Suchergebnisse

The objective of this study was to evaluate the morphogenetic and structural characteristics of tropical grasses managed under different regrowth periods. The experiment was conducted at the Federal Institute of Science and Technology Education of Rio Grande do Norte, located in the municipality of Apodi-RN, Brazil. The study design was in randomized blocks and the treatments were allocated in a 3x4 factorial arrangement, with three cultivars (Andropogon, Buffel and Massai) in four regrowth periods (21, 35, 49 and 63 days). The interaction between cultivar and age was significant for all studied variables, with the exception of leaf blade width and accumulation rate. The highest leaf appearance rates were observed in Buffel grass, regardless of the regrowth age. This characteristic was not influenced by age only in Andropogon grass. Higher stem elongation rates were observed in Buffel grass, while the lowest were observed in Massai grass until 35 days of regrowth, attributed to the presence of inflorescences. Canopy heights in Massai and Andropogon grass were greater than Buffel grass until 35 days of regrowth, Andropogon grass had higher height from 35 days of regrowth than the others. Andropogon grass showed higher rates of accumulation than Massai grass only at 21 days of regrowth, and no effects of regrowth age were observed for this variable. Buffel grass should be defoliated at 21 days, while Andropogon and Massai grass can be managed without losses between 21 and 63 days of regrowth.

The objective of this study was to evaluate the effect of parity on linear trait types in Guzerá cows using multivariate techniques. Data were collected from 68 purebred Guzera females, young (1st and 2nd calving order) and adults (3rd to 7th calving order). Measurements were collected using a tape measure, a hypometer, a 40 cm graduated ruler and a 180° protractor. PRCOMP procedure of the R program was used for analyzing the main components. The variables related to rump (height, angularity, ileum and ischium length and width), body (length), udder (height of posterior ligament) and milk production were more important to explain the phenotypic variation in Guzerá cattle. Young Guzerá cows had lower body length, narrower rumps, better udder ligaments and lower milk yield than adult cows.

The objective of this study was to analyze colostrum and milk compositions of ewes kept in pasture receiving different types/levels of supplementation and to analyze milk composition variation throughout the initial third lactation period. After confirmation of pregnancy, 54 ewes were kept in pasture and supplemented from the final third of gestation until weaning with multiple mixture or concentrate (0.4% or 0.8% of body weight). Milk collections were carried out in the postpartum period to collect colostrum (day 0), and on the seventh, 14th, 21st and 28th milking days. Samples were obtained by manual milking and analyzed for protein, fat, casein, lactose, total solids and defatted dry extract. No effects from the different types of supplementation were observed on the colostrum composition or in relation to milk composition. An effect of supplementation was only found for lactose contents, which were higher for animals that consumed a higher level of supplementation. In relation to the milking days, a linear decrease in protein, casein, total solids and defatted dry extract contents was observed between the seventh and the 28th day of lactation. No interaction between type of supplementation and the milking days was observed. The different types of supplementation did not alter the colostrum composition of Santa Inês crossbred ewes, however they had an influence on milk composition. Protein, casein, total solids and defatted dry extract decrease linearly between the seventh and the 28th day of lactation.

The objective was to evaluate the physico-chemical composition, somatic cell count and electrical conductivity of the milk from lactating Zebu cows. For this, monthly milk samples were collected on the official milk control day intended for analysis of electrical conductivity of milk (ECM), somatic cell count (SCC) and milk composition. We used monthly data from 680 controls, from 10 Gyr and 17 Guzerat cows from a herd located in the city of São Gonçalo do Amarante/RN, from August to November 2013. Analyses of variance, mean test and Pearson correlation analysis were conducted. The levels of fat (% F), protein (% P), lactose (% L), total solids (% TS) and non-fat dry extract (% NFDE) were dependent variables for the ECM and SCC. The milk of Gyr cows for ECM, SCC, GOR, PROT, LACT, TS and NFDE were respectively, 3.88±1.18 mS/cm, 1629±2195 thousands cells/mL, 4.71±1.77%, 3.29±0.31%, 4.5±0.33%, 13.5±1.78%, 8.79±0.37%, and for the Guzerat breed 3.59±0.88 mS/cm 1356±1793 thousands cells/mL, 4.47±0.98%, 3.43±0.32%, 4.52±0.24%, 13.5±1.19%, 9.02±0.48%. No significant correlations between SCC and ECM characteristics were observed. However, when the correlation of each of these parameters and milk composition in different classes for each breed was analyzed, a significant correlation of the SCC was observed with the protein and lactose in Gyr, of the ECM with the lactose and SCC with total solids and fat for the Guzerat cows.

The aim of this study was to examine the use of antioxidants on the oxidative stability of poultry offal oil used in the pet food industry. Five commercial synthetic and two natural antioxidants were used in the following treatments: Control (CON); CON + (BHT + BHA + ETH95); CON + (BHT + BHA); CON + (BHA + PG + CA); CON + (BHT + BHA + ETH70); CON + BHA; CON + (ASC + rosemary); and CON + (ASC + tocopherols). Inclusion levels were 0.5% for the synthetic and 0.625% for the natural antioxidants. Oxidative stability was determined at three temperatures (90, 110 and 130 ºC). To determine the fatty acid profile, the original sample of the offal oil was considered a negative control. The fatty acids were determined based on the preparation of methyl esters by a transesterification reaction with methanol in alkaline medium, followed by gas chromatography analysis. The different fatty acid types were identified by comparing the retention times of the fatty acid methyl ester standards with the retention times of the observed peaks. Compositional data analysis was carried out. Without the use of antioxidant, induction time is shorter, resulting in lower oxidative stability of the offal oil and consequent loss of its quality due to less time taken to oxidize. The antioxidants used in CON + (BHT + BHA + ETH95), CON + (BHA + PG + CA) and CON + BHA better preserved the essential fatty acids (linolenic and linoleic). Natural antioxidants exhibited higher oxidation, with higher proportions of saturated fatty acids and the worst ω6:ω3 ratios. In conclusion, the synthetic antioxidants used in CON + (BHT + BHA + ETH95), CON + (BHA + PG + CA) and CON + BHA provided greater protection against oxidation and better preserved the essential fatty acids. The natural antioxidants tested in the present study did not provide satisfactory protection.

It was aimed to evaluate anti-GnRH vaccine efficiency on productive characteristics, seminal performance, size, and histology of testicles of lambs submitted to immunocastration. Twenty contemporary Texel lambs were evaluated, being 10 animals received two doses of 1 mL of anti-GnRH vaccine and 10 received two doses of 1 mL of saline, with an interval of 30 days. Seminal characteristics, weight and histological cut for the testicles, productive performance, and blood parameters were analyzed. Andrological monitoring was carried out every 30 days. All animals were kept on pasture of Urochloa spp. receiving daily supplementation protein-energetic by 90 days. There was effect of immunocastration on slaughter weight (44.3 vs. 48.3 kg), total gain (9.9 vs. 10.3 kg), daily gain (104.5 vs. 108.9 g/day), and feed conversion (5.83 vs. 5.97) respectively to immunocastrated and intact lambs. There was immunocastration effect on testicle weight (0.09 vs. 0.35 g), motility (4.5 vs. 61.0%), vigor (0.40 vs. 3.00), volume (0.09 vs. 0.74 mL) and swirling (0.20 vs. 2.70) in the third semen collection. Immunocastration through two doses of 1 mL of anti-GnRH vaccine with a 30-day interval between doses, causes infertility in sheep and can be adopted for lambs.