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Stress neuroendocrine systems (hypothalamic–pituitary–adrenal axis and sympathetic nervous system) were studied in 100 female pigs from each of the five main genetic lines used in Europe for pork production: Piétrain, Large White, Landrace, Duroc and Meishan. Levels of cortisol and catecholamines were measured in urine collected at the farm, after transportation to the slaughterhouse and the next morning before slaughter. With the exception of the Piétrain line that showed intermediate levels of cortisol despite its extreme leanness, a significant positive relationship was found between basal cortisol levels and fatness, both across and within (except in Piétrain and Duroc) lines. Basal cortisol levels were 2.46-fold higher in Meishan (20.46 ng/mg creatinine) than in Large White pigs (8.30 ng/mg creatinine), the two extreme breeds. Post-transportation levels were highest but proportional to basal levels, suggesting that the adrenal reactivity to adrenocorticotropic hormone is a major source of variability between lines. Levels of catecholamines were less variable between lines but correlated also with fatness, partlyviapartial correlations with cortisol levels. In serum collected at exsanguination, creatine kinase activity was correlated with muscularity across the five breeds. However, this was due to a much larger activity than expected in Piétrain pigs, although all animals were negative for the allele of the ryanodine receptor gene responsible for stress sensitivity. Serum glucose levels were inversely related to fatness. These data show that the differences between breeds or lines can be utilised by cross-breeding and that this can lead to changes in stress hormones and in turn to some degree of changes in carcass traits.
Although stocking rate is a key management variable influencing the structure and composition of pastures, only few studies have simultaneously analysed the seasonal patterns of pasture use by cattle, and the adjustments the animals make to maintain intake of a high-quality diet over the grazing season. Therefore, over a 3-year study, we recorded diet selection, plot use and impact of heifers on sward structure and quality under three different stocking rates (0.6, 1.0 and 1.4 livestock units (LU) per ha) in a species-rich mountain pasture of central France. Measurements were made on three occasions between early June and the end of September each year. Overall, heifers selected for bites dominated by legumes or forbs, and against reproductive grass, whatever the stocking rate or season. Selection for tall mixed (P < 0.05), short mixed (P < 0.05) and short pure grass bites (P < 0.01) was more pronounced in plots grazed at the lowest stocking rate. Although heifers’ selection for short patches decreased at the end of the season (P < 0.001), they continued to graze previously grazed areas, thus exhibiting a typical ‘patch grazing’ pattern, with the animals that grazed at the lowest stocking rate tending to better maintain their selection for short patches in September (treatment × period: P = 0.078). Neither diet quality nor individual animal performance were affected by the different stocking rate treatments despite high variability in the quantity and quality of herbage offered and differences in diet selection. However, at the 1.4 LU per ha stocking rate, the quantity of forage available per animal at the end of the season, 0.79 t dry matter (DM) per ha of green leaves with the median of sward height at 4.6 cm, approached levels limiting cattle’s ability to compensate for the effects of increasing stocking rate. In plots grazed at 0.6 LU per ha, the total herbage biomass remained higher than 3 t DM per ha with more than 30% of plot area still covered by reproductive grass patches at the end of the grazing season, which in the medium term should affect the botanical composition of these pastures. Sward heterogeneity was high in plots grazed at 1.0 LU per ha, with sufficient herbage availability (1.1 t DM per ha of green leaves) to maintain animal performance, and more than 15% of plot area was kept at a reproductive stage at the end of the grazing season. Hence, it could represent the optimal balance to satisfy both livestock production and conservation management objectives.
