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The gastrointestinal tract microbiome is essential for regulating nutrient absorption, gut immune function, and host growth and development. In the present study, we characterized the development of ileum and cecum microbiota in pullets throughout the rearing period, encompassing a period from the day of hatching to 18 weeks of age. The growth performance and intestinal microbiome (ileum and cecum) of pullets were analyzed at 1, 5, 11, and 18 weeks of age. The richness of the ileum and cecum bacterial communities (alpha diversity) was higher in pullets at 18 weeks of age than in those at 1 and 5 weeks of age. Microbiota from weeks 1, 5, 11, and 18 were distinctly grouped in a NMDS plot, representing beta diversity within the ileum. However, the results for cecum microbiota did not reveal evident separation among the different age groups in the weighted UniFrac. In conclusion, our findings demonstrate variations and diversification in ileum and cecum microbiota across different rearing stages in pullets. These insights have the potential to inform the development of nutritional strategies that promote gut health and contribute to the improved development of pullets. [ABSTRACT FROM AUTHOR]

The gastrointestinal tract microbiome is essential for regulating nutrient absorption, gut immune function, and host growth and development. In the present study, we characterized the development of ileum and cecum microbiota in pullets throughout the rearing period, encompassing a period from the day of hatching to 18 weeks of age. The growth performance and intestinal microbiome (ileum and cecum) of pullets were analyzed at 1, 5, 11, and 18 weeks of age. The richness of the ileum and cecum bacterial communities (alpha diversity) was higher in pullets at 18 weeks of age than in those at 1 and 5 weeks of age. Microbiota from weeks 1, 5, 11, and 18 were distinctly grouped in a NMDS plot, representing beta diversity within the ileum. However, the results for cecum microbiota did not reveal evident separation among the different age groups in the weighted UniFrac. In conclusion, our findings demonstrate variations and diversification in ileum and cecum microbiota across different rearing stages in pullets. These insights have the potential to inform the development of nutritional strategies that promote gut health and contribute to the improved development of pullets.

Simple Summary: The objective of this study was to describe the development of aggressive pecking, gentle feather pecking and severe feather pecking of non-beak-trimmed laying hen pullets during the first 4 weeks of life. The pecking behavior patterns were observed in three different experimental groups, which differed in stocking rates and the provision of enrichment material. The enrichment materials were suitable and intensely used by the pullets. The provision of pecking blocks and pecking stones is recommended as a preventive measure from the first day of life onwards for pullets housed in commercial rearing aviaries. There was no effect of reduced stocking rate, most likely due to the low variation in stocking rates. The objective of this study was to describe the ontogeny of the severe feather pecking (SFP), gentle feather pecking (GFP), aggressive pecking (AP), and enrichment pecking (EP) of non-beak-trimmed Lohmann Brown (LB)-pullets during the first 4 weeks of life (observation on 1st, 8th, 15th, 22nd, and 29th days of life) while they were kept within the compartments of a commercial rearing aviary (without access to a litter area). All chicks were placed into compartments of the middle tier of the aviary on the 1st day of life. On the 10th day of life, half of the chicks of each compartment were moved into the compartments of the lower tier. The aviary floor was covered with chick paper before the placement of the chicks and fully or partially removed from the 15th day of life onwards. The pecking behavior patterns were observed in three experimental groups (EG): NE (not enriched): group size until/after 10th day of life: 230/115; 120.8/60.4 birds/m2, no enrichment; EL (enriched, low stocking rate): group size until/after 10th day of life: 203/101, 106.6/53.6 birds/m2; and EH (enriched, high stocking rate): group size until/after 10th day of life: 230/115;120.8/60.4 birds/m2, both pecking stones and blocks as enrichment) in two rearing periods. For each pecking behavior pattern, an independent regression model with the parameters EG, chick paper, observation day, and functional area was estimated. GFP, SFP, and EP increased with age during the observation. The AP rate was highest in all EGs on the first day of life and decreased during the observation period. A pairwise comparison of NE (high stocking rate without enrichment) with EH (high stocking rate with enrichment and with EL (low stocking rate with enrichment) showed a significant effect of the EG on pecking behavior, with more SFP, AP, and GFP in NE. There were no differences between EL and EH, indicating that the provision of pecking materials had more influence than the stocking rate. However, we presumed that the difference between the stocking rates were too small to observe an effect. AP, SFP, and GFP were significantly higher on wired slats, as compared to the perches and the vicinity of the enrichment materials. The enrichment materials were suitable and intensely used by the pullets. The provision of pecking blocks and pecking stones was recommended as a preventive measure from the first day of life onwards for pullets housed in commercial rearing aviaries. There was no effect of reduced stocking rate, most likely due to the low variation in stocking rates. [ABSTRACT FROM AUTHOR]

