Modeling the performance of broilers under heat stress

A meta-analysis was developed to model performance depression in heat stress (HS), to analyze the influence of HS type (cyclic or constant), and to assess the correlation between dietary electrolyte bal- ance (DEB) and HS in broilers. Two databases (Dat) with performance and temperature were constructed (initial phase − up to 21 d of age − 14 articles, 7,667 ani- mals, average replicate number treatment-ARN/T, 5 and growing phase − over 21 d of age − 74 articles and 25,145 broilers, ARN/T, 7). The criteria for article selec- tion were (1) experiments using at least 2 temperatures (thermoneutral and high temperature); (2) results of ADFI and ADG; (3) feed and water ad libitum during the experiment. Each treatment was classified as cyclic or constant HS and the HS group response was calcu- lated relative to the thermoneutral group. Performance was evaluated as raw data or as relativized information (indicated as “HS effect or 61⁄4”), expressed as a percentage of the difference between results. The models to predict “HS effect” showed that for the initial phase, only ADG was influenced by HS, while for the grower phase, pre- diction equations were created for ADFI and ADG. Con- sidering the simplest models, there was a reduction of 1.4% in ADFI and 2.1% in ADG for each unit (°C) above the upper critical temperature for broilers older than 21 d. Feed conversion (FC) was not affected by HS in any of the studied phases. Constant HS proved to be more negative than cyclic HS to broiler performance after 21 d of age. The relation between DEB and performance of broilers under HS was analyzed considering broilers over 21 d of age, and very weak correlations were observed. It was concluded that HS affects broilers over 21 d more, although FC is not affected. ADFI is the most important variable affected by HS and the relation between the DEB of the diet and HS is very weak. The empirical models generated in this study accurately predicted ADG and ADFI of broilers exposed to HS and can be used to minimize those effects on poultry production

An in-situ assessment of Dorsal Cranial Myopathy in broilers, approaching regarding meteorological influences in South Brazil, classification, and appearance of the lesions during industrial processing

Broiler meat is a high-quality food for humans, and is worldwide consumed. Brazil plays an important role in the poultry industry and in its South region is situated the most important pro- ducer. Recently, alterations on the meat aspect have aroused the interest of researchers to clarify their causes. The objective of this investigation was to evaluate the relationship between environ- mental conditions and seasons on the prevalence of Dorsal Cranial Myopathy (DCM) and also, to generate a DCM classification in scores, for griller-type broilers. Carcasses were picked out from several stages of industrial processing from a slaughterhouse located in South Brazil. The preva- lence of DCM was measured using the database of partial condemnations of the Official Inspection Service during 19 months. Meteorological data were obtained from the National Institute of Meteo- rology (in Portuguese Instituto Nacional de Meteorologia- INMET), of the Ministry of Agriculture, Livestock and Supply. In addition, microorganisms with public health importance were measured on samples taken from the muscles with DCM. The prevalence of DCM was compared among sea- sons using Analysis of Variance (ANOVA). The relation with other environmental conditions was accessed using a principal component analysis. Partial condemnations by DCM were higher (P 0.05). Visually, it could be noted that the hemorrhagic lesion of the Anterior latissimus dorsi (ALD) muscle diminished during the processing line, making the DCM imperceptible, even in those carcasses with severe DCM score at the beginning of the process. In conclusion, the climate features approached here could be correlated to this emerging myopathy. However, this lesion does not represent a food security issue for the consumers regarding evaluated microorganisms, as this kind of lesion tends to disappear in the final sellable product

Genetic selection modulates feeding behavior of group-housed pigs exposed to daily cyclic high ambient temperatures

