Monensin Supplementation Research Articles

Effect of supplementation of developing replacement heifers with monensin or bambermycins on gain and pregnancy rates

ABSTRACT Medicated feed additives have been shown to increase BW gain and decrease age at puberty; therefore, heifers were provided nonmedicated control (CNTRL), bambermycins (BAMB, Gainpro, Huvepharma Inc., Sofia, Bulgaria), or monensin (MON, Rumensin, Elanco Animal Health, Greenfield, IN) supplements to determine effects on growth performance and reproductive development. Spring-calving (block 1; n = 70 heifers; BW = 208 ± 21.7 kg; age = 231 ± 17.0 d) and fall-calving (block 2; n = 72 heifers; BW = 225 ± 31.7 kg; age = 276 ± 12.8 d) heifers were allotted to treatments [n = 4 groups in CNTRL and 5 groups in BAMB and MON (block 1), 4 groups per treatment (block 2)] by breed, BW, and source. Heifers in block 1 grazed tall fescue [Lolium arundinaceum (Schreb.) Darbysh.] for 188 d; heifers in block 2 grazed bermudagrass (Cynodon dactylon) pasture and tall fescue for 161 d. The BW at breeding and ADG of CNTRL (323 ± 4.8 kg and 0.68 ± 0.0167 kg/d, respectively) was less (P ≤ 0.04) than medicated, yet MON (346 ± 4.6 kg and 0.73 ± 0.0163 kg/d) and BAMB (344 ± 4.6 kg and 0.74 ± 0.0163 kg/d) did not differ (P ≥ 0.69). Prebreeding reproductive tract scores (3.5 ± 0.60), cycling activity (61 ± 12.3%), and AI (30 ± 12.3%) and total pregnancy rates (82 ± 11.5%) did not differ (P ≥ 0.25) among treatments. This experiment indicates that BAMB and MON effectively increased growth performance of heifers but did not affect reproductive development or pregnancy rates.

Influence of a blend of functional oils or monensin on nutrient intake and digestibility, ruminal fermentation and milk production of dairy cows

Cashew nut shell liquid (CNSL) and castor oil (CO) are considered functional oils since they present antitumor, antioxidant, gastroprotective, and antibiotic properties. The objective of this study was to evaluate the effects a commercial blend of functional oils (CNSL and CO) and monensin supplementation on nutrient intake and total tract apparent digestibility, ruminal fermentation, milk yield and composition, N utilization, microbial protein synthesis, and blood metabolites of dairy cows. Twenty-four multiparous Holstein cows (150.2±61.4days in milk, 619±76kg of BW and 29.1±4.0kg/d of milk yield, mean±SD) were used in a replicated 3×3 Latin square experimental design, in which six ruminally cannulated cows were used to assess ruminal fermentation. The animals were randomly assigned to one of the following three treatments: control (CON; without additive); 500mg/kg DM of functional oil (FO; commercial blend of CNSL and CO), and 22mg/kg DM of monensin sodium (MON). The treatments did not affect either nutrient intake or digestibility of diets. Both feed additives provided an increase in ruminal propionate molar proportion compared to CON. In addition, FO increased ruminal propionate concentration when compared to MON and CON. Although both additives increased (P<0.01) milk and protein yields, MON had lower milk fat concentration compared to CON, not differing from FO. Monensin and FO increased milk nitrogen excretion.Neither rumen microbial N synthesis nor blood glucose concentration were changed by the supplements. Finally, FO decreased (P<0.001) blood urea concentration compared to CON or MON, besides increasing milk yield without altering nutrient intake; thus, it might be an alternative to monensin in lactating cow diets.

