Resumo em Inglês:

ABSTRACT This experiment was conducted in outdoor tanks to evaluate the effect of inclusion of ractopamine at increasing levels (0, 4, 8, 12, and 16 mg kg−1) as additive in Nile tilapia (Oreochromis niloticus) diet in the final grow-out period (750-920 g) during 31 days. Therefore, 400 fish were housed into 20 experimental tanks, in a completely randomized design with five treatments and four replications. Growth performance, body yield, and chemical composition of fish muscle and organs were evaluated. Fish fed diets containing up to 16 mg kg−1 of ractopamine for 31 days did not improve growth or performance parameters. However, lipid percentage of abdominal muscle was different in fish fed ractopamine, reaching the lowest level of 199.3 g kg−1 of ether extract at 8 mg kg−1 treatment. Other body chemical composition parameters did not differ between animals treated or not treated. Feeding ractopamine up to 31 days has limited effect on body composition in Nile tilapia (~900 g), without any changes in growth parameters. This is a lower metabolic response in this species when compared with mammals and other terrestrial animals.

Resumo em Inglês:

ABSTRACT The objective of this study was to determine whether infrared thermography is a useful tool for the recognition of dairy cows in a state of thermal heat stress, as well as to identify the best region of the animal to be evaluated for this recognition. Physiological variables, including rectal temperature, respiratory frequency, cardiac frequency, and panting score were recorded in 38 lactating cows. For the assessment of environmental parameters, a digital black globe thermometer (TGD-200 model) was used. Thermographic photographs of different regions of the body of cows were taken using an infrared camera (FLIR® System T300) and indicated respective superficial temperature. Physiological variables and superficial body temperature in different regions varied between genetic groups (Girolando: ½ Holstein × ½ Gir and ¾ Holstein × ¼ Gir; purebred Holstein). The environmental temperature ranged from 20.7 to 37.9 °C with a relative humidity reaching 95%. The mean rectal temperature (40.84 °C), respiratory frequency (111.36 breaths/min), and cardiac frequency (99.22 beats/min) were higher for pure Holstein than for Girolando cows. Positive correlations were found between the physiological parameters and thermographic measures. The highest positive correlation (0.74) was found between the temperature in the lateral region of the udder and rectal temperature. Thermography is a good indicator of thermal comfort. The best region to identify heat stress in cows using thermography is the lateral region of the udder.

Resumo em Inglês:

ABSTRACT This study aimed to evaluate the biometric and chemical characteristics of five sugarcane varieties (RB 863129, RB 867515, RB 92579, RB 943365, and RB 98710) grown in a semi-arid climate for use as forage. The experiment was designed as randomized blocks, in a 5 × 2 factorial arrangement (five sugarcane varieties and two evaluation times, 407 and 483 days). Response variables included dry matter productivity, morphological characteristics, chemical composition, digestibility, and ratios among neutral detergent fiber (NDF), Brix, and Pol. For the biometric analyses, there was an interaction effect between the evaluated varieties and harvest times on the variables fresh matter yield, uncovered internodes, and stalk density (MID -middle internode density). Regarding stalk density (MID), at 407 days, there was no significant difference among the varieties (1.19 g cm−3). For the fractionated parts, there was an effect of harvest time on the amount of fresh matter and dry matter of tops produced, which was highest at 407 days of age. A significant difference was detected among the varieties for contents of dry matter and total digestible nutrients. The variable in vitro neutral detergent fiber digestibility was influenced by the time, decreasing by 53.62 g kg−1 at 483 days. In the analysis of Brix and Pol yields per hectare, it was observed that variables ton of Brix per hectare and ton of sucrose per hectare averaged 15.12 and 10.14 t ha−1, respectively, and the NDF:Brix and NDF:Pol ratios were higher for variety RB 863129, with 2.93 and 3.68, respectively. Variety RB 867515 is suggested for forage production in semi-arid conditions, as it is best adapted to the local soil-climatic conditions and to the water deficit, especially at 407 days.

