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A commercial feed additive, OmniGen-AF® (OMN; Phibro Animal Health, Teaneck, NJ), has shown positive impacts on thermoregulation and milk production in confined dairy cows. This study was carried out to evaluate whether OMN has similar effects on grazing dairy cows. For the latter purpose, feed intake, milk production, blood metabolites, and body temperature (including surface, rectal, and thermal imaging) were assessed. This study was performed in a commercial dairy farm at Mato Grosso do Sul State in Brazil and lasted for 84 d. Thirty-six multiparous Holstein cows (136 ± 52 days in milk, 23.8 ± 4.96 kg/d milk yield, and 518 ± 65 body weight, at the start of experiment) were enrolled to a completely randomized experiment and assigned either to control (0 g/d of OMN) or OMN (50 g/d). Cows were maintained under a rotational grazing system in pens uniformly covered with Panicum maximum (cv. Mombasa). After milking, cows were fed fixed amounts of corn silage with concentrate level adjusted according to average milk yield from the previous wk. OMN was top-dressed and hand mixed in the upper portion of corn silage and concentrate mixture. The average temperature-humidity index (THI) throughout experiment was 77.8 (29.8 °C air temperature and 52 ± 15.6% relative humidity), suggesting that heat stress (THI > 68) likely impacted cows. OMN increased pasture intake, milk and milk fat yields, and milk fat content. OMN decreased urea N concentration and somatic cell count in milk. Treatments neither influenced body weight nor body condition score. OMN increased blood glucose and ionized calcium concentrations, and decreased blood aspartate aminotransferase and alkaline phosphatase concentration. OMN reduced rectal temperature, body surface temperature, and respiration rate of cows. This study showed evidence that OMN improves performance and reduces signs of heat stress of grazing cows under an environment with high THI.

Our objective was to evaluate the association between body condition score (BCS) change during the transition period with fertility, non-esterified fatty acids (NEFA) and beta-hydroxybutyrate (BHBA) concentrations, milk yield, and health problems of Holstein cows in a retrospective cohort study. Holstein cows (n = 232) were assessed for BCS (5 point scale; 0.25 point increments) and had blood collected at 21 and 7 d before, on the day of, and 7 and 21 d after calving. Blood samples were assayed for NEFA and BHBA concentrations. All cows received a timed artificial insemination (TAI) at 65 ± 3 days in milk (DIM) following a Presynch-Ovsynch protocol with a progesterone implant during the Ovsynch protocol. Cows were grouped based on BCS change after calving as to whether they: 1) lost (L), 2) maintained (M), or 3) gained (G) BCS. Data were analyzed by logistic regression with GLIMMIX and ANOVA with repeated measures using the MIXED procedures of SAS. Both NEFA and BHBA concentrations after calving differed (P 0.01) for cows that lost, maintained, or gained BCS from 21 d before to 21 d after calving (NEFA: 0.51 ± 0.01; 0.45 ± 0.01; 0.42 ± 0.01 mmol/L; BHBA: 0.73 ± 0.02; 0.70 ± 0.02; 0.68 ± 0.02 mmol/L; respectively; mean ± SEM). By design, BCS change after calving differed (P 0.01) among groups and was -0.38; 0.00; and 0.35 for cows in groups L, M, and G, respectively. At 21 d before and 21 d after calving, BCS differed (P 0.01) among groups and was [before (2.97, 2.70, and 2.57) and after (2.54, 2.70, and 2.90)] for cows in groups L, M, and G, respectively. Between evaluated days, higher circulating NEFA and BHBA concentrations were observed 7 d after calving. Change in BCS affected (P 0.01) pregnancy/AI (P/AI), days to first ovulation, and percentage of cyclic cows at 50 DIM. At 32 d after TAI, P/AI differed (P 0.01) for cows that lost [18% (11/84)], maintained [33% (26/80)], or gained [47% (32/68)] BCS. Cows that lost BCS during the transition period had more health events (P 0.01), than cows that gained or maintained BCS. In conclusion, changes in BCS during the transition period affected NEFA and BHBA concentrations, fertility, and occurrence of health problems during the lactation.

