The Carbon Navigator has been developed to support the objective of reducing the carbon intensity of the dairy and beef sectors of Irish agriculture. The system is designed as a knowledge transfer (KT) tool aimed at supporting the realisation at farm level of the mitigation potential. The objective of this paper is to outline the potential role of KT in reducing greenhouse gas emissions in the context of a growing body of science, which identifies potential mitigation. The EU policy framework for agriculture and the environment is examined in terms of its effectiveness in supporting the reduction in emission intensity of agriculture. The important role for KT in reducing agricultural emissions is highlighted. The Carbon Navigator is introduced as a potential aid to achieving improved adoption of emission-reducing technologies and practices at farm level. The paper outlines the criteria guiding the selection of mitigation technologies in Irish ruminant agriculture, describes the technologies and practices included in the system and outlines the basis for their inclusion. The approach of developing the Carbon Navigator to integrate into existing infrastructure and data systems as well as into the existing KT systems is outlined.

Offspring born from normal litter size (10 to 15 piglets) but classified as having lower than average birth weight (average of the sow herd used: 1.46 ± 0.2 kg; mean ± s.d.) carry at birth negative phenotypic traits normally associated with intrauterine growth restriction, such as brain-sparing and impaired myofiber hyperplasia. The objective of the study was to assess long-term effects of intrauterine crowding by comparing postnatal performance, carcass characteristics and pork quality of offspring born from litters with higher (>1.7 kg) or lower (<1.3 kg) than average litter birth weight. From a population of multiparous Swiss Large White sows (parity 2 to 6), 16 litters with high (H = 1.75 kg) or low (L = 1.26 kg) average litter birth weight were selected. At farrowing, two female pigs and two castrated pigs were chosen from each litter: from the H-litters those with the intermediate (HI = 1.79 kg) and lowest (HL = 1.40 kg) birth weight, and from L-litters those with the highest (LH = 1.49 kg) and intermediate (LI = 1.26 kg) birth weight. Average birth weight of the selected HI and LI piglets differed (P < 0.05), whereas birth weight of the HL- and LH-piglets were similar (P > 0.05). These pigs were fattened in group pen and slaughtered at 165 days of age. Pre-weaning performance of the litters and growth performance, carcass and meat quality traits of the selected pigs were assessed. Number of stillborn and pig mortality were greater (P < 0.05) in L- than in H-litters. Consequently, fewer (P < 0.05) piglets were weaned and average litter weaning weight decreased by 38% (P < 0.05). The selected pigs of the L-litters displayed catch-up growth during the starter and grower–finisher periods, leading to similar (P > 0.05) slaughter weight at 165 days of age. However, HL-gilts were more feed efficient and had leaner carcasses than HI-, LH- and LI-pigs (birth weight class × gender interaction P < 0.05). Meat quality traits were mostly similar between groups. The marked between-litter birth weight variation observed in normal size litters had therefore no evident negative impact on growth potential and quality of pigs from the lower birth weight group.

Footrot is a highly contagious bacterial disease of sheep affecting the interdigital skin and surrounding soft and hard horn of a hoof, often resulting in severe lameness. This study was aimed at estimating the effect of footrot on weight gain of affected animals, and characterising the variation between animals in terms of phenotypic, environmental and genetic components. A general approach was developed describing the relationship between the disease and weight gain, defining new traits such as the maximum weight loss as a result of disease and the time after infection that this occurs. In two trials, 1267 Merino sheep were artificially challenged with footrot when 10 months old and re-infected through exposure to footrot on pasture 33 weeks later. Their feet were scored for footrot and live weights were measured approximately every 3 weeks. From data on animals that were not affected by footrot throughout each trial, normal growth curves were calculated and applied to affected animals to predict their growth had they remained healthy, so that weight loss as a result of footrot could be predicted. Animals with average footrot severity in the two trials suffered weight losses of 0.5 to 2.5 kg live weight, but most animals regained lost live weight later in the trials as footrot healed following vaccination. The estimates of the heritabilities of weight loss, adjusted for the severity of footrot, were about 0.30 and 0.15 in the experimental and natural challenge groups, respectively. Animals with higher genotypic values for weights at the start of each trial appeared to cope better with infections, in terms of lower weight losses. The time of highest footrot score and the time of maximum weight loss after infection had only very small genetic components.