The aim of the study was to observe and quantify the intake of water by piglets in the sucking period up to 28 days. An attempt was made to compare the quantity of taken water sinks in four different periods, similar to the occurrence of calendar seasons in Poland's climatic conditions. The research was conducted in the conditions of a pig farm, producing fatteners in a closed cycle. The observations included 17 litters obtained from Polish Landrace (PL) sows mated by four Polish Large White (PLW) boars. They were conducted during the full calendar year in four groups, depending on the date of birth and rearing: from 1 December to 28 February (Group I), from 1 March to 31 May (Group II), from 1 June to 31 August (Group III) and from 1 September to 30 November (Group IV). The number piglets in litters, total weight of litter and individual weight of piglets were similar among groups. Some piglets (Group I) started taking water from the first day of life, but it was a small amount. The regular intake of all piglets started at 3 days of age. The highest water intake was recorded in spring-summer (Group II and III), and as a percentage of 1 kg body weight of piglets, the highest consumption occurred in group II (March-May). It was hypothesized that the increased water requirement in the spring and summer months may be due to the variability of the conditions related to the outdoor temperature, the length of the light day and thus the varied life activities of the piglets. Perhaps, it is also related to atavistic symptoms in pigs. However, this requires further research.

The objective of this study was to describe the ontogeny of the severe feather pecking (SFP), gentle feather pecking (GFP), aggressive pecking (AP), and enrichment pecking (EP) of non-beak-trimmed Lohmann Brown (LB)-pullets during the first 4 weeks of life (observation on 1st, 8th, 15th, 22nd, and 29th days of life) while they were kept within the compartments of a commercial rearing aviary (without access to a litter area). All chicks were placed into compartments of the middle tier of the aviary on the 1st day of life. On the 10th day of life, half of the chicks of each compartment were moved into the compartments of the lower tier. The aviary floor was covered with chick paper before the placement of the chicks and fully or partially removed from the 15th day of life onwards. The pecking behavior patterns were observed in three experimental groups (EG): NE (not enriched): group size until/after 10th day of life: 230/115; 120.8/60.4 birds/m2, no enrichment; EL (enriched, low stocking rate): group size until/after 10th day of life: 203/101, 106.6/53.6 birds/m2; and EH (enriched, high stocking rate): group size until/after 10th day of life: 230/115;120.8/60.4 birds/m2, both pecking stones and blocks as enrichment) in two rearing periods. For each pecking behavior pattern, an independent regression model with the parameters EG, chick paper, observation day, and functional area was estimated. GFP, SFP, and EP increased with age during the observation. The AP rate was highest in all EGs on the first day of life and decreased during the observation period. A pairwise comparison of NE (high stocking rate without enrichment) with EH (high stocking rate with enrichment and with EL (low stocking rate with enrichment) showed a significant effect of the EG on pecking behavior, with more SFP, AP, and GFP in NE. There were no differences between EL and EH, indicating that the provision of pecking materials had more influence than the stocking rate. However, we presumed that the difference between the stocking rates were too small to observe an effect. AP, SFP, and GFP were significantly higher on wired slats, as compared to the perches and the vicinity of the enrichment materials. The enrichment materials were suitable and intensely used by the pullets. The provision of pecking blocks and pecking stones was recommended as a preventive measure from the first day of life onwards for pullets housed in commercial rearing aviaries. There was no effect of reduced stocking rate, most likely due to the low variation in stocking rates.

