In order to improve foal carcass quality, it is necessary in particular to improve the carcass dressing percentage and tissue composition. Thus, it is important to establish relationships between grading systems and these parameters. This research was conducted to study the effect of slaughter age (13 v. 26 months) and finishing feed (standard v. linseed feed) on carcass characteristics such as subcutaneous fat colour plus classification of foals for the degree of fatness and conformation. For this study, 46 foals of crossbred genotype (Galician Mountain×Burguete) were used. Finishing feed did not affect any parameter, whereas slaughter age influenced all parameters (P<0.05). The oldest foals had higher carcass measurements, 13% more of meat, 4% more of bone, 12% more of fat, and 4% and 9% bigger fore- and hindquarter, respectively. Consequently, bigger valuable prime cuts were obtained. Nevertheless, the meat : bone ratio was very similar for both 13- and 26-month-old foals (2.88). Most of 26-month-old foals were classified in ‘E’ (Extra) and ‘5’ (Complete fat cover) categories of conformation and degree of fatness. Most of the carcasses showed subcutaneous fat described as yellowish-white irrespective of age or diet. A regression model found that conformation (36%) and degree of fatness (33%) in live animals was positively linked with carcass tissue composition. It is therefore suggested that producers aim for older slaughter ages than 13 months and that the foal meat industry establishes grading systems to predict carcass quality. Further studies should be necessary to find the optimal slaughter age to obtain carcasses in the best categories of degree of fatness and conformation. New studies should be recommended to improve the meat : bone ratio of foal carcasses as it estimates the aptitude for meat production.

Selection in native local breeds needs great carefulness due to the small population size and the risk of inbreeding. Furthermore, most breeds are dual-purpose, and milk and beef attitudes are antagonistic. For preservation purposes functional traits need to be considered. Focusing on the small local Rendena cattle, this study aimed to analyse the genetic correlations among milk, beef and udder health traits and the response to selection predicted under different scenarios. The study considered milk, fat and protein yields (MY), factor scores for udder volume (UV), conformation (UC) and muscularity obtained from type traits scored on primiparous cows, and performance test traits (PT) measured on young bulls at test station: average daily gain, in vivo SEUROP fleshiness, in vivo dressing percentage. Somatic cell score (SCS) was considered as a functional trait, with a possibility of restricting its genetic gain to zero. The study considered 281 497 MY test-day data collected on 16 974 cows, and data from linear type evaluation on 11 992 primiparous cows for factor scores. The PT data were recorded on 1428 young bulls, and SCS obtained from cell counts at milk recording. Bi-trait restricted maximum likelihood animal model analyses were performed to assess genetic parameters. Heritability varied from 0.157 (fat) to 0.442 (dressing percentage). Udder volume and MY resulted positively genetically correlated (average correlation 0.427), whereas the low-negative genetic correlation between MY and UC (−0.141) suggested a negative impact of milk gain on udder form. Beef traits of factor muscularity and PT showed medium-high favourable genetic correlations (from 0.357 to 0.984), excluding a null correlation between daily gain and muscularity. The genetic correlation MY v. muscularity was unfavourable (−0.328 on average), whereas null correlations were found in MY v. PT, apart from fat v. dressing percentage (−0.151). Somatic cell score showed low unfavourable correlations with protein (0.111) and UV (0.092), and favourable correlations with UC (−0.193). Response to selection in different scenarios indicated a good balanced gain for milk and beef when standardized economic weights of 0.66 and 0.34 are given to the two attitudes, and SCS genetic gain is restricted. Current genetic trends (MY and PT increasing, but muscularity lessening) reflect a stronger selection for milk, suggesting a slight progressive change towards a milk conformation. Aiming to preserve the dual-purpose characteristics of a breed, proper breeding policies taking into account the genetic relationships among traits and including functional traits should be applied in local dual-purpose populations.