Thirty-five mature Churra ewes, ranging in live weight from 30·3 to 52·6 kg and in body condition score from 1·25 to 4·00 were used to study the relationship between body condition score (BCS), live weight (LW) and body composition and fat distribution in ewes of this breed, which is one of the major sheep breeds of northern Spain. The procedure at slaughter and at subsequent dissection was designed to partition each body into two components, carcass and ‘non-carcass’. Right side carcasses and ‘non-carcass’ components were used to analyse the chemical composition. From the left side of the lumbar region a joint was cut and dissected into muscle, bone, subcutaneous and intermuscular fat. According to the results obtained, omental fat represented the highest proportion of total internal fat regardless of the level of fatness. Distribution of internal fat was similar to that observed in other milk production breeds. Regressions on LW explained more of the variation than those on BCS for individual internal fat depots and chemically determined ‘non-carcass’ fat. The prediction of total body fat afforded by LW was better than that provided by BCS. The subcutaneous and intermuscular fat depots in the lumbar joint were well correlated with BCS, carcass fat and total fat in the body, validating the use of this region for assessing BCS in Churra ewes. Nevertheless, the correlation coefficient with the omental depot was not statistically significant. The results of this study suggest that BCS was not as accurate for estimating body composition and fat depots in mature Churra ewes as has been shown previously in other breeds. The single most effective prediction index was LW. However, the utilization of both BCS and LW together provided more accurate estimations.

Six ewes with twin lambs were allocated to each of six restricted feeding treatments with 10, 0·8, 0·6, 0·4, 0·2 or 0 of the diet as perennial ryegrass and the remainder as white clover, and to two treatments with either perennial ryegrass or white clover offered alone ad libitum. Fresh herbage was offered and measurements were made over 8 weeks, with the exception of the ad libitum clover treatment which was terminated after 5 weeks. All lambs were allowed access to clover from 14 days of age. Digestibilities of the herbages were measured during four periods in the experiment.

Increasing the proportion of clover in the diet significantly increased the intake of nitrogen by the ewes and the growth rate of their lambs, but had no effect on the live-weight changes of ewes on the restricted treatments. When there was no restriction of intake, ewes ate slightly more clover than ryegrass and lost less weight, but mean daily live-weight gains of their lambs over the first 5 weeks did not differ significantly (0·30 and 0·34 kg for ryegrass and clover, respectively).

When ryegrass and clover were eaten alone or together their organic matter digestibilities (OMD) did not change, although OMD declined with increasing level of intake.

Initial body condition of the ewes had a significant effect on the decline of ewe live weight and body condition during lactation, and on lamb live-weight gain

The nutritional effects of sulla (Hedysarum coronarium L.) forage containing condensed tannins (CT) on growth of lambs, and carcass and meat quality were investigated. Thirty-two male Comisana lambs aged 100 ± 8 days weighing 19.0 ± 2.8 kg were fed fresh forage of sulla or CT-free annual ryegrass (Lolium multiflorum Lam. subsp. Wersterwoldicum) for 49 days until slaughter; in addition, each lamb was supplied with 200 g/days of concentrate. Eight lambs per diet had been previously treated with anthelmintic drugs to remove nematode parasites. Measurements of BW and feed intake, and counts of faecal nematode eggs were made. Carcass parameters were recorded after slaughter, and tissue components of the hind leg were determined. Longissimus dorsi meat was evaluated for pH, colour, thawing and cooking losses, Warner-Bratzler shear force, chemical composition and sensory properties based on triangle tests. Relative to ryegrass-fed lambs, sulla-fed lambs had significantly greater dry matter (DM) and protein intake, a more favourable feed conversion ratio, and superior growth rate, final BW at 150 days of age, carcass weight, yield and fatness. These results were attributed to the high protein and non-structural carbohydrate content of sulla, and also to the moderate CT content of sulla (16.7 and 20.3 g/kg of DM in offered and consumed sulla forage, respectively). Anthelmintic treatment did not affect lamb growth, as the level of parasitic infection (initial and final) was low. The physical, chemical and sensory properties of the lamb meat were not influenced by diet.