EFEITO DA MONENSINA SÓDICA SOBRE O PERFIL METABÓLICO DE OVELHAS ANTES E APÓS O PARTO

Resumo O estudo foi realizado com o intuito de avaliar o efeito da monensina, suplementada a partir de 60 dias antes do parto (dap) e por 30 dias pós-parto, sobre o perfil metabólico e hormonal de ovelhas. As ovelhas prenhas (n=13), foram divididas, de forma aleatória, em dois grupos, um que recebeu a monensina (n=7) (30 mg/dia) e o controle (n=6). Amostras de sangue e fluido ruminal foram colhidas aos 60, 50, 40, 30, 20 e 10 dias antes do parto, no momento do parto e nos 10, 20 e 30 dias pós-parto. As variáveis mensuradas foram: glicose, frutosamina, ácidos graxos não esterificados (AGNEs), β-hidroxibutirato, colesterol, triglicérides, proteína total, albumina, ureia e pesquisa de corpos cetônicos na urina. As determinações hormonais foram cortisol e a insulina. No fluido ruminal foi determinado o pH e a concentração dos ácidos graxos voláteis. Na análise estatística foi empregada a ANOVA e estudo de correlação (P&lt;0,05). A monensina elevou (P&lt;0,05) a concentração do propionato no rúmen e frutosamina e insulina no sangue. A administração da monensina promoveu melhora em alguns indicadores do balanço energético.

064 Effect of monensin supplementation on Brahman cow performance and postpartum follicular development

064 Effect of monensin supplementation on Brahman cow performance and postpartum follicular development

Effects of Feeding Garlic and Juniper Berry Essential Oils on Milk Fatty Acid Composition of Dairy Cows.

Essential oils (EOs) from plant extracts have been reported to have an antibacterial activity against gram-negative and gram-positive bacteria. Several of the gram-positive bacteria are involved in ruminal biohydrogenation of fatty acids (FAs), thus suggesting that feeding EOs could lower biohydrogenation of FA because of a decrease in the number of bacteria involved in that process. As a result, milk FA profiles are expected to be modified. In addition, monensin was approved as an antibiotic to be fed in dairy cattle, and it was reported that dairy cows supplemented with monensin produced milk containing higher concentration of 18:1 t10 and 18:1 t11. The objective of this study was to evaluate the effects of two EOs (garlic and juniper berry oils) and monensin on FA profiles of milk fat. Four ruminally fistulated Holstein dairy cows were used in a 4 × 4 Latin square experiment. Cows were fed for ad libitum intake a total mixed ration without supplementation (control), or supplemented with monensin (330 mg/head per day), garlic oil (5 g/head per day), or juniper berry oil (2 g/head per day). The FA composition of saturated, monounsaturated, or polyunsaturated was not affected by supplementation of EO and monensin. However, proportion of conjugated linoleic acid trans 10, cis 12 (CLA t10, c12) was higher (P < 0.05) for cows fed EO or monensin than for control cows. Supplementation of monensin increased (P < 0.05) the proportion of total trans FA compared with the control. These results indicate that supplementation of the dairy cow diet with garlic or juniper berry EO or monensin had the potential to increase the proportion of CLA t10, c12 in milk fat with minimal overall effects on FA of milk fat. The results also confirm the increase of 18:1 t10 in milk fat by feeding monensin to dairy cows.

Relationships between ruminal Gram-positive bacteria and methane from lactating dairy cows supplemented with monensin and tallow, alone or in combination

The aim of this study was to explore the relationships between a Gram-positive bacterial population and methane production in the rumen of dairy cows supplemented with monensin and tallow, alone or in combination. Under each treatment condition, the following ruminal fermentation parameters were measured: pH, oxidation-reduction potential (ORP), VFA, and methane production. Quantification of Gram-positive bacteria present in the rumen was performed by amplifying the 16S rDNA gene using PCR. Diversity analysis of Gram-positive bacteria was performed by PCR–denaturing gradient gel electrophoresis (DGGE), and bacterial taxonomy data were obtained by bioinformatics tools. Neither additive affected the pH or ORP, but they both reduced the total quantity of VFA. Supplementation with monensin, tallow, or their combination caused a decrease in methane production compared to the control diet. The best treatment to reduce methane production was monensin, with a reduction of 7.2% compared to the control diet. Supplementation with monensin or tallow did not affect the bacterial population. The Shannon diversity index was higher with monensin supplementation than with the other treatments. The analysis of each DGGE microbial community by the unweighted pair group method with averaging (UPGMA) revealed two clusters, one group with the control and monensin diets and the other with the tallow and combination diets. Taxonomic analysis of the dominant bands from the DGGE gel with the use of the Ribosomal Database Project (RBP) revealed that the Ruminococcaceae family was predominant, followed by the Lachnospiraceae family. Correspondence analysis (CA) suggested that both were negatively correlated with methane production in all treatments.

