BEM-ESTAR DE GALINHAS POEDEIRAS EM DIFERENTES DENSIDADES DE ALOJAMENTO

Comparative assessment of growth performance, heat resistance and carcass traits in four poultry genotypes reared in hot-humid tropical environment

This study investigated the impact of heat stress on growth and carcass traits in four poultry genotypes-Giriraja, Country chicken, Naked Neck and Kadaknath reared in a hot and humid tropical environment. Birds from all genotypes had ad libitum access to feed and water while being challenged with consistently high environmental temperatures in the experimental shed. Daily diurnal meteorological data were recorded inside and outside the shed. The study specifically examined growth variables and carcass characteristics. Significant differences (p < 0.01) were observed in body weight and average daily gain at various intervals. Notably, feed intake showed significant differences (p < 0.01) across weeks, indicating interactions between genotypes and time intervals. The feed conversion ratio (FCR) varied significantly (p < 0.01), with the highest FCR recorded in the Kadaknath breed. Livability percentages were similar across groups, except for Giriraja, which had significantly lower livability (p < 0.01). Carcass traits, including dressing, wings, feathers and giblet percentages, showed significant differences among genotypes (p < 0.01). Hepatic mRNA expression of growth-related genes revealed numerical variations, with Naked Neck displaying the highest (p < 0.05) fold change in IGF-1 expression compared to other genotypes. The study recognized in the Naked Neck genotype to possess higher resilience in maintaining homoeostasis and uncompromised growth under heat stress, providing valuable insights for sustainable poultry farming in challenging environmental conditions.

Threonine-to-lysine ratio in laying hens: physiological parameters and organ weight

The objective of this study was to evaluate the effect of threonine:digestible lysine ratio in the diet on the physiological variables and weight of organs of light laying hens. Two hundred and ten 47 week-old Dekalb White laying hens were distributed in a completely randomized design, with five levels of threonine (0.507; 0.552; 0.597; 0.642 and 0.677%) and seven replicates of six birds each. The experimental period was 10 weeks, totaling 62 days and more eight days for the animals to adapt. The physiological parameters of cloacal temperature (CT), respiratory rate (RR) and average surface temperature (AST) were recorded weekly (7:00 am, 10:00 am, 1:00 pm, 4:00 pm, and 7:00 pm); after solid and water fasting, the birds were slaughtered to assess the absolute weight of the organs. The time of day influenced (p < 0.05) the physiological parameters RR and AST, and CT showed a significant effect (p < 0.05) of increasing levels of digestible threonine. The total weight of the pancreas, proventriculus and lung showed a significant effect (p < 0.05) of the increase in the levels of digestible threonine. The respiratory rate is affected by the levels of threonine in the diet. The 0.687% level promoted hypertrophy of the pancreas, proventriculus and lung, promoting more significant activity of these organs.

Dietary supplementation with β-mannanase and probiotics as a strategy to improve laying hen's welfare

A trend toward animal welfare improvement is observed in animal production, in addition to restrictions imposed on the use of antimicrobials. This study's objective was to evaluate whether β-mannanase and probiotic supplementation can change hen's behavior. Light weight laying hens (36 weeks old) were housed in cages randomly allocated to one of four different treatments: control group, fed non-supplemented diets; diets supplemented with 300 g/ton of β-mannanase; diets supplemented with 50 g/ton of probiotic; or diets containing both 300 g/ton of β-mannanase and 50 g/ton of probiotic. The behavior of 24 birds was recorded for a week using video cameras. The frequency and time of main behaviors (eating, walking, standing, sitting, drinking, and exploring) were analyzed in three periods per day (from 09:00 to 09:15; from 01:00 to 01:15, and from 04:00 to 04:15), as well as the time of other behaviors (leg-stretching and wings, scratching, wing-flapping, aggressive and non-aggressive pecks). Frequency and lesion scores were also analyzed using a visual score of three body regions: neck, tail, and cloaca; as well as comb injuries. β-mannanase was able to increase the frequency of feeding behavior by 49% (P < 0.05) and hens also spend 20% (P < 0.05) more time in this behavior compared to the control treatment. The use of probiotics also enhanced by 39% (P < 0.05) the frequency and 19% the time (P < 0.05) and the supplementation with combined additives was able to increase by 29% (P < 0.05) the frequency and 25% (P < 0.05) the time in feeding behavior. β-mannanase and probiotics also increased the frequency and time spent exploring behavior (P < 0.05) and promoted a higher frequency in standing behavior (P < 0.05) and decreased the time spent on sitting behaviors (P < 0.05). The combined additives showed less frequency and time in sitting behaviors (P < 0.05), while increased wing-flapping behavior (P < 0.05). All the treatments were able to reduce pecking (P < 0.05). Therefore, the addition of β-mannanase and probiotics to laying hen diets is an effective strategy to improve bird welfare.