This experiment investigated the effects of increasing the dietary content of bacterial protein meal (BPM) on the protein and energy metabolism of pigs from weaning to a live weight of 80 kg. Four litters with four castrated male pigs in each litter were used. The litters were divided into two blocks according to age. One pig from each litter was fed one of the four experimental diets. Soya-bean meal was replaced with BPM on the basis of digestible protein, and the BPM contents in the four diets were 0% (BP0), 5% (BP5), 10% (BP10) and 15% (BP15), corresponding to 0%, 17%, 35% and 52% of the digestible nitrogen (N), respectively. Four balance periods were performed, at the start of which the pigs weighed 9.5 kg, 20.7 kg, 45.3 kg and 77.2 kg, respectively. Once during each balance period, 22-h respiration experiments were performed using indirect calorimetry. Daily weight gain, feed intake and feed conversion rate were the same for all diets. The apparent digestibility of N was lower on diet BP10 than on BP0 (P = 0.002), whereas the apparent digestibility of energy was similar on all diets. The retention of nitrogen did not differ between diets and was 1.50, 1.53, 1.33 and 1.46 g N per kg0.75 per day on BP0, BP5, BP10 and BP15, respectively. Neither metabolisable energy intake nor heat production were affected by inclusion level of BPM. Retention of energy was 620 (BP0), 696 (BP5), 613 (BP10) and 664 kJ/kg0.75 per day (BP15), the differences among diets being non-significant. The N-free respiratory quotient was similar on all diets. It was concluded that the overall protein and energy metabolism in growing pigs were not affected when up to 50% of dietary N was derived from BPM.

The effects of an increase of rumen fill obtained with polystyrene cubes, and able to stimulate mechanically the rumen wall were investigated on alimentary behaviour and reticulo-rumen motility in sheep. The introduction through a rumen cannula of a volume of polystyrene cubes equal to one-quarter of the ruminal pool size depressed the daily intake of both low-quality cocksfoot hay and good-quality lucerne hay (P < 0·05). Surprisingly, the time spent ruminating was slightly increased and the frequency of contractions during rumination was significantly increased (P < 0·05). In addition, in the sheep fed enterally with a liquid into the rumen, either the mechanical stimulation of the rumen dorsal wall or the introduction of hay (200 g) into the rumen, induced a rumination molility pattern. It is concluded that the intensity of mechanical stimulation of the dorsal sac of the rumen by food particles, which depends upon rumen fill, reduces the time spent eating to increase the duration and intensity of rumination.

Farrowing is an intrinsically risky process for both the sow and the piglets that can cause welfare and economic problems. The effects of the non-steroidal anti-inflammatory drug meloxicam on post-farrowing behaviour of sows, and the performance of piglets were investigated. A total of 48 sows were randomly allocated at the day of farrowing (day 0) into two homogeneous groups regarding parity, and treated with either meloxicam or saline solution as placebo. For each sow, number of position changes, total time lying and standing or sitting, feed intake and rectal temperature (RT) were recorded during 3 days after farrowing. Piglets were individually weighed at farrowing and at weaning. The number of position changes did not show significant differences between treatments (P = 0.79). Sows spent significantly less time lying during day +3 after farrowing in the meloxicam group than in the placebo group (P = 0.04). Feed intake and RT showed a parity effect (P < 0.001 in both cases); however, no treatment effect was observed (P = 0.67 and P = 0.47, respectively). Pre-weaning mortality rate in piglets was not affected by treatment. In litters from multiparous sows, piglets of low birth weight (defined as percentile 15: BW <1180 g) had an average daily gain significantly higher in the meloxicam group than in the placebo group (196.6 ± 7.2 v. 166.6 ± 9.1 g/day; P = 0.03). Although the administration of meloxicam 90 min after farrowing showed a positive effect on the total time lying of the sows, additional investigations are required to better qualify relevant indicators of pain following farrowing in sows and to specify the analgesic effects of meloxicam on piglet performance.