Effect of Grape Pomace Powder, Mangosteen Peel Powder and Monensin on Nutrient Digestibility, Rumen Fermentation, Nitrogen Balance and Microbial Protein Synthesis in Dairy Steers.

This study was designed to investigate the effect of grape pomace powder (GPP), mangosteen peel powder (MPP) and monensin on feed intake, nutrients digestibility, microorganisms, rumen fermentation characteristic, microbial protein synthesis and nitrogen balance in dairy steers. Four, rumen fistulated dairy steers with initial body weight (BW) of 220±15 kg were randomly assigned according to a 4×4 Latin square design to receive four treatments. The treatments were as follows: T1 = control, T2 = supplementation with monensin at 33 mg/kg diet, T3 = supplementation with GPP at 2% of dry matter intake, and T4 = supplementation with MPP at 30 g/kg diet. The steers were offered the concentrate diet at 0.2% BW and 3% urea treated rice straw (UTRS) was fed ad libitum. It was found that GPP supplemented group had higher UTRS intake and nutrient digestibility in terms of neutral detergent fiber and acid detergent fiber than those in control group (p<0.05). Ammonia nitrogen (NH3-N) and blood urea-nitrogen concentration were higher in monensin, GPP and MPP supplemented groups (p<0.05). Total volatile fatty acids and propionate in the GPP group were higher than those in the control group (p<0.05) while acetate concentration, and acetate to propionate ratio were decreased (p<0.01) when steers were supplemented with GPP, monensin, and MPP, respectively. Moreover, protozoal populations in GPP, MPP, and monensin supplementation were significantly lower than those in the control group (p<0.05), while cellulolytic bacterial population was significantly higher in the control group (p<0.05). Nitrogen retention, microbial crude protein and efficiency of microbial nitrogen synthesis were found significantly higher in steers that received GPP (p<0.05). Based on this study it could be concluded that the GPP has potential as an alternative feed supplement in concentrate diets which can result in improved rumen fermentation efficiency, digestibility and microbial protein synthesis in steers fed on treated rice straw.

The effects of increasing garlic powder and monensin supplementation on feed intake, nutrient digestibility, growth performance and blood parameters of growing calves.

The objective of this study was to evaluate the effects of increasing garlic powder and monensin supplementation on feed intake, nutrient digestibility, growth performance and blood metabolites of growing calves. Forty Holstein calves (BW=100±11kg) were randomly assigned to four dietary treatments (n=10) in a complete randomized design. Experimental treatments consisted of the following: (i) basal diet (control), (ii) basal diet supplemented with 0.0003% of dietary dry matter (DM) sodium monensin, (iii) low level of garlic powder (Low-GAR; 0.5% of dietary DM) and (iv) high level of garlic powder (High-GAR; 1% of dietary DM). DM intake (DMI) and DM digestibility were (p<0.05) decreased by High-GAR. However, calves supplemented with Low-GAR had a similar DMI to the control calves and similar DM digestibility to the control and monensin groups. The digestibility of other nutrients were not affected by the treatments. Although supplementing monensin relative to Low-GAR increased the DMI (p<0.05), average daily gain was similar between Low-GAR and monensin supplemented calves, which were higher than the control and High-GAR groups (p<0.05). As a result, feed conversion ratio was improved in the Low-GAR group versus other treatment groups (p<0.05). Administrating garlic powder decreased the blood low-density lipoprotein (LDL) and non-esterified fatty acids (p<0.05) without affecting the blood triglyceride, high-density lipoprotein and beta-hydroxybutyric acid concentrations. In conclusion, the calves fed the Low-GAR showed an improved FCR and blood metabolites without changing the DMI and nutrient digestibility. It suggests that garlic powder could be used as an alternative to monensin for growing calves under the current feeding conditions.