In the process of developing a generic Hazard Analysis and Critical Control Point (HACCP)-like system for securing animal health and welfare in organic egg production, an expert panel analysis was used to perform the initial hazard analysis. Eighteen advisers and researchers in organic egg production were included in the expert panel. In a series of four questionnaires, the expert panel first scored 34 health and welfare problems seen in Danish organic egg production. Based on scorings of severity and occurrence, 10 problems were selected for further analysis. The experts subsequently suggested and scored risk factors for those problems and finally suggested control points, alarm values indicating the need for corrective actions in order to control the risk factors and monitoring frequencies of these. The 10 selected problems were hunger, thirst, piling, crop impaction, blackhead, pasteurellosis, bone fractures, cannibalism, predators and red mites. A total of 154 different risk factors were suggested for these problems. The 41 risk factors which rated highest in a combined scoring of importance and occurrence were selected for further analysis. There was a high degree of consensus between experts when scoring both problems and risk factors. The level of consensus, as defined by an interquartile range ⩽1, was 79% to 100% when scoring the health and welfare problems (scale 1–5) and 77% to 95% when scoring the risk factors (scale 1–4). On average, 5.8 control points were suggested for every risk factor. Alarm values were often not detailed enough to be of practical significance and further analysis is needed in order to define these. The experts were highly diverse in their suggested monitoring frequencies and establishment of monitoring schemes should be part of developing the farm specific systems. An expert panel analysis based on questionnaires was a useful tool during the first steps of developing a HACCP plan, conducting a hazard analysis and suggesting control points. However, care should be taken regarding the panel’s size and fields of expertise in order to assure that the panel fully covers the field of interest throughout the study. A further development of the hazard analysis into a farm-specific HACCP system would include assembling an on-farm HACCP team consisting of farmers and advisors for the practical application of control points, alarm values and monitoring schemes. The results from the fourth questionnaire would be useful as input for this work.
Two parallel schemes of crosses were practised involving the Spanish maternal line called V-line (V) and Saudi Gabali (S) rabbits. The first scheme began by crossing Saudi Gabali bucks with V-line does to get the F1 cross (½S½V), then does of this F1 were backcrossed with bucks of V-line to get ¾V¼S, then the progenies of the backcross were inter se mated to get (¾V¼S)2, followed by two more generations of inter se mating of (¾V¼S)2 to get a new synthetic maternal line named Saudi 2. The second scheme began by crossing V-line bucks with Saudi does to get the F1 cross (½V½S), then does of this F1 cross were backcrossed with Saudi bucks to get ½S½V, then progeny of this backcross were inter se mated to get (¾S¼V)2, followed by two generations of inter se mating of (¾S¼V)2 to form a new synthetic paternal line named Saudi 3. A generalised least-square procedure was used to estimate differences between lines in direct and maternal additive effects, direct and maternal heterosis, and direct recombination losses. A total number of 2497 ejaculates of 642 bucks were evaluated for ejaculate volume (VE), pH of semen, sperm concentration (SC), percentage of motile spermatozoa (MS), percentage of spermatozoa with abnormal form (AS), percentage of dead spermatozoa (DS) and libido score (LS). The estimates of direct additive effect for DS (14.2%), SC (12.4%) and AS (12.0%) were moderate and favourable to Saudi rabbits. Maternal additive effects for VE (11.7%) were in favour of genes of V-line carried by the dams of bucks, while these estimates were in favour of Saudi genes for DS (18.6%), AS (13.2%), MS (10.8%) and SC (10.0%). Positive estimates of direct heterosis recorded for SC (13.5%), VE (10.6%) and MS (10.5%) and the negative estimates recorded for AS (−21.5%) and DS (−20.3%) were moderate and well disposed to semen parameters of crossbred bucks. Positive estimates of maternal heterosis for VE (24.0%), MS (21.8%), SC (10.3%) and LS (10.2%) of bucks, and the negative estimates for percentage of DS (−14.7%) and AS (−9.6%) were also significantly favourable. Estimates of direct recombination losses for the majority of semen traits were always not significant.
