Social-pair judgment bias testing in slow-growing broiler chickens raised in low- or high-complexity environments.

Impacts of environmental complexity on affective states in slow-growing broiler chickens (Gallus gallus domesticus) are unknown. Chickens' performance in judgment bias tests (JBT) can be limited as they are tested individually, causing fear and anxiety. The objectives were to apply a social-pair JBT to assess the effect of environmental complexity on slow-growing broiler chickens` affective states, and assess the impact of fearfulness, anxiety, and chronic stress on JBT performance. Six-hundred Hubbard Redbro broilers were housed in six low-complexity (similar to commercial) or six high-complexity (permanent and temporary enrichments) pens. Twelve chicken pairs were trained (1 pair/pen, n = 24 chickens) using a multimodal approach (visual and spatial cues), with reward and neutral cues of opposing color and location. Three ambiguous cues were tested: near-positive, middle, and near-neutral cues. Approach and pecking behavior were recorded. Eighty-three percent of chickens (20/24) were successfully trained in 13 days. Fearfulness, anxiety, and chronic stress did not impact chickens' performance. Chickens successfully discriminated between cues. Low-complexity chickens approached the middle cue faster than high-complexity chickens, indicating that they were in a more positive affective state. The environmental complexity provided in this study did not improve affective states in slow-growing broiler chickens compared to a control. A social-pair JBT resulted in excellent learning and testing outcomes in slow-growing broilers.

Efeito dos níveis de lisina/proteína ideal sobre desempenho, características de carcaça, digestibilidade e parâmetros sanguíneos de suínos machos, castrados, da raça Duroc, de 30kg a 50kg / [Effects of lysine/ideal protein level on performance, carcass characteristics, digestibility and blood parameters of Duroc barrows from 30 to 50kg]

Objetivou-se avaliar níveis de proteína e aminoácidos, mantendo-se as relações entre os aminoácidos para suínos machos, castrados, de30kg a 50kg. Foram utilizados 50 suínos machos, castrados, com peso inicial de 30,35±1,96kg, distribuídos em delineamento experimental inteiramente ao acaso, com cinco tratamentos e cinco repetições com dois animais por unidade experimental. Os tratamentos consistiram em níveis de lisina digestível, mantendo-se a relação com os demais aminoácidos digestíveis: 0,73%; 0,83%; 0,93%; 1,03% e 1,13% na dieta. Avaliou-se desempenho, avaliação de carcaça, parâmetros sanguíneos e digestibilidade das dietas. Houve efeito quadrático para ganho de peso, conversão alimentar e níveis de creatinina em função dos níveis de lisina, com níveis ótimos estimados em 0,92%, 0,93% e 0,93%, respectivamente. As características de carcaça não foram influenciadas significativamente pelos tratamentos. Constatou-se efeito linear positivo para digestibilidade aparente da proteína bruta, da proteína total e da ureia sérica. Conclui-se que os níveis de proteína e lisina digestível recomendados para dietas de suínos machos, castrados, da raça Duroc, na fase de crescimento I, são de 16,70% e 0,93%, respectivamente, pois esses níveis proporcionaram melhorias no ganho de peso, na conversão alimentar e na creatinina sérica.(AU)

The objective of this study was to evaluate digestible lysine levels, keeping the relation among amino acids for Duroc barrows from 30 to 50kg. Fifty Duroc barrows (30.35±1.96kg live weight) were allotted in a completely randomized experimental design, divided in five treatments with five replicates and two animals in each experimental unit. The treatments consisted of digestible lysine levels (0.73%; 0.83%; 0.93%; 1.03% and 1.13%), keeping the relation with other essential amino acids. Performance, carcass characteristics, blood parameters and digestibility of the diets were evaluated. There was a quadratic response on weight gain, feed conversion and creatinine serum concentration as a function of the digestible lysine levels, with the greater levels obtained at 0.92%, 0.93% and 0.93%, respectively. The carcass characteristics were not influenced by the treatments. There was a linear increase of apparent digestibility of crude protein, total serum protein and urea. Results suggest that the requirement of protein and digestible lysine was 16.70% and 0.93%, respectively, providing improvements on weight gain, feed conversion and creatinine serum concentration of Duroc barrows in the growth phase.(AU)

Desempenho e características de carcaça de suínos em crescimento alimentados com torta de algodão e complexo enzimático / Performance and carcass characteristics of growing pigs fed diets containing cottonseed cake with and enzyme complex

Objetivou-se avaliar o efeito da inclusão da torta de algodão (TA) com adição de enzimas na ração de suínos na fase de crescimento e seus efeitos sobre o desempenho, as características de carcaças, bem como sua viabilidade econômica. Para tanto, foram utilizados 20 suínos machos castrados, distribuídos em um delineamento em blocos ao acaso, com peso corporal inicial de 56,28±5,78kg e final de 79,79±7,32kg. Os níveis de inclusão da TA foram 0%, 8%, 16% e 24%. Todas as rações tiveram os valores de exigência em energia metabolizável, proteína bruta e fósforo subestimados em 1,5% com a utilização de 300g/t do complexo enzimático. Os parâmetros de desempenho e as características de carcaça não apresentaram diferenças significativas entre os níveis de inclusão da TA. A torta de algodão pode ser utilizada em até o nível de 24% de inclusão com adição de complexo enzimático em rações de suínos na fase de crescimento II, sem alterar os parâmetros de desempenho e as características de carcaças, além de apresentar redução do custo/kg de suíno produzido.(AU)

The objective of this study was to evaluate the inclusion of cottonseed cake (CC) with enzyme complex in the diet of pigs in the growth phase and its effects on performance, carcass characteristics and economic viability. Thus, 20 barrows were distributed in a completely randomized block design, with initial body weight of 56.28±5.78kg and final weight of 79.79±7.32kg. The inclusion levels of CC were 0%, 8%, 16% and 24%. All diets had the requirement values of metabolizable energy, crude protein and phosphorus underestimated by 1.5% and were added to 300g/t enzyme complex. The performance parameters and carcass characteristics there was no difference between the levels of inclusion of cottonseed cake. The cottonseed cake can be used up to the 24% inclusion level with addition of enzyme complex in the growth phase II, without affecting performance and carcass characteristics, besides reducing the cost/kg of pig produced.(AU)