Studies comparing methodologies for fatty acids are very important, since they can influence the quality and final quantification of the lipid fraction. Objective-to compare different extraction ...methods for total lipids and to evaluate the effect of these methodologies on the quantitative composition of fatty acids in milk of lactating ewes raised in tropical pastures. The methodologies used were simple direct transesterification, using the HPLC grade organic solvent n-hexane, Bligh; Dyer (cold extraction, extracting mixture proportions 5, 10, and 15 mL in a ratio of 2:1:1 (v/v/v) of chloroform-methanol-water). The fatty acid methyl esters were separated by gas chromatography coupled with a flame ionization detector (GC-FID). The results show that there was no significant difference (p <0.05) in the total lipid content between the extraction methods. However, the Bligh's method; Dyer obtained the best yield of lipids to be extracted from ewe's milk, since the volume with 15 mL of the extraction solution was able to identify 87% of the chromatographic peaks. It was also observed that ewe's milk has a higher percentage of palmitic, stearic and oleic fatty acids, with percentages of 20.1%, 15.5% and 33.1%, respectively. Therefore, an extraction mixture with a volume of 15 mL used in this study may be an alternative to perform the extraction of milk fat from high lactating ewes in tropical pastures as a routine method, as it expresses the best lipid content of this food.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Waste management practices are vital for human health and the environment in a world where natural resources stress is expected to increase with the growth of population. Our study aimed to evaluate ...the potential use of crop-livestock residue as a bulking agent associated with the ideal level of hydrated lime for the stabilization and sanitization of urban sewage sludge through the alkalization-composting process. Therefore, we determined the alkalization efficiency on the heavy metal concentration in urban sewage sludge, quantified the viable eggs of helminths in pure and alkalized sludge, and measured the rate of earthworms (Eisenia fetida) surviving in the vermicomposting process using different levels of alkalized urban sewage sludge associated with crop-livestock residue. Four sequential trials were carried out in a completely randomized design with three replicates. The lime alkalization reduced the levels of Ba, As, Pb, Cu, Cr, Mo, Ni, and Zn compared to the pure urban sewage sludge. Using 30% w/w of lime in the urban sewage sludge (SS-30) for composting process reduced the viable helminth eggs by 71, 72, and 69% for sugarcane bagasse (Saccharum officinarum; SB), fresh chopped Napier-grass (Pennisetum purpureum; NG), and bovine ruminal content (BR), respectively. The ideal level of hydrated lime for stabilization and sanitization of urban sewage sludge was found to be 30%, which was able to reduce the heavy metals. The residues have the potential as a bulking agent for the composting of urban sewage sludge when associated with alkalization. The lime alkalization decreases the total number of helminth eggs and the number of viable eggs. The possibility of starting a vermicomposting using the mixtures is promising, evidenced by the earthworm survival in composting urban sewage sludge mixed with crop-livestock residues after 45 days of composting. The earthworm survival is maintained by an association of at least 80% of the crop-livestock residues.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
We hypothesized that the protein source in supplements and the insolation and ambient temperature changes in different seasons could cause changes in the skin of Nellore steers during the rearing ...phase on warm-climate pasture. The objective of this study was to evaluate the effects of replacing true protein (soybean meal) with NPN (extruded urea) in the supplement on the skin characteristics of steers grazing on Marandu grass pastures. Thirty-six Nellore steers with an average initial weight of 250.0 kg and 15 months of age were used. Skin biopsies were performed at three different times: summer, autumn, and winter. The protein source has effects on the length of the glandular portion, number of follicles, and gland area in steers during the rearing phase at different seasons of the year. In the summer, the skin presented a higher compact structure, while in the autumn and winter, the skin presented a sparser arrangement. Skin from steers that received soybean meal in supplement had a more significant number of follicles in the summer and a smaller area and length of sweat glands. The dermis thickness of steers supplemented with soybean meal was greater than that of urea supplemented. The epidermis thickness and dermis of the steers' skin were greater at the autumn (April). Sweat gland depth was greater in autumn (April) and winter (July) than in summer (December). The protein source in the supplement alters the skin characteristics by increasing of dermis thickness of Nellore steers during the growth phase. The insolation and ambient temperature changes in different seasons alter the skin structure by increasing the epidermis and dermis thickness, sweat glands depth, and glands area of the skin of steers during the growth phase.