The purpose of the present study was to compare the influence of adding no or 8% fat of varying sources (coconut oil, fish oil, rapeseed oil and sunflower oil) to diets for sows 1 week prior to farrowing and during lactation on the composition of fatty acids in plasma and tissues of the progeny while sucking and 3 weeks after weaning from the sow. A control diet without supplemental fat and four diets supplemented with 8% of coconut oil, rapeseed oil, fish oil or sunflower oil were provided to lactating sows (n = 15), and during the post-weaning period the same weaner diet was provided to all piglets (n = 15 litters), which were housed litterwise. The dietary ratio of n-6:n-3 fatty acids of the maternal diets largely influenced the progeny, as the ratio varying from 1.2 (fish oil) to 12.2 (sunflower oil) in the sow milk was reflected in plasma and adipose tissues of the sucking progeny. The liver showed similar variations according to dietary treatments, but a lower n-6:n-3 fatty acids ratio. From day 4 to later on during the suckling period, the concentration of C14:0, C16:0 and C18:1 in the liver of the piglets decreased, irrespective of the dietary treatments of sows. In plasma and liver, the total concentration of saturated fatty acids (SAFA), monounsaturated fatty acids (MUFA) and polyunsaturated fatty acids (PUFA) did not differ markedly in piglets sucking sows fed different dietary fatty acids, whereas the adipose tissue of piglets sucking sows fed sunflower oil and coconut oil showed the highest proportion of PUFA and SAFA, respectively. Weaning lowered the concentration of lipid-soluble extracts in plasma and the concentration of fatty acids in the liver of the piglets. Within the post-weaning period, dietary treatments of sows, rather than age of piglets, influenced the fatty acid composition of plasma and adipose tissue of the piglets, whereas the hepatic fatty acid profile was more affected by the age of the piglets during the post-weaning period. This study shows that the fatty acid profile of plasma and tissues of the progeny is highly dependent on the maternal dietary composition, and that the dietary impact persists for up to 3 weeks after the suckling period.
Sixteen castrated male Large White × Landrace pigs were employed to investigate the muscle type-specific changes of gene expression in response to recombinant porcine growth hormone (rpGH) administration. Pigs were injected intramuscularly with rpGH (4 mg/day, n = 8) or saline (n = 8) for 28 days. Semi-quantitative reverse transcription-polymerase chain reaction (RT-PCR) was used to determine the mRNA abundance of genes related to muscle growth in longissimus dorsi (LD) and semitendinosus (ST) muscles. Myofibre-type composition was characterised by the ratio of the expression of myosin heavy chain (MyHC) 1, 2a or 2b relative to 2x. The results showed that the relative myofibre-type composition of neither LD nor ST was affected by rpGH administration. rpGH administration did not induce significant changes in the abundances of myostatin and myogenin mRNA in both types of muscle. MyoD and calpain 3 mRNA were significantly increased after rpGH treatment in ST muscle, whereas the difference was not significant in LD muscle. A tendency of down-regulation was observed for PGC-1α mRNA expression in ST muscle of rpGH-treated group (P = 0.16). These results suggest that myoD, calpain 3 and probably PGC-1α may be involved in the mechanism of exogenous GH action on skeletal muscle growth; rpGH up-regulates mRNA expression of myoD and calpain 3 in a muscle type-specific manner, being more remarkable in ST than in LD, whereas no influences of rpGH on the mRNA expression of myostatin and myogenin were detected.
Boar taint is a major meat-quality defect in pigs and is due to excessive accumulation of skatole and androstenone in adipose tissue. The present work investigated the relationship between carcass weight, levels of skatole and androstenone in adipose tissue, and expression of the hepatic androstenone-metabolising enzyme 3β-hydroxysteroid dehydrogenase (3β-HSD), in 22 entire male and 22 entire female crossbred pigs (Large White (40%) × Landrace (40%) × Duroc (20%)). Animals of each gender were divided into two subgroups (11 pigs in each subgroup): (i) conventional weight (carcass weight 59 to 77 kg) and (ii) heavy weight (carcass weight 84 to 95 kg). No relationship between carcass weight and adipose tissue skatole level was found for entire male pigs (r2 = 0.013, P > 0.05). There was a significant negative relationship between carcass weight and expression of the hepatic 3β-HSD protein (r2 = 0.502, P < 0.001) and a significant negative relationship between 3β-HSD protein expression and androstenone level in adipose tissue (r2 = 0.24, P < 0.05) in entire males. No relationship was found between carcass weight and 3β-HSD protein expression in female pigs (r2 = 0.001, P > 0.05). 3β-HSD expression was 59% higher in conventional-weight male pigs when compared with heavy-weight animals (P < 0.05) and 36% higher in heavy-weight females when compared with heavy-weight males (P < 0.05). It is concluded that an increase in slaughter weight of entire commercial crossbred Large White pigs is accompanied by inhibition of expression of the hepatic 3β-HSD protein, which might result in a reduced rate of hepatic androstenone clearance with its subsequent accumulation in adipose tissue. It is suggested that regulation of pig hepatic 3β-HSD expression is under the control of sex hormones.
