In endangered and local pig breeds of small population sizes, production has to focus on alternative niche markets with an emphasis on specific product and meat quality traits to achieve economic competiveness. For designing breeding strategies on meat quality, an adequate performance testing scheme focussing on phenotyped selection candidates is required. For the endangered German pig breed ‘Bunte Bentheimer’ (BB), no breeding program has been designed until now, and no performance testing scheme has been implemented. For local breeds, mainly reared in small-scale production systems, a performance test based on in vivo indicator traits might be a promising alternative in order to increase genetic gain for meat quality traits. Hence, the main objective of this study was to design and evaluate breeding strategies for the improvement of meat quality within the BB breed using in vivo indicator traits and genetic markers. The in vivo indicator trait was backfat thickness measured by ultrasound (BFiv), and genetic markers were allele variants at the ryanodine receptor 1 (RYR1) locus. In total, 1116 records of production and meat quality traits were collected, including 613 in vivo ultrasound measurements and 713 carcass and meat quality records. Additionally, 700 pigs were genotyped at the RYR1 locus. Data were used (1) to estimate genetic (co)variance components for production and meat quality traits, (2) to estimate allele substitution effects at the RYR1 locus using a selective genotyping approach and (3) to evaluate breeding strategies on meat quality by combining results from quantitative-genetic and molecular-genetic approaches. Heritability for the production trait BFiv was 0.27, and 0.48 for backfat thickness measured on carcass. Estimated heritabilities for meat quality traits ranged from 0.14 for meat brightness to 0.78 for the intramuscular fat content (IMF). Genetic correlations between BFiv and IMF were higher than estimates based on carcass backfat measurements (0.39 v. 0.25). The presence of the unfavorable n allele was associated with increased electric conductivity, paler meat and higher drip loss. The allele substitution effect on IMF was unfavorable, indicating lower IMF when the n allele is present. A breeding strategy including the phenotype (BFiv) combined with genetic marker information at the RYR1 locus from the selection candidate, resulted in a 20% increase in accuracy and selection response when compared with a breeding strategy without genetic marker information.

In this experiment, which is based on a cohort of 44 Lipizzan mares from the Austrian state stud farm of Piber, we present new statistical techniques for the analysis of shape and equine conformation using image data. In addition, we examined which strategies and procedures of image processing techniques led to a successful interpretation of the traits implemented in horse breeding programs. A total of 246 two-dimensional anatomical and somatometric landmarks were digitized from standardized photographs, and the variation of shape has been analyzed by the use of generalized orthogonal least-squares Procrustes (generalized Procrustes analysis (GPA)) procedures. The resulting shape variables have been regressed on the results from linear type trait classifications. In addition, the rating scores of six conformation classifiers were tested for agreement, yielding an inter-rater correlation (inter-class correlation) ranging from 0.41 to 0.68, respectively, a κ coefficient ranging from 0.16 to 0.53. From the 12 linear type traits assessed on a valuating scale, only the type-related traits (type, breed-type and harmony) revealed significant (P<0.05) results in the regression analysis of shape variables on linear type traits. The other nine traits were characterized by a lower agreement between classifiers and did not result in a significant ‘shape regression’. Finally, the ‘horse shape space’ defined by shape variables resulting from GPA procedures offered the possibility to assist in trait definition and in the evaluation of ratings, and it is an adequate biological and objective scale to human perception of conformation, which is expressed in numerical data only.

The objectives of the present study were to investigate the influence of yearling weight on the occurrence of early pregnancy and to determine differences between precocious and non-precocious heifers in terms of pre- and postnatal calf mortality, calf weight and height, mature cow weight, and stayability of the cow in the herd. Data from 26 977 females of a Nelore herd that participated in the breeding season between 1986 and 2004 were analyzed. The influence of yearling weight on sexual precocity and differences between precocious and non-precocious heifers in pre- and postnatal calf mortality and stayability were analyzed using the GENMOD procedure of the SAS program. Differences in the growth traits between precocious and non-precocious animals were estimated by contrast analysis. Three groups were analyzed for postnatal mortality: first calving of the heifers, calves born from the third calving and all offspring of the cow. In order to have a standardized calving to conception period for all females (precocious and non-precocious), calves born from the second calving were not included in the analysis. This was necessary because the first calving to conception period (days open) of precocious heifers was longer than for non-precocious due to farm reproductive management. No differences in postnatal mortality rates, from the third calving, were observed between the two groups of heifers studied. Analysis of all offspring of the dams showed a 9% higher probability of death of calves born to precocious heifers compared with calves born to non-precocious heifers. With respect to stayability, precocious heifers presented 33% greater odds to remain in the herd until 5 and 6 years of age and 28% greater odds to remain in the herd until 7 years when compared with non-precocious heifers. Precocious heifers weaned calves (205 days) significantly heavier than non-precocious ones, 1.410 and 0.797 kg considering the weaning weights of all offspring and of the third calving, respectively. With respect to sexual precocity, the results suggest that the probability of heifers to become pregnant at 16 months of age increases with increasing weight. However, heifers weighing more than 240 kg present practically the same pregnancy probability. Nevertheless, exposure of heifers during the early breeding season is recommended for beef cattle herds raised in tropical regions in view of the numerous benefits demonstrated here.