This study was conducted to evaluate the effect of genetic selection (Lines A and B; Line A pigs have a greater proportion of Pietrain genes than those from Line B and therefore, selected for improved lean tissue accretion) on the feeding behavior of group-housed pigs exposed to daily cyclic high ambient temperatures. Feeding behavior of 78 barrows housed together in a single room was recorded in real time by five automatic feeders. The feeders registered each visit of each pig (day, hour, min, and second) and the amount of feed requested. Daily cyclic high ambient temperature was induced exposing pigs at 22˚C from 18.00 to 10.00 h and 30˚C from 10.01 to 17.59 h. From this temperature variation, dayperiod was divided into: 22˚C(06-10h), from 6.00 to 10.00 h; 30˚C(10-18h), from 10.01 to 17.59 h; and 22˚C(18-06h), from 18.00 to 5.59 h. Meal criteria was estimated based on the probability of animals starting a new feeding event within the next minute since the last visit (Pstart). After defining the meal criteria, the number of meals (n), feed intake rate (g/min), feed intake (g/meal), feeder occupancy (min/meal), and interval between meals (min) of each animal were calculated. Greatest probability of starting to feed was observed at 22˚C(06-10h), followed by 30˚C(10-18h) and then 22˚C(18-06h). Regardless of time period, pigs from line A had greater feed intake rate and lower feed intake, feed occupancy per meal and probability of starting a meal when compared with line B pigs. Only line A pigs had greater feed intake and feeder occupancy per meal at 22˚C(18-06h) than remainder of the day. This indicates that pig feeding pattern is strongly related to the circadian rhythm. However, the genetic selection for improved lean tissue accretion may modulate pigs feeding behavior under daily cyclic high ambient temperatures

Prandial correlations and structure of the ingestive behavior of pigs in precision feeding programs

The feeding behavior of growing-finishing pigs was analyzed to study prandial correlations and the probability of starting a new feeding event. The data were collected in real-time based on 157,632 visits by a group of 70 growing-finishing pigs (from 30.4 to 115.5 kg body weight, BW) to automatic feeders. The data were collected over 84 days, during which period the pigs were kept in conventional (by phase and by group) or precision (with daily and individual adjustments) feeding programs. A criterion to delimit each meal was then defined based on the probability of an animal starting a new feeding event within the next minute since the last visit. Prandial correlations were established between meal size and interval before meal (pre-prandial) or interval after meal (postprandial) using Pearson correlation analysis. Post-prandial correlations (which can be interpreted as hunger-regulating mechanisms) were slightly stronger than pre-prandial correlations (which can be interpreted as satiety regulation mechanisms). Both correlations decreased as the animals’ age increased but were little influenced by the feeding programs. The information generated in this study allows a better understanding of pigs’ feeding behavior regulation mechanisms and could be used in the future to improve precision feeding programs

Growth performance and intestinal health of broilers fed a standard or low-protein diet with the addition of a protease

We evaluated the effects of a protease supplementation on the growth performance and intestinal health of broilers. Cobb chicks (392; 1-42 d) were divided into four treatments (seven replicates of 14 birds each). There were two feed formulations: a standard diet (SD) and a low crude protein and digestible amino acids diet (Low CP&AA). The two diets were either supplemented (+P) or not (−P) with a protease (Jefo Protease; 1.25 g kg−1). Performance was evaluated by feeding phases (1-7, 8-21, 21-35, and 35-42 d). On day 28, ileum samples were analyzed by a morphometric index for histological alterations (I See Inside Scoring System – ISI). Broilers fed the Low CP&AA had a poor feed conversion ratio (FCR); however, the addition of the protease to the Low CP&AA positively affected FCR and body weight gain and promoted a performance similar to the group fed SD−P. Birds fed diets supplemented with the protease presented the best ISI morphological index, mainly as a result of the low number of alterations regarding the lamina propria, epithelial thickness, and enterocyte proliferation. It is possible to conclude that the enzyme improves feed conversion and lamina propria, epithelial thickness, and proliferation of enterocytes index of broiler chickens when added to a standard diet or with a low crude protein and digestible amino acids diet

A preliminary assessment of the potential health and genetic impacts of releasing confiscated passerines into the wild: A reduced-risk approach