Appropriate thyroid gland function and thyroid hormone activity are considered crucial to sustain the productive performance in domestic animals (growth, milk or hair fibre production). Changes of blood thyroid hormone concentrations are an indirect measure of the changes in thyroid gland activity and circulating thyroid hormones can be considered as indicators of the metabolic and nutritional status of the animals. Thyroid hormones play a pivotal role in the mechanisms permitting the animals to live and breed in the surrounding environment. Variations in hormone bioactivity allow the animals to adapt their metabolic balance to different environmental conditions, changes in nutrient requirements and availability, and to homeorhetic changes during different physiological stages. This is particularly important in the free-ranging and grazing animals, such as traditionally reared small ruminants, whose main physiological functions (feed intake, reproduction, hair growth) are markedly seasonal. Many investigations dealt with the involvement of thyroid hormones in the expression of endogenous seasonal rhythms, such as reproduction and hair growth cycles in fibre-producing (wool, mohair, cashmere) sheep and goats. Important knowledge about the pattern of thyroid hormone metabolism and their role in ontogenetic development has been obtained from studies in the ovine foetus and in the newborn. Many endogenous (breed, age, gender, physiological state) and environmental factors (climate, season, with a primary role of nutrition) are able to affect thyroid activity and hormone concentrations in blood, acting at the level of hypothalamus, pituitary and/or thyroid gland, as well as on peripheral monodeiodination. Knowledge on such topics mirror physiological changes and possibly allows the monitoring and manipulation of thyroid physiology, in order to improve animal health, welfare and production.
Colostrum yield and composition of 40 Landrace×Large White sows were determined from the onset of parturition until 24 h post partum. Colostrum yield was calculated by adding individual piglets’ colostrum intakes for each litter. Colostrum was assayed for prolactin, progesterone, oestradiol-17β, immunoglobulin G and its nutritional composition was determined. Piglets’ individual colostrum intake averaged 300 ± 7 g and sows’ colostrum yield averaged 3.67 ± 0.14 kg (minimum 1.91 kg, maximum 5.31 kg). Live weight and characteristics at birth (umbilical cord already ruptured, splayleg, difficulty to breathe) were the major factors influencing individual colostrum intake. Colostrum yield was not affected by litter size, tended to be influenced by parity (P = 0.059) and was lower when farrowing was induced (P = 0.017). On the other hand, no relationships were found between hormone concentrations in colostrum and colostrum yield. Mean piglet birth weight and litter weight variation at birth were related to colostrum yield (r = 0.38; P = 0.015 and r = −0.34; P = 0.030, respectively). These results suggest that determinism of colostrum yield depends, in part, on global vitality of the litter but seems to be, most probably, affected by the capacity of sows to produce enough colostrum for the whole litter. Further studies are needed to understand the endocrine regulation of colostrum secretion in sows.
The quality of the attachment of meat to bone is often reported to be insufficient by more and more poultry’s consumers. This is particularly true for thigh meat in broilers. The aim of this study was to compare muscle to bone attachment (namely, tendons) from a biomechanical and a biochemical point of view in 50 standard (S) and 50 Label Rouge (LR) chickens. Carcasses weighted around 1.7 kg in the two groups. Two tendons were harvested and proceeded for passive stretch tests, prior to cooking or not, to determine main mechanical characteristics (maximum load, stiffness and longitudinal strain). Biochemical parameters such as dry matter percentage, total collagen content, collagen solubility and sulphated glycosaminoglycans (sGAGs) content were also determined. Results showed that biomechanical values differ largely between the two studied tendons. For a given tendon, the values were also different between the two groups of chickens mainly after cooking. The results clearly showed that, mainly after cooking, the mechanical resistance of tendon to stretch was better in LR than in S chickens. LR chickens were reported to have tendons with higher collagen and sGAGs contents associated with a lower collagen solubility. These differences may explain biomechanical differences observed for the two types of tendons and could be due to increased age and/or higher physical activity of LR chickens.