Effects of monensin on production and energy metabolism in early lactation cows

The aim of the research was to investigate effects of monensin controlled-release capsules on production and metabolism in early lactation cows, with relation to the time of administration of monensin. The study was performed in 2014 (from 01/05/2014 to 01/10/2014) at a Lithuanian cattle farm having 500 dairy cows. Four experimental groups were applied as follows: 1) Group 1 (G1) control (no supplementation, n = 20); 2) Group 2 (G2) with supplementation of monensin (32.4 g monensin controlled-release capsule (MCRC), n = 20). Both groups were on 30th day before expected calving; 3) Group 3 (G3) control (no supplementation, n = 10); 4) Group 4 (G4) with supplementation of monensin (32.4 g monensin controlled-release capsule (MCRC), n = 10). Both groups were on day 1 post partum. Group 2 (G2) received MCRC 30 days before calving, Group 4 (G4) 1 day after calving. Experimental and control cows received the same diet and were exposed to the same environment and management conditions during the entire experimental protocol. Blood samples were collected from the coccygeal vessels: G1 and G2 cows from day –30 (before expected calving, prior to supplementation), each day, up to 30 days post partum; G3 and G4 from day 1 post partum, each day, up to 30 days post partum. Blood serum was tested for beta-hydroxybutyrates (BHB) and glucose concentration. The daily milk yield was measured electronically (DairyPlan C21, Westfalia Surge Inc., GEA). Milk was sampled once monthly. Samples were analyzed for contents of fat, protein, lactose, urea, and somatic cells count. The BHB concentration decreased more efficiently after the supplementation of MCRC after calving. After supplementation with monensin on the first day after calving, it has been identified that the BHB concentration in serum of experimental group (G4) cows statistically significantly decreased after 3 days (p &lt; 0.05). During this period, the average BHB concentration of control group (G3) cows was 0.414 (±0.05) mmol/l, while the BHB concentration of experimental group (G4) cows was 0.27 (±0.03) mmol/l. Statistically significant differences between the experimental and the control groups were observed during the entire study (p &lt; 0.05). After calving, cows supplemented with monensin showed statistically significant higher production of milk (p &lt; 0.05) than the control group. Statistically significant differences in the blood glucose and BHB concentration, quantity of milk and production average between two experimental groups (G2 and G4) were not identified.

Stocking rate and monensin supplemental level effects on growth performance of beef cattle consuming warm-season grasses.

The objective of this study was to evaluate the effects of monensin supplementation on animals receiving warm-season grass with limited supplementation. In Exp. 1, treatments were a factorial combination of 2 stocking rates (1.2 and 1.7 animal unit [AU] [500 kg BW]/ha) and supplementation with monensin (200 mg/d) or control (no monensin) distributed in a complete randomized design with 3 replicates. Thirty Angus × Brahman crossbred heifers (Bos taurus × Bos indicus) with initial BW of 343 ± 8 kg were randomly allocated into 12 bahiagrass (Paspalum notatum) pastures and supplemented with 0.4 kg DM of concentrate (14% CP and 78% TDN) daily for 86 d. Herbage mass (HM) and nutritive value evaluations were conducted every 14 d, and heifers were weighed every 28 d. There was no effect (P ≥ 0.97) of monensin on HM, herbage allowance (HA), and ADG; however, animals receiving monensin had greater (P = 0.03) plasma urea nitrogen (PUN) concentrations. The stocking rate treatments had similar HM in June (P = 0.20) and July (P = 0.18), but the higher stocking rate decreased (P < 0.01) HM and HA during August and September. Average daily gain was greater (P < 0.01) for the pastures with the lower stocking rate in August but not different in July and September (P ≥ 0.15). Gain per hectare tended to be greater on pastures with the higher stocking rate (P ≤ 0.06). In Exp. 2, treatments were 3 levels of monensin (125, 250, and 375 mg/animal per day) and control (no monensin) tested in a 4 × 4 Latin square with a 10-d adaptation period followed by 5 d of rumen fluid collection and total DMI evaluation. Blood samples were collected on d 4 and 5 of the collection period. Ground stargrass (Cynodon nlemfuensis) hay (11.0% CP and 52% in vitro digestible organic matter) was offered daily. The steers received the same supplementation regimen as in Exp. 1. Total DMI was not different among treatments (P = 0.64). There was a linear increase (P ≤ 0.01) in propionate and a tendency for decreased acetate (P ≤ 0.09) concentrations in the rumen with increasing levels of monensin; however, there was no effect (P ≥ 0.19) of monensin levels on ruminal pH and ruminal concentrations of butyrate and ammonia. In addition, there was no effect (P ≥ 0.73) of monensin levels on plasma concentrations of glucose, insulin, IGF-1, and PUN. In summary, monensin supplementation effects were not detected at either stocking rate and may not be effective in increasing performance of beef cattle grazing low-quality warm-season grasses with limited supplementation.

