their protein and carbohydrate fractions; we also evaluated the effects of substituting the protein source of the conventional supplement by DDG on consumption and nutrient digestibility in confined finishing cattle. Thirty-six male Nellore cattle with a mean age of 24 months were used. The treatments were: FA: concentrate with corn as an energy source and cottonseed meal as a protein source; DDG50: concentrate with a 50% substitution of the FA protein source by DDG; DDG100: concentrate with 100% substitution of the FA protein source by DDG. The experimental design was completely randomized with three treatments and three replicates (pens) containing four animals per pen. We found that the use of DDG in the finishing phase did not interfere with the animals’ food intake or the digestibility of the nutrients (p > 0.05). Nutrients were used by the animals; therefore, DDGs may be viable substitutes of cottonseed meal. We conclude that the bromatological composition of this co-product is influenced a lot during processing; therefore, the nutritional values of this co-product present in the composition tables may not be true.
A trial was carried out with four Holstein x Nellore crossbred steers (225±22kg of BW) fitted with ruminal and abomasal cannulaes in a 4 x 4 Latin Square design to evaluate the intakeand the total and partial apparent digestibilities of nutrients, ruminal parameters, and microbial synthesis. Diets consisted of 60% silage and 40% concentrate formulated to be isonitrogenous (12.5% of crude protein, dry matter basis). Treatments consisted of different proportions of Brachiaria brizantha grass silage and sorghum silage: 100:0; 67:33; 33:67, and 0:100%, respectively, on dry matter basis. The intake of dry matter, organic matter, crude protein, ether extract, non-fiber carbohydrates, and total digestible nutrients linearly increased (P<0.01) as levels of sorghum silage increased. The total apparent digestibility of dry matter, organic matter, and neutral detergent fiber linearly increased with sorghum silage levels (P<0.02). The highest ruminal NH3-N (13.63mg/dL) levels occurred at 2.94h post-feeding whereas the lowest ruminal pH (5.87) was measured at 5.21h post-feeding. Microbial efficiency was not affected (P>0.05) by the treatments. The use of 67% of sorghum silage and 33% of grass silage increased intakeanddigestibility of nutrients without affecting ruminal pH, ruminal NH3-N, and microbial efficiency.
ABSTRACT - The objective of this study was to evaluate the effects of supplementation with nitrogenous compounds on intake, digestibility, and rumen microbial synthesis in cattle fed low-quality tropical forage. Five crossbred heifers, averaging 209 kg and fitted with ruminal fistulla, were used. The animals were fed ad libitum with signal grass (Brachiaria decumbens Stapf.) hay, which had crude protein (CP) content of 5.08%, as dry matter (DM) basis. The five treatments were defined according to the increasing level of CP in the diet (0, 3, 5, 7, and 9 percentile points above the forage CP level). The supplement consisted of the following nitrogen sources: urea, ammonium sulfate and albumin (4.5:0.5:1.0, respectively). The experiment was carried out according to a 5 × 5 Latin square design, with five experimental periods. The average CP levels in the diets were: 5.28, 8.08, 9.82, 11.87, and 13.63% on DM basis. The intakes of DM, organic matter (OM), and neutral detergent fiber (NDF) showed a quadratic response according to CP levels in the diet, with maximum responses at 10.83%, 10.78%, and 10.37% CP, respectively. The digestibility coefficients of OM and NDF showed a linear-response-plateau response according to CP levels, with the plateau beginning (maximum response) at 7.93% and 7.55% CP, respectively. The average daily concentration of rumen ammonia nitrogen (RAN) was positively related with CP levels. The RAN estimate associated with the maximum DM intake was 15.33 mg/dL. It was observed that intestinal flow of microbial nitrogenous compounds and nitrogen intake became equivalent to each other at 7.13% of CP.
Calibration equations to estimate OMd showed great results using the dataset “PERIOD MEAN” (R 2 c = 0.97 and R 2 cv = 0.91; RPD = 3.42), with the RMSEC = 1.62 and RMSECV = 2.99 (Figure 2C). We relate such variation for RMSEC/RMSECV to the greater variation in digestibility (33 to 85%), caused by different growth stage and maturity of the forage used in this study. Viable relationships between NIRS data and in vivo nutritional values of fresh temperate forages were also reported by Decruyenaere et al. (2009) with an R 2 > 0.90 and RPD higher than 3 for all fecal databases used, with SECV varying from 0.021 to 0.018. According to Dixon and Coates (2009), feces reflects chemical and biological characteristics of the forage consumed by animals as well as their physiological status. This chemical composition can be detected by NIRS and successfully correlated to diet composition, explaining the relevance of F.NIRS for estimating nutrient intakeanddigestibility of the forage and feed.