This study aimed to evaluate the effects of diet supplementation with monensin and saponins alone or combined with essential oils (EOs) on the nutrient intake and apparent digestibility, rumen fermentation parameters, microbial population, nitrogen balance, ruminal microbial protein synthesis, blood metabolites, and milk composition, yield and fatty acid profile of mid- to late-lactating Jersey cows. Eight ruminally cannulated lactating Jersey cows (average 17.6 ± 5.5 kg/day of milk yield and 100.5 ± 26.6 days of milk (mean ± SD)) were distributed in a replicated 4 × 4 Latin square design with 21-day periods (last seven days for sampling). Treatment sequences were randomly designated to cows and consisted of: (1) CON - Control, no feed additive; (2) SAP - 16 g/cow/day of a supplement based on whole-seed fenugreek powder (variety Fenucold) standardized to diosgenin, one of the major steroidal sapogenins of fenugreek (2000 mg/kg); (3) SAPEO - SAP supplement combined with a blend of natural EOs with major components of carvacrol (2500 mg/kg), cinnamaldehyde (5600 mg/kg) and limonene (3000 mg/kg); and (4) MON - Monensin, inclusion of monensin sodium in the diet at 24 mg/kg DM. Cows fed CON showed higher dry matter, organic matter, crude protein and ether extract intakes than animals fed MON, whereas higher neutral detergent fibre intake was observed in animals fed SAPEO than those fed MON (P

The aim of this study was to evaluate dietary monensin (MON) and incrementing levels of copaiba ( Copaifera spp .) essential oil (CO) on nutrient intake, time spent eating and ruminating, performance, carcass traits, and meat quality of feedlot lambs. Sixty non-castrated Crossed White Dorper lambs were randomly assigned to the following treatments: control (CON), basal diet with no feed additives; MON, dietary inclusion of 25 mg/kg DM of MON (Rumensin ® , Elanco Eli Lilly and Company, Sao Paulo, Brazil); and copaiba essential oil (CO), dietary inclusion of 0.5, 1.0, and 1.5 g/kg DM of CO diluted into isopropyl alcohol (7 mL). Animals were fed a diet with 53:47 of forage to concentrate ratio. Monensin dietary inclusion was compared with the other treatments through Dunnett’s test, and the effects of CO levels were evaluated through linear and quadratic contrasts. Dry matter intake, average daily gain (ADG), and time spent eating were recorded through the feedlot period. Immediately after slaughtering and at 24 h postmortem, carcass traits were assessed and meat samples were taken to meat quality analyses, respectively. Control and MON-treated lambs had lower ADG in comparison with those fed CO at 0.5 g/kg DM. There was a positive quadratic effect on feed efficiency and ADG according to CO levels, wherein the highest values were observed in lambs fed CO at 0.5 g/kg. Nutrient intake was not affected by treatments. Copaiba essential oil provision linearly increased the time spent eating and quadratically affected the time spent ruminating while lambs were lying, wherein the highest value of time spent ruminating was found in lambs fed CO at 0.5 g/kg. Neither carcass traits nor subprimal yield were affected by CO levels, but MON-fed lambs had lower fat thickness and external length compared to CON and those CO-fed lambs. Copaiba essential oil provision at 1.5 g/kg increased cooking losses of Longissimus dorsi in comparison with MON. Further, CO supply at 1.5 g/kg increased Warner Bratzler shear force and decreased L* intensity in Semimembranosus meat in relation to MON. Copaiba essential oil had a negative quadratic effect on the ether extract content in Gluteo biceps . This study demonstrated that CO supplementation ranging from 0.5 to 0.75 g/kg can improve feed efficiency and ADG, consequently decreasing the feedlot time of lambs, and CO can be used in place of MON in feedlot lamb diets.