In the first study, we tested the ability of a commercial feed additive (OmniGen-AF) to affect markers of innate immunity in immunosuppressed sheep and the ability of a pathogen challenge (mould) to affect the immune response to the additive. Treatments consisted of (1) control, (2) immunosuppressed with dexamethasone (DEX), (3) immunosuppressed plus the feed additive, (4) immunosuppressed plus Aspergillus fumigatus and (5) immunosuppressed, A. fumigatus and the additive. Animal health was monitored and indexes of innate immunity (neutrophil L-selectin and interleukin-1β (IL-1β)) were collected. DEX caused immunosuppression (i.e. reduced abundance of neutrophil L-selectin and IL-1β). This immunosuppressive effect was countered by the provision of the additive in the ration. Provision of mould in the ration increased the ability of the additive to regulate markers of innate immune function. A second study was completed to re-assess the properties of the additive and other feed products. The study consisted of seven treatments: (1) immunosuppressed, (2) immunosuppressed with additive, (3) immunosuppressed with additive in pelleted form (low-temperature pellet) and (4) immunosuppressed with additive in a high-temperature pellet. The remaining three treatments assessed abilities of three other additives to regulate markers of innate immune function. In this study, OmniGen-AF increased expression of neutrophil L-selectin abundance in immunosuppressed animals and this was unaffected by the pelleting temperature. None of the other additives affected markers of innate immunity. In these studies we discovered mechanisms by which a feed product may affect the immune function of ruminant livestock. The product countered DEX-dependent down-regulation of markers of innate immune function and its actions were enhanced by the presence of pathogen (mould) in the ration.
This investigation was designed to evaluate the effects of feeding either free range or in confinement using concentrated diets with the same ingredients and oil source (5.5% of olive oleins) but with different antioxidant supplementation [control diet with a basal level of α-tocopheryl acetate (control); 200 mg/kg synthetic all-rac-α-tocopheryl acetate (Eall-rac); 200 mg/kg natural RRR-α-tocopheryl-acetate (ERRR-); flavonoid extract-enriched diet (AFlav); and phenolic compound-enriched extract (APhen)] on the fatty acid composition and lipid oxidation of Iberian pig muscle longissimus dorsi. The α-tocopherol concentration was significantly higher in muscles from free-range and ERRR- pigs than in muscles from Eall-rac pigs, and γ-tocopherol was only detected in muscles from free-range pigs. Longissimus dorsi muscles from free-range pigs had a significantly lower content of saturated fatty acids and higher content of polyunsaturated fatty acids than muscles from the other five groups of pigs fed in confinement; however, no significant effect on monounsaturated fatty acids was observed. No effect of dietary antioxidant supplementation (synthetic or natural α-tocopherol, flavonoid extract, or phenol extract) on the fatty acid composition of muscles was observed. A significant influence of dietary treatment on lipid oxidation was observed after 3 (P < 0.01), and 7 and 10 (P < 0.001) days of refrigerated storage, respectively. The lowest thiobarbituric acid-reactive substances (TBARS) values were found in pork chops from the free-range and ERRR- groups, intermediate values from the Eall-rac group, followed by AFlav and APhen, while the highest TBARS values corresponded to muscles from pigs fed the control concentrate. The source of α-tocopherol had a significant effect on lipid oxidation (P < 0.05), whereas the AFlav and APhen groups had similar TBARS values.