The illegal capture and trade of wild birds have long been threats to biodiversity. The rehabilitation and release of confiscated animals may be a useful conservation tool in species management. However, differences between populations regarding health (e.g., different pathogens) and adaptation (e.g., local adaptation) must be taken into account, since both can negatively impact the recipient population. In this pilot study, we used two of the most illegally trafficked Brazilian wild passerine species, namely the red-crested cardinal (Paroaria coronata) and green-winged saltator (Saltator similis) as case studies and assessed some of the health threats that the release of confiscated passerines may pose to free-living birds. We also investigated the level of difference in mitochondrial genetic structure among populations living in different ecoregions. Blood, feces, and oropharyngeal swabs from confiscated (n = 115) and free-living (n = 120) passerines from the release sites were tested for the Newcastle disease virus, Salmonella spp., and Mycoplasma gallisepticum. These are considered major avian diseases by the Brazilian National Avian Health Program. We analyzed mtDNA to study the difference in genetic structure between populations using samples from 127 free-living passerines. We found no evidence of the Newcastle disease virus or Salmonella spp. in confiscated or free-living passerines from either species. However, the levels of infection with M. galissepticum detected in our study for red-crested cardinals and green-winged saltators calls for a high degree of caution in captive release programs. The difference in genetic structure between populations occurring in different regions was low, and was not significant between those from the Pampa/Subtropical Grasslands region. These results suggest that it may be possible to establish a cost-effective and sensitive protocol for releasing confiscated songbirds, provided that further genome-wide studies indicate that the functional genetic diversity among (at least some of the) populations is also low.Fil: Cruz, Cláudio E. F.. Universidade Federal do Rio Grande do Sul; BrasilFil: Funkler, Gustavo R.. Universidade Federal do Rio Grande do Sul; Brasil. Laboratório Porto Belo; BrasilFil: Zani, André L. S.. Universidade Federal do Rio Grande do Sul; BrasilFil: Wagner, Paulo G. C.. Centro de Triagem de Animais Silvestres; BrasilFil: Andretta, Ines. Universidade Federal do Rio Grande do Sul; BrasilFil: Segura, Luciano Noel. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. División Zoología de Vertebrados; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; ArgentinaFil: Fagundes, Nelson J. R.. Universidade Federal do Rio Grande do Sul; Brasi

Meta‑analysis of ileal digestibility of amino acids and minerals in pigs fed diets containing enzymes

O objetivo deste trabalho foi avaliar, por meio da meta‑análise, o efeito da fitase e da xilanase sobre a digestibilidade ileal aparente (DIa) de aminoácidos, cálcio e fósforo, em suínos em fase de crescimento. A base de dados consistiu de 21 artigos publicados entre 1998 e 2009, no total de 82 tratamentos e 644 suínos. A meta-análise foi realizada por análise gráfica, de correlação, de variância‑covariância. As concentrações de fósforo fítico e as frações fibra em detergente neutro, fibra em detergente ácido e lignina em detergente ácido, nas dietas, apresentaram correlações baixas e negativas com a DIa do cálcio, fósforo e aminoácidos. A adição de fitase às dietas aumentou em 2% a DIa da arginina, em 14% a do cálcio e em 34% a do fósforo. A DIa da arginina, fenilalanina, isoleucina e lisina foi 3,3% superior em suínos alimentados com dietas com xilanase, em relação às dietas sem a enzima. O fósforo fítico e as fibras, nas dietas, reduzem a DIa do cálcio, do fósforo e dos aminoácidos essenciais. O uso de fitase e xilanase, nas dietas, melhora o aproveitamento de cálcio, fósforo e alguns aminoácidos. No entanto, o excesso de cálcio e fósforo nas dietas reduz a ação da fitase sobre a digestibilidade ileal dos nutrientes.The objective of this study was to evaluate the effect of phytase and xylanase on the apparent ileal digestibility (aID) of amino acids, calcium and phosphorus in growing pigs through meta-analysis. The database consisted of 21 articles published between 1998 and 2009, with a total of 82 treatments and 644 pigs. A meta-analysis was performed by graphical, correlation, variance and covariance analyses. Concentrations of phytic phosphorus and the fractions neutral detergent fiber, acid detergent fiber and acid detergent lignin, in the diet, showed a low and negative correlation with aID of calcium, phosphorus and amino acids. The addition of phytase in the diets increased the aID of arginine in 2%, calcium in 14% and phosphorus in 34%. The aID of arginine, phenylalanine, isoleucine and lysine was 3.3% higher in pigs fed diets containing xylanase, in comparison to the diets without the enzyme. Phytic phosphorus and fiber in the diets reduce the aID of calcium, phosphorus and essential amino acids. The use of phytase and xylanase in the diets improves the utilization of calcium, phosphorus and some amino acids. However, excessive calcium and phosphorus in the diets reduces the phytase action on the ileal digestibility of the nutrients