Despite the well-known importance of an adequate colostral immunoglobulin (Ig) transfer to calf health and survival, failed transfer of passive immunity (FTPI) remains a widespread problem in dairy farming. The aim of this study was to investigate the management factors associated with FTPI in newborn calves, evaluating particularly the combined effect of delivery time, amount and quality of the first colostrum meal. The study was conducted from March to August 2014 on 21 Italian dairy farms. Farmers were asked as first to answer a farm-level questionnaire on calf management. Blood sampling was then performed on overall 244 calves (1 to 5 days of age) born from Holstein cows, and a sample of the first colostrum meal of each calf was collected. Individual information on calves and the respective colostrum management were recorded. Serum and colostrum Ig concentrations were assessed by electrophoresis. A mixed effects multivariable logistic regression model was used to investigate the association of the variables obtained from both the management questionnaire and the individual calf data with FTPI (calf serum Ig concentration <10.0 g/l). A cumulative colostrum management score (CMS) that considered delivery time, amount and quality of the first colostrum meal was generated for 236 calves, with higher values indicating better colostrum management. Overall, 41.0% of the calves were found having FTPI, and within-farm percentage of FTPI was over 20.0% in 71.4% of the farms. The risk of having FTPI was higher both for Holstein purebred calves compared with Holstein-beef crossbreds and for females compared with males. Moreover, it increased by 13% with every hour of delay of the first colostrum meal provision since birth, whereas it decreased by 59% and 3%, respectively, with every additional liter of colostrum given and every additional gram of Ig per liter contained in the colostrum fed. Calf serum Ig concentration varied significantly according to the CMS, increasing by 1.53 g/l with every additional CMS point. In order to completely avoid FTPI, calves should receive at least 2.5 l of high-quality colostrum (Ig concentration >87.6 g/l) within 1.0 h from birth. Considerable improvements are still needed about colostrum management for newborn calves in dairy farms. The results of this study will help in developing farm-specific programs for reducing the occurrence of FTPI.

Carcass data were collected from 24 kids (average live weight of 12.5±5.5 kg; range 4.5 to 22.4 kg) of Jarmelista Portuguese native breed, to evaluate bioelectrical impedance analysis (BIA) as a technique for prediction of light kid carcass and muscle chemical composition. Resistance (Rs, Ω) and reactance (Xc, Ω), were measured in the cold carcasses with a single frequency bioelectrical impedance analyzer and, together with impedance (Z, Ω), two electrical volume measurements (VolA and VolB, cm2/Ω), carcass cold weight (CCW), carcass compactness and several carcass linear measurements were fitted as independent variables to predict carcass composition by stepwise regression analysis. The amount of variation explained by VolA and VolB only reached a significant level (P<0.01 and P<0.05, respectively) for muscle weight, moisture, protein and fat-free soft tissue content, even so with low accuracy, with VolA providing the best results (0.326⩽R2⩽0.366). Quite differently, individual BIA parameters (Rs, Xc and Z) explained a very large amount of variation in dissectible carcass fat weight (0.814⩽R2⩽0.862; P<0.01). These individual BIA parameters also explained a large amount of variation in subcutaneous and intermuscular fat weights (respectively 0.749⩽R2⩽0.793 and 0.718⩽R2⩽0.760; P<0.01), and in muscle chemical fat weight (0.663⩽R2⩽0.684; P<0.01). Still significant but much lower was the variation in muscle, moisture, protein and fat-free soft tissue weights (0.344⩽R2⩽0.393; P<0.01) explained by BIA parameters. Still, the best models for estimation of muscle, moisture, protein and fat-free soft tissue weights included Rs in addition to CCW, and accounted for 97.1% to 99.8% (P<0.01) of the variation observed, with CCW by itself accounting for 97.0% to 99.6% (P<0.01) of that variation. Resistance was the only independent variable selected for the best model predicting subcutaneous fat weight. It was also selected for the best models predicting carcass fat weight (combined with carcass length, CL; R2=0.943; P<0.01) and intermuscular fat weight (combined with CCW; R2=0.945; P<0.01). The best model predicting muscle chemical fat weight combined CCW and Z, explaining 85.6% (P<0.01) of the variation observed. These results indicate BIA as a useful tool for prediction of light kids’ carcass composition.

