Strategies to alleviate heat stress on performance and physiological parameters in feedlot-finished cattle under heat stress conditions. A systematic review-meta-analysis.

Strategies to alleviate heat stress on live performance - dry matter intake (DMI), average daily gain (ADG), and feed conversion efficiency (FCE) - and on physiological parameters - respiratory rate (RR) and panting score (PS) - of feedlot-finished cattle were evaluated by systematic review-meta-analysis. Using the PICO framework were identified 3813 records, with 31 publications and 6729 cattle being considered in the meta-analysis (MA). The comparison most reported was sun vs. shade (n = 24 publications), followed by shade vs. shade (area per animal and effectivity in reduce solar load) (n = 7 publications) and sun vs. sprinkling (n = 4 publications). Cattle with access to shade with total reduction in solar load improved ADG (p = 0.008) and FCE (p = 0.024), and reduced RR (p < 0.001) compared to unshaded animals. Cattle with access to shade with a height between 3 and 4 m increased ADG (p < 0.001), tended to improve FCE (p = 0.054), and reduced RR (p < 0.001) compared to unshaded animals. An area of shade from 2 to 4 m2/animal increased ADG (p = 0.002), and higher than 4 m2/animal reduced RR (p < 0.001) compared to unshaded animals. Animals that received sprinkling volume below 1 L/animal/min improved ADG (p = 0.008) compared to unshaded animals. Cattle with access to shade with a high area per animal improved DMI (p = 0.023) and ADG (p < 0.001) compared to animals with a low area. In univariate meta-regression, it was observed that the variables significantly (P < 0.05) influencing DMI were THI category; influencing ADG were cattle gender, THI category, and coat color; influencing FCE were cattle age and hemisphere; and influencing RR were country, THI category and climate. Performance and physiological parameters of feedlot-finished cattle under heat stress depend on animal and environmental characteristics.

Metabolic and productive parameters of lactating dairy cows under heat stress conditions supplemented with plant polyphenol extract.

The impact of heat stress on dairy cattle leads to significant economic losses and a negative impact on the welfare of the animals. The objective of this research was to evaluate the effect of the nutritional additive (Thermoplus®) in dairy cows under postpartum heat stress conditions, and its effects on the metabolic profile, production and quality of milk. Eighteen lactating Holstein cows (8 multiparous and ten primiparous), in a free-stall system, with a mean body condition score (BCS) of 3.14 ± 0.05, live weight of 624.55 ± 18, 61 kg, with initial mean days in milk (DIM) of 90 ± 10.11, were selected. The animals were grouped into a control (CG, n = 9) and a treatment (TG, n = 9). Both groups underwent 14 days of diet adaptation, the TG received the basal diet supplemented with 50 g of the additive, once a day, individually, while the control group received only the total diet. Data collection of metabolic and productive parameters were evaluated on days -14 (before adaptation), 1 (after the diet adaptation period), 16, 30, and 44. Milk, blood, and body condition score (BCS) were collected once a day, and heart rate, respiratory rate, and rectal temperature were collected twice a day. Serum concentrations of albumin, calcium, magnesium, glucose, gamma-glutamyl transferase (GGT), beta-hydroxybutyrate (BHBA), non-esterified fatty acids (NEFAs), and paraoxonase-1 (PON-1) were evaluated. In the milk, the percentage of fat, protein, lactose, and total solids were determined in each sampling. Milk yield was measured daily. Humidity and ambient temperature values were collected on the days of the collection every 30 min, from 5:30 am to 5:00 pm, to calculate the temperature-humidity index (THI). Statistical analyzes were performed using the SAS software (version 9.3, SAS Institute Inc., Cary, NC, USA). The THI ranged from 62.22 to 79.47. Our findings showed that when the THI was greater than 72, the animals in the TG were able to maintain milk yield (Odds ratio (OD) = -0.0577,), and the animals in the CG had a greater chance of reducing it (OD = -0.2301). Multiparous cows in the TG had higher milk yield than CG (32.57 ± 0.34 vs 30.50 ± 0.36 kg per day; P = 0.0078) and lower SCC (34.110 ± 6,940 vs 665.50 ± 214.41 cells per ml; P = 0.03), with the same percentages of total solids (P > 0.05). In multiparous metabolic markers, TG when compared CG had higher albumin concentrations (2.50 ± 0.07 vs 2.12 ± 0.07 g/dl; < 0.001), equal PON-1 (P > 0.05), and higher BHBA levels (0.49 ± 0.03 vs 0.39 ± 0.04 mmol/l). Primiparous from the CG had higher concentrations of NEFA (0.18 ± 0.02 mmol/l) than multiparous from the same group (0.09 ± 0.02 mmol/l) P = 0.0265. The use of the plant polyphenol extract in postpartum Holstein cows challenged by heat stress had beneficial effects on the production and health of the mammary gland in multiparous cows without decreasing milk solids. The non-reduction of the activities of the acute phase proteins indicates an immunomodulatory and inflammatory-reducing effect of the product used.

The use of infrared thermography as an indicator of methane production in hair sheep.