Assessing the implications of mycotoxins on productive efficiency of broilers and growing pigs

The effects of mycotoxins on the productive performance of growing pigs and broilers were evaluated using meta-analytical approach. Two databases were constructed: (1) Broilers, with information collected from 51,497 birds and published in 158 scientific papers from 1980 to 2016; and (2) Pigs, with information collected from 7,743 animals and published in 72 scientific papers from 1980 to 2015. The meta-analyses were performed independently for each specie, following three sequential analyses: graphical, correlation, and variance-covariance. Broilers and pigs challenged by mycotoxins reduced (p < 0.05) feed intake by 9 and 6 %, weight gain by 15 and 11 %, and feed efficiency by 6 and 4 % compared with non-challenged animals, respectively. Aflatoxins were the most studied mycotoxins in both databases. Birds and pigs challenged by aflatoxins reduced (p < 0.05) feed intake by 10 and 8 %, growth by 15 and 11 %, and feed efficiency by 6 and 7 % compared to non-challenged animals, respectively. In both databases, variation on growth performance due to mycotoxins showed a linear relationship (p < 0.05) with the feed intake variation caused by the challenge. The intercepts of the regression-based equations were different from zero and negative, which may indicate that mycotoxins altered the maintenance requirements in challenged animals. In conclusion, both broilers and growing pigs show losses in performance responses and worse nutritional efficiency when challenged by mycotoxins

Wild animals housed at the IBAMA triage center in Southern Brazil, 2005–2021: a glimpse into the endless conflicts between man and other animals

Spurred on by the illegal billion-dollar revenue, the capture and trade of wild fauna remain the leading illegal activities in Brazil, and elsewhere. We present and discuss insights into the wild animals housed at the Wild Animal Triage Center in Southern Brazil. Recorded data from 2005 to 2021 were used. A total of 36,950 animals were sheltered in that period, and most of them were common passerines (24,182) such as the Saffron Finch, and Red-crested Cardinal, among many others confiscated after inspections or reports. Passerines have long been the top trafficked species in Brazil and abroad, where birdkeeping has strong cultural and economic values. The totals per class were 29,784 birds (80.6%), 2,584 (7.0%) insects, 2,237 (6.1%) reptiles, and 2,170 (5.9%) mammals. Since they were mostly surrendered by the population rather than seized, most mammals, insects, and reptiles were probably unwanted guests in human spaces, tendency that illustrates the human difficulty in coexisting with wildlife. A total of 3,085 animals exhibited some threat or risk of extinction, which, as a general rule, grants them conservation priority. However, regardless of class, most animals (31,142) in this study were rated as least concern on the red lists, a trend in wildlife trafficking linked to the category criteria of being widely distributed species with abundant populations, and often, in close contact with human neighbors. Maintaining an abundance of common and nonthreatened species can be justified by the greater extent of their ecosystem services, from a local to global scale. Our results further highlight the urgent need to change our ways of interacting with wildlife, outstandingly the irresponsible ownership of animals