Interaction of sunflower oil with monensin on milk composition, milk fatty acid profile, digestion, and ruminal fermentation in dairy cows

Abstract Four ruminally fistulated multiparous Holstein cows were assigned to a 4 × 4 Latin square design to determine the interaction between sunflower oil and monensin supplementation on intake, milk production, total apparent digestibility of the diet (TTAD), ruminal fermentation characteristics and milk fatty acid profile. The experimental diets consisted of a 2 × 2 factorial arrangement of treatments: (1) control (no sunflower oil and no monensin; CON), (2) diet containing (dry matter (DM) basis) 42 g/kg sunflower oil (OIL), (3) control with monensin (16 mg/kg of DM; MON), and (4) diet containing (DM basis) 42 g/kg sunflower oil and 16 mg/kg monensin (MIX). Sunflower oil supplementation tended to decrease DM intake and yield of milk fat. Sunflower oil decreased milk urea N concentration likely as a result of better N utilization, suggesting that sunflower oil contributes to decrease deamination and amount of amino acids used for gluconeogenesis. There were interactions between monensin and oil supplementation for acetate, propionate, and the acetate to propionate ratio in the rumen as a result of lower proportion of acetate and higher proportion of propionate for cows fed MON compared to those fed CON. Molar proportions of butyrate and isobutyrate in the rumen were decreased by monensin and proportion of butyrate was increased by oil. There was no interaction between monensin and oil for milk FA profile. Sunflower oil supplementation decreased proportions of all short-chain and most medium-chain FA. Compared with cows fed no oil, those supplemented with sunflower oil had higher proportions of total trans FA and monensin had no effect. This study suggests that supplementing dairy cow diets containing a corn-based concentrate with a combination of monensin and sunflower oil adds no further improvements in milk FA profile to supplementing sunflower oil alone although the lack of effect on parameters with large numerical changes such as DM intake and milk yield should be confirmed using more animals.

Effect of dietary monensin supplementation and amino acid balancing on lactation performance by dairy cows

A replicated-pen experiment was conducted to determine effects of dietary monensin supplementation and amino acid balancing on lactation performance by dairy cows. Cows (n = 128) were stratified by breed, parity, and DIM and randomly assigned to 16 pens of 8 cows each. Pens were randomly assigned to 1 of 4 treatments in a 2 × 2 factorial arrangement of treatments: control (no monensin or amino acid balancing), amino acid balanced (AA), control plus monensin (CNMN), or AA plus monensin (AAMN) for a 2-wk covariate period followed by a 10-wk treatment period. The TMR contained, on average (DM basis), corn silage (37.5%), alfalfa silage (23.0%), and concentrate mixture (39.5%). The AA and AAMN treatments were supplemented with blood meal and ruminally protected methionine to achieve a 3:1 lysine:methionine ratio in the metabolizable protein. The CNMN and AAMN treatments were formulated to provide a monensin intake of 540 mg/d per cow. Data were analyzed with pen as the experimental unit. Dry matter intake was reduced (P < 0.01) by monensin supplementation (26.9 vs. 27.6 kg/d per cow). Feed conversion was greater (P = 0.03) for cows fed monensin (1.81 vs. 1.75 kg of milk/kg of DMI). Milk protein percentage and yield were increased (P < 0.01 and P = 0.03, respectively) by amino acid balancing (3.15 vs. 3.08% and 1.53 vs. 1.49 kg/d per cow, respectively). Component-corrected feed-conversion ratios were greater (P = 0.02) for cows fed monensin. Dietary monensin supplementation increased feed-conversion ratios through reduced DMI, and milk protein percentage and yield were greater for cows fed the amino acid–balanced diets.