Mixing pigs from different social groups is known to cause turmoil which often results in skin lacerations as well as dark, firm and dry meat. Nine hundred and sixty commercial crossbred pigs were used for this experiment, divided into eight consignments. Within each consignment the pigs were divided into groups of about 15. The pigs in each group had coexisted for at least 6 weeks prior to slaughter. Thirty min before loading for slaughter, groups of pigs were either mixed with unfamiliar pigs or not mixed. Similarly, on arrival at the abattoir, groups of pigs were either mixed or not mixed. Hence there were four possible treatment combinations: pigs mixed with unfamiliar animals at loading, mixed at unloading, mixed at both points, or pigs which had remained in their social groups for at least 6 weeks prior to slaughter. Carcasses were dressed according to normal practice. After 20 h in the chiller room carcasses were assessed for skin blemish and fibre optic probe (FOP) values were measured in the longissimus dorsi muscle. Mixing pigs at either loading or unloading, or at both points, had no significant effect on the FOP value, but it did have a significant effect on the frequency of skin blemish values. Skin blemish values increased due to mixing at the farm (+0·36, Meat and Livestock Commission scale) however mixing at both places did not have an additive effect. The results indicate that the ideal movement system might be to keep pigs in their farm pen social groups until the point of slaughter.

Forty male commercial hybrid pigs, half castrated at 10 days of age, were used in a study to determine whether boars at bacon weight (90 kg live weight) have different fat quality from barrows. Fat quality was defined as the firmness and cohesiveness of subcutaneous fat, both properties being measured using an Instron materials testing instrument. Within each group of boars and barrows, half the pigs were fed a normal commercial diet and half a lower energy diet at a lower level of food intake. The latter diet provided relatively more energy as C18:2 (linoleic acid).

Firmness of subcutaneous fat was related to fat thickness and to concentrations of the chemical components in the fat which are affected by fat thickness. The single best predictor of firmness was C18:0 (stearic acid). Cohesiveness was less closely related to fat thickness and was most associated with the concentration of C18:2.

On the low energy/high C18:2 diet, all the pigs were judged to have soft fat, the difference between boars and barrows being small and explained by the difference in fat thickness. On the normal commercial diet, some barrows had particularly firm fat but they had thicker fat than any of the boars. Most (0·84) of the pigs in the experiment had P2 values (fat thickness over the m. longissimus at the last rib) between 8 and 15 mm. In this range there was no difference in firmness between boars and barrows. Cohesiveness was also similar between boars and barrows.

Relationships between the intake of energy and the rate of gain on the one hand, and the chemical composition of gain on the other were studied in bacon pigs, assuming that: (1) the only important determinants of the energy balance are the expenditures of energy in maintenance, in protein deposition and in fat deposition; (2) the net energy cost of fat or of protein deposition remains constant in pigs of all ages and live-weights, whatever the level of nutrition; (3) the average maintenance requirements of pigs growing over the same live-weight range and kept under similar conditions are constant, irrespective of their daily gains; (4) the ratio of non-fat components to protein in the gains of pigs over a similar live-weight range is virtually constant. Deductions based on these assumptions enabled the expression of the feed conversion ratio as a function of the average daily protein deposition, the average daily maintenance requirements and the average daily intake of energy to be made. The dependence of the feed conversion ratio on each of these three factors was demonstrated.

After the substitution of plausible values for the energy costs of protein and of fat deposition, as well as for the average maintenance requirements, equations were derived for the estimation of the content of protein and of fat in the live-weight gain, when the total feed consumption and the number of days on test (20 to 90 kg.) were known. Using these equations, the average gain of fat and of protein in each year were estimated for the Danish Progeny Testing Stations during the period from 1926–7 to 1962–3. It was found that the decrease of the feed conversion ratio and consequent reduction in fat deposition which were achieved during this period, were accounted for mainly by an increase in daily protein deposition.