An increasing number of producers opt to finish their lambs in on-farm feedlots. Therefore, detailed production information is required to implement precision finishing of lambs of different genotypes. Precision finishing monitors growth, feed intake and efficiency to optimize management. In this study, feedlot production characteristics of Dohne Merino, Dormer, Dorper, Meatmaster, Merino, Namaqua Afrikaner, and South African Mutton Merino (SAMM) lambs were evaluated. The lambs were reared in a feedlot and fed a diet with 10.41 MJ metabolizable energy (ME)/kg feed and 19.06% crude protein. Feed intake and body weight were recorded weekly from an initial weight of 30 kg until they had the subcutaneous fat cover needed to produce an A2 carcass. Subcutaneous fat was measured on the Longissimus lumborum muscle with an ultrasound scanner. Dorper, Meatmaster and Namaqua Afrikaner had the shortest rearing periods in the feedlot, and were market ready at a lower live weight (P <0.05). As a result, these lambs consumed less feed in the feedlot. Namaqua Afrikaner and Merino lambs were least efficient: 7.08 and 5.63 kg feed/kg gain, respectively. Dohne Merino, Dormer, Dorper, and Meatmaster rams and Dorper ewes were more efficient; approximately 3.58 kg feed/kg gain. Dohne Merino and Dormer rams had the highest growth rates: approximately 465 g/day. The end weights described in this study could be used as an indication for producers of the ideal slaughter weights for breeds of different maturity types. [ABSTRACT FROM AUTHOR]

Inadequate possibilities to perform oral manipulation behavior for pigs can lead to misdirection and thus tail biting. Our study aimed to analyze manipulation behaviors of weaner pigs with focus on tail biting and the relationship with agonistic characteristics of the piglets during suckling. We analyzed the individual manipulation behavior of 188 weaner pigs. General health condition and tail lesions were determined weekly. Correlations were estimated between weight at weaning and at the end of rearing period, frequency of manipulative rearing behaviors and Dominance and social tension index based on suckling behavior. Principal component and cluster analyses were performed to identify groups of piglets which showed similar suckling and rearing behaviors. Tail biting increased at the middle and end of rearing with switching roles of biters and victims. Tail lesions were correlated with received tail biting behavior but occurred with a delay of more than a week. The frequency of performed tail biting was correlated with dominance index (rs = −0.256, p < 0.01) and weaning weight (rs = −0.199, p < 0.05). We assume that performed tail biting is more often observed in pigs who show mainly submissive behavior in teat disputes.

Copyright of Journal of Central European Agriculture is the property of Journal of Central European Agriculture and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In this study, the effects of environmental enrichment, stocking density, and microclimate on feather condition, skin injuries, and other health parameters were investigated. During 2 rearing periods (RP), non-beak-trimmed Lohmann Brown hybrid pullets were housed in an aviary system for rearing with cages and from week 5 of age onwards with access to a litter area. All pullets were reared in the same barn and under practical conditions. In total, 9,187 (RP 1) and 9,090 (RP 2) pullets were distributed in 9 units, and each unit was assigned to 1 of 3 experimental groups (EG). In the control group (EG 1), the pullets were kept without environmental enrichment and at a commonly used stocking density (22 to 23 pullets per m²). Each unit of the 2 treatment groups was provided with 3 types of environmental enrichment simultaneously (pecking stones, pecking blocks, and lucerne bales), and the pullets were kept at a lower than usual (18 pullets per m²) (EG 2) or commonly used stocking density (EG 3). In each RP, the plumage condition, injuries and health of the pullets, and the microclimate of the housing system were examined 5 times. The statistical relationships of enrichment, stocking density, and microclimate with animal health were estimated via regression models. We found that the provision of environmental enrichment had a significant increasing effect on the plumage quality in week 17. Furthermore, significant relationships were found between several predictors (temperature in the housing system, dust concentration, and age of the pullets) and response variables (plumage condition, body injuries, head injuries, bodyweight, difference to the target weight and uniformity). The results of this study showed that increasing temperature in the housing system and increasing age of the pullets are significantly associated with the occurrence of feather damage and skin injuries during rearing. With stocking densities as high as we used (all > 17 pullets per m²), no significant positive effect of a reduced stocking density could be observed. [ABSTRACT FROM AUTHOR]

Copyright of Journal of the Chinese Society of Animal Science is the property of Chinese Society of Animal Science and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

