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This study aimed to evaluate the effects of organic acid (OA; Mold-Zap, Alltech, Nicholasville, KY) inclusion in the total mixed ration (TMR) and feeding frequency of TMR for lactating dairy cows on intake, total-tract apparent digestibility, sorting index, feeding behavior, ruminal fermentation, milk yield and composition, nitrogen balance, and serum metabolites. Twenty-four lactating Holstein cows, 4 with rumen cannulas, with (mean ± standard error) 247 ± 22.2 d in milk, 672 ± 14.6 kg of body weight, and 31.1 ± 1.09 kg of milk yield at the beginning of the experiment were used. The cows were distributed in a balanced and contemporary 4 × 4 Latin square experimental design and randomly assigned in a 2 × 2 factorial arrangement to evaluate OA [0 (OA−) or 0.5 (OA+) L of Mold-Zap/tonne of TMR on a natural matter basis] and feeding frequency of TMR offered once a day (1×) or twice a day (2×). Each experimental period lasted 21 d, with 14 d for acclimation and 7 d for data collection. The treatments were tested for TMR, in which its temperature was recorded every 2 h through a 24-h period in each experimental period. Organic acid-treated TMR showed a lower temperature during the 24-h period compared with nontreated TMR. The OA and feeding frequency had no effect on intake and total-tract apparent digestibility of dry matter and nutrients, aside from a tendency to increase neutral detergent fiber digestibility in cows fed 2×. Also, cows fed 1× tended to select more particles between 19 and 8 mm and refused particles smaller than 4 mm, whereas cows fed OA tended to select more particles smaller than 4 mm. Cows fed OA had greater milk yield and milk protein and lactose yields, but tended to have higher 3.5% fat-corrected milk yield. Neither treatment influenced ruminal and serum variables nor milk fat yield and milk production efficiency. Cows fed OA spent less time idling and tended to have lower rumination time, and tended to have higher time spent drinking water and eating, whereas animals fed 1× spent more time drinking water. Under the conditions of this experiment, we conclude that it was possible to reduce the feeding frequency of TMR, without negative effects on dairy cow performance. However, the use of OA resulted in higher milk yield and mitigated TMR temperature rise regardless of feeding frequency. The effect of external factors such as collective stimulation of intake and stage of lactation on feeding frequency effect must be surveyed in further research.

Peppers (Capsicum spp.) contain capsaicin, an organic compound with a group of alkaloids that has shown thermoregulation properties in humans and mice, and may influence glucose and lipid metabolism in ruminants. An experiment was conducted to evaluate different doses of a feed additive containing encapsulated pepper on milk yield and composition, dry matter intake, feed sorting index, total-tract apparent digestibility of nutrients, purine derivatives excretion, and serum concentrations of urea-N and glucose, N excretion, respiration rate, rectal temperature, and skin temperature in different regions (forehead, face, and rumen). Thirty-six Holstein cows (150 ± 102.1 d in milk and 29.3 ± 5.81 kg/d milk yield) were used in a 9-wk randomized complete block (n = 12) design experiment. Following a 2-wk covariate period, cows were blocked according to parity, days in milk, and milk yield and were randomly assigned to the following treatments: 0 (CAP0), 0.75 (CAP75), or 1.5 (CAP150) g/d of a feed additive containing encapsulated pepper (1 g/kg, Capcin; NutriQuest) added to the concentrate along with minerals. Treatment differences were evaluated through orthogonal contrasts (CAP0 vs. CAP75 + CAP150 or CAP75 vs. CAP150). The average temperature-humidity index during the experiment was 72.0 ± 2.07. Dry matter intake was greater in cows fed a feed additive containing encapsulated pepper (CAP) treatments (CAP75 and CAP150) compared with CAP0. Cows fed CAP150 tended to have greater dry matter intake than those in CAP75 group. Feeding CAP decreased sorting for feed particles with size between 8 and 4 mm. An interaction effect between treatment and week was observed for crude protein digestibility whereas cows fed CAP150 had the greatest digestibility on the third week of experiment. Orthogonal contrasts did not detect differences in serum concentrations of glucose and urea-N, or purine derivatives excretion. Nitrogen excretion (as % of N intake) in milk, urine, and feces was not altered by treatments. Feeding CAP increased yields of 3.5% fat-corrected milk, fat, protein, and lactose. A tendency toward greater milk protein content was observed for cows fed CAP150 than CAP75. No differences were detected on respiration rate, rectal temperature, and skin temperature of cows. A feed additive containing encapsulated pepper fed at 0.75 or 1.5 g/d can improve yield of fat-corrected milk and milk solids by increasing feed intake without affecting nutrient digestibility and body temperature of lactating cows during the hot season.