The aquaculture industry depends upon the development of sustainable protein sources to replace fishmeal (FM) in aquafeeds and the products derived from soybeans are some of the most studied plant feedstuffs. A key area of investigation for continuing to improve modern aquafeeds includes the evaluation of varying proportions and combinations of plant ingredients to identify mixtures that are more efficiently utilized by the fish. This study investigated the effects of increasing soybean meal (SBM) by replacing a mix of plant ingredients in low FM (20%) diets on growth, blood biochemistry profile and gut histology on European sea bass. Five isonitrogenous and isolipidic experimental diets were formulated: four diets containing increasing SBM levels (0, 10, 20 and 30%; 0SBM, 10SBM, 20SBM and 30SBM, respectively) with a low content of FM (20%) and one control diet (0% SBM; 35% FM). Diets containing SBM brought to comparable performance and protein utilization, while 0SBM had negative impact on feed conversion rate and protein utilization. Blood parameters suggested an optimal nutritional status under all feeding treatments, even though slightly decreased values were reported at increasing dietary SBM. Histology examination did not show any changes indicative of soy-induced enteritis. We can conclude that for European sea bass: (i) different blends of plant protein did not affect feed intake despite the 20% FM dietary level; (ii) the inclusion of SBM maintains optimal growth and feed utilization in low FM diets; (iii) blood biochemistry profile showed a good nutritional status under all feeding regimes; (iv) no evidence of soy-induced enteritis was reported in any group fed low FM diets. For formulation of practical diets in on-growing of European sea bass, SBM up to 30% can be successfully incorporated into feeds containing low FM inclusion.

A targeted quantitative metabolomics approach was used to study temporal changes of serum metabolites in cows that normally released their fetal membranes and those that retained the placenta. We identified and measured serum concentrations of 128 metabolites including amino acids, acylcarnitines, biogenic amines, glycerophospholipids, sphingolipids and hexose at −8 and −4 weeks before parturition, during the week of retained placenta (RP) diagnosis, and at +4 and +8 weeks after parturition. In addition, we aimed at identifying metabolite signatures of pre-RP in the serum that might be used as predictive biomarkers for risk of developing RP in dairy cows. Results revealed major alterations in the metabolite fingerprints of pre-RP cows starting as early as −8 weeks before parturition and continuing as far as +8 weeks after calving. Biomarker candidates found in this study are mainly biomarkers of inflammation which might not be specific to RP. Therefore, the relevance of serum Lys, Orn, acetylornithine, lysophophatidylcholine LysoPC a C28:0, Asp, Leu and Ile as potential serum biomarkers for prediction of risk of RP in dairy cows will have to be tested in the future. In addition, lower concentrations of LysoPCs, Trp, and higher kynurenine in the serum during prepartum and the week of occurrence of RP suggest involvement of inflammation in the pathobiology of RP.

Most dairy cattle populations found in different countries around the world are small to medium sized and use many artificial insemination bulls imported from different foreign countries. The Walloon population in the southern part of Belgium is a good example for such a small-scale population. Wallonia has also a very active community of Holstein breeders requesting high level genetic evaluation services. Single-step Genomic BLUP (ssGBLUP) methods allow the simultaneous use of genomic, pedigree and phenotypic information and could reduce potential biases in the estimation of genomically enhanced breeding values (GEBV). Therefore, in the context of implementing a Walloon genomic evaluation system for Holsteins, it was considered as the best option. However, in contrast to multi-step genomic predictions, natively ssGBLUP will only use local phenotypic information and is unable to use directly important other sources of information coming from abroad, for example Multiple Across Country Evaluation (MACE) results as provided by the Interbull Center (Uppsala, Sweden). Therefore, we developed and implemented single-step Genomic Bayesian Prediction (ssGBayes), as an alternative method for the Walloon genomic evaluations. The ssGBayes method approximated the correct system of equations directly using estimated breeding values (EBV) and associated reliabilities (REL) without any explicit deregression step. In the Walloon genomic evaluation, local information refers to Walloon EBV and REL and foreign information refers to MACE EBV and associated REL. Combining simultaneously all available genotypes, pedigree, local and foreign information in an evaluation can be achieved but adding contributions to left-hand and right-hand sides subtracting double-counted contributions. Correct propagation of external information avoiding double counting of contributions due to relationships and due to records can be achieved. This ssGBayes method computed more accurate predictions for all types of animals. For example, for genotyped animals with low Walloon REL (<0.25) without MACE results but sired by genotyped bulls with MACE results, the average increase of REL for the studied traits was 0.38 points of which 0.08 points could be traced to the inclusion of MACE information. For other categories of genotyped animals, the contribution by MACE information was also high. The Walloon genomic evaluation system passed for the first time the Interbull GEBV tests for several traits in July 2013. Recent experiences reported here refer to its use in April 2016 for the routine genomic evaluations of milk production, udder health and type traits. Results showed that the proposed methodology should also be of interest for other, similar, populations.