Infrared thermography may be an alternative technology for measuring the amount of CH4 produced and has the advantages of low cost, speed and efficiency in obtaining results. The study's objective was to determine if the infrared thermography is adequate for predicting the emission of CH4 in hair sheep and the best time after feeding to carry out the measurement. Twelve Santa Inês lambs (females, non-pregnant, with twelve months old and mean body weight of 39.3 ± 2.1 kg) remained for two days in respirometric chambers, in a semi-closed system, to determine the CH4 production. The animals were divided into two treatments, according to the diet provided. During this period, seven thermographic photographs were taken, at times - 1 h, -0.5 h, 0 h, 0.5 h, 1 h, 2 h, 3 h, 5 h, and 7 h, according to the feeding time, defined as 0 h. CH4 production was measured over 24 h. Thermographic images measured the maximum, minimum, average and point temperatures at the left and right flanks. The temperature difference between the left and right flanks (left minus right) was calculated each time. Pearson correlation coefficients, multiple regression and principal component analysis were carried out in SAS®. The best prediction of emission intensity of CH4 (kg of CH4 per dry matter intake) was obtained at 3 h after feeding: CH4/DMI = 13.9016-0,38673 * DifP2 + 3.39089 * DifMed2 (R² = 0.48), using the difference between left and right flanks for point and average temperature measures. Therefore, infrared thermography can be used as an indicator of CH4 production in hair sheep three hours after feeding.

Metabolic profile of transition period in ewes and its influence on passive immunity transference in lambs.

The intensification of ewe production, focusing on increasing prolificity, results in a higher incidence of metabolic disorders, especially in the transition period, which can lead to production losses with consequences for the health of the animals. The objective of this study was to evaluate the metabolic profile in transition period Lacaune ewes according to the parity and litter size born and its influence on the transference of passive immunity. Nineteen Lacaune ewes, with initial mean body weight of 76.36 ± 10.37 kg (SD), kept in a semi-extensive system and receiving the same diet, were used. Ewes were classified according to parity (primiparous and multiparous) and the litter size born at parturition (1, 2, and 3). On days - 14, - 7, and - 4 of the expected date of parturition and on days 1, 4, 7, and 14 days postpartum, blood sampling, the evaluation of the body condition score (BCS), and the weighing of animals were performed. Blood samples were taken from the lambs 48 h after birth. Colostrum was collected up to 6 h postpartum to determine the brix percentage. Serum concentrations of total plasma proteins (TPP), albumin, aspartate aminotransferase (AST), gamma-glutamyl transferase (GGT), beta-hydroxybutyrate (BHB), non-esterified fatty acids (NEFA), paraoxonase (PON1), calcium (Ca), and magnesium (Mg) were evaluated. In lambs, the blood parameters evaluated were TPP, albumin, GGT, and PON1. Lamb plasma was used to estimate colostrum efficiency, brix percentage immunity, and total plasma protein (PPT). Productive data, pre- and postpartum metabolic variables for ewes, lambs, and those related to colostrum brix were analyzed. The BCS had a reduction (p < 0.0001) in the postpartum period, which is evidenced on days 7 and 14 (2.88 and 2.73, respectively). Serum concentration of BHB presented the highest concentrations in the prepartum period for ewes that gave birth to triplets, from day - 14, and for ewes that gave birth to twins on day - 4 (p = 0.0245). Serum concentration of NEFA demonstrated the highest value on day 14 in primiparous (1.07; p = 0.0402). Calcium had the lowest concentrations on day 1 (8.85 mg/dl, p < 0.0001) and magnesium on day 3 (1.79 mg/dl, p < 0.0001) postpartum. The multiparous with two lambs had higher brix percentages (30.5%), and the lowest value was observed in primiparous ewes that gave birth to a single lamb (27.06%; p = 0.0395). Triplet lambs had the lowest weight (3.73 kg, p = 0.0007), and the best brix percentage in plasma was observed in twins (10.29%, p = 0.0174). Regardless of the parity, the ewes that presented the greatest metabolic challenge were those that gave birth to triplets, and these lambs presented the worst immunity and the lowest live weight. The quality of colostrum was influenced by the parity, and multiparous ewes that gave birth to triplets had the lowest brix percentage in the colostrum.

Performance, carcass, and meat traits of locally adapted Brazilian cattle breeds under feedlot conditions.