As people pay more attention on animal welfare, the alternative systems, like perch systems, usually with multi tiers, are increasingly used for poultry production. Pullets need good spatial capabilities to utilize resources distributed on different tiers and display certain behaviours in such systems. However, the majority of pullets in China are housed in conventional cage systems which are considered adverse for the development of spatial skill since the performance of behaviours like perching, jumping and flying are restricted. A lack of such exercises weakens pullets’ ability to negotiate the level changes and results in poor adaptability in multi-tier systems, which contributes to problems of behaviours, such as disproportionate distribution in different space, high ratio of floor laying and injures. 240 Jingfen No.2 parent layer breeders were used in present study to investigate the effect of perch provision during rearing period on pullets’ adaptability before and after transfer into the multi-tier perch system, aimed at improving pullets’ adaptability in such cage-free system from traditional rearing cage system. Each rearing cage accommodates 8 pullets, providing each pullet with 487.5 cm2 cage floor area. 2 factors including manipulation time (age of 63 days and 73 days) and positions of perch addition (along the width of the cage and along the depth of the cage) were taken into account. Each treatment was replicated in 6 cages and the rest 6 cages were used as control groups. Altogether 30 cages were used. All pullets were transferred into the perch system on the ages of 83 days and pullets from 5 different cages were put together and put on the system floor. The number of roosting pullets after light off and individual behaviours during the daytime were observed in cages. Distributions of pullets and individual behaviours during the daytime in perch unit were compared. The results showed that: 1. the addition of perches in rearing cages significantly affected on the number of roosting pullets at the first night (Ptime*position<0.01). Utilization of width perches on the age of 63 days was significantly higher than that on the age of 73 days (P<0.01) and higher than that of depth perches (P<0.01). Averaged 4.5-5.3 pullets roosted on the perches on the 10th night with the ratio of perch use ranging from 75% to 88%, and no significant difference was found among treatments. 2. The accumulative frequency of standing, lying and preening on the cage floor decreased in perch cages, along with increased feeding and locomotion and decreased pecking behaviours of the whole group. The proportion of perching behaviour during the daytime was 12.8%-21.6%, and more pullets preferred to stay on perch, with heads toward to the wire mesh of the cage. 3. In the ramp perch units, the proportions of pullets from perch groups were 74.2% and 65.6% respectively on elevated platforms in the perch system for the 2 ages during the initial 5 days after transfer, and it is 59.2% for the control group, which is significant difference compared with perch group of 63 days age (P<0.05). However, perch utilization was rare in 2 modified perch units. Overall, the results indicated that the provision of perches in rearing cages is advantageous for pullets’ adaptability to the stereo space in the perch system after transfer, and earlier experience of perch during rearing period is better. It is suggested that perches should be provided in pullet rearing cages as early as possible in order to improve the adaptability of pullets after being transfered to perch system. [ABSTRACT FROM AUTHOR]

Poultry are the main source ofCampylobacterinfection worldwide. To obtain information onCampylobacter-infected flocks and create a reference for preventing and controllingCampylobacterat farm level,Campylobacterisolates were recovered from broilers and the environments of nine chicken flocks in two farms during growth. The genetic relationship between theCampylobacterisolates was determined using multilocus sequence typing. Flocks were colonized as early as 3 weeks after introduction to the farm. The highest colonization rate was more than 90% and occurred 4–6 weeks after introduction to the farm. Quantitative data showed that the highestCampylobacterloads appeared at 1–2 weeks after initial colonization.Campylobacterloads in cloacal swabs in four flocks were significantly higher at 5 weeks than at 3 weeks (P < 0.05). Multilocus sequence typing of 171 selected isolates revealed 20 sequence types (STs), which consisted of 12 STs forCampylobacter jejuniand eight forCampylobacter coliisolates. The STs of theCampylobacterisolates recovered from farm 1 were more diversified than those from farm 2. The STs of environmental samples were highly consistent with those of the cloacal swab samples. The consistency betweenCampylobacterSTs in the environmental and cloacal swab samples suggested that the environment might be one of the main sources of infection. Thus, our study highlights the prevalence and contamination load ofCampylobacterin broilers during their rearing period and emphasizes the need for control and prevention measures forCampylobacterinfection in broilers, which is also important for human health. [ABSTRACT FROM PUBLISHER]