The potential combined effects of oleic, linoleic and linolenic acids supplementation on lactation performance and the milk fatty acid (FA) profile in dairy cows have not been well investigated. Our objective was to examine the effects of supplementation with a combination of these FA as well as the effects of removing each from the combination on lactation performance and the milk FA profile in dairy cows. Eight Holstein cows (101±11 days in milk) received four intravenously infused treatments in a 4×4 Latin square design, and each period lasted for 12 days which consisted of 5 days of infusion and 7 days of recovery. The control treatment (CTL) contained 58.30, 58.17 and 39.96 g/day of C18 : 1 cis-9; C18 : 2 cis-9, cis-12; and C18 : 3 cis-9, cis-12, cis-15, respectively. The other three treatments were designated −−C18 : 1 (20.68, 61.17 and 41.72 g/day of C18 : 1 cis-9; C18 : 2 cis-9, cis-12; and C18 : 3 cis-9, cis-12, cis-15, respectively), −C18 : 2 (61.49, 19.55 and 42.13 g/day of C18 : 1 cis-9; C18 : 2 cis-9, cis-12; and C18 : 3 cis-9, cis-12, cis-15, respectively) and −C18 : 3 (60.89, 60.16 and 1.53 g/day of C18 : 1 cis-9; C18 : 2 cis-9, cis-12; and C18 : 3 cis-9, cis-12, cis-15, respectively). Dry matter intake and lactose content were not affected by the treatments, but the milk protein content was lower in cows treated with −C18 : 2 than that in CTL-treated cows. Milk yield as well as milk fat, protein and lactose yields were higher in cows treated with −C18 : 3 than the yields in CTL-treated cows, and these yields increased linearly as the unsaturation degree of the supplemental FA decreased. Compared with the CTL treatment, the −C18 : 2 treatment decreased milk C18 : 2 cis-9 content (by 2.80%) and yield (by 22.12 g/day), and the −C18 : 3 treatment decreased milk C18 : 3 cis-9, cis-12, cis-15 content (by 2.72%) and yield (by 22.33 g/day). In contrast, removing C18 : 1 cis-9 did not affect the milk content or yield of C18 : 1 cis-9. The −C18 : 2-treated cows had a higher C18 : 1 cis-9 content and tended to have a higher C18 : 1 cis-9 yield than CTL-treated cows. The yields of C8 : 0, C14 : 0 and C16 : 0 as well as <C16 : 0 tended to increase linearly as the unsaturation degree of the supplemental FA decreased (P=0.06, 0.07, 0.07 and 0.09, respectively). These results indicated that supplementation with C18 unsaturated FA might not independently affect the lactation performance and the milk FA profile of dairy cows.