Little is known about the performance, carcass, and meat traits of locally adapted cattle in Brazil. This study aimed to compare the growth, slaughter, and carcass traits as well as meat quality of two local breeds (Curraleiro Pé-Duro and Pantaneiro) with the Nelore breed. Fifteen 30-month-old steers of each breed were weighted (Curraleiro Pé-Duro = 264.80 kg; Nelore = 346.80 kg; Pantaneiro = 316.20 kg) and raised in a feedlot condition for 112 days, with measurements to assess growth and slaughter, visual and carcass and meat traits. Data were submitted to variance and multivariate analyses. Nelore and Curraleiro Pé-Duro had similar Gluteus medius depths. Pantaneiro and Curraleiro Pé-Duro were superior for leg compactness index (P < 0.05) and had higher eye muscle area than Nelore (P < 0.05). Although there was no difference in daily weight gain and slaughter weight between breeds, Curraleiro Pé-Duro had a lower initial weight (264.80 kg) when compared to Nelore (346.80 kg; P < 0.05). Nelore and Curraleiro Pé-Duro deposited more fat than Pantaneiro (P < 0.05), while Curraleiro Pé-Duro and Pantaneiro had more muscle than Nelore (P < 0.05), which also had more bone and a higher percentage of second-quality cuts (P < 0.05). Meat from Nelore also showed lower succulence than Pantaneiro (P < 0.05) and higher shear force than the other breeds (P < 0.05). Pantaneiro's meat had the most capacity to retain water (P < 0.05), lower shear force (P < 0.05), and was more succulent (P < 0.05) when compared to the other breeds. Multivariate analysis showed that Pantaneiro, Curraleiro Pé-Duro, and Nelore breeds can be considered distinct in growth, carcass, and meat traits, with the local breeds showing superior meat traits. The local breeds Curraleiro Pé-Duro and Pantaneiro presented characteristics similar or better to those of the Nelore, proving to be animals with great productive potential and generate high meat quality under feedlot conditions.

Spatialization of breeding values of Brangus animals associated with climatic, physical, and socio-economic factors.

This study was realized to analyze the combinations of climatic, physical, and socio-economic variables on distribution of breeding values for performance characteristics and scrotal circumference of Brangus cattle. Records of 84,703 Brangus animals, born from 2000 to 2010 distributed in 65 farms in Brazil were used. The characteristics analyzed were average daily gain from birth to weaning and from weaning to yearling (WW and YW), visual scores of conformations (WC and YC), muscle score (WM and YM), precocity score (WP and YS), and size score (WS and YS) at weaning and yearling and scrotal circumference (SC) at yearling. Components of (co)variance estimated through the animal model employing methodology to AIREML. Mean estimates of direct heritability obtained for visual scores at weaning (WC 0.16, WM 0.16, WP 0.19, and WS 0.22) were lower than those obtained at yearling (YC 0.28, YM 0.26, YP 0.24, and YS 0.40). WW had heritability greater than YW (0.27 and 0.12) and a heritability of 0.36 obtained for SC. Canonical, discriminant, and cluster analyses were performed in the SAS® 9.4 program. Three clusters of genetic values averages per farm were formed according to climatic, physical, and socio-economic variables. Brangus animals are from states of RS, PR, SP, MG, GO, MG, and MS. The highest breeding values were strongly related to thermal amplitude and municipality area. Spatial distribution of the breeding value of Brangus animals can help in the development of environmental indices, genetic evaluations, and the choice of animals for certain environments.

Brazilian Sport Horse: genetic parameters for approval of Brasileiro de Hipismo stallions.

The aim of this study was to evaluate genetic parameters for subjective scores given at the Brazilian Sport Horse (BSH) Stallion Approval by estimating heritability (h2) for morphological, gait, and jumping traits and genetic correlations (γg) among the functional ones and by verifying selection feasibility. The analysis included 1179 complete evaluations from 294 horses, by 4.26 ± 0.96 judges. Each trait was evaluated using mixed models in SAS® v9.2, considering the individual as a random effect. Variance components and genetic parameters were obtained by single and two-trait animal models in a derivative-free restricted maximum likelihood analysis. Since many jumping traits were not described in Breed Regulation, mixed model results were used to enlighten the criteria adopted in the assignment of scores. Balanced bodies and conformations that favor collection were preferred by judges and presented moderate heritabilities. Additive variation was found for most jumping traits, with heritability equal to 0.74 (se = 0.04) for overall jump, and estimates for the separate aspects of the jump movement ranging from near null to 0.43 (se = 0.07) for temperament. Morphological scores had little effect over gait and jump scores while trot may be indicative of some additive value for jump distance and canter for hind limb mechanics. Conformation evaluations of separate body regions presented heritability estimates similar to previous studies and may provide more informative breeding values.

Spatial dynamics of the Girolando breed in Brazil: analysis of genetic integration and environmental factors.

Brazil is one of the world's largest milk producers. Several scientific studies have been developed related to landscape analyses that combine genetic with landscape structure data. In the present study, we aimed to analyze the relationship between genetic, environmental, and socioeconomic aspects of production in Girolando cattle in Brazil, as well as verify the spatial patterns of its genetic diversity. Genetic values and accuracy of 46,289 animals were used as well as information from DNA of 310 Girolando animals. Canonic, discriminant, and cluster analyses were conducted in SAS® and K-means method in ArcGIS 10.3 software. The relationship between genetic and geographic distance was analyzed using different methods in software Alleles in Space®. Clusters with animals with higher genetic values for milk production are located in municipalities with lower gross domestic product, fewer family-based establishments, and lower human development index. These clusters are associated with regions with higher area planted with crops, lower percentage of pastures that were less degraded, higher humidity, lower temperature range, and lower normalized difference vegetation index (NDVI) values. The greater the geographical distance between groups of animals, the greater the genetic distance between them with a significant distinction over 504 km. There is high genetic heterogeneity among animals. From these results, it will be possible to develop methodologies for better evaluation of the animals within the production systems.

Heat tolerance in Brazilian hair sheep.