The objective of the study was to assess the dimensionality of seven linear traits (body condition score, body stature, body length, heart girth, navel height, body depth and flank circumference) in Nguni cows using factor analysis and indicate the relationship between the extracted latent variables and calving interval (CI) and age at first calving (AFC). The traits were measured between December 2012 and November 2013 on 1559 Nguni cows kept under thornveld, succulent karoo, grassland and bushveld vegetation types. Low partial correlations (−0.04 to 0.51), high Kaiser statistic for measure of sampling adequacy scores and significance of the Bartlett sphericity test (P<0.01) showed that there were significant phenotypic correlations between the linear traits and the data were suitable for factor analysis. Two factors had eigenvalues >1. Factor 1 included body condition score, body depth, flank circumference and heart girth and represented body capacity of cows. Factor 2 included body length, body stature and navel height and represented frame size of cows. CI and AFC decreased linearly with increase of factor 1. There was a quadratic increase in AFC as factor 2 increased (P<0.05). It was concluded that the linear type traits under study can be grouped into two distinct factors, one linked to body capacity and the other to the frame size of the cows. Small-framed cows with large body capacities have shorter CI and AFC.

This study was conducted by two trials to investigate effects of sequential feeding with low- and high-protein diets on growth traits and plasma metabolites in geese. In Trial I, the effect of sequential feeding under time-restricted feeding system was investigated. Seventy-two White Roman goslings were randomly allotted into either sequential feeding (S1) or control feeding (C1) group. All goslings were fed for 1 h at morning and at evening, respectively, from 2 to 8 weeks of age. S1 group was offered 13% CP diet at morning and 19% CP diet at evening. C1 group was offered the same diet (16% CP; mixed equally with the two diets mentioned above) at both morning and evening. Blood samples were hourly collected for 4 h after feeding at both morning and evening for the determination of the postprandial plasma levels of glucose, triacylglycerol and uric acid at the end of experiment. Results showed that BW, average daily gain (ADG), and daily feed intake (FI) were not different between groups, but the feed efficiency (FE) in S1 group was significantly higher than that in C1 group (P<0.05). The areas under curve (AUC) of plasma postprandial levels of glucose, triacylglycerol and uric acid were not affected by treatment, but the AUC of triacylglycerol and uric acid in morning were lower than those in evening (P<0.05). In Trial II, the effect of sequential feeding under ad libitum feeding system was investigated. Twenty-four goslings were randomly allotted into either sequential feeding (S2) or control feeding (C2) group. Diets were altered at 0600 and 1800 h, respectively, and geese were fed ad libitum from 4 to 8 weeks of age. S2 group was offered 14% CP diet at morning and 20% CP diet at evening. C2 group was supplied the same diet (mixed with the two diets according to the ratio of diets consumed by S2 group on the preceded day) at both morning and evening. Results showed that the ADG in S2 group was higher than those in C2 group (P<0.05). Summarized data from both trials showed that sequential feeding improves daily gain and FE in growing geese.