Toasting time (TT) of rapeseed meal (RSM), the diet processing (DP) method and the interaction between both on the apparent CP digestion along the gastrointestinal tract and the apparent ileal digestibility (AID) of amino acids of growing pigs were investigated. The experiment consisted of a 3×3 factorial design of TT of RSM (0, 60 and 120 min) and DP method (mash, pelleting and extrusion). In total, 81 boars with a starting BW of 20 kg were euthanized 4 h after their last feeding. The gastrointestinal tract was dissected and the small intestine divided in three sections of similar length. Samples were collected from the stomach, 1.5 m from the ends of each of the three sections of the small intestine, and the rectum. The apparent digestibility (AD) of CP for each of the small intestine sections was used to calculate the rate of CP digestion. Increasing the TT of RSM resulted in lower protein solubility, lower lysine/reactive lysine contents and higher protein denaturation, indicative of the occurrence of protein aggregation and Maillard reactions. There were significant effects (P⩽0.01) of TT on the AD of CP in the different sections of the gastrointestinal tract. The rate of CP digestion of the 0 min toasted RSM diets was 23% and 35% higher than that of the 60 and 120 min toasted RSM diets, respectively. There was a significant interaction (P=0.04) between TT and DP for the AID of CP. Although pelleting of the 0 and 60 min toasted RSM diets did not change the AID of CP with respect to the mash diets, pelleting of the 120 min toasted RSM diet increased the AID of CP by 9.3% units. Extrusion increased the AID of CP of the 0 and 60 min toasted RSM diets by 3.4% and 4.3% units with respect to the mash diets, whereas extrusion of the 120 min toasted RSM diet increased the AID of CP by 6.9% units. Similar positive effects of pelleting and extrusion were obtained for the AID of lysine and reactive lysine, especially in the diets with higher TT. In conclusion, processing (pelleting and extrusion) of RSM containing diets can ameliorate the negative effects of RSM toasting on protein and amino acid digestibility; these effects were larger for the RSM toasted for longer times.

On pig farms, a high proportion of the cost of production comes from feed costs. However, the use of alternative ingredients such as legume seeds may help to reduce this cost. In fact, legume seeds are an important source of essential amino acids (EAA) and can therefore be an alternative to oilseed meals. However, the accurate use of these legume seeds requires a precise knowledge of the standardized ileal digestibility (SID) of EAA, which may vary depending on its botanical variety. A meta-analysis was performed on a database compiling data from 41 studies published between 1981 and 2013 and 178 dietary treatments. Models of prediction of the SID of EAA as well as the dietary concentration of digestible standardized EAA (dEAA) were obtained, based on the chemical composition of ingredients reported in the publications. The effect of the type of legume seeds (faba bean, lupin, pea and soya bean), surgical procedures (T-cannula, re-entrant cannulas, post valve T-cannulas and ileo-rectal anastomosis), and BW of pigs (BW⩽25 kg BW>25 kg) were also tested in each model. Results showed that dietary CP and crude fibre (CF) were, respectively, the best predictors of each EAA SID for faba bean, lupin and pea (R2=0.42 to 0.89) and soya bean (R2=0.32 to 0.77). For the dEAA content, the best prediction models included dietary CP and ADF for faba bean, lupin and pea and soya bean, respectively, with R2 ranging from 0.66 to 0.98. Models developed in this study allow predicting the digestibility of EAA in these alternatives feedstuffs.

Recently developed innovations may improve the economic and environmental sustainability of pig production systems. Generic models are needed to assess the impact of innovations on farm performance. Here we developed a stochastic bio-economic farm model for a typical farrow-to-finish pig farm to assess the impact of innovations on private and social profits. The model accounts for emissions of greenhouse gases from feed production and manure by using the shadow price of CO2, and for stochasticity of economic and biological parameters. The model was applied to assess the impact of using locally produced alternative feed sources (i.e. co-products) in the diets of finishing pigs on private and social profits of a typical Brazilian farrow-to-finish pig farm. Three cases were defined: a reference case (with a standard corn–soybean meal-based finishing diet), a macaúba case (with a macaúba kernel cake-based finishing diet) and a co-products case (with a co-products-based finishing diet). Pigs were assumed to be fed to equal net energy intakes in the three cases. Social profits are 34% to 38% lower than private profits in the three cases. Private and social profits are about 11% and 14% higher for the macaúba case than the reference case, whereas they are 3% and 7% lower for the co-products case, respectively. Environmental costs are higher under the alternative cases than the reference case suggesting that other benefits (e.g. costs and land use) should be considered to utilize co-products. The CV of farm profits is between 75% and 87% in the three cases following from the volatility of prices over time and variations in biological parameters between fattening pigs.