1. Using the data from the dissection of 24 sides of beef from Hereford, Dairy Shorthorn and Friesian steers on four levels of nutrition a critical study has been made of the relation of the weight of tissue in an anatomical joint to the total weight of the same tissue in the whole side.

2. There was a significant eifect of breed and level of nutrition in the case of bone. The heaviest breed (Friesians) had a bigger proportion of bone in those bones which support the animal (i.e. the radius-ulna, humerus, femur and tibia-fibula) than had the lighter breeds (Herefords and Shorthorns). The effect of level of nutrition was not the same for all the bones and was difficult to interpret. There was little or no significant effect of breed or level of nutrition on the distribution of muscular or fatty tissue among the joints.

3. The relation of the weight (in kg.) of a tissue (x) in a joint to that in the whole side (y) was expressed by groups of equations of the form, y = a+bx, there being a separate group for bone, muscular tissue, subcutaneous fatty tissue, intermuscular fatty tissue and total fatty tissue. Tables are provided giving the values for the constants ‘a’ and ‘b’ and standard errors of prediction joint by joint for each tissue.

4. No general significance could be attached to the values for the constant ‘a’ but for each tissue there was a correlation between the value for ‘b’ and the inverse of the average weight of tissue in the corresponding joint. For each tissue there were one or two joints which were significantly aberrant. Aberrance is associated either with exceptionally high or with exceptionally low levels of errors of prediction.

5. The high order of magnitude for the standard errors of prediction for estimating muscular tissue (± 12·2 1b. or more) and for estimating total fatty tissue (± 12·7 1b. for the loin), led to exploring the following rule of thumb method.

6. The weight of muscular tissue in a carcass is approximately one-third of the live-weight of the animal, the weight of bone, tendon etc. is onequarter of the weight of muscular tissue and the remainder of the weight of a carcass is the weight of fatty tissue.

7. Using the weights of the animals on the farm, the weight of the sides after hanging in the slaughter house overnight, and the weights of the tissue after dissection it was shown that the above method of estimation gave values for muscular tissue within ± 10·1 1b., for fatty tissue ± 11·8 1b. and for bone etc. ± 3·1. These values compare favourably with those calculated from the weight of muscular tissue in a joint (±12·2 1b. for the foreshin), and fatty tissue (neglecting thorax ±7·0 1b. and 13th rib ±9·8 1b.) ± 12·7 1b. for the loin. The estimate of bone etc. from the weight of radiusulna (± 1·7 1b.) was somewhat better.

8. The general conclusion is that in studies of meat quality, and of the effect of breed and plane of nutrition on meat quality (including carcass conformation) it will be necessary to dissect the whole side or carcass joint by joint, tissue by tissue and muscle by muscle. There are no adequate short cuts.

The consistency of differences between varieties in nutritive value of cereal straws was tested over 3 years consecutively for nine varieties of spring barley and 10 varieties of winter wheat straw and over 2 years consecutively for 12 varieties of winter barley and six varieties of oats. For all varieties there were large year-to-year differences in nutritive value measured by ruminal degradation characteristics using the nylon bag technique. For spring barley there were large differences between varieties and the correlations between varieties in different years were mostly in excess of r = 0·90 for 48-h degradability and maximum potential degradability. For winter wheat the correlations between varieties for different years were lower but mostly significant. For the winter barley differences between varieties were less, but even so differences between varieties in different years were significant. For oats differences between the varieties were small and there was no significant correlation within varieties between years. The results suggest that the nutritive value of cereal straws is generally consistent between years and is a characteristic that could be improved by selection.