The objective of the study was to estimate genetic trends from 1977 to 1998 in the French Large White (LW) breed for stillbirth and associated traits measured at farrowing using frozen semen. Two groups of pigs (G77 and G98) were obtained by inseminating LW sows with semen from LW boars born either in 1977 or in 1998. A second generation was produced by inter se mating in each group. Farrowing was thoroughly supervised through both direct observations and video recording all long farrowing on a total of 137 first- and second-parity litters produced by sows from this second generation (68 G77 and 69 G98 litters, respectively). Measurements included birth time, weight and birth characteristics (including orientation, presence of cyanosis or oedema, membrane obstruction, umbilical cord length/content) of each piglet, as well as sow traits (weight and backfat thickness, farrowing duration, litter size and within-litter variation of weights at birth). The data were analysed using linear or generalised linear mixed models, according to the definition of the trait (continuous or binary data). The importance of several effects to piglet probability of stillbirth was then quantified by computing the reduction of variance associated with the addition of each effect in the model. Litter size did not significantly differ in first parity, but was higher in G98 second-parity sows: the differences for global (including pre partum dead piglets) and total numbers of piglets born per litter were +2.3 ± 1.1 and +1.3 ± 0.6, respectively. G98 sows also had a higher number of stillbirths in both parities (+0.7 ± 0.3 stillborn per litter). Piglets from G98 litters were heavier at birth (+130 ± 40 g for birth weight adjusted for litter size), without any increase in within-litter heterogeneity of birth weight. No significant difference was detected between G77 and G88 groups for farrowing length and the distribution of time interval between piglet births. G98 stillborn piglets had longer and more often empty umbilical cords at birth. G98 piglets born alive also had more often umbilical nodes than G77 piglets. These characteristics were considered as indicators of increased farrowing difficulties and risk of hypoxia at birth in G98 pigs. Time of birth of each piglet, sow fatness at farrowing and time of first placenta expulsion were the main factors of variation of the piglet’s probability of stillbirth.
A multidisciplinary research programme was developed to get a scientific expertise for the quality assessment of products obtained from cloned livestock. Thirty-seven bovine Holstein female clones of five different genotypes and their products were analysed in comparison with 38 control animals obtained by conventional artificial insemination and raised under the same conditions at the same experimental farm. Animal evaluation included over 150 criteria and more than 10 000 measurements to check the physiological status and health over a 3-year period. All the parameters studied were in the normal range for age and breed, but some significant differences were detected between clone and control groups in terms of delayed onset of puberty in clones, higher neutrophil counts in haematology or lower biochemical plasma concentrations of gamma glutamyl transferase. Milk and meat analyses were conformable to expected values. We, however, found some differences in fatty acid (FA) composition of milk and muscle suggesting a possible deviation in lipid metabolism as assessed by higher delta-9 desaturase activity indexes in both milk and muscles from clones compared with controls. Repeated muscle biopsies in the semitendinosus muscle of the same animals demonstrated a higher oxidative activity in muscle of young clones (8 months of age) compared with controls, suggesting a delayed muscle maturation in clones. Nutritional evaluation of milk and meat using the rat feeding trials did not show any difference between clone and control products for food intake, growth rate, body composition of the rats, nor for possible allergenicity. Possible reactivation of bovine endogenous retroviruses (BERVs) was analysed and compared between normal and cloned cattle. As expected, these BERV sequences are not transcribed and no RNA was detected in the blood of clones, donor animals or controls; therefore, it may be assumed that the sanitary risk associated with BERV sequences is not higher in cattle derived from somatic nuclear transfer than in cattle born from conventional reproduction. Our results confirm that the quality and safety of products (milk and meat) from adult and clinically healthy cloned cattle is globally similar to normal animals. However, from a strictly biological point of view, the slightly delayed maturation we observed in the muscle of clones together with some marginal differences identified in FA composition of both muscle and milk, point to the need for more refined analysis to totally exclude any risks from the consumption of those products.