We evaluated the effects of heat stress (HS) and methionine supplementation on biological markers of stress and expression of the genes for superoxide dismutase (SOD), thioredoxin (TRx), thioredoxin reductase 1 (TRxR1) and methionine sulfoxide reductase A (MsrA) in broilers aged 1 to 21 or 22 to 42 days. The broilers were divided into two treatments, one with the recommended level of methionine supplementation (MS, supplementation of dl-2-hydroxy-4-methylthiobutanoic acid (dl-HMTBA)) and one without methionine supplementation (MD). The animals were maintained at a temperature of thermal comfort or one of HS (38°C for 24 h). Mortality was only observed in 42-day-old broilers exposed to HS and fed the MD diet, and the rate was 5%. Starter period: we observed an interaction effect between diet and temperature on the gene expression of TRxR1 and MsrA, and expression of these genes was higher in the HS animals that received the MS diet than that in birds with the MD diet. Grower period: the expression of SOD, TRxR1 and MsrA genes, activities of aspartate aminotransferase (AST) and creatine kinase (CK) and content of creatinine were influenced by both study variables. In the HS animals, the expression of these genes, AST activity and creatinine content increased and CK activity decreased. In the animals on the MD diet, the expression of these genes and AST and creatinine values were higher and the CK activity was lower than those for the birds on the MS diet. Our results indicated that under HS conditions, the supplementation with dl-HMTBA could mitigate major damage caused by stress through the action on some genes related to TRx complex activity.

Floor space allowance for pigs has substantial effects on pig growth and welfare. Data from 30 papers examining the influence of floor space allowance on the growth of finishing pigs was used in a meta-analysis to develop alternative prediction equations for average daily gain (ADG), average daily feed intake (ADFI) and gain : feed ratio (G : F). Treatment means were compiled in a database that contained 30 papers for ADG and 28 papers for ADFI and G : F. The predictor variables evaluated were floor space (m2/pig), k (floor space/final BW0.67), Initial BW, Final BW, feed space (pigs per feeder hole), water space (pigs per waterer), group size (pigs per pen), gender, floor type and study length (d). Multivariable general linear mixed model regression equations were used. Floor space treatments within each experiment were the observational and experimental unit. The optimum equations to predict ADG, ADFI and G : F were: ADG, g=337.57+(16 468×k)−(237 350×k2)−(3.1209×initial BW (kg))+(2.569×final BW (kg))+(71.6918×k×initial BW (kg)); ADFI, g=833.41+(24 785×k)−(388 998×k2)−(3.0027×initial BW (kg))+(11.246×final BW (kg))+(187.61×k×initial BW (kg)); G : F=predicted ADG/predicted ADFI. Overall, the meta-analysis indicates that BW is an important predictor of ADG and ADFI even after computing the constant coefficient k, which utilizes final BW in its calculation. This suggests including initial and final BW improves the prediction over using k as a predictor alone. In addition, the analysis also indicated that G : F of finishing pigs is influenced by floor space allowance, whereas individual studies have concluded variable results.

Accurate measurement of herbage intake rate is critical to advance knowledge of the ecology of grazing ruminants. This experiment tested the integration of behavioral and acoustic measurements of chewing and biting to estimate herbage dry matter intake (DMI) in dairy cows offered micro-swards of contrasting plant structure. Micro-swards constructed with plastic pots were offered to three lactating Holstein cows (608±24.9 kg of BW) in individual grazing sessions (n=48). Treatments were a factorial combination of two forage species (alfalfa and fescue) and two plant heights (tall=25±3.8 cm and short=12±1.9 cm) and were offered on a gradient of increasing herbage mass (10 to 30 pots) and number of bites (~10 to 40 bites). During each grazing session, sounds of biting and chewing were recorded with a wireless microphone placed on the cows’ foreheads and a digital video camera to allow synchronized audio and video recordings. Dry matter intake rate was higher in tall alfalfa than in the other three treatments (32±1.6 v. 19±1.2 g/min). A high proportion of jaw movements in every grazing session (23 to 36%) were compound jaw movements (chew-bites) that appeared to be a key component of chewing and biting efficiency and of the ability of cows to regulate intake rate. Dry matter intake was accurately predicted based on easily observable behavioral and acoustic variables. Chewing sound energy measured as energy flux density (EFD) was linearly related to DMI, with 74% of EFD variation explained by DMI. Total chewing EFD, number of chew-bites and plant height (tall v. short) were the most important predictors of DMI. The best model explained 91% of the variation in DMI with a coefficient of variation of 17%. Ingestive sounds integrate valuable information to remotely monitor feeding behavior and predict DMI in grazing cows.

