Animal Feed Science and Technology最新文献

We aimed to assess whether guanidinoacetic acid (GAA) affects the performance, metabolism, and placental vascularization of pregnant beef cows during late gestation as well as its impact on the offspring’s performance. Twenty-eight pregnant Brahman cows, averaging 532±15.1 kg and carrying male (n=15) and female (n=13) fetuses, were used. The basal diet consisted of 688 g/kg corn silage, 147 g/kg sugarcane bagasse, 47.7 g/kg corn, 89.6 g/kg soybean meal, 6.86 g/kg urea, and 21.2 g/kg mineral mixture (DM basis). Cows were fed the experimental diets from 180 to 270 days of gestation. The following treatments were evaluated: control (no addition of GAA) or addition of 0.2 % GAA to the total diet (DM basis). There was no effect (P≥0.37) of GAA on voluntary intake. Similarly, GAA addition did not affect (P≥0.54) cows performance variables, except for ribeye area (REA), which had a lower (P<0.01) variation compared to the initial REA in cows fed dietary GAA compared to the control group. Dietary GAA increased (P≤0.02) both serum nitric oxide and placental vascularization compared to cows fed the control diet. There was no effect (P≥0.43) of GAA on urine and serum creatine concentrations. In contrast, dietary GAA increased (P≤0.03) plasma concentration of arginine, ornithine, citrulline, and tyrosine compared to the control. Conversely, dietary GAA decreased (P<0.02) plasma methionine concentration. Dietary GAA increased AGAT activity (P<0.03) in the liver, with no differences observed (P>0.68) on GAMT activity. There was no effect (P≥0.15) of GAA on performance of the offspring. Addition of GAA in maternal diet did not affect skeletal muscle fiber number (P>0.09) and diameter (P>0.23) of the offspring. Guanidinoacetic acid decreases skeletal muscle mobilization and enhances placental vascularization of beef cows during late gestation. However, providing GAA seems to not affect the performance of the offspring.

Two experiments were conducted to test the hypothesis that particle size or origin of field peas does not influence apparent total tract digestibility (ATTD) or standardized total tract digestibility (STTD) of P, but that increasing levels of phytase will increase ATTD and STTD of P in field peas when fed to growing pigs. In experiment 1, one source of field peas was obtained from the U.S., and two sources were obtained from Canada (i.e., Canada 1 and Canada 2). The U.S. field peas were ground to 265, 457, or 678 µm, whereas the Canada 1 peas were ground to 253 µm, and the Canada 2 source was ground to 411 µm. The five batches of field peas were each included in one diet and fed to 50 growing pigs (16.36 ± 1.19 kg) with 10 replicate pigs per diet. In experiment 2, six diets based on the U.S. field peas ground to 678 µm were formulated to contain 0, 250, 500, 1000, 2000, or 4000 units per kg of microbial phytase and fed to 48 pigs (15.26 ± 0.91 kg) with eight replicate pigs per diet. In both experiments, field peas were the only source of P in the diets. Pigs were housed individually in metabolism crates and feces were collected for four days. Results of experiment 1 indicated that the ATTD and STTD of P were not affected by source of peas or by particle size of the field peas and it was concluded that growing location and variety do not influence STTD of P in field peas. Results of experiment 2 indicated that the ATTD of Ca and P and the STTD of P increased (linear, P < 0.001) as phytase increased in the diets, and fecal excretion of Ca and P was reduced as the concentration of dietary phytase increased (linear, P < 0.001). It was, therefore, concluded that if microbial phytase is included in diets containing field peas, the inclusion of feed phosphate can be reduced, and manure concentration of P will also be reduced. In conclusion, the hypotheses that neither growing location nor particle size influences STTD of P were confirmed, and the hypothesis that increased concentration of dietary phytase increases STTD of P was also confirmed.