The present study was undertaken to study different methodological aspects of quantifying CO2 production and milk intake of suckling piglets using the doubly labelled water (DLW) technique. In total, 37 piglets were enriched intraperitoneally with DLW to study equilibration time of 18O (n = 3), to validate the estimation of milk intake and CO2 production (n = 10) of piglets fed milk replacer and to quantify milk intake and CO2 production of piglets nursed ordinarily by sows (n = 24). Enrichment of 18O in expired air was analysed without any sample preparation, whereas enrichment of 18O in serum was analysed after a minimum step of sample preparation, which included pipetting of the sample, blowing gaseous CO2 into the vial for 3 s and equilibrating for 24 h. The 18O enrichment of CO2 in expired air was constant within 30–40 min of intraperitoneal injection, suggesting that DLW was equilibrated within the body water by that time. For piglets fed milk replacer, the estimation of the daily CO2 production by the DLW method (64.0 ± 2.7 l CO2/day) was in agreement with that obtained by respiration trials (64.7 ± 1.8 l CO2/day). Furthermore, the intake of milk replacer (891 ± 63 g/day) determined by deuterium oxide (D2O) dilution was similar in magnitude to that found by weighing the milk disappearance (910 ± 58 g/day). The milk intake of piglets fed milk replacer was comparable with that of sucking piglets, but sucking piglets had a remarkably higher CO2 production than artificially reared piglets, which likely was caused by a higher intake of milk solids and a higher activity level. For sucking piglets, the daily CO2 production increased curvilinearly with increasing live weight (LW) in kg: piglet CO2 production (l/day) = 25.75 × LW − 1.01 × LW2. In conclusion, 18O equilibrates fast within the body water pool when administered intraperitoneally, and the accuracy of assessing milk intake and rate of CO2 production using the DLW technique is promising. Assessment of excess enrichment of 18O in serum proved to be robust. Finally, the CO2 production of piglets fed milk replacer differs considerably from that of sucking piglets.
The objective was to reduce the incidence of liver abscesses (LAs) in young bulls by reducing the starch content of the concentrate and increasing the straw intake by adding molasses without reducing performance. Eighty-five Danish Friesian bulls (146 ± 2.6 kg live weight (LW)) were allocated to four treatment groups in a 2 × 2 factorial design and were ad libitum fed either a high (H) (43%) or a low (L) (25%) starch concentrate, and either chopped barley straw (S) or a mixture (Sm) of chopped barley straw and sugar-beet molasses (75:25). The bulls were slaughtered at 440 (±4.2) kg LW (11.3 months of age) on average. The concentrate dry-matter intake (DMI) was 7.5% higher (P < 0.001), the roughage DMI was 12% higher (P < 0.01), whereas the total net energy intake was 7% lower (P < 0.001) for the L compared with the H concentrate. By adding molasses to the straw, roughage DMI increased from 0.50 to 0.96 kg/day (P < 0.001). Average daily gain (ADG) was not affected by treatment. Feed conversion efficiency (FCE) for dry matter (FCEDM) was decreased (P < 0.001), whereas FCE for net energy (FCENE) was increased with the L concentrate (P < 0.01), suggesting a lower utilisation of the cell wall fraction with the H starch concentrate. There were no major effects of treatment on carcass characteristics. The higher roughage intake with Sm prevented rumen wall damage, but did not reduce the number of animals with LAs. The L concentrate did not affect the rumen wall but reduced the level of LA (2 v. 9 animals, P < 0.02). There was a higher level of respiratory diseases in animals fed the H concentrate (P < 0.05). The experiment showed that it was possible to maintain performance and reduce LA by using a lower starch content of the concentrate.
Freezing/thawing procedures induce enhanced reactive oxygen species (ROS) formation in mammalian sperm and these ROS may be a cause for the decrease in sperm function following cryopreservation. In the present study, we used a chemiluminescence method to detect ROS-induced damage in goat spermatozoa. Iron-induced luminescence of fresh and frozen/thawed sperm cells was assessed using a luminometer. It was shown that the freezing/thawing procedure had a significant effect on some luminescence parameters. Semen freezing significantly increased the values of integral, peak max, T.half (rise) and T.max (peak) parameters. A significant correlation was observed between the percentage of motile spermatozoa and integral, peak max and T.half (rise) parameters. In conclusion, the results of the present study indicate that measurement of induced luminescence can be an alternative, sensitive and relatively simple method for assessing the effect of cryopreservation on oxidative damage to spermatozoa.