Mechanisms responsible for excellent marbling in Japanese black cattle, Wagyu, remain to be established. Because both muscle cells and intramuscular adipocytes are developed from mesenchymal progenitor cells during early muscle development, we hypothesized that intramuscular progenitor cells in Wagyu cattle have attenuated myogenic capacity in favor of adipogenesis, leading to high marbling but reduced muscle growth. Biceps femoris muscle biopsy samples were obtained from both Angus (n=3) and Wagyu (n=3) cattle at 12 months of age. Compared with Angus, the density of satellite cells was much lower in Wagyu muscle (by 45.8±10%, P<0.05). Consistently, the formation of myotubes from muscle-derived progenitor cells was also lower (by 64.2±12.9%, P<0.05), but adipogenic capacity was greater in Wagyu. The average muscle fiber diameter was larger in Wagyu (by 23.9±6.8%, P=0.089) despite less muscle mass, suggesting less muscle fiber formation in Wagyu compared with Angus cattle. Because satellite cells are derived from fetal myogenic cells, the reduction in satellite cell density together with lower muscle fiber formation suggests that myogenesis was attenuated during early muscle development in Wagyu cattle. Given the shared pool of mesenchymal progenitor cells, the attenuated myogenesis likely shifts progenitor cells to adipogenesis during early development, which may contribute to high intramuscular adipocyte formation in Wagyu cattle.

Light-emitting diode (LED) light bulbs are becoming more prevalent in broiler production as they are dimmable and more energy efficient than compact fluorescent lamps. Although there is some research on how spectrum of light can affect production, little has been conducted on how it may affect stress, and behavior. To determine how different spectrum of light produced by LED lights could affect production, stress and behavior we raised broilers under either 2700 K (WARM) or 5000 K (COOL) color temperature LED bulbs. To determine stress susceptibility bilateral asymmetry (ASYM, n=128), plasma corticosterone concentrations (CORT, n=40) and heterophil/lymphocyte ratios (HL, n=80) were measured. Fear was measured using tonic immobility (TI, n=128), inversion (INV, n=128) and isolation (ISO, n=128). Weight gain and feed conversion ratio (FCR) were also determined. The COOL birds had lower ASYM (1.65±0.08 mm, P=0.001), CORT (5.8±1.2 ng/dl, P=0.01) and HL (0.16±0.01, P=0.03) than the WARM birds (2.38±0.14 mm, 13.4±2.7 ng/dl and 0.21±0.02, respectively). The COOL birds righted faster during TI (136.2±11.1 s, P=0.001), flapped less intensely during INV (4.1±0.1 flaps/s, P<0.001) and vocalized less during ISO (45.3±2.8 vocalizations, P=0.005) when compared with WARM birds (207.2±15.8 s, 4.9±0.1 flaps/s and 56.5±2.9 vocalizations). The COOL birds (2.89±0.03 kg, P=0.02) grew to a heavier weight at the end of 42 day then WARM birds (2.79±0.03 kg). The COOL birds (1.54±0.03) had better FCR (P=0.02) than WARM birds (1.61±0.01). These results demonstrate that raising broilers under 5000 K LED lights can reduce their stress, fear and increase weight gain when compared with 2700 K. These results indicate that the spectrum of light used for rearing of broilers is not only important for production, but also for welfare of the birds.