The aim of this study was to assess the effects of substituting traditional forage fiber sources with cottonseed cake in the diet on both the quantitative and qualitative characteristics of carcass ...and meat in Nelore young bulls. Twenty-four Nelore steers starting with an average weight of 377.8 ± 43.5 kg, were individually housed in stalls and provided with individualized feeding over a 112-day confinement period. The study followed a completely randomized design with two treatments and 12 replications. The diets incorporated either whole plant corn silage (WPCS) and, cottonseed cake (CSC) as fiber sources, at a rate of 300 g/kg of dry matter. The CSC diet promoted higher carcass weight. Aging animal meat for seven days significantly decreased the shear force from 83.4 to 71.6 N. Although diets did not influence meat composition, WPCS diet provided higher concentrations of C16:1, C18:1n9c, C18:3n3, and C22:2 acid, and CSC diet higher concentrations of C15:0, C18:1n9t, C18:2n6c, and 20:3n3. The WPCS diet provided higher concentrations of monounsaturated fatty acids and ω9, and the CSC diet had higher concentrations of ω6 and ω6:ω3 ratio in meat. Cottonseed cake used as a fiber source increases the concentration of polyunsaturated fatty acids and ω6 fatty acids in the meat of young bulls finished in feedlot.
Urea is a compound widely used as a feed additive for ruminants; however, when used profusely, it can lead animals to intoxication. Another factor that affects the effectiveness of urea is the lack ...of synchronization between the nitrogen and the availability of carbohydrates, necessary for better development of the ruminal microbiota. In order to circumvent these problems and improve the efficiency in urea use, the present study developed two new nutritional additives (F16 and F17) with different carbohydrate sources. One of the products developed (F16) used sugarcane molasses as a carbohydrate source, while the other (F17) used cassava starch. In addition to the carbohydrate source, both products contained the same amounts of urea, sulfur, calcium carbonate and were coated with carnauba wax. The supplements developed and two other commercial products based on extruded urea (UE) and polymer-coated urea (UP) were tested for solubility and cumulative gas production. The wax used in the coating process of the developed products (F16 and F17) proved to be efficient in reducing the solubility of the ingredients used. During chemical composition analysis it was verified that both supplements developed contained protein equivalent above 150% of crude protein. The cumulative gas production showed a higher production related to the product F17 (p < 0.05). Through thermogravimetric analysis, it was found the chemical integrity of the ingredients that make up the supplements developed. Therefore, is possible to reduce the solubility of urea using carnauba wax as a coating material. The formula with cassava starch associated with urea (F17) had a better synchronization during the degradation of its ingredients.
It was aimed to evaluate the use of cottonseed cake (CSC) as a source of physically effective neutral detergent fibre (peNDF) to replace corn silage (CS) in diet of feedlot-finished cattle. The ...design used was completely randomised, with 2 treatments (30% CSC and 30% CS) and 12 replications. There was interaction between fibre source and nutrient in the material retained in the Penn State Particle Separator. The highest concentrations (P = 0.0001) of peNDF and the in vitro digestibility of peNDF (DpeNDF) were for CSC. There was a higher (p < 0.05) dry matter intake (DMI) and neutral detergent fibre (NDF) intake (NDFI) by the animals on the CSC diet. The CSC-fed steers showed higher (P = 0.0001) final body weight (BW) and total weight gain. The steers fed CSC showed a longer (P = 0.0001) feeding time, feed efficiency, and lower rumination time (P = 0.0001) and rumination efficiency (P = 0.0001). There were positive correlations between the variables: rumination time × intake, rumination time × NDFI and peNDF × DpeNDF. It was observed that there was a negative correlation between the variables: rumination time × peNDF, rumination time × DpeNDF, NDFI × peNDF, and NDFI × DpeNDF. Cottonseed cake is an alternative source of peNDF for feedlot beef cattle.