Performance of early-lactation dairy cows as affected by dietary starch and monensin supplementation

The objective of this study was to evaluate the effect of postpartum dietary starch content and monensin supplementation throughout the periparturient period and into early lactation on production performance of dairy cows during early lactation. Prior to parturition, primiparous (n=21) and multiparous (n=49) Holstein cows were fed a common controlled-energy close-up diet with a daily topdress of either 0 or 400mg/d monensin. From d 1 to 21 postpartum, cows were fed a high-starch (HS; 26.2% starch, 34.3% NDF, 22.7% ADF, 15.5% CP) or low-starch (LS; 21.5% starch, 36.9% NDF, 25.2% ADF, 15.4% CP) total mixed ration with a daily topdress of either 0mg/d of monensin or 450mg/d monensin (MON), continuing with prepartum topdress treatment assignment. From d 22 through 63 postpartum, cows were fed HS and continued with their assigned daily topdress. Interactions of starch content and MON supplementation were not significant for any of the variables measured. Cows fed HS from wk 1 to 3 postpartum had higher early-lactation milk yields (starch × week interaction) compared with LS cows, but HS cows also had lower percentages of milk fat, true protein, lactose, and total solids during the same period, resulting in similar yields of energy-corrected milk (ECM) between starch treatments. Cows fed HS had higher early-lactation dry matter intake (DMI; starch × week interaction) and lost less body condition score during wk 1 to 3, contributing to improved energy balance postpartum. No effect of starch treatment was observed on apparent total-tract dry matter or starch digestibilities assessed during d 18 to 19 (±2) postpartum, although cows fed the LS diet had greater apparent total-tract NDF digestibility compared with cows fed the HS diet. Cows fed MON had higher DMI and higher milk yields during the first 9 wk of lactation. However, all cows had similar yields of ECM because of trends for lower milk fat content during early lactation. In part because of similar yields of ECM between these treatments and higher DMI for cows fed MON, ECM per DMI during the first 9 wk of lactation was not affected by MON treatment. There was no effect of MON treatment on apparent total-tract dry matter, NDF, or starch digestibilities. Overall, cows fed more propiogenic diets in early lactation (HS or MON) had increased milk yield and DMI during the immediate postpartum period, indicating that diets with greater propiogenic capacity do not have detrimental effects on early-lactation DMI.

Metabolism of early-lactation dairy cows as affected by dietary starch and monensin supplementation

The objective of this study was to evaluate the effect of dietary starch content and monensin (MON) on metabolism of dairy cows during early lactation. Before parturition, primiparous (n=21) and multiparous (n=49) Holstein cows were fed a common controlled-energy close-up diet with a daily topdress of either 0 or 400mg/d monensin. From d 1 to 21 postpartum, cows were fed a high-starch (HS; 26.2% starch, 34.3% neutral detergent fiber, 22.7% acid detergent fiber, 15.5% crude protein) or low-starch (LS; 21.5% starch, 36.9% neutral detergent fiber, 25.2% acid detergent fiber, 15.4% crude protein) total mixed ration with a daily topdress of either 0mg/d monensin (CON) or 450mg/d monensin (MON), continuing with prepartum topdress assignment. From d 22 through 63 postpartum, all cows were fed HS and continued with the assigned topdress treatment until d 63. Cows fed HS had higher plasma glucose and insulin and lower nonesterified fatty acids (NEFA) than cows fed LS during d 1 to 21 postpartum. Cows fed LS had elevated early-lactation β-hydroxybutyrate (BHBA) compared with cows fed HS. Cows fed HS had greater insulin resistance and increased plasma haptoglobin in the early lactation period. There was no effect of MON on postpartum plasma NEFA. Cows fed MON had higher plasma glucose compared with CON cows, which was driven by a MON × parity interaction in which primiparous cows fed MON had greater plasma glucose concentrations than cows fed CON. Cows fed MON had lower plasma BHBA compared with CON, which was contributed to by a MON × parity interaction in which primiparous cows fed MON had lower BHBA concentrations than CON. Starch treatment had no effect on overall liver triglyceride content. Primiparous cows fed MON had increased liver triglyceride content compared with CON primiparous cows, and multiparous cows fed MON had decreased liver triglyceride content compared with CON cows. Multiparous cows fed LS with MON had higher liver glycogen content than multiparous cows fed the LS without MON, with no effect of MON treatment for multiparous cows fed HS. There was no effect of starch or MON treatment on liver capacity to oxidize propionate to CO2, and effects of starch on gluconeogenesis were not significant. Cows fed MON tended to have greater capacity to convert propionate to glucose than CON. Supplementation with MON increased the ratio of glucose to CO2, which indicated that cows fed MON had a greater propensity to convert propionate to glucose. Overall, cows fed more propiogenic diets in early lactation (high starch or monensin) exhibited improved energy metabolism during early lactation.