To study the effect of feeding silages with different botanical composition, on rumen and lamb fat, 30 male lambs were assigned to five different silage groups for 11 weeks: botanically diverse silage (BDS); white clover silage (WCS); red clover silage (RCS), intensive English ryegrass silage (IRS) and crushed linseed and maize silage (MSL). Besides the silages, animals received organic wheat and barley and the MSL group additionally received bicarbonate (15 g/day). Silages were sampled when the bales were opened and analysed for fatty acid (FA) content and chemical composition. At slaughter, ruminal contents were sampled and 24 h after slaughter, longissimus muscle and subcutaneous (SC) fat were sampled. All samples were analysed for FA composition. The MSL group ingested the highest amount of FA (35.8 g/day v. 13.5, 19.4, 17.2 and 30.4 g/day for MSL v. BDS, WCS, RCS and IRS, respectively) and the sum of the major polyunsaturated FA, C18:2 n-6 and C18:3 n-3, was similar for groups BDS, WCS, RCS and MSL (61.3 g/100 g, 62.3 g/100 g, 62.3 g/100 g, 63.7 g/100 g of FA methylesters (FAME), respectively), while group IRS ingested higher proportions of these FA (74.5 g/100 g of FAME). Rumen data showed that animals fed BDS presented higher proportions of biohydrogenation intermediates, particularly C18:1 t11 and CLA c9t11, suggesting partial inhibition of rumen biohydrogenation. In the MSL group, the content of C18:3 n-3 in the rumen was highest, most probably due to reduced lipolysis and hence biohydrogenation through the combined effect of esterified C18:3 n-3 and seed protection. Additionally, C18:3 n-3 proportions were higher in rumen contents of RCS animals compared with WCS animals, which could be due to the activity of the polyphenol oxidase enzyme in the RC silages. Proportions of C18:3 n-3 were similar between treatments both for SC and intramuscular (IM) fat, whereas CLA c9t11 content was higher in the SC fat of BDS animals and lower in the IM fat of IRS animals compared with the other forage groups. No differences were found for C20:4 n-6, C20:5 n-3, C22:5 n-3 and C22:6 n-3 in the IM fat of the animals. Nevertheless, indices for desaturation and elongation activity in muscle of BDS animals suggest some stimulation of the first three steps of desaturation and elongation (Δ6-desaturase, elongase and Δ5-desaturase) of long-chain FA.
A growth experiment with 108 lambs (breed: German Merino Landsheep) was carried out to examine the effect of gender, body weight (BW) and feeding intensity on the deposition of Fe, Zn, Cu and Mn in the empty body (whole animal minus contents of the gastrointestinal tract and bladder). The lambs (50% female and 50% male animals) were fed at three feeding levels (‘low’, ‘medium’ and ‘high’ by varying daily amounts of concentrate and hay) and slaughtered at different final BWs (30, 45 or 55 kg). Six male and six female animals were killed at a BW of 18 kg representing the animals’ BW at the beginning of the comparative slaughter experiment. There were significant main effects for the treatments growth rate and final weight on the daily rate of accretion of the trace elements examined. Feeding intensity had a marked influence on the accretion rate for Fe (P < 0.001), Zn (P < 0.001), Cu (P < 0.001) and Mn (P = 0.003). With increasing feeding intensity (low, medium, high) the daily deposition of these trace elements increased (4.4, 5.2, 6.6 mg/day for Fe; 4.9, 5.5, 6.9 mg/day for Zn; 0.20, 0.36, 0.44 mg/day for Cu; 0.14, 0.16, 0.21 mg/day for Mn). Heavier final BW led to increased daily retention of Zn (P < 0.001) and Mn (P = 0.002). Gender had a marked influence only on the accretion rate for Zn (P < 0.001). Ram lambs had a higher daily deposition of this element than female lambs. Related to 1000 g empty body gain, the following concentrations were found for the trace elements examined: Fe 26.1 mg, Zn 30.0 mg, Cu 1.41 mg and Mn 1.04 mg. A feeding influence was given for Zn (P < 0.001) and Cu (P = 0.039). Feeding level low had higher Zn and lower Cu concentrations. Male animals showed less Fe (P < 0.001) and Zn (P = 0.034) per kg empty body gain than females.