Cotton cake can be a sustainable and economically viable alternative to maize silage as an effective fibre source in the finishing diet of feedlot beef cattle. Thus, the objective was to evaluate the ...economic viability and the productive performance of Nellore steers finished in feedlots using cotton cake as a source of fibre, replacing maize silage in the diet. Twenty-four non-castrated Nellore steers, with an average weight of 377.8 kg and an age of approximately 24 months, kept in individual pens, were used. The diet was 30% roughage, in the form of maize silage, and a diet without forage containing 30% cotton cake as an effective fibre source, based on dry matter. The design used was completely randomised with two treatments and 12 replications. Effects (
p
< 0.05) of the dietary fibre source were observed for final body weight (BW), total weight gain, hot carcass weight (HCW) and carcass yield (CY). Revenue and net margin were higher for the treatment with cotton cake. The corn silage diet promoted higher total costs per animal (U$ 408.41 vs. U$ 336.06) and daily costs (U$ 3.65 vs. U$ 3.00). Greater differences were observed between fibre sources for the concentrate cost, and the maize silage diet had a cost U$ 98.29 higher than the treatment with cotton cake (U$ 314.04 vs. U$ 215.75). The cotton cake treatment had a higher cost of U$106.98/animal for the net margin. Cotton cake is a viable alternative and can be used as a source of fibre in forage-free diets without affecting production performance, promoting benefits in economic performance for finishing beef steers in feedlots.
This study was undertaken to determine whether equations for prediction of dry matter intake (DMI) by meat sheep are valid for animals raised solely on tropical pastures and to propose a new equation ...to predict the DMI of sheep raised on tropical pastures. The DMI prediction from published equations was evaluated by regressing the predicted and observed values, using the
F
test, for the identity of the parameters (β0 = 0 and β1 = 1) of the regression of predicted on observed data. If the null hypothesis is not rejected, the tested equation accurately estimates DMI. The proposed equation was evaluated in the same way as the published equations. The animal performance and pasture structure and chemical composition data used originated from an experiment conducted with 32 Santa Inês sheep raised on tropical pastures. In the analysis of model adequacy, the null hypothesis was rejected (
P
< 0.001) and the equations generated predictions that differ (β0 = 0 and β1 = 1) from the DMI observed under practical feeding conditions for grazing sheep. The proposed equation, DMI (%LW) = 7.16545 (± 0.76522) − 0.21799 (± 0.01812) * LW + 0.00273 (± 0.00034) * LW
2
–0.00688 (± 0.00299) * GT + 0.000007 (± 0.000002) * GT
2
+ 0.00271 (± 0.00108) * GHA, where LW is live weight (kg), GT is grazing time (min/day), and GHA is green herbage allowance (kg DM/100 kg LW), should be used to more accurately predict DMI by grazing sheep.
Abstract
Our hypothesis was that extrusion of urea associated with corn may reduce N solubilization and increase the nutritional quality of this food for ruminants. We aimed to physically and ...chemically characterize a corn and urea mixture before and after the extrusion process. It was evaluated morphological differences by scanning electron microscopy, nitrogen solubilization, and compound mass loss by thermogravimetry. In scanning electron microscopy, extruded urea showed agglomerated and defined structures, with changes in the morphology of starch granules and urea crystals, differing from the arrangement of the corn and urea mixture. The extruded urea maintained a constant nitrogen release pattern for up to 360 min. In thermogravimetry, extruded urea presented a higher temperature to initiate mass loss, that is, the disappearance of the material with increasing temperature, but the mass loss was lower when compared to the first event of the corn and urea mixture. In conclusion the process of extrusion of urea with corn modifies the original structures of these ingredients and controls the release of nitrogen from the urea, maintaining in its formation an energy source optimizing the use of nitrogen by ruminal bacteria, because the more synchronized the release of starch (energy) and nitrogen, the better the use by ruminal microorganisms.
We aimed to evaluate the effect of replacing corn silage by orange peel silage on nutrient intake, ruminal parameters and milk production of multiparous lactating Holstein cows. Eight fistulated ...Holstein cows averaging 587.5 ± 39.6 kg and 111 ± 22 d in milking were randomly assigned to a double 4 × 4 Latin square design carried out two times to determine the effects of feeding with orange peel silage (OPS) in substitution of whole plant corn silage (WPCS). The treatments were a control diet with WPCS only or diets with OPS replacing WPCS in the total mixed diet (250, 500, or 750 g/kg DM). All cows were fed the same 750 : 250 g/kg roughage : concentrate ratio. The DM intake and milk production were reduced with the OPS inclusion, with decreases in consumption of neutral detergent fibre and increased consumption of non-fibrous carbohydrates. Diets with 250 and 500 g/kg OPS showed similar milk production and protein content in milk to the standard WCPS diet, whilst 750 g/kg orange peel silage as roughage increased fat and protein contents significantly. The orange peel silage as a substitute for corn silage for feeding dairy cows did not show adverse changes in the rumen environment and showed promising results in the increase of fat in milk of Holstein cows.
PDF