Effects of hainanmycin or monensin supplementation on ruminal protein metabolism and populations of proteolytic bacteria in Holstein heifers

Three ruminally cannulated cows were used in a 3×3 Latin square design (21-d periods) to evaluate effects of hainanmycin (HAI) or monensin (MON) supplementation on ruminal protein metabolism and populations of proteolytic bacteria in Holstein heifers. The three dietary treatments were: (1) basal diet (control); (2) basal plus 20mg/heifer per day HAI and (3) basal plus 350mg/heifer per day MON. The supplementation with HAI and MON had minor effects on ruminal pH and total VFA. In general, HAI and MON decreased acetate, butyrate concentrations, and acetate to propionate ratio, and increased propionate concentration. Supplementation of HAI and Mon resulted in higher relative population sizes of the genus Prevotella and Prevotella ruminicola, and fewer Butyrivibrio fibrisolvens and hyper-ammonia-producing bacteria (P<0.05). HAI supplementation increased concentrations of peptide nitrogen and amino acid nitrogen, and reduced ammonia concentration (P<0.05), and decreased peptidase and deaminase activities (P<0.05). Overall, HAI was as effective as monensin as ionophore in regulation of ruminal protein metabolism and populations of proteolytic bacteria for dairy cows.

Effects of monensin and virginiamycin supplementation in finishing diets with distiller dried grains plus solubles on growth performance and digestive function of steers

Two trials were conducted to evaluate the influence of virginiamycin (26 mg/kg) and monensin (34 mg/kg) supplementation of a steam-flaked corn-based finishing diet containing 15% distiller dried grains plus solubles (DDGS) on growth performance and digestive function. In Trial 1, 135 steers (257 ± 21 kg) were used to evaluate treatment effects on 145-d growth performance. There were no treatment effects (P > 0.20) on dry matter intake (DMI). Antibiotic supplementation tended to increase average daily gain (ADG; 7%, P = 0.07); increased gain efficiency (11%, P < 0.01) and estimated dietary net energy (NE; 10%, P < 0.01). Carcass marbling score was greater (12%, P = 0.04) for virginiamycin vs. monensin. In Trial 2, three Holstein steers (300 ± 7 kg) were used in a 3 × 3 Latin square to evaluate treatment effects on digestion. Both monensin and virginiamycin depressed ruminal digestion of organic matter (OM; 6%, P < 0.01) and feed nitrogen (N, 15%, P = 0.03) and microbial protein synthesis (15%, P = 0.03). There were no treatment effects of total tract OM and N digestion. Antibiotic supplementation increased (2.3%, P = 0.02) ruminal pH, associated with decreased (7%, P = 0.04) ruminal volatile fatty acids (VFA) concentrations. It is concluded that monensin and virginiamycin supplementation of growing-finishing diets for feedlot cattle may enhance daily weight gain, gain efficiency and dietary energetics. These effects are associated with a shift towards great intestinal OM digestion and decreased ruminal degradation of feed N and microbial protein synthesis.