The objective of this study was to evaluate main indicators of milk production on total 60 commercial dairy herds from the Czech Republic during a 9-yr period (2006-2014). Breakeven points and sensitivity analysis were used and associations of age at first calving (AFC), milk yield (MY) and calving interval (CI) were analyzed. Lowest AFC≤749 d showed the highest fertility, the lowest death rate of calves and lowest profitability without subsidies -2.49 %. Highest MY≥9,000 kg showed the highest fertility, lowest AFC, lowest feed costs and total costs 8.58 CZK (0.32 EUR) per L of milk and subsequent highest profitability 2.37 %. The analysis of fertility showed that herds with the lowest CI (≤389 d) achieved lowest cow depreciation costs 0.71 CZK (0.03 EUR) per L of milk, highest total costs 9.72 CZK (0.36 EUR) per L of milk and highest profitability 1.29 %. Breakeven points for the price of milk ranged between 7.81 and 8.75 CZK (0.29 and 0.32 EUR) per L in yr 2007 and 2014. Increase in input prices should adversely affect the increase the price of milk. The increase of price of milk by 1 % in 2014 will cause an increase in profit of CZK 745 (27.6 EUR) per cow per year. [ABSTRACT FROM AUTHOR]

Os objetivos neste trabalho foram reavaliar as exigências em metionina+cistina (met+cis total) de frangas leves e semipesadas de 5 a 11 semanas de idade, considerando a forma física das rações, e o desempenho no período de 22 a 40 semanas, fase de postura. Foram utilizadas 1.120 frangas (560 leves e 560 semispesadas) em delineamento inteiramente casualizado, em esquema fatorial 5 ×2 ×2, com 20 combinações compostas de cinco níveis de met+cis total (0,56; 0,60; 0,64; 0,68 e 0,72), duas formas físicas da ração (farelada e peletizada) e duas linhagens (Dekalb White e Bovans Goldline), cada uma com quatro repetições de 14 aves. As rações basais foram suplementadas com DL-metionina (99%) para conter cinco níveis de met+cis total, segundo recomendações da literatura nacional e do manual da linhagem. As rações experimentais do período de cria foram isocalóricas em EM (2.900 kcal/kg), e isonutritivas em PB (17%), cálcio (1,00%) e fósforo disponível (0,45%) e continham 0,56; 0,60; 0,64; 0,68 ou 0,72 de met+cis total, enquanto, no período de produção, foi fornecida uma dieta única com 2.850 kcal/kg de EM, 16% PB, 3,70% de cálcio e 0,34% de fósforo disponível. As aves semipesadas apresentaram melhor desempenho em comparação às leves. A dieta peletizada promoveu melhores consumos total e diário de ração em comparação à dieta farelada. Na fase de postura, os níveis de met+cis afetaram a produção, o peso e a massa do ovo e a conversão por massa de ovo. Os níveis de met+cis e a forma física da dieta durante o período de cria afetam o desempenho das aves na fase de produção. A linhagem leve tem maior desempenho. Recomendam-se níveis diários 320 e 364 mg de met+cis para aves leves e semipesadas, respectivamente.The objective of this study was to reevaluate the requirements of Methionine+cystine (met+cis total) of light (L) and semi-heavy (SH) pullets at 5 to 11 weeks of age considering the physical shape of the feeds and the performance in the 22 to 40 week period, the laying phase. A total of 1,120 laying pullets (560 lightweight and 560 semiheavy) in a randomized completedesign in a 5 ×2 ×2 factorial scheme with 20 combinations consisting of five total Met+Cys levels (0.56; 0.60; 0.64; 0.68 or 0.72), two physical shapes (mashed and pelleted) of the feed and two lines (Dekalb White and Bovans Goldline) each with four replications of 14 birds each. The basal rations were supplemented with DL-Met. (99%) to provide five total Met+Cys levels according to the recommendations of the Brazilian literature and the line handbook. The experimental feeds of the growing period were isonutritive in ME (2,900 kcal/kg), CP (17%), Ca (1,000) and available P (0.450), containing total Met+Cy levels of 0.56; 0.60; 0.64; 0.68 and 0.72, while in the laying period, a single diet with 2,850 kcal/kg ME, (16%) CP, (3.70%) of Ca and (0.340%) of available P was fed. The semiheavy birds performed better compared to the light birds. The pelleted feed provided better total and daily feed intakes compared to the mashed feed. In the laying phase, the Met+Cys levels affected production, egg weight and mass and conversion to egg mass. The levels of Met+Cys and the physical shape of the feed over the laying period affected the subsequent performance of the birds in the laying period. The light line performed best. Levels of 320 and 364 mg Met+Cys daily are recommended for light and semi-heavy birds, respectively.