OBJECTIVE: The aim of this study was to evaluate heat tolerance using heat tolerance indices, physiological, physical, thermographic, and hematological parameters in Santa Ines and Morada Nova sheep breeds in the Federal District, Brazil. METHODS: Twenty-six adult hair sheep, one and a half years old, from two genetic groups (Santa Ines: 12 males and 4 females; Morada Nova: 7 males and 3 females) were used and data (rectal temperature, respiratory rate, heart rate, skin temperatures; hematological parameters) were collected during three consecutive days, twice a day (morning and afternoon), with a total of six repetitions. Also physical parameters (biometric measurements, skin and hair traits) and heat tolerance indices (temperature-humidity index, Iberia and Benezra) were evaluated. The analyses included analyses of variance, correlation, and principal components with a significance level of 5%. RESULTS: The environmental indices, in general, indicate a situation of thermal discomfort for the animals during the afternoon. Breed significantly influenced (p<0.001) physiological and physical characteristics of skin, hair, biometric measurements and Iberia and Benezra heat tolerance indices. Santa Ines animals were bigger and had longer, greater number and darker hair, thicker skin, greater respiratory rate and Benezra index and lower Iberia index compared with Morada Nova breed. CONCLUSION: Although both breeds can be considered adapted to the environmental conditions of the region, Morada Nova breed is most suitable for farming in the Midwest region. The positive correlation found between the thermographic temperatures and physiological parameters indicates that this technique can be used to evaluate thermal comfort. Also, it has the advantage that animals do not have to be handled, which favors animal welfare.

Scrotal infrared digital thermography as a predictor of seasonal effects on sperm traits in Braford bulls.

The aim of this study was to assess the seasonal effects of the environment on semen quality in bulls, using infrared thermography. Sperm motility (M), mass motion (MM), and vigor (VIG) were evaluated in sperm samples from 17 Bradford bulls aged approximately 24 months at the beginning of the study. Infrared thermography images and data were collected using an infrared FLIR T 300 camera and Quick Report 1.2 SP2 software to determine the temperature of the proximal and distal poles of the testis and to assess the testicular temperature gradient. The seasonal effects on physiological, seminal, and climatic variables were analyzed by the GLM ANOVA and CORR procedures using SAS®. The microclimatic factors were recorded in hourly intervals, and the daily mean temperature and mean relative humidity were calculated to determine the daily temperature-humidity index (THI) every day for 1 year. The temperature gradient (TG) variations of the testes were significantly higher in the autumn (4.5 °C), winter (4.0 °C), and spring (2.9 °C) compared to summer (0.9 °C) (P < 0.05). Ocular globe temperatures were lower in the winter (27.6 °C) and autumn (26.8 °C) compared to summer (33.9 °C) and spring (31.1 °C) (P < 0.05). The average MM (2.58), M (52.64), and VIG (2.70) of the semen decreased in the summer compared to other seasons (P < 0.01). The TG was negatively correlated with THI (-0.44; P < 0.05). For the seminal variables, MaD (-0.45; P < 0.05) and TD (-0.50; P < 0.01) presented a negative correlation with TG. The TG had a positive correlation between M and VIG, which had values of 0.36 and 0.35, respectively (P < 0.05). We have concluded that infrared thermography can be used to assess the testicular temperature gradient and its consequences on physical and quantitative aspects of sperm.

Technologies that affect the weaning rate in beef cattle production systems.

We investigated the differences between weaning rates and technologies adopted by farmers in cow-calf production systems in Rio Grande do Sul State, Brazil. Interviews were carried out with 73 farmers about 48 technologies that could affect reproductive performance. Data were analyzed by multivariate analysis using a non-hierarchical cluster method. The level of significance was set at P < 0.05. Three distinct clusters of farmers were created (R (2) = 0.90), named as low (LWR), intermediate (IWR), and high (HWR) weaning rate, with 100, 91, and 96 % of the farmers identified within their respective groups and average weaning rates of 59, 72, and 83 %, respectively. IWR and HWR farmers used more improved natural pasture, fixed-time artificial insemination, selection for birth weight, and proteinated salt compared to LWR. HWR farmers used more stocking rate control, and IWR farmers used more ultrasound to evaluate reproductive performance compared to the LWR group. IWR and HWR adopted more technologies related to nutrition and reproductive aspects of the herd in comparison to LWR. We concluded that farmers with higher technology use on farm had higher weaning rates which could be used to benefit less efficient farmers.

Effect of Density and Lineage on Dorsal Surface Temperature, Performance, and Carcass Condemnation of Broiler Grillers.