An evaluation of the European pig diversity has been carried on by several countries, with the support of the European Union over the period of 1994 to 2000. This article presents an overview of the results of this investigation, focussing on two genetic marker techniques, namely microsatellites (MS) and amplification of fragment length polymorphism (AFLP). Nearly 200 loci were characterised on about 50 individuals from each of 59 to 71 breeds, according to the marker considered. The analysis of diversity, based on genetic distances, led to similar conclusions for the two marker types (MS and AFLP), in spite of a markedly lower total diversity of AFLP compared to MS. The analysis of the MS loci showed that the allelic diversity pattern among breeds was quasi-independent from the diversity pattern based on allele frequencies. Genetic distances showed no particular clustering of local with international breeds, confirming the genetic uniqueness of the European local breeds compared to mainstream international breeds. The taxonomy of the local breeds revealed a cluster of the Iberian type breeds, in contrast with a wider dispersal of the breeds from other countries. Phylogeny often disagreed with documented breeds’ history, showing the complex migration/admixture patterns which underlie the breeds’ relationships. Methodologies developed in this investigation as well as the database and the DNA depository created should provide support for further innovative research in the field of domestic animal diversity management.

Supplementation with copper (Cu) improves deer antler characteristics, but it could modify meat quality and increase its Cu content to levels potentially harmful for humans. Here, we studied the effects of Cu bolus supplementation by means on quality and composition of sternocephalicus (ST) and rectus abdominis (RA) muscles (n=13 for each one) from yearling male red deer fed with a balanced diet. Each intraruminal bolus, containing 3.4 g of Cu, was administered orally in the treatment group to compare with the control group. Meat traits studied were pH at 24 h postmortem (pH24), colour, chemical composition, cholesterol content, fatty acid (FA) composition, amino acid (AA) profile and mineral content. In addition, the effect of Cu supplementation on mineral composition of liver and serum (at 0 and 90 days of treatment) was analysed. No interactions between Cu supplementation and muscle were observed for any trait. Supplementation with Cu increased the protein content of meat (P<0.01). However, Cu content of meat, liver and serum was not modified by supplementation. In fact, Cu content of meat (1.20 and 1.34 mg/kg for Cu supplemented and control deer, respectively) was much lower in both groups than 5 mg/kg of fresh weight allowed legally for food of animal origin. However, bolus of Cu tended to increase the meat content of zinc and significantly increased (P<0.05) the hepatic contents of sodium and lead. Muscles studied had different composition and characteristics. The RA muscle had significantly higher protein content (P<0.001), monounsaturated FA content (P<0.05) and essential/non-essential AA ratio (P<0.01) but lower pH24 (P<0.01) and polyunsaturated FA content (P=0.001) than the ST muscle. In addition, RA muscle had 14.4% less cholesterol (P=0.001) than ST muscle. Also, mineral profile differed between muscles with higher content of iron, significantly higher (P<0.001) content of zinc and lower content of calcium, magnesium and phosphorus (P<0.05) for ST muscle compared with RA. Therefore, supplementation with Cu modified deer meat characteristics, but it did not increase its concentration to toxic levels, making it a safe practice from this perspective. Despite the lower content of polyunsaturated FA, quality was better for RA than for ST muscle based on its higher content of protein with more essential/non-essential AA ratio and lower pH24 and cholesterol content.

Fifteen sexually mature rams, five each of Barki, Awassi (I, imported from Syria) and Awassi (LB, locally born in Egypt) were used in this study. Semen was collected monthly from rams for a period of 12 months to study semen characteristics. In addition, blood samples were collected from rams during the four seasons of the year to determine serum triiodothyronine (T3) and testosterone hormones. Results showed that Barki and Awassi (I and LB) rams are continuous breeders as they show sexual desire and produce semen all the year round. However, monthly variations in semen quality were detected. Relative testes volume, ejaculate volume, sperm concentration, total sperm output, sperm motility, percentage of live sperm and serum testosterone level were higher during summer months than at other months of the year. Serum T3 was significantly higher in winter and spring than that observed in summer and autumn. In addition, percentages of dead spermatozoa were higher in winter and early spring than in autumn and summer. Furthermore, summer months showed moderate percentages of abnormal spermatozoa and spermatozoa without intact acrosomes. These results indicate that ram semen quality in the subtropics may be better during summer months than during other months of the year.