An important behavioral need for laying hens is perching, but few studies have investigated perching behavior in commercial broiler breeder pullets. The aim of this study was to investigate perching behavior throughout the pullet period and preferences for different perch types and heights. We also investigated the effect of hybrid on perching and the potential effect of perches on keel bone damage (KBD) and footpad dermatitis (FPD). We followed four commercial broiler breeder pullet hen flocks (Ross 308, n = 2 and Hubbard JA 757, n = 2), each with three groups of birds (n = 2 500 hens); A-group ; four A frames consisting of four perch types (plastic, steel square, steel round and wood) placed on different heights (35 cm and 95 cm); S-group ; Siesta perches (a plastic perch 15 cm high) and C-group; control group without perches. Perch use was recorded by counting number of birds on the perches during the last hour before the light went off, at week 2, 5, 6, 7, 10, 12 and 15. At week 16, footpad dermatitis, keel bone deformations and keel bone fractures were scored in 30 random birds in each group (n = 90 birds/flock). Hubbard birds perched significantly more than Ross birds (P < 0.0001), and more birds perched on the Siesta perches than on the A frames (P = 0.046). Perching increased with age for Hubbard birds (P < 0.05), but not for the Ross birds. There were no effects of perch height or perch types on number of birds observed on the perches. There were no observed cases of bumblefoot, breast blisters, keel bone deformations or keel bone fractures. The incidence of FPD was low, with 73.6% of assessed birds receiving a score of 0, with no significant differences between hybrids or perch groups. In conclusion, Hubbard birds perched more than Ross 308 birds, and all birds perched more with age. None of the hybrids showed any preferences for perch type or height and increased perching had no negative effects on important health parameters. Broiler breeder pullets should therefore be given access to perches from day 1 to promote training and perch use. • Limited knowledge is available on perching behavior in broiler breeders, especially in pullets. • We investigated preference for perch heights and materials in different hybrids during the pullet period. • The pullets started using the perches at week 2, and perching increased with age. • Hubbard birds perches more than Ross 308 birds, and there were no preferences for perch height or perch materials. • There were no negative effects of perches on foot pads or keel bones at 16 weeks. [ABSTRACT FROM AUTHOR]

Simple Summary: Tail biting, a well-known problem in modern pig production, reduces pigs' welfare and causes economic losses. It is influenced by several external and internal factors, such as housing condition, management, genetics, and age of the animals. Within the internal factors, the individual predisposition to tail biting is difficult to identify. In our study, we analyzed the manipulation behaviors of weaner pigs and their relationship with agonistic behaviors of the piglets during suckling to identify groups of piglets which showed similar suckling and rearing behaviors. In our experiment tail biting increased at the middle and end of rearing. Most animals were observed as both biters and victims of tail biting. During our observations, we found indications that tail-biting pigs showed mainly submissive behavior in teat disputes. These pigs might compensate their submissiveness by biting tails to chase other pigs from resources with restricted access, such as feed or enrichment material. Further research should consider more aspects of a pigs' personality suitable for early identification of pigs predisposed for later tail biting. This early identification would allow intervention measures to be taken earlier, thereby reducing tail biting and its consequences. Inadequate possibilities to perform oral manipulation behavior for pigs can lead to misdirection and thus tail biting. Our study aimed to analyze manipulation behaviors of weaner pigs with focus on tail biting and the relationship with agonistic characteristics of the piglets during suckling. We analyzed the individual manipulation behavior of 188 weaner pigs. General health condition and tail lesions were determined weekly. Correlations were estimated between weight at weaning and at the end of rearing period, frequency of manipulative rearing behaviors and Dominance and social tension index based on suckling behavior. Principal component and cluster analyses were performed to identify groups of piglets which showed similar suckling and rearing behaviors. Tail biting increased at the middle and end of rearing with switching roles of biters and victims. Tail lesions were correlated with received tail biting behavior but occurred with a delay of more than a week. The frequency of performed tail biting was correlated with dominance index (rs = −0.256, p < 0.01) and weaning weight (rs = −0.199, p < 0.05). We assume that performed tail biting is more often observed in pigs who show mainly submissive behavior in teat disputes. [ABSTRACT FROM AUTHOR]