The study was conducted to evaluate whether adding a blend containing free and microencapsulated essential oils, combined with turmeric and tannin, can replace monensin as a performance improver, positively influencing animal health and meat quality. Fourteen male cattle with an average initial body weight of 253 kg and ten females with an average initial body weight of 239 kg were included in the experiment in a confinement system. The animals were divided into four independent groups: Males (M-PHYTO, inclusion of the phytogenic mixture; M-MONEN, inclusion of monensin); Females (F-PHYTO, inclusion of phytogenic; F-MONEN, inclusion of monensin). The diets were formulated for an average daily gain of 1.5 kg, with food provided twice daily. Data and biological samples were collected on days 33, 100, and 153. M-PHYTO and F-PHYTO showed greater average daily gain and body weight, with a tendency to consume more dry matter and feed efficiency. However, the apparent digestibility of nutrients was higher in animals in the MONEN group than those in the PHYTO group, regardless of sex. The total number of leukocytes in cattle in the M-PHYTO and F-PHYTO groups was higher due to the higher lymphocyte count in the blood of these animals. The activity of gamma-glutamyltransferase and aspartate aminotransferase in animals that consumed the phytogenic mixture was lower compared to animals that consumed monensin. TBARS levels were lower in the serum and meat of cattle in the M-PHYTO and F-PHYTO groups, as were the total thiol concentration and glutathione S-transferase activity in the blood and meat of these animals. Bacterial activity was greater in the rumen fluid of cattle that consumed the phytogenic, as demonstrated by the methylene blue reduction test. The total production of short-chain fatty acids and acetic acid showed an interaction between treatment and days for both sex classes and an effect of treatment for females, with a higher concentration in the rumen in the M-PHYTO and F-PHYTO groups. Propionic acid affected treatment and the treatment x day interaction for males and females, with the M-PHYTO and F-PHYTO groups showing higher concentrations. There was an interaction between treatment and day in the acetate/propionate ratio, being lower in M-PHYTO and F-PHYTO cattle. Treatment between ruminal microbiota groups had no effect. The rib eye area had more significant gains when consumed phytogenic by males and females. The subcutaneous and sirloin fat thickness was greater in F-PHYTO animals than in the control group; however, in males, the result was the opposite. The sum of polyunsaturated fatty acids in meat was higher in M-PHYTO compared to M-MONEN and lower in F-PHYTO meat compared to F-MONEN. These results indicate that the phytogenic mixture is a potential performance improver in the diet of growing and finishing cattle, regardless of sex, but meat characteristics differ between males and females.

Tannins have been extensively studied to decrease nitrogen excretion, however, the effects of tannins on animal production were inconsistent. The objective was to evaluate the effects of a mixture of quebracho-chestnut tannin extract (QCTE) supplementation on the production performance, nutrient digestibility, rumen fermentation patterns, and N partitioning in dairy cows. Sixty multiparous Holstein cows (mean ± standard deviation; average 717 ± 51 kg of body weight, 2.5 ± 0.2 of parity, 47 ± 1.9 kg/d of milk production, 78 ± 3.2 d of days in milk were randomly divided into four groups. Cows in different groups were provided QCTE at doses of 0, 10, 20, and 30 g/d per cow for 56 d. Although QCTE supplementation did not affect dry matter intake (DMI) and total-tract apparent digestibility of nutrients, milk yield and milk protein yield increased linearly (P = 0.01), and a trend for a linear (P = 0.07) increase in milk/DMI were observed with increasing QCTE supplementation. Increasing QCTE supplementation decreased the milk urea-N concentration and somatic cell count linearly (P < 0.05), tended to linearly (P < 0.1) decrease the concentration of blood urea-N and ruminal ammonia nitrogen, linearly (P < 0.05) increased levels of total antioxidant capacity and superoxide dismutase, and the molar proportions of ruminal propionate. Additionally, total N excretion was not affected by QCTE treatments, but QCTE supplementation linearly (P = 0.04) increased N utilization efficiency and tended to linearly (P = 0.1) decrease urea-N excretion in the urine. In conclusion, feeding QCTE at a dose of 30 g/d per head to cows in early lactation could increase antioxidant enzyme activities, improve production performance, and decrease environmentally labile urinary N excretion under the conditions of the study.