The first cause of death of dairy calves is often diarrhea which is mainly caused by pathogenic bacteria, which can result in excessive use of antibiotics. However, facing the increase concern by the industry and consumers, the use of antibiotics not only to control pathogens, but also to manipulate growth, has become a challenge. Alternative additives, such essential oils, have the potential to decrease antibiotic use, without reducing performance or increasing mortality of dairy calves. The objective of this study was to evaluate the use of a commercial blend of essential oils, incorporated into the calf starter and/or milk replacer to monitor the effect on overall calf performance, fecal scores and rumen fermentation parameters. A total of 30 Holstein calves received 6 l/day of a liquid diet, consisting of a commercial milk replacer containing 20% CP : 15% fat (EE). Calves had free choice access to water and calf starter. Weaning occurred at week 8, and calves were followed until the 10th week of age. Calves were assigned to one of the three treatment groups in a randomized block design. Treatments: (1) control without essential oils supplementation (C); (2) essential oils blend in the milk replacer at 400 mg/kg (MR) and (3) essential oils blend in the milk replacer (200 mg/kg) and starter feed (200 mg/kg) (MRS). From the 2nd week, calves were weighed and body measurements were taken, while concentrate intake and fecal scores were monitored daily. Blood samples were drawn weekly for determination of glucose and β-hydroxybutyrate. Fecal samples were collected weekly and analyzed for lactic acid bacteria and Enterobacteria; and ruminal fluid for determination of pH, short chain fatty acids, ammonia-N and counts of amylolytic and cellulolytic bacteria, and protozoa. Performance, fecal scores and intestines microorganisms were not affected by the essential oils supplementation. Ruminal and blood parameters were also not affected, with the exception the rumen ammonia-N concentration, with higher values when essential oils were supplemented in a combination of milk replacer and starter feed. Most of the evaluated parameters were affected by age of calves, mainly as a response to the increase in concentrate intake as animals’ aged. Essential oils are promising substitutes for antibiotics. However, the dose and routes of administration deserve further studies, allowing a better animal performance and health to be achieved.

Thirty Aberdeen Angus crossbred steers (281±16 kg) were used to test the effect of finishing feeding system on growth performance, meat quality and fatty acid (FA) profile in intramuscular fat. Steers were fed in confinement (forage:concentrate ratio of 50 : 50; DM basis) or with different levels of energy supplementation (0, 0.4, 0.8 and 1.2% BW) at pasture (Avena strigosa Schreb and Lolium multiflorum L.). There were no differences between treatments for ADG (average=1.60 kg/day), hot carcass weight (HCW) (average=229 kg) and subcutaneous fat depth (average=3 mm). Dressing % (P=0.06; tendency) and carcass ADG (P=0.02) linearly increased with level of supplementation for pasture steers. No differences were observed between treatments for tenderness, marbling, pH, color b*, or cooking loss and drip loss in samples of Longissimus dorsi. However L* increased linearly (P=0.05) with level of supplementation. The concentrations of myristic, palmitic, estearic and linoleic FA did not differ among treatments. The concentration of n-3 FA increased (P<0.001) in steers at pasture compared with confinement, but n-6 FA concentrations did not differ between feeding system. Supplementation up to 0.4% BW increase (P<0.001) conjugated linoleic acid (CLA) and linolenic FA concentrations in intramuscular fat when compared with confinement. The level of supplementation on pasture linearly decreased (P<0.001) n-3 and CLA and linearly increased (P=0.001) the n-6 : n-3 ratio. Finishing of steers grazing winter pasture with energy supplementation or in confinement fed a medium-concentrate diet did not affect meat quality (tenderness, marbling, parameter b* on the CIE L*a*b* scale, cooking and drip losses) except for a* and L*. However, intramuscular fat of animals finished at pasture with moderate level of supplementation compared to animals fed in confinement had greater concentration of CLA, linolenic, and n-3, and lower n-6 : n-3 in intramuscular fat.