• Size, age and rearing period of bluefin tuna affect the Hg accumulation. • Smaller and younger bluefin tuna show lower Hg concentrations than larger ones. • The longer the rearing period of bluefin tuna, the lower the Hg accumulation. • Mercury may pose a health risk to people consuming bluefin tuna (THQ > 1). • A maximum safe weekly consumption of 400 g is suggested. This study determines the levels of total mercury in muscle tissue from 268 reared Atlantic bluefin tuna in the Mediterranean Sea, detects variations on mercury concentrations in relation to biological parameters and rearing period and evaluates the health risk posed by fish consumption taking into consideration the size, age and rearing period. A total of 30 pooled samples were analyzed. The total Hg concentrations ranged from 0.49 to 1.60 mg/kg w.w. and showed a significant positive relationship with the size and age. It was found that the longer the rearing period, the lower the mercury concentration. The total Hg exceeded the maximum level defined by the European Commission Decision in a proportion of 40.0%. Since the value of Target Hazard Quotient was higher than 1 in all different groups (medium, large, 6 months and 18 months reared specimens), the maximum possible safe weekly consumption (400 g) is suggested. [ABSTRACT FROM AUTHOR]

Crabs show major differences in biochemical composition and nutritional value responding to various culture environments, growth stages and even sexes. In the present study, juvenile mud crab Scylla paramamosain (0.026 ± 0.010 g) were cultured at two earthen ponds with the respective salinity level of 25‰ and 5‰ for four months. The proximate composition, amino acid content and fatty acid profile in edible parts (muscle and hepatopancreas) of male and female crabs reared at different salinities and two rearing periods (three-month stage: 60–120 g and four-month stage: 150–300 g) were investigated and compared. Crabs at high salinity had significantly lower moisture contents in muscle and hepatopancreas, but had higher protein contents in muscle and higher ratio of n-3/n-6 highly unsaturated fatty acids (PUFA) in both edible parts, regardless of gender and rearing period. Additionally, significant differences in biochemical composition and nutritional value were also found between male and female crabs. For example, the contents of crude protein and most amino acids were higher in muscle and hepatopancreas of females, whereas males contained higher n-3 PUFA contents in both edible parts. Further, the contents of delicious amino acids (DAA) and essential amino acids (EAA) in muscle and the crude lipid content in hepatopancreas exhibited a higher trend at three-month stage than that at four-month stage. The results suggested that S. paramamosain reared at high salinity had better nutritional value than that at low salinity, while female and male crabs possess their respective advantages in terms of different nutritional composition. In addition, crabs had a better nutritional quality at three-month stage, even though they were at a smaller size. • S. paramamosain reared at high salinity water possess a superior nutritional quality than that at low salinity water. • Sexual differences in biochemical composition and nutritional value of muscle and hepatopancreas were detected. • The crabs have better nutritional quality at three-month rearing stage than that at four-month rearing stage. • This study provides valuable information for determining the appropriate rearing salinity and catching time. [ABSTRACT FROM AUTHOR]

In this study, the effects of environmental enrichment, stocking density, and microclimate on feather condition, skin injuries, and other health parameters were investigated. During 2 rearing periods (RP), non-beak-trimmed Lohmann Brown hybrid pullets were housed in an aviary system for rearing with cages and from week 5 of age onwards with access to a litter area. All pullets were reared in the same barn and under practical conditions. In total, 9,187 (RP 1) and 9,090 (RP 2) pullets were distributed in 9 units, and each unit was assigned to 1 of 3 experimental groups (EG). In the control group (EG 1), the pullets were kept without environmental enrichment and at a commonly used stocking density (22 to 23 pullets per m²). Each unit of the 2 treatment groups was provided with 3 types of environmental enrichment simultaneously (pecking stones, pecking blocks, and lucerne bales), and the pullets were kept at a lower than usual (18 pullets per m²) (EG 2) or commonly used stocking density (EG 3). In each RP, the plumage condition, injuries and health of the pullets, and the microclimate of the housing system were examined 5 times. The statistical relationships of enrichment, stocking density, and microclimate with animal health were estimated via regression models. We found that the provision of environmental enrichment had a significant increasing effect on the plumage quality in week 17. Furthermore, significant relationships were found between several predictors (temperature in the housing system, dust concentration, and age of the pullets) and response variables (plumage condition, body injuries, head injuries, bodyweight, difference to the target weight and uniformity). The results of this study showed that increasing temperature in the housing system and increasing age of the pullets are significantly associated with the occurrence of feather damage and skin injuries during rearing. With stocking densities as high as we used (all > 17 pullets per m²), no significant positive effect of a reduced stocking density could be observed., (© The Author(s) 2019. Published by Oxford University Press on behalf of Poultry Science Association.)