The objectives were to 1) determine whether genetic differences can be detected for carbohydrate fermentability among corn hybrids at silage maturities when the effects of drying and grinding are eliminated and 2) determine if in vitro starch digestibility (IVSD), a routine laboratory method used by commercial laboratories for hybrid evaluation, can detect differences when DM is controlled. Samples of whole corn plants from 3 hybrids (Brevant): B99B79SX (BMR, n = 7), B96T79SX, standard (STAN, n = 6), and B95U78SXE, floury-BMR (FL, n = 7), that had similar range of DM were selected. Sets of 8 ears were harvested concurrently and kernels removed from the ears by hand. Samples of undried kernels were quartered (QKERN) and in vitro gas production (IVGP) was measured for 120 h. More gas was produced by QKERN of FL than of STAN and BMR from 9 to 18 h (P < 0.05), and QKERN of FL produced more gas than BMR through 21 h (P < 0.05). The QKERN of FL had a shorter lag than STAN or BMR (P < 0.001) and a faster rate of gas production than BMR (P < 0.01), establishing that genetic differences are present at silage maturities. To determine whether the routine laboratory method can detect these differences, kernels (GKERN) and whole corn plants (GWP) were dried and ground to pass a 4-mm screen to measure IVSD after 3, 8, and 24 h. Particle size of GKERN was determined by dry sieving using a set of 13 sieves. For both GKERN and GWP, IVSD was lowest for BMR and highest for FL after 8 h. The IVSD8h of GKERN decreased as particle size increased at a similar rate for the 3 hybrids but the intercepts were different, with BMR being lowest and FL highest. Similarly, the IVSD8h of both GKERN and GWP decreased with increasing whole plant DM at a similar rate for the 3 hybrids and the magnitude of difference for IVSD8h was larger for the range in DM than the range in intercepts for the hybrids (0.123 vs 0.071 and 0.117 vs. 0.100, for GKERN and GWP, respectively). Plant maturity, or DM, has a larger effect on IVSD than hybrid type, and should therefore be controlled when evaluating genetic differences.

This study aimed to assess the effects of diets containing a blend of plant protein sources (cottonseed meal, sunflower meal, and jojoba meal) fermented with yeast (Saccharomyces cerevisiae) at three different levels (25 %, 50 %, and 75 %) instead of fishmeal (FM) on the growth performance, anti-nutritional factors content, and blood profile response of Nile tilapia (Oreochromis niloticus). Four experimental diet (33.6 % crude protein) and (18.61 MJ kg⁻¹ gross energy) were formulated. The study included four diets: a control diet, FCSJM-25 %, FCSJM-50 %, FCSJM-75 % which replaced fishmeal based on protein content. Fries (3.53± 0.07 g) were randomly allocated into twelve glass aquaria (180 L capacity) in triplicate per each treatment (25 fish/ aquarium) for 90 days. After the 90-day feeding trial, the results showed that fish fed the control diet, FCSJM-25 %, and FCSJM-50 % had the highest final body weight, weight gain, specific growth rate, and average daily gain, whereas fish fed FCSJM-75 % had the lowest values for these parameters. The best feed conversion ratio (FCR) was observed in fish fed FCSJM-25 % or FCSJM-50 % (P < 0.05). The highest apparent protein digestibility was found in fish fed the control diet or FCSJM-25 %. Diets with FCSJM-25 % had the highest white blood cells (WBCs) values (P < 0.05). Control diet, FCSJM-25 %, and FCSJM-50 % resulted in the highest levels of complement component (C3), C4, growth hormone, and IgM (P < 0.05). However, control diet had the highest triglyceride and HDL levels, while fish fed FCSJM-25 % had the highest levels of LDL (P < 0.05). Fish fed a diet with FCSJM-50 % recorded the highest cholesterol content. The control or FCSJM-25 % diets showed the highest values of creatinine, phosphorus, and calcium (P < 0.05). There were no significant differences in ALT, AST, and uric acid among the treatments. The study concluded that FM can be replaced with either FCSJM-25 % and FCSJM-50 % without affecting growth performance and feed utilization.