Resumo em Inglês:

ABSTRACT The objective of this study was to evaluate live weight and carcass traits, from birth to slaughter, and meat quality of Nellore (NEL), Curraleiro Pé-Duro (CPD), and crossbred (F1) products in the state of Piauí, Brazil. Progenies from CPD, NEL, and their F1 crossbred (½ NEL + ½ CPD), a total of 252, males and females, from birth to 24 months of age, were evaluated in a comparative study in growth performance. The steers were sent to slaughter at 28 months of age and carcasses and meat quality were analyzed. After slaughter, carcass weight, dressing percentage and Longissimus dorsi area (rib eye area) were evaluated; an index was created by the relationship between these measures per hundred kg of chilled carcass produced. To assess meat quality, the shear force, water-holding capacity, color, brightness, pH, and cooking loss were investigated. Results obtained showed that month and year of birth were significant on growth, indicating influence of climatic variables. Nellore offspring was heavier than F1 and this was heavier than CPD throughout the study period, including the hot and cold carcass. No differences were found in dressing percentage among NEL and F1, but CPD and F1 showed a rib eye area and index significantly higher than NEL. The meat from CPD group presented a stronger red coloration than the others, but there was no significant difference in the remaining meat qualitative variables among the three groups. Curraleiro Pé-Duro and F1 crossbred produce more meat per 100 kg of carcass than Nellore in natural pasture of Piauí State.

Resumo em Inglês:

ABSTRACT The objective was to evaluate the effect of cull pinto beans (CPB) (Phaseolus vulgaris) on performance of feedlot lambs. Seventy-two crossbred hair-breed lambs (Dorper × Pelibuey and Kathadin × Pelibuey) were used (75±6 days old and 18.7±3.89 kg of initial body weight). Animals were fed twice daily. Diets consisted of 20% alfalfa hay and 80% concentrate based on ground sorghum grain and were formulated to contain 17.9% crude protein and 2.60 Mcal/kg metabolizable energy. Treatments were (dry matter basis): no CPB (0%), 10% CPB, and 20% CPB. Lambs were blocked by body weight and treatments and arranged in a 2 × 3 arrangement of treatments. Body weights were recorded initially and subsequently at 14-day intervals for a total 70 number of days. Dry matter intake was recorded daily. Apparent dry matter digestibility was predicted using insoluble acid detergent fiber. Data were analyzed as a randomized complete block design. Final body weight and average daily gain decreased linearly with increasing CPB level and were greater for males than females. A level × gender interaction was observed for dry matter and crude protein digestibility. Data for hot carcass weight and cold carcass weight decreased linearly as CPB level increased and were greater for males. Carcass yield, longissimus muscle area, and dressing percentage were greater for males. Dressing percentage quadratically increased as CPB level increased. Cull pinto beans are a suitable ingredient for feedlot hair-breed lambs, but the inclusion of more than 10% of CPB level decreases animal performance.

Resumo em Inglês:

ABSTRACT The objective was to evaluate the effect of three levels of cull pinto beans (CPB; Phaseolus vulgaris) on ruminal fermentation, kinetics, and nutrient digestibility in hair lambs. Six cannulated lambs averaging 56.6±3.8 kg were used and were randomly assigned to one of three treatments. Treatments were: 0.0 kg kg−1 of CPB in the supplement (control); 0.25 kg kg−1 of CPB in the supplement (CB25); and 0.40 kg kg−1 of CPB in the supplement (CB40). Dry matter intake, ruminal pH, NH3, and volatile fatty acid (VFA) concentration, methane production, Kp (passage rate), MRT (mean retention time), and digestibility of dry matter, crude protein, and neutral detergent fiber were evaluated. Data were analyzed in a Latin square design, repeated in line, by MIXED procedure of SAS. Estimates used for Kp and MRT were obtained by a non-linear regression model (PROC NLIN). Dry matter intake was reduced by supplementation of CPB. No differences were found in ruminal pH or ruminal NH3. During the trial, differences were found for ruminal VFA concentration (mM), which were greater for the CB25 group. The propionate:acetate ratio was greater for the CB40 treatment. Methane production (mM/m) differed among treatments, but it was the greatest for the CB40 group. Passage rate (kg kg−1/h) and MRT (h) were similar among treatments and the digestibility (kg kg−1) of dry matter, crude protein, and neutral detergent fiber was not different among treatments. The inclusion of 0.25 kg kg−1 of CPB in the diet of hair lambs allows for appropriate nutrient digestion without affecting Kp and MRT and increases the molar proportion of the ability of VFA to maintain acetate:propionate ratio without increasing methane production.