The aims of this study were (i) to evaluate the effect of density, lineage, age, and time of day on dorsal surface temperature and (ii) to evaluate the effect of density and lineage on performance and carcass condemnations in broiler grillers. The evaluations were carried out in barns with the Dark House system, with two densities, 17 and 19 chickens/m2 and two lineages, Cobb and Ross. The dorsal surface temperature of the chickens was measured by infrared thermography at 7, 14, 21, 23, 25 and 27 days of age, four times a day. The average daily weight gain, feed conversion, mortality, partial carcass condemnations, as well as those due to arthritis and dermatosis were also evaluated. The highest dorsal surface temperatures were observed in Cobbs housed at a density of 17 chickens/m2, and in Ross housed at a density of 19 chickens/m2. Cobbs housed at a 17 chickens/m2 density showed the lowest feed conversion compared to Ross at the same density. Ross showed higher dorsal surface temperatures when compared to Cobbs at 14, 21, and 27 days. Cobbs showed higher percentages of partial carcass condemnation and arthritis compared to Ross. The higher density of broiler grillers in the Dark House system does not influence the dorsal surface temperature, performance, dermatosis, arthritis, and partial carcass condemnations.

Evaluation of different percentages of Duroc genes and gender on growth, carcass and meat quality traits for pigs.

The effect of different percentages of Duroc genes in crossbreeding (5, 50 and 100%), the gender (immunocastrated males - ICM and females) and their interaction was evaluated on growth, carcass and meat quality traits for pigs. Crossbreds (50% Duroc) had greater average daily feed intake, hot carcass weight and backfat thickness but lower meat yield when compared to 5% Duroc crossbreds and purebred (100% Duroc) animals (P < 0.05). Purebred (100% Duroc) animals had the lowest backfat thickness and subcutaneous fat thickness, and the greatest muscle depth and meat yield (P < 0.05). ICM animals had better feed conversion, greater average daily gain, hot carcass weight and amount of meat, and lower hot carcass yield, cold carcass weight, Longissimus thoracis depth, rib with belly and ham weights compared to females (P < 0.05). Marbling scores were greater in purebred (100%) animals (P < 0.05). The meat from 50% Duroc crossbreds and 100% Duroc purebred pigs was more reddish pink in color than 5% Duroc crossbreds (P < 0.05). Also, marbling scores were greater for females compared to ICM (P < 0.05). Purebred (100% Duroc) animals required more medications during production (P < 0.05).

Prevalence of bovine Babesia spp., Anaplasma marginale, and their co-infections in Latin America: Systematic review-meta-analysis.

Bovine parasitic sadness, comprised of the diseases babesiosis and anaplasmosis, has a large impact on cattle farming in several countries, as it compromises animal productivity. Using systematic review (SR)-meta-analysis (MA) methodology, our objective was to summarize and to investigate study characteristics associated with prevalence of Babesia spp. and Anaplasma marginale infection in Latin American cattle herds. Five electronic databases were used. The inclusion criteria were studies that assessed the prevalence of Babesia spp. and A. marginale in cattle in Brazil, Argentina, Uruguay, Paraguay, Colombia, and Mexico. The reported prevalences were converted to logistic scale and summarized using random effects MA. The heterogeneity was assessed, separately, for papers from Brazil and from the remaining countries. A total of 28 papers were included in this MA with a high heterogeneity (I2 > 95%). The prevalences of A. marginale, Babesia spp., and their co-infections, in Latin America, were 48.9% (95% CI: 30.3-67.8%), 39.8% (95% CI: 24.6-57.2%), and 26.1% (95% CI: 9.1-55.8%), respectively. The prevalence of A. marginale was higher due to the high prevalence of this agent in Mexico (67.1%). In Brazil, the prevalence was 36.6% for A. marginale, 62.6% for Babesia spp., and 8.2% for their co-infections. The North region of Brazil was reported with the highest prevalence for A. marginale (71.9%), while for Babesia spp., the prevalence was considerably divergent between regions, with the highest values also observed in the North region (97.4%), and the lowest in the South region (9.5%). For studies of Babesia spp. in cattle in Latin America, the heterogeneity was mainly explained by the diagnostic method (98.0%), and country (54.8%). When looking at Brazil alone, a similar pattern was observed, but with lower values (i.e., diagnostic method, 31.5%; region, 25.3%; and climate, 12,4%). The evaluated regions presented different levels of prevalence infections, with most of them being classified as high degree of enzootic instability, which can predispose to the occurrence of outbreaks.

Removal or substitution of in feed antimicrobials in swine production.

Antimicrobial substitutes are being used in pig production systems, to maintain the health of the animals without compromising their performance. The aim of this study is to evaluate the impact of either the removal of in feed antimicrobials or their substitution for feed additives, at the nursery and growing/finishing stages. At weaning, 1091 piglets were sexed, vaccinated, homogenized by weight and allocated to six treatments during the nursery stage (26-63 d): T1- feed with no antimicrobials nor additives; T2 - feed with antimicrobials; T3 - feed with prebiotic; T4 - feed with probiotic; T5 - feed with essential oils; T6 - feed with organic acids. The same treatments were applied to 840 pigs during the growing/finishing stages (64-167 d). There was no effect of the treatments on feed conversion at the nursery (P = 0.222) and the growing/finishing (P = 0.809) stages. The average daily gain did not differ across treatments in the nursery (P = 0.342) and in growing/finishing (P = 0.050). The cost of the interventions with injectable drugs was not different between the treatments neither at the nursery (P = 0.990) nor at the growing/finishing (P = 0.310). However, the pneumonia and pleurisy index for all treatments was equal or above 1.0, which indicates a respiratory challenge. There was an increase in the cost with antimicrobials or additives per kg of feed produced, which impacts the cost per kg of pig produced. In conclusion, the removal of antimicrobials in pig diets is financially feasible and their substitution by additives did not impact growing performance.

