocopherol supplements for dairy cows contain either the natural RRR form or the synthetic (all-rac) form, which contains all the eight possible stereoisomers (four possessing the 2R and four possessing the 2S configuration) in equimolar amounts. Recent data clearly suggest that an almost complete discrimination against the 2S isomers occurs in dairy cows. Thus, 1 g of the all-rac form is essentially equivalent to 0.5 g of the RRR form. With respect to the effect of vitamin E supplementation of dairy cows on health and milk quality, the majority of published studies suggests that vitamin E supplementation at the level 1000 to 4000 IU/cow per day during the dry period reduces both the frequency of intramammary infection and that of clinical mastitis and improves milk quality, as shown by a reduction in the levels of somatic cell count (SCC)/ml in milk, decreased plasmin activity and increased oxidative stability of milk. However, a recent study from the Netherlands suggested that vitamin E supplementation at the 3000 IU/cow per day level during the dry period when combined with high levels of plasma vitamin E at dry-off (>14.5 μmol/l) increases the incidence of mastitis. Data from previously unpublished survey studies and those from published vitamin E feeding trials, in which high levels of blood vitamin E were observed, were reanalyzed. All farms selected for the analysis implemented oral administration of vitamin E at the 3000 IU/cow per day level throughout or during the late dry period (4 weeks before the expected day of parturition). Dairy cows were divided into three groups, depending on blood α-tocopherol levels at dry-off: high (>6.25 μg/ml), medium (between 6.25 and 4.25 μg/ml) and low (<4.25 μg/ml). Data indicate that there were no differences in the incidence of mastitis and in the level of SCC/ml of milk between the three groups. Thus, supplementation of 3000 IU vitamin E/cow per day in the late dry period remains recommended because it is generally associated with decreased risk of mastitis. Conditional or opposite effects have not been repeated and require further research before changing recommendations for vitamin E supplementation.

The aim of this study was to determine the levels of cadmium, lead, iron, zinc, selenium, manganese, copper and molybdenum in different cuts of beef, pork, lamb, chicken and foal collected from supermarkets and butcheries in Switzerland. The concentrations of manganese, copper, molybdenum, zinc, iron, selenium, cadmium and lead were determined by inductively coupled plasma mass spectrometry (ICP-MS) after microwave digestion. Mean values and their respective coefficients of variation were calculated from the measured concentrations. The concentrations found for cadmium and lead ranged from 0.6 to 3.9 μg/100 g and 1.0 to 2.1 μg/100 g, respectively. Concentrations ranged between 0.5 and 3.3 mg/100 g for iron, 0.7 and 5.1 mg/100 g for zinc, 9 and 44 μg/100 g for selenium, 3.1 and 16.7 μg/100 g for manganese, 0.3 and 132 μg/100 g for copper and 0.9 and 3.2 μg/100 g for molybdenum. Differences found for the concentrations in meat from different species as well as between the individual meat cuts were notable for iron, zinc, selenium and copper. Manganese concentrations were found to vary unsystematically within muscles and species. Molybdenum concentrations were higher in chicken meat in comparison with the mammalian meats. The highest coefficients of variation were found for manganese (13% to 142%) and copper (13% to 224%), while the lowest was found for zinc (4% to 45%). In conclusion, in order to provide an accurate overview and to be able to calculate reliable dietary intakes, it is important to include the variability in food composition data.