It is essential to quantify the potential of tropical grasslands to allow significant feed efficiency for grazing livestock in controlled conditions such as at pasture. We conducted a quantitative analysis of published studies reporting the experimental results of average daily gains (ADG) and diet characteristics obtained specifically under grazing conditions (17 publications and 41 experiments), which have been less studied compared with controlled conditions in stalls. The database was analyzed to determine the average and range of values obtained for ADG (g/kg BW), dry matter digestibility, intake (DMI) and digestible DMI (DDMI, g/kg BW) and feed conversion efficiencies (FCE), as well as to predict the response of these parameters to the main strategies investigated in the literature – that is, mainly the stocking rate (SR) and the concentrate intake (CI). The ADG reached 1.2 kg BW per day and was directly linked to DDMI (ADG=−1.63+0.42 DDMI −0.0084 DDMI2, n=90, r.m.s.e=0.584, R2=0.93). The DDMI, which was representative of the nutrient input, was driven mainly by DMI rather than dry matter digestibility, whereas these two parameters did not correlate (r=0.068, P=0.56). The average global FCE (0.11 g ADG/g DDMI) showed a greater association with the metabolic FCE (0.17 g ADG/g DMI) than the digestive FCE (0.62). The CI (g DM/kg BW) increased ADG (ADG=2376+CI 56.1, n=16, r.m.s.e.=441, R2=0.95). The SR expressed as kg BW/ha decreased the individual ADG by 1.19 g/kg BW per additional ton of BW/ha, whereas the global ADG calculated per ha increased by 0.57 per additional ton BW/ha. When the SR was expressed as kg BW/ton DM and per ha rather than as kg BW/ha, the impact on the individual ADG decreased by 0.18 or 0.86 g per additional ton BW/ha, depending on the initial BW of the cattle. These results provide a better view of the potential performance and feeding of cattle in tropical grasslands. The results provide an improved quantification of the relationships between diet and performance, as well as the overall quantitative impact of SR and supplementation.

It is well-established that altering the proportion of starch and fibre in ruminant diets can alter ruminal and post-ruminal digestion, although quantitative evidence that this reduces enteric methane (CH4) production in dairy cattle is lacking. The objective of this study was to examine the effect of varying grass-to-maize silage ratio (70 : 30 and 30 : 70 DM basis), offered ad libitum, with either a concentrate that was high in starch or fibre, on CH4 production, intake, performance and milk composition of dairy cows. A total of 20 cows were allocated to one of the four experimental diets in a two-by-two factorial design run as a Latin square with each period lasting 28 days. Measurements were conducted during the final 7 days of each period. Cows offered the high maize silage ration had a higher dry matter intake (DMI), milk yield, milk energy output and lower CH4 emissions when expressed per kg DMI and per unit of ingested gross energy, but there was no difference in total CH4 production. Several of the milk long-chain fatty acids (FA) were affected by forage treatment with the most notable being an increase in 18:0, 18:1 c9, 18:2 c9 c12 and total mono unsaturated FA, observed in cows offered the higher inclusion of maize silage, and an increase in 18:3 c9 c12 c15 when offered the higher grass silage ration. Varying the composition of the concentrate had no effect on DMI or milk production; however, when the high-starch concentrate was fed, milk protein concentration and milk FAs, 10:0, 14:1, 15:0, 16:1, increased and 18:0 decreased. Interactions were observed for milk fat concentration, being lower in cows offered high-grass silage and high-fibre concentrates compared with the high-starch concentrate, and FA 17:0, which was the highest in milk from cows fed the high-grass silage diet supplemented with the high-starch concentrate. In conclusion, increasing the proportion of maize silage in the diets of dairy cows increased intake and performance, and reduced CH4 production, but only when expressed on a DM or energy intake basis, whereas starch-to-fibre ratio in the concentrate had little effect on performance or CH4 production.

Myogenesis is facilitated by four myogenic regulatory factors and is significantly inhibited by myostatin. The objective of the current study was to examine embryonic gene regulation of myostatin/myogenic regulatory factors, and subsequent manipulations of protein synthesis, in broiler embryos under induced hyperammonemia. Broiler eggs were injected with ammonium acetate solution four times over 48 h beginning on either embryonic day (ED) 15 or 17. Serum ammonia concentration was significantly higher (P<0.05) in ammonium acetate injected embryos for both ED17 and ED19 collected samples when compared with sham-injected controls. Expression of mRNA, extracted from pectoralis major of experimental and control embryos, was measured using real-time quantitative PCR for myostatin, myogenic regulatory factors myogenic factor 5, myogenic determination factor 1, myogenin, myogenic regulatory factor 4 and paired box 7. A significantly lower (P<0.01) myostatin expression was accompanied by a higher serum ammonia concentration in both ED17 and ED19 collected samples. Myogenic factor 5 expression was higher (P<0.05) in ED17 collected samples administered ammonium acetate. In both ED17 and ED19 collected samples, myogenic regulatory factor 4 was lower (P⩽0.05) in ammonium acetate injected embryos. No significant difference was seen in myogenic determination factor 1, myogenin or paired box 7 expression between treatment groups for either age of sample collection. In addition, there was no significant difference in BrdU staining of histological samples taken from treated and control embryos. Myostatin protein levels were evaluated by Western blot analysis, and also showed lower myostatin expression (P<0.05). Overall, it appears possible to inhibit myostatin expression through hyperammonemia, which is expected to have a positive effect on embryonic myogenesis and postnatal muscle growth.