Although the ﬁber intakeanddigestibility (NDF) did not show difference (P>0.05) among the diets, there was a reduction of acetate concentration in the rumen. The seed digestion occurs at a higher rate than cellulose digestion (Russel & Wilson, 1996) and probably higher than lipid digestion as well. In diets with oils, there was a lower amount of corn in the diet composition (approximately 10%), which, in turn, caused reduction in the availability of substrate for fermentation in the rumen and therefore, resulted in decreased concentration of acetate and butyrate. Based on this theory, the molar concentration of propionate was also expected to be lower; however, lipid digestion in the rumen favors the production of free fatty acids (which were subjected to biohydrogenation) and glycerol, which, in turn, is converted into propionate (Chalupa et al., 1986). The lower concentration of total SCFA in the rumen ﬂuid (P<0.05) in the diets containing oil is due to the lower concentration of acetate and butyrate in these diets.
However, the greatest inﬂuence of urea addition was on the digestibility of DM, OM and, especially, of CP from silages containing both levels of pulp, with a lower effect on the digestibility of NDF and ADF. The digestibility is a characteristic of the feed and indicates the percentage of each nutrient of a feed the animal might use. However, the inclusion of an additive in certain feed can change its digestion, as a result of the associative effect among the feeds (Hennessy et al., 1995). According to Van Soest (1994), when the protein availability peak does not happen simultaneously to the peak of production of volatile fatty acids in the rumen, the efﬁciencyoftheproductionofmicrobialproteindecreases, and, consequently, the ﬁber degradation is hindered, causing rumen ﬁll, which explains the lower digestibility of the ﬁber. Considering the inﬂuences of the association between the levels of pulp and urea in silages on intakeanddigestibility, it can be observed that the inclusion of the higher level of pulp and urea in silages did not stimulate feed intake (P>0.05); on the contrary, a slight decreasing trend could be observed in intake. The digestibility of all fractions, on the other hand, was beneﬁted by the inclusion of a higher level of pulp and by the inclusion of urea. Thus, the decision on the level of pulp to be included depends on the availability and cost of ingredients.
ABSTRACT - The objective of this work was to evaluate the effects of supplementation with nitrogenous compounds on intakeanddigestibility in cattle under grazing during dry season. It was used five Holstein × Zebu steers with average initial live weight of 236 kg, kept in five Brachiaria decumbens Stapf. paddocks (0.34 ha). The experiment was carried out according to a 5 × 5 Latin square design, with five supplementation levels and five experimental periods. The supplementation levels were the following: 0; 0.35; 0.70; 1.05, and 1.40 g of crude protein/kg live weight. A mixture of urea, ammonium sulfate and albumin (4.5:0.5:1.0, respectively) was used as nitrogen supplement. The average crude protein levels in the diet were 7.39; 8.92; 10.98; 12.55; and 13.62%, as dry matter basis, for the respective supplementation levels. Linear-response-plateau relationships were observed between intake estimates and diet crude protein levels. The linear-response-plateau pattern showed that intake was increased up to crude protein levels close to 9%, as dry matter basis. The estimates became unchangeable from this level. The total and ruminal digestibility coefficients of dry matter and neutral detergent fiber, and diet level of total digestible nutrients presented a positive linear pattern according to diet crude protein levels. The rumen ammonia nitrogen concentration was linearly increased by diet crude protein levels. This variable assumed the value of 8.00 mg/dL when the intake estimates reached the maximum values. Supplementation with nitrogen compounds in quantities that raise the crude protein content in the diet to levels close to 9% optimizes the use of low-quality forage by cattle under grazing.