Sugarcane is relatively affordable in subtropical regions and can be used as a forage source for cattle; however, its low fiber degradation in the rumen may impair diet digestibility and animal performance. The objective of this study was to evaluate the influence of a fibrolytic enzyme product in dairy heifers fed either corn silage or sugarcane silage-based diets on nutrient intake and digestibility, eating behavior, energy and N utilization, ruminal fermentation, microbial protein synthesis, and blood metabolites. Twelve Jersey heifers [8 ± 2.5 mo age and 160 ± 15 kg of live weight (LW), mean ± SD] were assigned to a Latin square design with 2 × 2 factorial treatment arrangement. Experimental periods had 14 days for treatment adaptation, 6 days for sampling, followed by 5 days of wash out. Treatment sequences consisted of: 1) diet with 549 g/kg DM sugarcane silage as forage source (SS); 2) diet with 653 g/kg DM corn silage as forage source (CS); 3) sugarcane silage and enzyme product (SSE; Fibrozyme™, Alltech, Nicholasville, KY), SS diet providing heifers with 20 g/d enzyme product through ruminal bolus; and 4) corn silage and enzyme product (CSE), CS diet providing heifers with 20 g/d enzyme product through ruminal bolus. Enzyme product was supplied once a day before the morning feeding. Heifers fed SS showed lower (P = 0.001) nutrient intake than those fed CS. Enzyme product had no effect on feed intake, but it increased (P ≤ 0.048) DM digestibility in heifers. An effect of the interaction between forage and enzyme was observed (P = 0.006) on NDF digestibility, in which enzyme supply increased NDF digestibility in 126 g/kg DM for heifers fed sugarcane silage. Moreover, enzyme supply increased (P = 0.030) the time spent eating of heifers, but it decreased (P = 0.012) the efficiency of cud chewing – DM (g/h). No interaction effect was noticed between forage and enzyme on eating behavior measures. Enzyme supply decreased (P = 0.012) N absorbed by heifers. An interaction between forage and enzyme was detected on urinary N, in which SSE treatment showed the lowest value of N in urine. Except for the higher (P = 0.012) ruminal propionate molar proportion in cows fed CS than those fed SS, no effects (P ≥ 0.212) of forage, enzyme, or forage and enzyme interaction were described on ruminal fermentation measures. Heifers fed sugarcane silage had lower (P = 0.008) microbial protein synthesis estimation than those fed corn silage. Enzyme provision increased (P = 0.045) urinary urea concentration and excretion (mg/kg LW), and decreased (P ≤ 0.012) daily urea clearance in heifers. In addition, no effect of the interaction between forage and enzyme (P ≥ 0.226) was described on N renal metabolism of heifers. Although the enzyme provision had no effect on NDF digestibility in heifers fed corn silage, it increased NDF digestibility in heifers fed sugarcane silage. The enzyme supply increased the time animals spent eating, but had no effect on ruminal fermentation of heifers.

Chitosan (CHI) is a derivative of the biopolymer chitin, found in high amounts in the shell wastes of crustaceans, and has antimicrobial properties. The objective of this study was to determine the influence of increasing doses of CHI for grazing cattle on nutrient intake and total apparent digestibility, ruminal fermentation parameters, microbial protein synthesis, nitrogen utilization, and urea and creatinine metabolism. Five rumen cannulated crossbred steers [3.6 mo and 300 ± 25 kg live weight (LW), mean ± SD] were used in a 5 × 5 Latin square experiment design with 21-d periods, in which the last 7 days were used for data collection. Steers were randomly designated to one treatment sequence containing chitosan (≥850 g/kg deacetylation degree, 0.32 g/mL density, pH 7.90, and viscosity