A high-fat diet is known to induce atherosclerosis in animal models. Dietary factors and timing of atherogenic food delivery may affect plasma lipoprotein content composition and its potential atherogenic effect. Increasingly often, humans spend periods/days eating in a completely unregulated way, ingesting excessive amounts of food rich in oils and fats, alternating with periods/days when food intake is more or less correct. We investigate the effect on lipid homeostasis of a high-fat diet administered either continuously or intermittently. We investigated control pigs receiving standard diet (C, n=7), pigs receiving a high-fat diet every day for 10 weeks (CHF, n=5), and pigs receiving a high-fat diet every other week for 10 weeks (IHF, n=7). IHF animals were shown to have a different lipid profile compared with CHF animals, with a significant increase in high-density lipoproteins (HDL) levels with respect to C and CHF groups. CHF also showed significantly higher values of TC/HDL cholesterol compared with C and IHF. Hepatic expression analysis of genes involved in lipid homeostasis showed an increasing trend of nuclear receptor LXRα along with its target genes in the CHF group and in the IHF group, whereas SREBP2 and LDLr were significantly inhibited. A significant correlation was found between ABCA1 expression and circulating levels of HDL-C. Periodic withdrawals of a high-fat atherogenic diet compared with a regular administration results in a different adaptive response of lipoprotein metabolism, which leads to a significantly higher plasma level of HDL-C and lower TC/HDL-C.

We studied the effects of the frequently used glucogenic dietary supplementation in dairy herds and the hormonal changes occurring during the normal estrous cycle on the composition and concentration of milk lipid components. Holstein dairy cows were synchronized with two injections of prostaglandin F2α (estrus=day 0). Animals were held as controls or drenched for 11 days (day −3 to day 8 of the cycle) with 850 ml/day liquid propylene glycol (treatment, n=13 per group). Blood and milk samples were collected on day 1 and 8 of the cycle. In both groups, plasma progesterone concentration increased ∼10-fold between 1 and 8 days post-estrus. Milk fatty acid composition was associated primarily with estrous-cycle day: polyunsaturated fatty acids increased by 16%, n-6 by 15% and n-3 by 1% from day 1 to 8 post-estrus. Polar lipid composition was also altered by cycle day: phosphatidylethanolamine concentration was 2-fold and 1.5-fold higher on day 1 v. day 8 post-estrus in the control and treatment groups, respectively. Phosphatidylserine concentration in milk was also affected by cycle day by treatment interaction (P=0.04). A progesterone level by treatment interaction influenced the triglyceride-to-phospholipid ratio in the milk (P=0.02). The results suggest that progesterone plays a role in modulating milk lipid composition and structure. Therefore, strategies designed to alter milk lipid composition should consider the cow’s reproductive status.

Previous studies have demonstrated that sperm head morphometry can be used as a potential diagnostic tool for detecting biophysical changes associated with sperm viability in bovine spermatozoa. In this study, sperm head morphometry was used to investigate its value as a biophysical marker for detecting volumetric changes in bovine spermatozoa under in vitro capacitating and non-capacitating incubation conditions. To further test this hypotesis, aliquots of pooled, washed bovine sperm were incubated in either Tyrode’s complete medium with heparin (TCMH; a capacitating medium containing Ca2+, NaHCO3 and heparin), Tyrode’s complete medium heparin-free (TCM; a medium containing just Ca2+ and NaHCO3) or Tyrode’s basal medium (TBM; a non-capacitating medium free of Ca2+, NaHCO3 and heparin, used as control). Aliquots of sperm were processed for morphometric analysis at different incubation-time intervals (0, 3 and 6 h at 38°C), and the chlortetracycline assay was used simultaneously to confirm the ability of the sperm to undergo capacitation (B pattern) and the acrosome reaction (AR pattern) status in each medium. After 3 h of incubation under TCMH conditions, a significant increase was observed in the percentage of B and AR patterns and a significant decrease was found in all sperm morphometric parameters (P<0.01). Interestingly, after 6 h of incubation in TCMH, the percentage of B and AR patterns increased drastically over time and marked differences were found in the dimensional and shape parameters, which were significantly smaller compared with TBM or TCM media (P<0.001). Significant correlations were observed between sperm size and AR pattern (r=−0.875, P<0.01). In conclusion, sperm head morphometry can be used as a potential biophysical marker for detecting volumetric changes during capacitation process in bovine spermatozoa.