The objective of this study was to examine the population structure of the Trakehner Horse breed. A total of 13 793 pedigree records were used for analysing the active breeding population and their ancestors dating back to 1950. Ancestors that were born before 1950 were called as base animals. The average generation interval was calculated as 10.2 years. The effective population size (Ne) was estimated by the increase in average year-wise inbreeding coefficient and average coancestry, respectively. Two methods were applied to estimate the effective population size: 1. Numerator-relationship-matrix (NRM), which did not consider missing ancestries. 2. Uncertain-parentage-matrix (UPM), which considered a probabilistic correction for unknown ancestors. There were no major differences between these two methods with respect to the rate of increase in inbreeding although the global levels using the UPM method were observed to be higher. Estimates for the inbreeding coefficients and the average coancestries varied little between both methods. The estimates of the effective population size per generation based on the rate of inbreeding ranged from 169 (NRM) to 150 (UPM) and 158 (NRM) to 144 (UPM) calculated by the average coancestry. From the early 1990s onwards, a strong increase in the rate of inbreeding was observed. This may be due to an increasing variance of the family size of sires and may be interpreted as a consequence of the growing use of artificial insemination. Analysing coancestries within and between the centrally managed regional breeding societies in Germany further revealed the Trakehner horse breed to be a genetically fragmented population with a main partition corresponding to formerly divided East and West Germany. The average rate of gene contributions (Thoroughbred (xx), Arab Horse breed (ox)) to the defined actual breeding population was calculated to be 22.3% xx-genes and 11.7% ox-genes.

Piglet neonatal diarrhoea is an important issue in modern pig production and is linked to increased mortality and poor growth rates, affecting long-term pig health, increasing use of medication and cost of production. Saccharomyces cerevisiae var. boulardii (SB) is a probiotic yeast with documented clinical efficacy in the prevention and treatment of diarrhoeal diseases in humans. The objectives of the current study were to evaluate the effect of SB on occurrence and severity of neonatal diarrhoea in piglets, mortality and growth rate. Forty-six litters (606 piglets) were randomly allocated to a control or SB treatment (n=23 per treatment). Within 24 h of farrowing, piglets assigned to the SB treatment received a single oral dose of a paste containing 3.3×109 CFU of SB CNCM I-1079. Piglets from the control litters received a placebo paste. Piglet weight, mortality and diarrhoea were recorded up to day 7 of age. It was shown that numbers of diarrhoea days were significantly correlated with increased mortality rate and reduced weight gain (P<0.05). SB treatment had no effect on growth or mortality in diarrhoeic litters. However, SB-supplemented litters had significantly lower faecal scores, indicating firmer faeces (P<0.01) and fewer numbers of diarrhoeic days (P<0.01) during the 1st week of life. Reduction in the number of diarrhoeic litters compared with the control group was observed following the probiotic administration (P<0.05). These results highlight the detrimental effects of neonatal diarrhoea on pre-weaning performance and suggest that SB, by reducing diarrhoea duration and severity, has the potential of improving enteric health in the early stages of life in pigs.

Rhythmic pineal melatonin biosynthesis develops in chick embryos incubated under a light (L)-dark (D) cycle of polychromatic white light. The spectral sensitivity of the embryonic pineal gland is not known and was investigated in this study. Broiler breeder eggs (Ross 308, n=450) were incubated under white, red, green or blue light under the 12L : 12D cycle. Melatonin was measured in extracts of pineal glands by radioimmunoassay. The daily rhythm of pineal melatonin levels in 20-day-old chick embryos was confirmed during the final stages of embryonic life under all four wavelengths of light with expected higher concentrations during dark- than light-times. The highest pineal melatonin levels were determined in chick embryos incubated under red and white light and lower levels under green light. The incubation under blue light resulted in the lowest melatonin biosynthesis. Pineal melatonin concentrations increased substantially on post-hatching day two compared with pre-hatching levels and we did not find differences between birds incubated and kept in either white or green light. Our results demonstrate a selective sensitivity of the chick embryo pineal gland to different wavelengths of light. Rhythmic melatonin production is suggested as a possible mechanism, which transfers information about the quality of ambient light to the developing avian embryo.