Carry-over and contamination of veterinary drugs in feed production lines for poultry and pigs.

The current model of pigs and poultry production has increased stocking density and reduced downtime between lots. This scenario may favour a rise of infection and disease risk in animals. To avoid this problem, routine use of drugs has been made, intensifying the possibility of residues in animal products and antimicrobial resistance. The aim of this study was to measure carry-over and contaminants of veterinary drugs included in the feed production lines for poultry and pigs. Samples were taken from 25 production lines. LC-MS/MS was used for simultaneous analysis of 62 active ingredients. In the medicated feed, 80.4% of the samples had a concentration of active ingredients different from the stated doses. In 70% of the feed samples, there was heterogeneity in the mixture of active ingredients. In subsequent feeds, carry-over was greater than 1% of the stated dose in 63% of cases. Of the 25 analysed lines, only one showed no contamination with other active ingredients. No correlations were found between the nutritional composition of the feed and carry-over. The present study demonstrated that the current production model allows the occurrence of unwanted drugs in feed-in doses that can contaminate animal products and can select antimicrobial-resistant bacteria.

Eurytrema coelomaticum infection: correlation between parasite burden and impairment of pancreatic exocrine enzyme secretion / Eurytrema coelomaticum: correlação entre carga parasitária e insuficiência pancreática exócrina

Eurytrema coelomaticum is a trematode reported in the pancreatic ducts of ruminants. It is conjectured that may cause disorders in the pancreas, as well as digestive and metabolic processes dependent on them. This study, determined if there is an impairment of exocrine pancreatic function, and correlated it with parasite burden. Pancreas, blood, and fecal samples were collected from 119 bovines at a abattoir. Stool samples were subjected to the gelatin and x-ray film digestion tests (to detect the presence of trypsin in feces). Using blood samples, the following biochemical tests were performed: amylase, lipase, glucose, fructosamine, cholesterol, triglycerides, total protein, albumin, and globulins. Analyses were correlated with pancreatic parasite burden. Cattle with a high parasitic load presented higher incidence of negative tests in both gelatin digestion and x-ray film digestion tests (P < 0.001) when compared to non-parasitized animals and those with a low parasitic load. Changes in those tests only occurred if the parasitemia was moderate or severe. The activity of the amylase and lipase enzymes was significantly higher in animals with low parasitemia (P < 0.05), compared to non-parasitized animals and with a high parasitic burden. In this study, in cases of high parasitemia, negative results were observed in both gelatin and x-ray film in the feces digestion tests. However, the low infection of E. coelomaticum, higher levels of serum amylase and lipase that also indicated loss of pancreatic exocrine functions were reported.

Eurytrema coelomaticum, um trematódeo de ductos pancreáticos de ruminantes. Conjectura-se que possa ocasionar transtornos nas funções pancreáticas, mais especificamente nos processos digestivos e metabólicos dependentes destas. Neste estudo, o objetivo foi determinar se há comprometimento da função pancreática exócrina, correlacionado-a a carga parasitária. Foram utilizados pâncreas e respectivas amostras de sangue e fezes de 119 bovinos. As amostras de fezes foram submetidas aos testes de digestão da gelatina em tubo e digestão de filme radiográfico, ambos para detecção de tripsina nas fezes. Foram realizados os seguintes exames bioquímicos em amostras de sangue: amilase, lipase, glicemia, frutosamina, colesterol, triglicerídeos, proteínas totais, albumina e globulinas. Após isto, as análises bioquímicas foram correlacionadas com a quantidade numérica de parasitas encontrados no pâncreas (post-mortem). Houve maior quantidade de testes negativos (digestão do filme radiográfico e prova de digestão da gelatina) nos animais com alta carga parasitária (P < 0.001), quando comparados aos animais não parasitados e com baixa carga parasitária. Portanto, os exames supracitados se alteram somente se a quantidade de parasitas for moderada ou severa. As atividades das enzimas amilase e lipase foram significativamente maiores nos animais que apresentavam baixa parasitemia (P < 0.05), em comparação com os animais com alta carga parasitária e não parasitados. Conclui-se que em quadros de alta parasitemia há alteração significativa nos testes de digestão nas fezes, e que em quadros de baixa parasitemia há alterações significativas nos valores de amilase e lipase séricas, ambos comprovando alterações pancreáticas importantes, de acordo com o quadro de parasitemia.

Heat Tolerance in Curraleiro Pe-Duro, Pantaneiro and Nelore Cattle Using Thermographic Images.