Resumo em Inglês:

ABSTRACT This study was intended to evaluate body size structure and growth parameters of crossbred heifers fed at four nutritional levels to achieve puberty earlier. Animals were classified depending on their level of crossing between Nelore and Hereford and subjected to four nutritional levels (kg day−1) as follows: 0.5 (light; n = 32), 0.75 (medium; n = 32), 1.00 (high; n = 29), and 1.25 (very high; n = 27). Heifers at puberty and at weaning were individually classified for growth parameters. The fat thickness and longissimus muscle area throughout the experimental period were determined by ultrasonography. The height, heart girth, frame, and weight:height ratio were variables used to evaluate body traits. Univariate analysis of variance using the GLIM MIXED procedure os SPSS was performed and the significance level was set at 0.05. Age and body weight at puberty were 388±1.9 days and 331.4±1.3 kg, respectively. Body condition score demonstrated an interaction between nutritional level and crossbred degree. Heifers with the highest degree of Nelore had higher fat thickness and lower weight:height ratio compared with other racial groups at puberty. Pearson correlation coefficient showed a negative association for body condition score (−0.34) and fat thickness (−0.58) compared with age at puberty. The increased fat thickness at younger ages at puberty was observed in all racial groups. The increased weight:height ratio at younger ages at puberty was observed in all racial groups. We observed higher values for a frame in animals at the higher level of supplementation. There is a greater correlation between live weight gain and phenotypic traits during weaning to achieve puberty at an earlier age in crossbred heifers.

Resumo em Inglês:

ABSTRACT The objective of this paper was to analyze financial management practices in dairy production systems. More specifically, we sought to identify which milk producers adopt financial management practices. We conducted 55 semi-structured questionnaires in the Western Region of Paraná. The data were processed through descriptive and multivariate statistical analysis. The analysis of hierarchical clusters defined, based on variables related to financial management practices, two distinct groups. The first group included milk producers who do not adopt financial management practices (N = 49) and the second group described the milk producers who do adopt these practices (N = 6). We then used Common Factor Analysis, along with structural, technical, productive, and socioeconomic variables to define the three factors that best explained the variance between the clusters: factor 1 - structural; factor 2 - social; factor 3 - informational. Smaller dairy production systems, with lower production, managed by younger producers, and employing younger workers, are those adopting financial management practices. Therefore, the scarcity of resources is not a limiting factor in the adoption of financial management practices.

Resumo em Inglês:

ABSTRACT The objective of this study was to evaluate the effect of temperature-humidity index (THI) on the milk coagulation properties of Holstein-Friesian dairy cattle from northeast part of Italy. A total of 592 individual milk samples from six dairy herds were evaluated. The milk coagulation properties traits analysed were milk rennet coagulation time and curd firmness, as well as the fat, protein, and casein contents, pH, milk aptitude to coagulate (IAC), and the somatic cell count. The THI was determined during the periods of sample collection. The THI results showed that values of up to 75 did not significantly change the IAC values; however, when the THI values were above 75, the IAC decreased significantly. The control of THI can be used to guarantee appropriate milk coagulation properties.