A total of 48 sub-adult hares and adult reproducing farmed hares were used to characterize carcass and meat traits according to the age and gender of animals. With respect to carcass traits, when age increased, the carcass weight significantly increased (2022 to 3391 g; P<0.001), but dressing out percentages did not change. The dissectible fat (1.3% to 2.2%; P<0.05) and Longissimus lumborum (LL) proportions (13.5% to 14.5%; P<0.001) and muscle-to-bone ratio of hind legs (5.11 to 6.23; P<0.001) increased, whereas the hind leg proportions decreased (37.3% to 36.3%; P=0.01). As for the meat quality, the pH of hind leg (5.74 to 5.83; P<0.001) and LL (5.53 to 5.69; P<0.001) increased with age, while the L* index decreased in both cuts (42.9 to 34.4 in hind leg; 45.1 to 40.3 in LL; P<0.001). The redness index increased at the hind leg (4.07 to 5.76; P<0.001), while it decreased at LL (3.03 to 1.46; P<0.001). In the case of the hind leg, meat thawing losses decreased (1.58% to 1.02%), and shear force increased (2.97 to 4.02 kg/g). In the case of LL, thawing losses decreased (8.79% to 4.91%; P<0.001) in the adult hares compared with the sub-adult ones. Meat water and protein contents decreased in the hind leg and LL of the adult hares compared with the sub-adult ones, whereas ether extract increased in a restricted range in LL only (0.92% to 1.11%; P<0.001). In the case of the hind leg, the rate of the saturated fatty acids (SFA) decreased (41.0% to 26.7%), and the rate of the polyunsaturated fatty acids (PUFA) increased (34.0% to 45.3%) (P<0.001). In the case of LL, SFA (38.6% to 42.9%) and monounsaturated fatty acids (19.4% to 27.2%) increased, whereas PUFA decreased (42.0% to 30.1%) when the age increased (P<0.001). Gender affected only the slaughter results and carcass traits. In conclusion, farmed hares have favourable slaughter results (high dressing percentage), carcass traits (high hind legs and loins rates), and meat nutritional value (high-protein, low-fat meat). This fact would offer additional commercial opportunities, in addition to restocking, to hare farmers.

The suitability of a single mid-season targeted selective treatment (TST) for gastrointestinal nematodes control, based on flexible average daily weight gain (ADWG) thresholds, was investigated in 23 groups of first grazing season calves. In each group, animals were weighed three times: before turnout, at mid-season and at housing. Just after the first weighing, each group was divided in two homogenous sub-groups in terms of age, breed and weight, and randomly allocated to one of two sub-groups intented for two different mid-season anthelmintic treatment strategies: (1) a treatment of all calves composing the sub-group (whole-group treatment (WT)) or (2) a targeted selective weight gain-based treatment (TST) of the animals showing an individual pre-treatment ADWG inferior to the mean pre-treatment ADWG of the corresponding WT sub-group. Anthelmintic treatment (levamisole 7.5 mg/kg BW) was performed 3 to 4 months after turnout. At housing, two parasitological parameters (the anti-Ostertagia ostertagi antibody level-Ostertagia optical density ratio (ODR) and the pepsinogen level) and a clinical parameter (the breech soiling score) were assessed at individual level in each group. Then, the high exposed groups to gastrointestinal nematode (GIN) were defined as groups for which untreated animals exhibited a mean Ostertagia ODR ⩾0.7 and among these groups, the ones characterized by high abomasal damage due to Ostertagia for which untreated animals exhibited a mean pepsinogen level ⩾2.5 U Tyr were also identified. Among TST sub-groups, the treatment ADWG thresholds varied from 338 to 941 g/day and the percentage of treated animals from 28% to 75%. Pre- and post-treatment ADWG as well as parasitological and clinical parameters measured at housing were similar between TST and WT sub-groups including the 17 high exposed groups to GIN. Within these 17 groups, the treatment allowed to significantly improve post-treatment ADWG compared with untreated animals. In the six high exposed groups showing mean pepsinogen level ⩾2.5 U Tyr, the average effect of treatment on post-treatment ADWG was the highest and estimated up to 14 kg after a grazing duration of 4 months. In contrast, in six other groups showing mean Ostertagia ODR<0.7 in untreated animals, no effect of treatment was seen suggesting an absence of production losses related to a low level of GIN infection. This study highlighted the suitability of a convenient mid-season TST strategy for first grazing season calves, based on the use of flexible thresholds of ADWG, allowing similar growth compared with a whole-group treatment while keeping a GIN population in refugia.