The objective of the present study was to evaluate the association of Bacillus toyonensis, Saccharomyces cerevisiae var. boulardii, and sodium monensin on feed intake, apparent digestibility, ruminal, urinary, and serum variables in the diet of steers. Four Angus × Nellore crossbred steers, with 403.0 ± 75.5 kg of BW, rumen cannulated and housed individually were used. The animals were submitted to a 4 ×4 Latin square design, receiving the following treatments: monensin only (MO); monensin + B. toyonensis (MBT); monensin + S. cerevisiae boulardii (MSB); and B. toyonensis + S. cerevisiae boulardii (BTSB). Treatments with monensin (MO, MBT and MSB) presented lower DM intake than BTSB, but similar apparent digestibility between treatments. No difference was observed between treatments for ruminal pH, but BTSB presented higher NH₃-N concentration than MBT and MSB and did not differ from MO. All concentrations in the blood serum and urinary variables were found within the physiological range or close to normal, and no difference was observed in the retained nitrogen. The BTSB treatment showed potential as a feed additive for cattle, by controlling rumen pH and similar concentrations of NH₃-N, total SCFA, and retained nitrogen to MO treatment, but when probiotics were combined with monensin no beneficial effect was observed under the studied conditions.

This study aimed to evaluate the effect of increasing concentrate levels in AGRI-002E sorghum silage (SS)-based diets on nutrient intake and digestibility, ruminal pH and ammonia concentration, Nitrogen (N) balance, efficiency of microbial protein synthesis, and in situ degradability of complete diets. Five rumen-cannulated Nellore bulls (age = 8 ± 1.0 months; initial BW = 242 ± 5 kg) received five dietary treatments in a 5×5 Latin square experimental design. The dietary treatments consisted of five concentrate levels (0, 200, 400, 600, and 800 g of concentrate/kg on a DM basis) in SS-based diets. The experiment lasted 120 d, with five periods of 24 d. Each period consisted of 17 d for dietary adaptation, and 7 d for data collection. In situ degradability assays were conducted to estimate ruminal degradability. Total feces and urine collection were performed to estimate nutrient intake and digestibility and estimate N balance. Omasal and ruminal digesta collection were performed to estimate ruminal digestibility and ruminal parameters. Increasing concentrate levels in SS-based diets led to linear increases (P<0.001) in the intake of dry matter (DM), organic matter (OM), crude protein (CP), and ether extract (EE). Neutral detergent fiber corrected for ash and protein contamination (apNDF) and starch intake showed quadratic responses (P≤0.008). Ruminal digestibility of DM, OM and CP responded quadratically (P≤0.040), while apNDF exhibited linear decrease (P=0.003). Starch ruminal digestibility exhibited a cubic effect (P=0.016). Apparent total-tract digestibility of DM, OM, and EE increased linearly (P≤0.001), whereas apNDF, and CP digestibility decreased linearly (P≤0.012), and starch presented a quadratic effect (P=0.029). In situ ruminal degradation parameters increased linearly with higher concentrate levels (P<0.001). Ruminal pH exhibited a quadratic pattern (P=0.006), ammonia concentration linearly decreased (P=0.003). Total volatile fatty acids, and butyrate showed linear increases (P<0.001), acetate and propionate had quadratic effects (P<0.001), while the ratio Acetate to Propionate decreased linearly (P<0.001). N intake, fecal N excretion, retained N, total digestible nutrients, digestible organic matter, and microbial production increased linearly (P<0.001), although urine N excretion, urinary urea, and blood urea concentration decreased linearly (P<0.028). Therefore, increasing concentrate levels in AGRI-002E sorghum silage-based diets improve TDN intake, microbial protein synthesis efficiency, in situ ruminal degradability parameters, and nitrogen utilization. Moreover, our findings indicate that AGRI-002E sorghum silage demonstrates potential as a fiber source for high-concentrate diets. However, its effectiveness is limited without concentrate supplementation, emphasizing the importance of balanced dietary composition for optimal utilization in beef cattle.