Enzyme additives have been added to forage at ensiling to improve nutritive value. The aim of this study was to evaluate effects of adding exogenous enzymes to silage on fermentative losses and profile, aerobic stability, chemical composition, in vitro degradation, microbial quality, and nutrients intake and digestibility. Treatments were control (CON); addition of exo-1,4-α-glycosidase glucoamylase (GLU; Kerazyme 3035, Kera Nutrição Animal, Bento Gonçalves, Brazil); addition of β-glucan 4-glucanhydrolase (CEL); and GLU + CEL. Data from the silo experiment were analyzed using PROC MIXED of SAS, with fixed effects of glucoamylase and cellulase, and interaction effect between them. In vivo experiment analyses also included fixed effect of Latin Square and period, and random effect of animal within Latin Square. CEL increased (P ≤ 0.038) gas losses and effluents production, CEL and GLU decreased (P = 0.039) DM recovery compared to control but not differ from GLU+CEL. CEL silage had higher (P ≤ 0.021) starch and crude protein and in vitro digestibility of DM and NDF (P ≤ 0.032), while GLU had higher (P = 0.001) ADF. CEL showed lower (P = 0.012) ethanol content and higher (P = 0.02) anaerobic bacteria counts, while GLU showed higher (P = 0.012) lactate concentration and lower (P ≤ 0.002) counts of bacteria and fungi. Lambs fed with CEL presented higher (P ≤ 0.012) digestibility coefficients for DM, OM, CP and NDF. Decrease on DM recovery indicates no improvements on the nutritive value of silage. On the other hand, cellulolytic enzyme positively affected animal digestion.

This study aimed to evaluate the effects of partially replacing corn silage (CS) with whole-plant soybean silage (SS) or black oat silage (OS) on nutrient intake and digestibility, in vitro neutral detergent fiber degradability of silages, feeding behavior, rumen fermentation, and performance of dairy cows. Twenty-four lactating Holstein cows (6 of which were rumen-cannulated) with 32.5 ± 4.92 kg/d milk yield, 150 ± 84.8 days in milk, and 644 ± 79.0 kg of body weight were used in a 3 × 3 Latin square design to evaluate the following treatments: (1) corn silage diet (CSD): using corn silage as the only forage source in the diet [48% dietary dry matter (DM)]; (2) whole-plant soybean silage diet (SSD): SS replacing 16% of corn silage from CSD; and (3) black oat silage diet (OSD): OS replacing 16% of corn silage from CSD. The inclusion of OS and SS decreased intakes of DM, organic matter, and crude protein. Corn silage had the greatest in vivo effective degradability of DM, and SS had the least effective degradability of neutral detergent fiber. The OSD treatment decreased milk and protein yields, whereas SSD increased rumen ammonia nitrogen concentration compared with the other diets. Cows fed OSD exhibited a greater preference for feed with small particles (