Welfare of domestic birds and rabbits transported in containers

This opinion, produced upon a request from the European Commission, focuses on transport of domestic birds and rabbits in containers (e.g. any crate, box, receptacle or other rigid structure used for the transport of animals, but not the means of transport itself). It describes and assesses current transport practices in the EU, based on data from literature, Member States and expert opinion. The species and categories of domestic birds assessed were mainly chickens for meat (broilers), end-of-lay hens and day-old chicks. They included to a lesser extent pullets, turkeys, ducks, geese, quails and game birds, due to limited scientific evidence. The opinion focuses on road transport to slaughterhouses or to production sites. For day-old chicks, air transport is also addressed. The relevant stages of transport considered are preparation, loading, journey, arrival and uncrating. Welfare consequences associated with current transport practices were identified for each stage. For loading and uncrating, the highly relevant welfare consequences identified are handling stress, injuries, restriction of movement and sensory overstimulation. For the journey and arrival, injuries, restriction of movement, sensory overstimulation, motion stress, heat stress, cold stress, prolonged hunger and prolonged thirst are identified as highly relevant. For each welfare consequence, animal-based measures (ABMs) and hazards were identified and assessed, and both preventive and corrective or mitigative measures proposed. Recommendations on quantitative criteria to prevent or mitigate welfare consequences are provided for microclimatic conditions, space allowances and journey times for all categories of animals, where scientific evidence and expert opinion support such outcomes.

ANÁLISE DAS VARIÁVEIS AMBIENTAIS E FISIOLÓGICAS DE AVES POEDEIRAS COM E SEM ENRIQUECIMENTO AMBIENTAL

Objetivou-se, verificar a influência dos tratamentos com e sem enriquecimento ambiental sobre o comportamento de poedeiras e a qualidade dos ovos, bem como estudar as variáveis térmicas temperatura e umidade durante os horários em que foram avaliados o comportamento de interação das aves com o enriquecimento empregado. O experimento foi conduzido em delineamento em blocos casualizados (DBC), com dois tratamentos (gaiolas convencionais com enriquecimento e gaiolas convencionais sem enriquecimento) e 18 repetições por tratamento, duas aves por repetição, durante 28 dias. Os dados coletados no experimento foram analisados com auxílio do programa para análises estatística e genéticas - SAEG (SAEG, 2009), por meio de análise de variância e submetidos a teste Fisher a 5% probabilidade para detectar diferença significativa existente entre os tratamentos avaliados para variáveis ambientais e fisiológicas mensuradas. Para análise do comportamento das aves, os dados foram analisados por meio do Teste de χ². De acordo com as temperaturas aferidas nos sensores, houve uma diferença evidente entre os horários de coleta dos dados. Não houve efeito significativo dos tratamentos sobre as características de peso dos ovos, altura de albúmen, índice de gema, espessura de casca e Unidade Haugh. Não foi observado efeito dos blocos laterais na temperatura retal, porém houve um efeito significativo para blocos sobre as variáveis temperatura média da pele e temperatura média corporal.

Thermoregulatory, behavioral and productive responses of laying hens supplemented with different types and dosages of phytases raised in a hot environment: An integrative approach