The objective of this study was to compare physiological and thermographic responses to heat stress in three breeds of cattle. Fifteen animals of each of the Nelore, Pantaneiro and Curraleiro Pe-Duro breeds, of approximately two years of age, were evaluated. Heart and respiratory rates, rectal and surface temperature of animals as well as soil temperature were recorded at 8:30 and 15:30 on six days. Variance, correlation, principal factors and canonical analyses were carried out. There were significant differences in the rectal temperature, heart and respiratory rate between breeds (p < 0.001). Nelore and Pantaneiro breeds had the highest rectal temperatures and the lowest respiratory rate (p < 0.001). Breed was also significant for surface temperatures (p < 0.05) showing that this factor significantly affected the response of the animal to heat tolerance in different ways. The Curraleiro Pe-Duro breed had the lowest surface temperatures independent of the period evaluated, with fewer animals that suffered with the climatic conditions, so this may be considered the best adapted when heat challenged under the experimental conditions. Thermography data showed a good correlation with the physiological indexes, and body area, neck and rump were the main points.

Performance and financial efficiency of three dairy production systems in southern Brazil / Desempeño productivo y eficiencia financiera en tres sistemas de producción lechera en el sur de Brasil / Desempenho produtivo e a e iciência inanceira em três sistemas de produção de leite no sul do Brasil

Abstract Background: Factors such as herd composition, productivity, milk quality and technology level influence the costs and profitability of milk production. Objective: To evaluate indicators that could predict production performance and financial efficiency in three dairy production systems in southern Brazil. Methods: Monthly records of milk quality, production performance and costs from fifty dairy farms were collected. The farms were classified into grazing, semi-feedlot, or feedlot systems. Total revenues, effective operational cost, total operational cost, total cost, gross margin, net income, total cost leveling point, profitability and final milk price were calculated. Results: The feedlot system resulted in greater herd size and milk production per lactating cow (p<0.05), but greater variable costs compared to semi-feedlot and grazing systems. On the other hand, the grazing system achieved greater profitability per year. Factor II (fat and protein rates), and Factor III (herd size and productivity per area) were associated with milk price per liter paid to the farmer (p<0.05), together accounting for approximately 13% of this price. Conclusion: Dairy production systems are influenced by area, lactating cows, productive performance, productivity per area, milk quality, and use of artificial insemination as well as supplementation (concentrate and minerals). Nearly 13% of milk price can be attributed to its fat and protein content as well as herd size and productivity per area.

Resumen Antecedentes: Factores tales como composición del rebaño, productividad, calidad de la leche y nivel tecnológico pueden afectar los costos y rentabilidad de la producción lechera. Objetivo: Evaluar indicadores que puedan predecir el rendimiento productivo y eficiencia financiera en tres sistemas de producción lechera en el sur de Brasil. Métodos: Se recolectaron y analizaron registros mensuales de calidad de la leche, rendimiento productivo y costos de cincuenta granjas lecheras. Las granjas se clasificaron en tres sistemas: pastoreo, semi-confinamiento, y confinamiento. Se calcularon los ingresos totales, el costo operativo efectivo, el costo operativo total, el costo total, el margen bruto, el beneficio neto, el punto de nivelación del costo total, la rentabilidad, y el precio final de la leche. Resultados: El sistema de confinamiento presentó mayor densidad animal y producción de leche por vaca lactante (p<0,05), pero mayores costos variables en comparación con los sistemas de semi-confinamiento y pastoreo. Por otro lado, el sistema de pastoreo tuvo mayor rentabilidad por año. El Factor II (tasas de grasa y proteína) y el Factor III (tasa de ganancia y productividad por área) se asociaron al precio por litro de leche pagado al productor (p<0,05), representando juntos aproximadamente el 13% de ese precio. Conclusión: Los sistemas de producción lechera están influenciados por el área, las vacas lactantes, el rendimiento productivo, la productividad por unidad de área, la calidad de la leche y el uso de inseminación artificial, así como por la suplementación (concentrado y minerales). Casi 13% del precio de la leche se puede atribuir a su contenido de grasa y proteína, así como al tamaño de la granja y productividad por área.

Resumo Antecedentes: Fatores relacionados à composição do rebanho, produtividade, qualidade do leite e uso de tecnologias podem impactar os custos e a lucratividade da produção de leite. Objetivo: Avaliar indicadores que possam predizer a produtividade e a eficiência financeira em três sistemas de produção de leite no sul do Brasil. Métodos: Registros mensais de qualidade do leite, desempenho da produção e custos de cinquenta fazendas leiteiras foram coletados. As fazendas foram classificadas em sistemas de pastejo, semi-confinamento ou confinamento. As receitas totais, o custo operacional efetivo, o custo operacional total, o custo total, a margem bruta, o lucro líquido, o ponto de nivelamento total do custo, a lucratividade e o preço final do leite foram calculados. Resultados: O sistema de confinamento apresentou maior taxa de lotação e produção de leite por vaca lactante (p<0,05), porém maiores custos variáveis totais em relação aos sistemas de semi-confinamento e pastejo. Por outro lado, o sistema de pastejo alcançou maior rentabilidade por ano. O Fator II (taxas de gordura e proteína) e o Fator III (taxa de lotação e produtividade por área) foram associados ao preço do leite por litro pago ao produtor (p<0,05), representando juntos aproximadamente 13% desse preço. Conclusões: Os sistemas de produção leiteira foram influenciados pela área, vacas em lactação, desempenho produtivo, produtividade por área, qualidade do leite e uso de inseminação artificial, bem como pela suplementação (concentrado e minerais). Quase 13% do preço do leite pode ser atribuído ao seu teor de gordura e proteína, assim como a taxa de lotação e a produtividade por área.