The objective of this study was to evaluate the effects of exogenous enzymes on nutrient intake and digestibility, rumen fermentation, and productivity of mid-lactating cows. Experiment 1 was designed to test increasing doses [0, 0.5, 1.0, or 1.5 g/kg of dry matter (DM)] of a combination of 2 enzyme products with xylanase and β-glucanase activities (Ronozyme Wx and Ronozyme VP, respectively; DSM Nutritional Products) on rumen fermentation and total apparent digestibility. Enzyme combinations had a ratio of endo-1,3(4)-β-glucanase to endo-1,4-β-xylanase of 8:2 (wt/wt). For experiment 1, 8 rumen cannulated lactating cows were used into a double 4 × 4 Latin square design experiment with 14 d of diet adaptation and 7 d of sampling. Despite no differences in feed intake, carbohydrases linearly increased neutral detergent fiber digestibility. Treatments marginally affected rumen fermentation, where a linear trend for lower rumen pH and a linear trend for greater isobutyrate concentration were observed with increasing enzyme dose. A trend for lower rumen NH3-N concentration was observed for cows receiving carbohydrases in comparison with control group. When comparing all enzyme treatments against control group, cows fed enzymes tended to produce more 3.5% fat-corrected milk (FCM), produced more milk fat, and had greater blood glucose concentration. Experiment 2 evaluated 3 doses (0, 0.5, or 0.75 g/kg of DM) of the same combination of enzyme products on performance of cows (n = 36) in a complete randomized block (n = 12) design. Cows received treatments for 9 wk. No interaction effects between treatments and time were observed for all variables assessed in this study. In agreement with experiment 1, no differences were detected for feed intake, but cows fed the enzyme products tended to produce more 3.5% FCM and milk fat compared with control. In addition, cows fed enzymes exhibited greater efficiency of FCM production (FCM ÷ DM intake) compared with control. No differences were detected for intake and productivity when comparing the 2 doses of carbohydrases. In summary, the enzyme products tested in this study may improve feed efficiency due to greater milk fat concentration.

The objective of this study was to evaluate the effects of feed additives on intake and digestibility of nutrients, milk yield and composition, feeding behavior, and physiological parameters of dairy cows during the hot season. Forty Holstein cows were assigned to a randomized block design experiment with a 2 × 2 factorial treatment arrangement to evaluate (1) control diet without inclusion of additives; (2) monensin (MON), 20 mg/kg diet dry matter sodium monensin (Rumensin; Elanco); (3) Milk Sacc+ (MS+), inclusion of 40 g/cow per d of Milk Sacc+ (a blend of live yeast and organic minerals, Alltech); and (4) combination of MON and MS+. The average temperature-humidity index throughout the experimental period was 73 ± 2.84 (standard deviation). The experiment lasted 11 wk, including 2 preliminary weeks for covariate adjustments. Cows fed MS+ increased dry matter intake (% body weight), milk yield, 3.5% fat-corrected milk, and solids yield, and cows fed MON had greater milk urea nitrogen content in comparison with counterparts. Feeding MS+ increased the intake of feed particles with size between 8 and 19 mm and decreased the intake of particles shorter than 4 mm compared with other treatments. Rumination time (min/d) and chewing time (min/kg of neutral detergent fiber) were lower for cows fed MS+. Physiologic parameters (i.e., heart and respiratory rates, and body temperature) were not affected by the treatments. Overall, the use of monensin did not differ from control, and Milk Sacc+ improved performance of cows.