ABSTRACT - The present study tested brown propolis in crude or extract form as a feed supplement for feedlot lambs to identify the type that most improves in vivo nutrient digestibility. Digestibility was assessed by both total fecal collection and internal markers and the results obtained by these techniques were compared. The completely randomized design was used to compare feed intakeand nutrient digestibility of 24 male lambs aged seven months among four dietary treatments (crude brown propolis, propolis ethanol extract, monensin sodium, and control). Methods of feces collection were compared using a completely randomized split-plot design, with experimental diets corresponding to the main factor and the methods to estimate fecal production as the sub-factor. The diets had a roughage:concentrate ratio of 50:50, with Tifton-85 bermudagrass hay (Cynodon spp.) as roughage, and ground corn, soybean meal and minerals as concentrate. The lambs fed diets with crude propolis had higher feed intake than those fed diets containing monensin sodium. The different diets did not affect dry matter, organic matter, crude protein, neutral detergent ﬁber, or acid detergent ﬁber digestibility, but crude propolis supplementation provided higher ether extract digestibility than monensin sodium. Nutrient digestibility, as indicated by indigestible neutral detergent ﬁber, indigestible acid detergent ﬁber and sequentially-determined indigestible acid detergent ﬁber, was lower than that found with the fecal collection method. The addition of brown propolis has the same effect as monensin, but neither maximized nutrient availability in the diet of feedlot lambs at 7 months of age. Digestibility assessment using the internal markers indigestible neutral detergent ﬁber, indigestible acid detergent ﬁber and sequentially-determined indigestible acid detergent ﬁber is not an efﬁcient method compared with total feces collection.
ABSTRACT - The objective of this study was to evaluate the effect of different sources of lipids in the diets of dairy cows on the intakeanddigestibility of nutritional fractions, and milk production and composition. The experiment was conducted in a 42-hectare area divided into eight paddocks covered with Brachiaria brizantha. Twelve crossbred Holstein × Zebu cows were distributed into three simultaneous 4 × 4 Latin squares. The treatments consisted of different sources of lipids, as follows: diet with no extra source of lipids; diet with cottonseed as the source of lipids; diet with soy oil; and diet with used frying soy oil. The intakes of dry matter, neutral detergent fiber, crude protein, total carbohydrates, and non- fibrous carbohydrates were similar for all diets. The use of lipid sources caused a decrease in the apparent digestibility of dry matter, neutral detergent fiber, non-fibrous carbohydrates, and crude protein. The levels of protein, lactose, and defatted dry matter were reduced with the use of lipid sources but did not affect milk production. The use of cottonseed, soy oil, and used frying soy oil as sources of lipids in diets for lactating cows at pasture do not improve milk production, and their use is therefore optional.
The objective was to evaluate the intakeand the apparent digestibility in sheep fed on marandu grass silages added with dehydrated barley. Twenty crossbred Santa Inês lambs were used, with a mean initial weight of 30+4.5 kg and mean age of 14+2 months. The ex- perimental sheep were distributed into a completely randomized design and lining, with five treatments and four repetitions, with treatments levels of inclusion of 0, 10, 20, 30 and 40% natural matter of naturally dehydrated brewery residue for 36 hours to the marandu grass silage to feed the sheep. The evaluation period lasted 21 days, 15 for adaptation to the diets and 7 days for data collection. The data was submitted to analysis of variance, and when significant (P<0.05) the treatment means were analysed by regression. The inclusion of dehydrated barley to silage showed a linear increase in water intake (P<0.05), increased by 0.02% per unit of dehydrated barley. A quadratic effect was observed for the levels of dehydrated barley on the dry matter intake (DM), estimating a maximum consumption of 2.86% DM for silages containing 17.8% dehydrated barley. The crude protein intake (CP) behaved quadratically, with the maximum value estimated of 0.29% CP at a level of 22.5% dehydrated barley. Ether extract (EE) intake also exhibited quadratic behaviour (P<0.05), with the maximum value estimated of 0.2% EE at a level of 28.25% dehydrated barley. The regression study showed quadratic behaviour; with the maximum estimated value of neutral detergent fibre was 2.33% at a level of 34.58% dehydrated barley. No statistical significance was found for the intake of acid detergent fibre or organic matter (P>0.05). It was concluded that the addition of levels of 20 to 30% of dehydrated barley to silage resulted in a positive response for the dry matter intake, crude protein, Ether extract and neutral detergent fibre.
Calpains are enzymes that are responsible for the meat tenderness process, through the proteolysis of myofibrillar proteins and depend on the calcium concentrations in the muscle tissue for their activation (Veiseth, Shackelford, Wheeler, & Koohmaraie, 2001). We hypothesized that the mobilization of calcium caused by excess P in the diet would lead to the starvation of calcium in the muscle, which would impair the activity of calpain during the period of rigor mortis and meat maturation. Thus, our hypothesis is that P supplementation with or without the addition of other minerals, ionophores, and antibiotics would not alter the intakeanddigestibility of nutrients. Additionally, we investigated the possible effects of extra P in the diet on meat quality. Thus, the aim of the current study was to evaluate the intakeand apparent digestibility of nutrients, and quality of aged meat in Nellore cattle feedlot fed with P supplementation with or without the addition of other minerals, ionophores, and antibiotics.