Performance and mortality of hares were evaluated for 2 consecutive years in a large farm in Veneto Region (Northern Italy). On average, fertile reproductive pairs (n=318) gave birth 4.8 times and produced 11.4 live leverets, weaned 8.4 leverets and produced 7.0 growing hares (60 days) every year. Mean mortality was 3.6%, 22.9%, 9.7% and 2.5% in newborn (0 to 2 days of age), suckling (3 to 25 days), growing (26 to 60 days) and sub-adult (61 days until sale) hares, respectively. The main causes of mortality were enteric diseases (75.5%, 75.9% and 12.1% in suckling, growing and sub-adult hares, respectively), followed by respiratory diseases (3.4%, 8.0% and 36.2% in suckling, growing and sub-adult hares, respectively), starvation (11.3% and 8.8% in suckling and growing hares, respectively) and trauma (7.1%, 2.3% and 30.2% in suckling, growing and sub-adult hares, respectively). In reproducing hares, mortality was 24.7% and 15.4% in 2010 and 2011, respectively. Respiratory diseases (34.8%) and ulcerative pododermatitis (18.9%) were the most common pathological changes detected in reproducing hares. Farmed hares seem to be affected by diseases resembling those of rabbits reared under intensive conditions. It seems necessary to improve the husbandry of hares to reach satisfactory technical standards and to preserve their health.

Hypothermia, experienced by piglets, has been related to piglet deaths and high and early use of a heated creep area is considered important to prevent hypothermia. The aims of the present study were to investigate how a newly invented radiant heat source, eHeat, would affect piglets’ use of the creep area and whether light in the creep area works as an attractant on piglets. A total of 39 sows, divided between two batches, were randomly distributed to three heat source treatments: (1) standard infrared heat lamp (CONT, n=19), (2) eHeat with light (EL, n=10) and (3) eHeat without light (ENL, n=10). Recordings of piglets’ use of the creep area were made as scan sampling every 10 min for 3 h during two periods, one in daylight (0900 to 1200 h) and one in darkness (2100 to 2400 h), on day 1, 2, 3, 7, 14 and 21 postpartum. On the same days, piglets were weighted. Results showed an interaction between treatment and observation period (P<0.05) with a lower use of the creep area during darkness compared with daylight for CONT and EL litters, but not for ENL litters. Piglets average daily weight gain was not affected by treatment, but was positively correlated with piglets’ birth weight and was lower in batch 1 compared with batch 2. Seen from the present results, neither eHeat nor light worked as an attractant on piglets; in contrast, piglets preferred to sleep in the dark and it would therefore be recommended to turn off the light in the creep area during darkness. Heating up the creep area without light can be accomplished by using a radiant heat source such as eHeat in contrast to the normally used light-emitting infrared heat lamp.

Play behaviour has been proposed as a measure of good welfare in growing animals and locomotor play by calves is often reduced after weaning off milk. Adjusting weaning age according to individual calves’ abilities to eat solid feed maintains energy intake and weight gain during weaning. We investigated the effects of this method of weaning on locomotor play of calves and the relationship between locomotor play and energy intake and weight gains. We measured the running behaviour of 56 Holstein heifer calves before and after weaning. Calves were housed in groups of eight, fed milk, grain starter and hay from automated feeders. Weaning began when their voluntary intake of grain starter reached either 200 or 400 g/day, and weaning was completed when starter intake reached either 800 or 1600 g/day. Before weaning, older calves ran less than young ones; and the duration of running correlated with weight gains and digestible energy intake. Immediately after weaning, digestible energy intake and locomotor play decreased but no correlation was observed between these variables. One week after weaning, the duration of running was correlated with both energy intake and weight gain. Digestible energy intake increased but locomotor play continued to decrease. The amount of running a calf does after weaning partly reflects energy intake and weight gain, supporting suggestions that locomotor play is good indicator of welfare and fitness of growing animals. However, the decline in locomotor play following weaning is not solely due to decreased energy intake.