Resumo em Inglês:

ABSTRACT This study was conducted to estimate the effect of dietary supplementation with fermented fish meal on growth performance, blood metabolites, and fecal microflora in weaning pigs. A total of 180 weaned pigs ((Landrace ×Yorkshire) × Duroc; with average body weight of 6.0 kg) were randomly distributed among three dietary treatments (0, 0.2, and 0.5% fermented fish meal) in three replicate pens (20 heads per pen) in a completely randomized trial over three weeks. Addition of fermented fish meal to weanling pig diets had a linear effect on average feed intake and a quadratic trend on final body weight, average daily gain, and gain:feed ratio throughout the whole period (but not initial body weight). Hematocrit, monocyte, immunoglobulin G, and blood urea nitrogen levels responded linearly and quadratically with increasing levels of dietary fermented fish meal. Moreover, we found a linear correlation between the diets and lymphocyte and insulin levels among the different dietary treatments. In contrast, red blood cells, white blood cells, hemoglobin, insulin-like growth factor 1, and glucose levels were not affected by diets with different levels of fermented fish. During the experimental period, diets with 0.2% and 0.5% fermented fish meal showed a reduction in Salmonella enterica and Escherichia coli populations (but not E. coli populations at week 3) that were linear, quadratic, or both, compared with controls. In particular, there was a significant reduction in S. enterica population when pigs were fed 0.5% fermented fish meal over the period of 3 weeks). Dietary supplementation with 0.2% and 0.5% fermented fish meal can be used as a protein source to improve growth performance and the parameters chosen for the blood profile, which reduces harmful microorganisms in the feces of weanling pigs.

Resumo em Inglês:

ABSTRACT If the world population continues to increase exponentially, wealth and education inequalities might become more pronounced in the developing world. Thus, offering affordable, high-quality protein food to people will become more important and daunting than ever. Past and future challenges will increasingly demand quicker and more innovative and efficient solutions. Animal scientists around the globe currently face many challenging issues: from ensuring food security to prevent excess of nutrient intake by humans, from animal welfare to working with genetic-engineered animals, from carbon footprint to water footprint, and from improved animal nutrition to altering the rumen microbiome. Many of these issues are most likely to continue (or to exacerbate further) in the coming years, but animal scientists have many options to surmount the obstacles posed to the livestock industry through tools that are presently available. The frequency, interval, and intensity of livestock impacts, however, differ across regions, production systems, and among livestock species. These differences are such that the generalization of these issues is impossible and dangerous. For instance, when we discuss domesticated ruminant nutrition in the human food context, we look for the most efficient ruminant feeds that complement, rather than compete with, grains grown for direct human nutrition. Greater scrutiny and standardization are needed when developing and validating methodologies to assess short- and long-term impacts of livestock production. Failure in correctly quantifying these impacts may lead to disregard and disbelief by the livestock industry, increased public confusion, and the development of illusionary solutions that may amplify the impacts, thereby invalidating its original intent.

Resumo em Inglês:

ABSTRACT Despite tremendous advancements in the livestock sector, additional opportunities exist to improve even further livestock production around the globe. Forecasting is not an exact science and it relies heavily on past and current knowledge. Improvements in the nutritional sciences (both human and animal) include a better understanding of agents that cause deterioration of human health, improving the quality of animal products, applying effective fetal programming, developing new feeds and feeding strategies, and revisiting longstanding technologies. Improvements in the understanding of the rumen microbiome will enable scientists to increase the fermentation efficiency and, hopefully, select microbial species of greater interest. Improvements in remote sensing and ground-based instrumentation, telecommunications, and weather forecasting technologies will aid in the continued improvements of early warning systems to assist livestock producers in reducing risk and adapting to the changing environment. Broad utilization of sensor technologies will allow scientists to collect real-time data and, when combined with mathematical modeling, decision support systems will become an indispensable managerial tool for livestock production with the possibility to automate low-level decisions on the farm, such as supplementation schedules, sorting of animals, and early detection of disease and outbreaks. The identification of feed efficient animals may be the single most impactful advancement towards long-term livestock sustainability and the promise of feeding the world animal products. We contend that education across societal levels is the first step to solve current and future challenges of the livestock industry. The dilemma has been who will take the first step forward.