This study had the following objectives: (i) to evaluate the thermoregulatory and behavioral responses of light laying hens supplemented with different types and dosages of phytases in the two day shifts; and (ii) to integrate the thermoregulatory and behavioral responses with performance of these birds raised in a hot environment. 270 light laying hens of the Hy-Line White lineage, with a body weight of 1.60 ± 0.092 kg were distributed in a completely randomized design in a 2 × 2 + 1 factorial model with two types of phytases (bacterial and fungal) and two dosages (450 and 900 FTU), and a control diet. The day shift (morning and afternoon) was considered as a fixed effect in the factorial arrangement. Principal component analysis (P_CA), correspondence analysis (C_A) and canonical discriminant analysis (C_DA) were used. There was no interaction (P > 0.05) between phytases and dosages for thermoregulatory responses. Respiratory rate (R_R), cloacal temperature (C_T), and surface temperature with feathers (S_TWF) and featherless (S_TF) were higher (P < 0.001) in the afternoon. Birds show different thermoregulatory and behavioral responses in the two shifts of the day. We also observed that birds supplemented with bacterial and fungal phytase showed similar thermoregulatory and behavioral responses to the control group in both day shifts. Expression of the "eating" activity was greater in the morning, while the birds remained sitting longer in the afternoon. Egg production was higher (P < 0.001) in birds supplemented with bacterial phytase. The phytase dosages had no effect on thermoregulatory, behavioral or performance responses. Egg production, feed conversion per dozen eggs corresponded to 81.1% of the differences between bacterial and fungal phytase supplementation and group control. Thus, we conclude that: (i) phytase dietary supplementation has no effect on the thermoregulatory responses of laying hens reared in a hot environment; (ii) birds supplemented with bacterial phytase showed higher egg production; and (iii) phytases (450 and 900 FTU) do not interfere with productive, behavioral and thermoregulatory responses.

Does dietary supplementation with phytases affect the thermoregulatory and behavioral responses of pullets in a tropical environment?

Dietary supplementation of two types of phytases (fungal and bacterial) with different dosages (300 and 900 FTUs) was evaluated in the thermoregulatory and behavioral responses of replacement pullets in a tropical environment. 288 Hy-Line White laying birds with a mean weight of 639.60 ± 6.05 g, clinically healthy, and eight weeks old were used in the study. Respiratory rate (RR, breaths. min^-1), Cloacal temperature (CT, °C), Surface temperature with feathers (STWF, °C), and Surface temperature featherless (STF, °C) were measured in the morning and afternoon. Behavioral data were observed through the following activities: sitting, eating, drinking, exploring feathers (EF), non-aggressive pecking (NAP), and object pecking (OP) recorded every 10 min from 6 a.m. to 5 p.m. Environmental variables were measured along with thermoregulatory and behavioral responses. There was an interaction for RR between phytase and period of the day (P < 0.05). The lowest RR (morning) was observed in fungal phytase. STF and STWF were higher (P < 0.05) in the afternoon. Birds supplemented with fungal phytase showed lower STWF (P < 0.05). The variables that contributed to explain physiological and behavioral responses are shown in order of importance for (i) periods of day: morning (sitting, STWF, drinking, eating, and CT) and afternoon (STF, STWF, OP, drinking, eating, RR and sitting); (ii) phytases: fungal (STF, STWF, RR, sitting, eating and drinking); and bacterial (RR, STF, STWF, CT and sitting). Thermoregulatory and behavioral responses were similar between dosages, but different between types of phytases. Birds supplemented with fungal phytase used sensible heat dissipation mechanisms and exhibited thermal comfort behaviors. The 300 and 900 FTUs phytase doses did not influence the thermoregulatory and behavioral responses of birds, while they showed natural heat dissipation and heat stress behaviors in the afternoon. We recommend a dietary supplementation of 300 FTUs fungal phytases.

COMPARAÇÃO ENTRE SISTEMAS DE AVALIAÇÃO AMBIENTAL EM GALPÕES DE GALINHAS POEDEIRAS NA REGIÃO DE DOURADOS – MS

Considerando que fatores ambientais como temperatura e umidade influenciam na produção animal, estes devem ser observados com o máximo de precisão possível, para assim, evitar tomadas de decisões baseadas em dados distorcidos. Desta forma, o objetivo deste trabalho foi coletar dados climáticos próximos a um galpão para produção de galinhas poedeiras e compará-los com os medidos por uma agência meteorológica oficial, verificando possíveis desvios devido à distância geográfica existente. O experimento foi realizado na cidade de Dourados – MS, com coletas de dados climáticos na UFGD e Embrapa Agropecuária Oeste, em abril de 2014. Foram escolhidos 8 dias aleatórios, onde se leu a temperatura, velocidade do vento e umidade relativa do ar. Por meio dos valores médios do índice de temperatura e umidade (ITU) obtidos para o galpão e dados oficiais foi possível concluir que a curva de ITU adquirida para a agencia climática oficial representa uma curva ideal para a realidade local de Dourados-MS, porém seus dados não representaram a situação local medida in loco no horário mais quente do dia.