This experiment was designed to evaluate the effects of combining calcium salts of soybean oil fatty acids (CSFA) and two rumen degradable protein (RDP) levels on feed intake, ruminal fermentation, N metabolism, and performance of lactating cows fed corn silage-based diets containing 164 g/kg of crude protein and 6.72 MJ/kg of net energy. Eight rumen cannulated Holstein cows (207 ± 23.6 days in milk and 33.4 ± 2.45 kg/d of milk yield) were used in a 4 × 4 Latin square design with a 2 × 2 factorial treatment structure. Treatments consisted of diets with or without CSFA at 33.2 g/kg dry matter (DM) combined with either low (98 g/kg DM) or high level (110 g/kg DM) of RDP. Microbial protein synthesis was evaluated using the omasal sampling technique along with the triple marker system of digesta flow and 15N as a microbial marker. There was no interaction effect (P ≥ 0.15) between CSFA and RDP for all variables analyzed. Fat supplementation reduced (P ≤ 0.010) intake of nutrients (except ether extract), tended to increase (P = 0.076) rumination time, and increased (P = 0.015) ruminal pH. Calcium salts of fatty acids decreased (P ≤ 0.014) DM and organic matter ruminal digestibility and tended to reduce (P = 0.096) neutral detergent fiber ruminal digestibility. Dietary CSFA did not affect (P ≥ 0.32) ruminal flows of total non-ammonia N and microbial non-ammonia N, but increased (P = 0.022) microbial protein synthesis efficiency. Cows fed CSFA had greater (P ≤ 0.043) milk yield, feed efficiency, and N secreted in milk (g/kg N intake), and lower (P

An increase in total mixed ration (TMR) temperature is associated with a growth of undesirable microorganisms and decreases in feed intake in dairy cows. We evaluated the effects preservative products containing organic acids (OA) added to TMR on intake and digestibility of nutrients, rumen fermentation, milk yield and composition, nitrogen utilization, blood parameters, ingestive behavior of cows. Twenty-five Holstein cows (147.4 ± 87.9 days in milk, 668.7 ± 78.5 kg of body weight and 34.4 ± 4.2 kg/d milk yield), 10 of which were rumen-cannulated, were assigned to a 5 × 5 Latin square experiment containing the following treatments: control (CON), no OA added to TMR; and four preservatives composed mainly of either formic acid (FLE), sodium formate (SOL), propionic acid (SPE) in liquid form, or propionic acid (PER) in solid form added to TMR. The OA products used in this study were manufactured by Perstorp Waspik BV (Waspik, The Netherlands). Products were added daily to the TMR at 4 ml/kg natural matter (NM) for the liquid products (FLE, SPE, PER), and at 4 g/kg for the solid product (SOL). The experimental barn temperature, relative humidity, and temperature-humidity index during the experiment were 24.4 ± 4.29 °C, 75.0 ± 16.39%, and 72.7 ± 5.31 (mean ± SD), respectively. Each experimental period consisted of 14 days for adaptation to treatments and five days for sampling. Differences among treatments were studied using orthogonal contrasts, as follows: the effect of OA [control versus OA (SPE + SOL + PER + FLE)], the effect of OA composition [formic acid (FLE + SOL) versus propionic acid (PER + SPE)], the effect of different formic acid products (FLE versus SOL); and the effect of different propionic acid products (SPE versus PER). Organic acids increased feed intake (23.6 and 24.4 kg/d for CON and OA, respectively) and reduced sorting of feed particles with 8–19 mm size and shorter than 4 mm. Organic acids, however, decreased the total VFA concentration and increased pH of rumen fluid. Cows fed TMR with OA had greater fat-corrected milk production and milk protein content compared with CON. Organic acids avoided an increase in TMR temperature within 24 h air exposure. Organic acids, regardless of their composition, can maintain TMR temperature stable for longer periods and improve the performance of dairy cows.