Effects of genetic group, pregnancy and age on carcass traits, meat quality and fatty acid profile in female sheep / Efectos de grupo genético, preñez y edad sobre la canal, calidad de carne y perfil de ácidos grasos en ovejas / Efeitos do grupo genético, da prenhes e da idade sobre as características da carcaça, qualidade da carne e perfil dos ácidos graxos em ovelhas

Abstract Background: Little information is available on carcass quality in nulliparous and primiparous ewes of different breeds and genetic groups. Objective: To evaluate the effect of genetic group, pregnancy, age and their interactions on carcass traits, meat quality and fatty acid profile in sheep. Methods: Eighty-five Santa Ines ewes and their crosses with Texel, Dorper and Ile de France, aged 12 month were bred with White Dorper rams to assess the influence of pregnancy on carcass composition and meat quality. After weaning, all ewes (nulliparous and primiparous) were fattened for slaughter at 21 months of age. A further 24 six to twenty one-month-old female lambs from the same genetic groups were included in the analysis to determine the fatty acid profile. Results: Genetic group affected muscle and fat weight as well as the eye muscle length. Fat weight, muscle and fat ratios, subcutaneous fat thickness and cooking loss were affected by pregnancy with nulliparous females being fatter. Meat purpose breeds such as Dorper, Texel and Ile de France showed better meat quality compared to the Santa Ines hair breed. Of the 19 identified fatty acids, saturated were present in greater quantities, especially stearic and palmitic. Omega-6 content was influenced by age and pregnancy. Conclusions: Younger and nulliparous females have better carcass quality in terms of fatty acid composition.

Resumen Antecedentes: Existe poca información sobre la calidad de la canal en ovejas jóvenes nulíparas y primíparas de diferentes razas y grupos genéticos. Objetivo: Evaluar la influencia del grupo genético, de la preñez, de la edad y sus interacciones sobre la composición de la canal, calidad de la carne y perfil de ácidos grasos en la carne de ovejas. Métodos: Ochenta y cinco ovejas de 12 meses de edad de raza Santa Inés y sus cruces con Texel, Dorper y Ile de France fueron cruzadas con carneros White Dorper para evaluar la influencia de la gestación sobre la composición de la canal y la calidad de la carne. Después del destete, todas las ovejas (nulíparas y primíparas) fueron engordadas y sacrificadas a los 21 meses de edad. Otras 24 ovejas de seis a veintiún meses de edad del mismo grupo genético fueron incluidas en el análisis para determinar el perfil de ácidos grasos. Resultado s: El grupo genético afectó el peso del músculo y de la grasa, como también la longitud del ojo del músculo. El peso de la grasa, porcentajes de músculo y grasa, el grosor de la grasa subcutánea y las perdidas por cocción fueron afectadas por la preñez, siendo más gordas las hembras nulíparas. Los grupos genéticos especializados en producir carne como Dorper, Texel e Ile de France mostraron mejor calidad de carne comparado con la raza Santa Inés. De los 19 ácidos grasos identificados, los saturados estaban presentes en mayores cantidades, especialmente esteárico y palmítico. Los contenidos de Omega-6 fueron influenciados por la edad y la preñez. Conclusiones: Las ovejas más jóvenes y nulíparas tienen mejor calidad de carcasa en términos de composición de ácidos grasos.

Resumo Antecedentes: Existe pouca informação sobre a qualidade da carcaça em ovelhas jovens nulíparas e primíparas de diferentes raças e grupos genéticos. Objetivo: Avaliar a influência do grupo genético, da prenhes, da idade e suas interações sobre as características da carcaça, qualidade da carne e perfil de ácidos graxos na carne de ovelhas. Métodos: Oitenta e cinco ovelhas Santa Inês e suas cruzas com Texel, Dorper e Ile de France com 12 meses de idade foram cruzadas com carneiros White Dorper para avaliar a influência da prenhes sobre a composição da carcaça e a qualidade da carne. Após o desmame, todas as ovelhas (nulíparas e primíparas) foram engordadas para serem abatidas aos 21 meses de idade. Mais 24 ovelhas com idade variando entre seis a vinte e um meses do mesmo grupo genético foram incluídas na análise para determinar o perfil de ácidos graxos. Resultados: O grupo genético influenciou os pesos do musculo e da gordura bem como o comprimento da área de olho de lombo. O peso da gordura, a relação músculo e gordura, a espessura de gordura subcutânea e as perdas por cocção foram influenciadas pela prenhes, sendo as fêmeas nulíparas as mais gordas. Os grupos genéticos especializados em produção de carne como o Dorper, o Texel e o Ile de France apresentaram melhor qualidade de carne comparado a raça Santa Inês. Dos 19 ácidos graxos identificados, os presentes em maiores quantidades foram os saturados, principalmente o esteárico e o palmítico. O Conteúdo de ômega 6 foi influenciado pela idade e pela prenhes. Conclusões: As fêmeas jovens e nulíparas apresentam melhor qualidade de carcaça em termos de composição de ácidos graxos.