Past positive experiences can increase herbivores’ motivation to eat low-quality foods. However, this is not always translated into a higher preference for low-quality foods in choice tests among foods of higher nutritional quality. Foraging behavior is also affected by properties of the feeding context because the quality and abundance of foods in nature change in time and space. We hypothesized that in a choice situation, the expression of a past positive experience with a low-quality food is modulated by the costs associated with selecting a high-quality food option. A total of 24 sheep were randomly assigned into two groups (n=12). During conditioning phase, one group (CS+; i.e., conditioned group) was fed with oat hay (a low-quality food) for 20 min and immediately after a ration of soybean meal (a nutritious food), whereas the other group was also fed with oat hay but the offer of soybean meal was delayed 5 h (CS−; i.e., control group). After conditioning, we assessed sheep motivation to eat the oat hay in an experimental arena in which accessibility to alfalfa hay (a high-quality food) was increasingly restricted. When alfalfa hay was readily accessible, CS+ and CS− sheep almost exclusively selected this food, showing a small and similar preference for oat hay. However, when accessibility to alfalfa hay decreased, intake and selection of oat hay was greater in the CS+ sheep than in the CS− sheep. The latter was a consequence of differential changes in behavior between groups; for example, sheep in CS+ spent more time foraging oat hay and were more likely to switch to oat hay if they had previously been eating alfalfa hay than sheep in CS−. Our results show that behavioral expression of the conditioned preference for a low-quality food depends on parameters of the feeding context (e.g., availability). We suggest that this can be the link between learning models and optimal foraging models of diet selection.

This study aimed at evaluating short- and long-term effects of housing beef cattle on deep litter (DL) or concrete fully slatted floor (FS) on their welfare. Animal-based measures of the Welfare Quality® assessment protocol for cattle were used to assess health status and behaviour of bulls. The assessment was carried out in a large commercial farm on 15 batches of bulls (4 DL and 11 FS) 1 month after their receiving day (short-term) and on 12 batches (three DL and nine FS) the week before slaughter (long-term). Signs of better comfort on deep litter in terms of shorter lying down durations (5.1±0.5 v. 6.5±0.4 s; P<0.05) and lower risk of hairless patches (odds ratio=0.09; 95% confidence interval=0.01 to 0.68; P<0.05) were already observed after 1 month. Heavy bulls after a long-term housing on FS showed a higher prevalence of bursitis, hairless patches and lesions/swellings than animals on DL. Bulls on fully slatted floor were at higher risk of early culling (odds ratio=6.44; 95% confidence interval=1.57 to 26.37; P<0.01), mainly due to musculoskeletal system pathologies/lameness. Deep litter proved to be a valid alternative to slatted floor, making animals more confident to interact with powerful movements such as mounting at the end of the finishing period. A negative aspect of the deep litter was the poor cleanliness of the bulls. Compared with the fully slatted floor, there were higher odds ratios for dirty bulls at both, the short- (odds ratio=25.09; 95% confidence interval=8.96 to 70.22; P<0.001) and the long-term housing (odds ratio=276.13; 95% confidence interval=98.21 to 776.38; P<0.001). In order to improve health and welfare of beef cattle finished at a heavy weight, deep litter systems are a promising alternative to fully slatted floors. However, proper management of deep litter is necessary to maintain satisfactory cleanliness of the bulls.

Hair may be a useful matrix to detect cumulative cortisol concentrations in studies of animal welfare and chronic stress. The aim of this study was to validate a protocol for cortisol detection in hair from dairy cattle by enzyme immunoassay (EIA). Seventeen adult Holstein–Friesian dairy cows were used during the milking period. Hair cortisol concentration was assessed in 25-day-old hair samples taken from the frontal region of the head, analysing black and white coloured hair separately. Concentrations of cortisol metabolites were determined in faeces collected twice a week during the same period of time. There was a high correlation between cortisol values in faeces and cortisol in white colour hair samples but such correlation was not significant with the black colour hair samples. The intra- and inter-assay coefficients of variation were 4.9% and 10.6%, respectively. The linearity showed R2=0.98 and mean percentage error of −10.8±1.55%. The extraction efficiency was 89.0±23.52% and the parallelism test showed similar slopes. Cortisol detection in hair by using EIA seems to be a valid method to represent long-term circulating cortisol levels in dairy cattle.