design. The treatments consisted of five levels of replacement with Guandu: 0, 8.4, 16.8, 25.2, or 36.4 %. We sampled the food offered, leftovers and feces to calculate intakeanddigestibility, and the ingestive behavior was monitored for 24 hours. Regression analysis was applied with 5% significance. The nutrient intakeand the digestibility of dry matter, organic matter and protein decreased linearly with increasing levels of Guandu hay in the diet (p < 0.05). On the other hand, the neutral detergent fiber digestibility increased linearly, without change the water intakeand ingestive behavior with replacement levels of Tifton hay with Guandu hay in the diet (p < 0.05). The replacement of up to 36.4% Tifton hay with Guandu hay in the dairy goat diet reduces the intakeanddigestibility of dry matter, organic matter and protein, and increasesfiber digestibility, without changing the ingestive behavior and water intake.
Promoting the increase in the intake of sugarcane silage treated with calcium oxide is the interest of nutritionists; however, the effect desired, which is the augmentation of intake, does not always occur. However, simply improving the cell wall components of sugarcane is enough to make it a viable roughage in the feeding of ruminants. Reports published by Santos (2007), who utilized calcium oxide in the sugarcane, showed that it was capable of reducing the concentration of cell wall components with decrease in the NDF and ADF, improving the digestibility coefﬁcient of the dry matter and organic matter, observed in the silages treated with 1.5% calcium oxide. The authors observed that different doses of quicklime (1.0 and 1.5% in the natural matter) in sugarcane silages signiﬁcantly reduced the production of ethanol and promoted greater recovery of dry matter and soluble carbohydrates.
We evaluated the effects of increasing levels of crude glycerin in multiple supplements for grazing beef cattle on intake, nutrient digestibility, pH, ruminal ammoniacal nitrogen, and serum glucose. Five Nellore steers (initial BW of 480 kg [SD 15]), grazing a tropical pasture, were used in a 5 × 5 Latin square design. The treatments used were control (no supplementation; only a mineral mixture ad libitum) and four levels of crude glycerin (0, 80, 160, 240 g/kg of supplements). Supplementation type had no impact (P > 0.05) on pH at 0 and 4 h after supplementation. Animals supplemented with different levels of crude glycerin showed higher N-NH 3 values (P < 0.05) at 4 h after
quality of sheep finished in feedlot. Twenty five crossbred Dorper x St. Ines wethers, with 24 ± 2.0 kg average weight were housed in individual pens. The experimental design was completely randomized. Levels of CG in gross diet caused a decreasing linear effect (P<0.05) on dry matter , crude protein, neutral detergent fiber and non-fiber carbohydrates intake. Glycerin levels in the diet showed decreasing linear effect (P<0.05) on dry matter, crude protein, neutral detergent fiber and non-fibrous carbohydrates intake. Opposite result was observed for lipids intake. Digestibility coefficients of dry matter and non- fibrous carbohydrates decreased linearly (P<0.05) with glycerin levels, while the opposite was observed to ether extract digestibility coefficient (P<0.05). There were no effect (P> 0.05) levels of glycerin on animal performance. For morphometric measurements of carcass and meat characteristics, no significant difference (P>0.05) levels of glycerin for hot carcass weight, chilled carcass weight, hot carcass yield, Chilled carcass yields, loss cooling, state of greasing, carcass length, leg length, depth of leg, chest depth, loin eye area, texture, marbling and color. However, the influence was observed (P<0.05) of increasing levels of crude glycerin on carcass conformation and carcass fat thickness. The use of crude glycerin reduced nutrient intake of the animals, however, did not influence the performance and carcass characteristics and is indicated its use in the diet of sheep.