This study aimed to evaluate the effects of replacing corn silage (CS) with whole-plant soybean silage (SS) in dairy cow diets on nutrient intake and apparent total-tract digestibility, rumen fermentation, milk yield, composition and fatty acid profile of milk, serum metabolites, and feeding behavior. Twenty-four Holstein cows were enrolled to a replicated 4 × 4 Latin square experiment (21 d-periods), with samples and data collected during the last 7 d of each period. Treatments consisted of a control diet (CON) with 480 g/kg DM CS, and SS (ensiled at R5.5 phenological stage) replacing CS at 167, 333, and 500 g/kg DM. Soybean silage linearly decreased DM intake and digestibility, and intake of feed particles shorter than 4 mm. Cows fed SS had a linear increase in ruminal pH and ruminal concentrations of butyrate, branched-chain fatty acids, and NH3-N. Soybean silage linearly decreased milk and solids yield. Dietary inclusion of SS at expense of CS linearly increased milk fat concentration of unsaturated (C18:1 and C18:2) and long chain fatty acids (>C16). Microbial protein synthesis was linearly decreased and blood urea nitrogen concentration was linearly increased by SS treatments. Soybean silage had a positive quadratic effect on periods of rumination and chewing (min/d). Replacing CS with SS ensiled at R5.5 phenological stage decreases feed intake and performance of cows, without affecting milk fat content. Dietary SS, however, can be used to modulate ruminal fermentation and increase long-chain fatty acids (>C16) and unsaturated fatty acids proportion on milk fat.

Made available in DSpace on 2020-12-10T19:54:25Z (GMT). No. of bitstreams: 0 Previous issue date: 2019-12-01 Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) The present study aimed to evaluate N-15 and purine bases (PB) as markers for ruminal bacterial nitrogen (N) outflow in dairy cows. Additionally, the effects of calcium salts of fatty acids (CSFA) in diets with different levels of rumen degradable protein (RDP) on PB omasal flow, urinary recovery of purine derivatives (PD), and endogenous excretion of PD were evaluated. Eight ruminal cannulated Holstein cows, with 207 +/- 23.6 (mean +/- SD) days in milk, 618 +/- 39.0 kg of body weight, and 33.4 +/- 2.45 kg/d of milk yield were used in a replicated 4 x 4 Latin square design. Four treatments were arranged in a 2 x 2 factorial design to evaluate the following factors: CSFA addition [-CS: basal diet without CSFA; and + CS: with 33.2 g/kg dry matter (DM) of CSFA]; and the level of RDP (LRDP: low RDP, with 98 g/kg DM of RDP; and HRDP: high RDP, with 110 g/kg DM of RDP). Particle-associated bacteria (PAB) showed lower (P < 0.008) N-15 enrichment and purine N to total bacterial N ratio than liquid associated bacteria (LAB). Increasing RDP concentration reduced (P = 0.007) 15 N enrichment and tended (P < 0.095) to reduce PB concentration in bacterial pellets. Purine bases overestimated (P < 0.002) LAB-NAN and total microbial flow but, regarding PAB-NAN flow, there was a trend of interaction (P = 0.067) between marker and fat supplementation effects. In the absence of fat supplementation, PB underestimated (P < 0.05) the flow of PAB-NAN compared to N-15 and failed to detect the negative effect of fat supplementation evidenced by N-15 labeling. Omasal PB flow tended to increase (P = 0.061) in low protein degradability diets, but PD excretion was constant (322 +/- 5,9 mmol/d, mean +/- SE) regardless of diet and, as a result, urinary recovery of PB decreased (P = 0.007). Daily excretion of creatinine and endogenous PD was also unaffected by the diet and averaged 0.262 mmol/kg BW and 0.640 mmol/kg BW degrees 75 , respectively. In conclusion, the response of PB and its urinary derivatives to variation in diet composition compared to N-15 reveals their weaknesses in the estimation of microbial synthesis. Univ Sao Paulo, Sch Vet Med & Anim Sci, Dept Anim Nutr & Anim Prod, BR-13635900 Pirassununga, Brazil Univ Fed Vicosa, Dept Anim Sci, BR-36570000 Vicosa, MG, Brazil Sao Paulo State Univ, Inst Biosci, Dept Phys & Biophys, BR-18618689 Botucatu, SP, Brazil Sao Paulo State Univ, Inst Biosci, Dept Phys & Biophys, BR-18618689 Botucatu, SP, Brazil FAPESP: 2016/02855-1 FAPESP: 2016/11760-4