Made available in DSpace on 2018-12-11T17:06:44Z (GMT). No. of bitstreams: 0 Previous issue date: 2016-09-01 Fat sources, besides the energy-rich content, have featured beneficial effects on dairy cow production, reproduction and health. This work aimed to study the biohydrogenation process and fatty acid abomasal flow in lactating dairy cows fed different fat sources. Eight rumen and abomasum cannulated cows (188 ± 27.3 days in milk, 18.9 ± 3.24 kg of milk yield, and 572 ± 59.6 kg of body weight) were used in a 4 × 4 Latin square design. Control (CON) diet without fat source, soybean oil (SO), raw soybean grain (SG) and calcium salts of unsaturated fatty acids (CS) were evaluated. Fat sources decreased dry matter (DM), crude protein and neutral detergent fiber (NDF) intake and increased ether extract (EE) intake and ruminal pH (P < 0.05). Acetate to propionate ratio was lower in animals fed diets with fat (P < 0.05). Diets had no effect on microbial protein synthesis, and energy and nitrogen balances. NDF digestibility and DM passage rate were lower in animals fed diets with fat sources (P < 0.05), while protected sources (SG and CS) tended to increase ruminal fiber digestibility (P = 0.092) in relation to SO diet. Intake and abomasal flow of FA were higher (P < 0.05) for animals supplemented with fat sources than those fed CON. Protected sources (SG and CS) promoted greater abomasal flow of linoleic acid (C18:2) and lower biohydrogenation rate compared to the SO diet. Fat sources increased unsaturated milk fatty acids and serum cholesterol concentration while protected sources (SG and CS) increased milk C18:2 cis concentration (P < 0.05). Fat sources improved ruminal fermentation without compromise nutrients digestion and increasing fatty acids abomasal flow and milk concentration. Raw soybean grain had higher ruminal biohydrogenation protection than calcium salts. Department of Animal Nutrition and Production University of Sao Paulo, Pirassununga Department of Animal Science UNESP−Universidade Estadual Paulista “Júlio de Mesquita Filho”, Jaboticabal Department of Animal Science UNESP−Universidade Estadual Paulista “Júlio de Mesquita Filho”, Jaboticabal

This study investigated the xylanases produced by Trichoderma piluliferum and T. viride. These enzymes were characterized and used as additives in bovine diet. The fungus T. piluliferum was a more efficient producer of xylanase (301 U g−1 dry substrate) when grown on wheat bran, with 75 or 80% moisture for 96 h. The optimum pH of the enzyme produced by T. piluliferum was 4.5, obtaining as the optimum temperature 50 °C. The enzyme was stable at a wide pH range (3.0–10.0), and it remained stable for 1 h at 40 °C. The best culture parameters for the cultivation of T. viride (671 U g−1 dry substrate) were as follows: wheat bran as substrate, 65, 70 and 75% initial moisture, and 48 h cultivation time. The optimum pH and temperature for the xylanase produced by this fungus were 6.0 and 45 °C, respectively, and the enzyme was stable at a wide pH range (3.0–10.0), maintaining its activity after 1 h at 40 °C. Both the enzyme extracts produced were effective at increasing digestibility of Tifton 185 hay, sugarcane silage, and corn silage. The enzymatic extracts proved promising for xylooligosaccharides production and showed low cellulase activity, indicating potential for application in biobleaching processes of cellulose pulp and paper.

The objective of this study was to evaluate the productive performance, nutrients digestion and metabolism of three different genetic groups fed with the same diet based on corn silage. 30 heifers in growth were used of three groups of cattle, the following: Nellore ( Bos taurus indicus ) (n = 10), Holstein ( Bos taurus taurus ) (n = 10), and Mediterranean buffaloes ( Bubalis bubalis ) (n = 10). The animals were fed in groups and received the same experimental diet composed of corn silage and concentrate for growing heifers. In the evaluation of animals the performance, consumption and total apparent digestibility of dry matter and nutrients with the aid of internal markers (chromic oxide) and external (iADF), rumen fermentation, excretion of purine derivatives, nitrogen balance and blood metabolites were measured. No differences were observed in animal performance. There were differences in nutrient intake and apparent digestibility of dry matter and nutrients in different groups of cattle. The concentration of ammonia nitrogen (NH3-N) and short chain fatty acids (SCFA) in the rumen were higher and lower, respectively, for the group of buffaloes in relation to other experimental groups evaluated. When considering the excretion of total purine derivatives, buffaloes showed the lowest value compared to other genetic groups evaluated; about 61.76% of the total genetic group Nellore and 57.62% of the total genetic group Holstein with an average of 33.67 mmol/day. For the buffaloes, the excretion of xanthine and hypoxanthine observed was of 5.11% of total purine derivatives. There was a better nitrogen balance (g/day) for groups of Holstein heifers and Nellore in relation to the group of buffalo heifers. There were differences in the concentrations of urea and urea nitrogen in serum and liver enzymes where the buffaloes had higher values in relation at the bovines. There is a great metabolic diversity among the experimental groups evaluated and it was more exacerbated among buffaloes and bovines, when submitted to the same diet and same management conditions.