ABSTRACT - The objective of this study was to evaluate intake, apparent digestibility, ingestive behavior and blood parameters of milking goats fed cactus pear (Opuntia ficus indica) and increasing urea levels in substitution to soybean meal. Ten multiparous Alpine goats with average weight of 31±6.0 kg were used and distributed into (5 × 5) Latin squares and assessed during five 17-day periods, receiving five treatments with the following substitution levels: 0; 5; 10; 15 and 20 g/kg of urea. Neutral detergent fiber (NDF), non-fiber carbohydrates, ether extract, organic matter and water intake values showed differences, whith average values ranging from 1.03 to 1.13; 0.12 to 0.14; 1.76 to 2.10 kg/day and 0.77 to 1.48 kg/day, respectively. The NDF and crude protein apparent digestibility values were significantly affected by urea levels. In relation to the ingestive behavior, the urea levels did not influence the feeding, idleness or rumination parameters. Difference was observed for the following physiological variables: feces frequency (11.5 to 15.9 times per day), urine frequency (10.8 to 14.2 times per day) and frequency of search for water (0.8 to 2.1 times per day). The urea levels influenced the blood parameters, whose average levels ranged from 29.83 to 40.76 mg/dL. Pear cactus and increasing urea levels in substitution to soybean meal do not alter the dry matter intake or ingestive behavior. The use of urea associated with forage cactus reduces water intakeand increases the blood urea concentration of milking goats.
The increased levels of starch in the supplement lowered ruminal pH values, and this did not negatively affect the normal ruminal fermentation pattern. Comparing the results obtained between supplements, it was found that the increase in the starch amount tended to increase the NB (p<0.06). Part of this effect appears to result from higher efficiency of microbial nitrogen utilization in the rumen. This argument is based on the linear decrease of RAN and SUN concentrations as starch supply in- creased. Additionally, the CP digestibility was decreased with the increase in starch supply (Table 3), which may reflect lesser loss of nitrogen as ammonia in the rumen. Whereas the nitrogen intake was similar for all supplements (Table 4), the decrease of those variables (i.e., RAN and SUN) could only be obtained through a better efficiency of microbial nitrogen utilization in the rumen. The increase in nitrogen assimilation by providing additional starch was reported under tropical grass feeding [4,7]. Greater microbial nitrogen assimilation implies an increase in metabolisable protein (MP) supply. This is supported by no signifi- cant changes in faecal nitrogen excretion (Table 4), indicating that any additional microbial nitrogen produced with the starch
bovine and bubaline fed sugar cane silages treated with microbial additive Lactobacillus buchneri (inoculate) and the addition of: cassava byproduct meal at 250 g/kg; soybean hulls at 250 g/kg; and urea at 33 g/kg, in natural matter were evaluated. The forage:concentrate ratio was 600:400 g/kg. Bubaline body weight (BW) was 403±49 kg and bovine BW was 492±10 kg. The experimental design consisted of two 4 × 4 Latin squares in a 4 × 2 factorial arrangement. The average DM intake did not differ between species, and the diet with urea showed lowest intake (13 g/kg BW). Among the diets, the one with soybean hulls addition increased the total digestibility of DM, organic matter (OM) and neutral detergent fiber (NDF), while addition of urea reduced the DM, OM and non-fibrous carbohydrates (NFC) total digestibility in both species. Bovines have higher ruminal digestibility of NFC in the diet with addition of inoculate, inoculate + soybean meal and inoculate + urea diets than bubaline. Ruminal liquid pH was higher for bubaline (6.61) than bovines (6.48). Diets with addition of cassava byproduct and soybean hulls presented higher ruminal short chain fatty acids concentrations. Ruminal ammonia concentration (N-NH 3 ) did not differ between species and the treatment with urea presented the highest value of N-NH 3 (17.25 mg/100 mL). Liquid passage rate was higher for bubaline (12.9%/h) than bovines (9.9%/h). Bubaline has higher microbial synthesis efficiency than bovine: 35.1 vs 24.6 g of N-microbial/kg OM of the total rumen digestibility, regardless of the diet.
Similar results for DM digestibility, NDF, CP, MO, CT and the TDN. DEE had a growing linear effect whereas DNFC presented a quadratic effect. Average daily gain (ADG), feed conversion (FC), initial body weight (BWinitial), final body weight (BWfinal), warm carcass weight (WCW) and warm carcass yield (WCR) showed no changes. It is concluded that the peel cassava may be included in diet until 30%, without change dry matter intakeand animal performance.
In the present work, decrease in the relationship between protein andintake of TDN was observed; even without affecting the N-balance, the lower content of metabolizable energy of diets containig StS and, consequently, lower intake of TDN, could result in impaired animal performance. Detmann et al. (2014) showed that the imbalance between energy and protein in diets for cattle affect the N-use efficiency and DM intake, and consequently, cattle performance. However, Castro-Montoya and Dickhoefer (2018) concluded that even though the legume silages in ruminant diets negatively affected DM intakeand nutrient digestibility, no negative effects on performance were observed, particularly at legume inclusion levels below 400 g/ kg DM. Thus, there is still a need for further studies with legume silage for sheep on performance and economic viability.