Effects of grain source and monensin level on growth performance, carcass traits and fatty acid profile in feedlot beef steers

A study was conducted to evaluate growth performance, carcass traits, and composition of fatty acid in carcass of feedlot steers fed diets varying in grain source and monensin levels. Two hundred crossbred steers (initial body weight [BW] 488±36.9kg) were blocked by BW, allotted to 20 pens, and then randomly assigned to 5 treatments (4 pens per treatment) with 2×2+1 factorial arrangement. Treatments were barley (100g/kg barley silage, 900g/kg barley-based concentrate, and 28mg/kg monensin) which is a standard feedlot diet for western Canadian feedlots, and diets substituting hard or soft wheat for barley combining with 28 or 44mg/kg monensin. Dry matter intake (DMI) was higher (P<0.02) for wheat than for barley diets but it was not different between hard and soft wheat diets. Increasing monensin supplementation reduced (P<0.01) DMI. Final BW, average daily gain and gain:feed were not different between treatments. Carcass traits were not affected by treatments except that dressing fraction was greater (P<0.05) for steers fed barley than wheat diets. Additionally, steers fed soft wheat had less (P<0.05) back fat and greater (P<0.05) meat yield compared with hard wheat diet. Substitution of wheat for barley grain did not affect the total monounsaturated fatty acid and polyunsaturated fatty acid, but decreased (P<0.05) vaccenic acid (t11-18:1; VA) and a-linolenic acid (18:3n-3; ALA) in the pars costalis diaphragmatic muscles of beef cattle. These results indicate that wheat can effectively replace barley grain in finishing ration without negatively influencing growth performance, carcass traits, and FA composition in beef. Supplementing monensin with higher level than currently practical level had no evident effect on growth rate, feed efficiency and carcass traits, although DMI was decreased.

Effect of daily or alternate-day distillers grains supplementation with or without monensin on performance of grazing calves

<h2>ABSTRACT</h2> The objective of these experiments was to determine the effect of daily or alternate day supplementation of dried distillers grains with solubles (DDGS) with or without monensin on performance of grazing calves. Treatments included (1) a negative control with no supplemental feed except free-choice mineral; (2) DDGS offered daily at 1.02kg as-fed per calf, including a mineral premix; (3) daily DDGS and monensin (Rumensin, Elanco, Greenfield, IN) at 1.02kg as-fed per calf, including a mineral premix supplying 160mg of monensin/calf daily; (4) alternate day DDGS to supply 2.04kg as-fed per calf, including the mineral premix offered on alternate days; and (5) alternate day DDGS and monensin to supply 2.04kg as-fed per calf, including a mineral premix and 320mg of monensin/calf on alternate days. Four experiments were conducted which included both steers (n=70) and heifers (n=230) grazing warm season grass based pastures (Exp. 1, 2, and 3) or nontoxic endophyte-infected tall fescue (Exp. 4). Supplementation increased ADG (P≤0.04) by 0.16 to 0.26kg/d in the 4 studies, with an average improvement (P<0.01) of 0.21kg/d. Monensin addition and supplement timing had no effect (P≥0.16) on BW, ADG, or supplemental efficiency in any of the 4 experiments. Supplementation increased ADG of growing beef calves regardless of pasture quality or basal cattle performance. The performance improvement was similar whether supplements were fed daily or on alternate days. Contrary to expected results, monensin inclusion in the supplement had no effect on animal performance or supplemental efficiency.

Desempenho, características de carcaça e expressão de genes em tourinhos alimentados com lipídeos e monensina

O objetivo deste trabalho foi avaliar o desempenho, as características de carcaça e as suas correlações com as expressões gênicas em tourinhos. Quarenta animais Red Norte foram confinados e distribuídos em delineamento inteiramente casualizado, em arranjo fatorial 2x2, e alimentados com grãos de soja moídos ou gordura protegida, com ou sem inclusão de monensina. As dietas foram formuladas para serem isonitrogenadas, com teores de extrato etéreo semelhante (6,5%), e tiveram silagem de milho como volumoso (40%). O período experimental foi de 84 dias, precedido por 14 dias de adaptação. Foram avaliadas as expressões dos genes PPARA, SREBP1c e SCD1. Animais alimentados com gordura protegida tiveram maior ganho de peso nos primeiros 56 dias de confinamento. O uso da monensina não afetou o ganho de peso diário dos animais, mas proporcionou aumento do rendimento de carcaça. Houve correlação de -0,40 entre o ganho de peso dos animais e a expressão do SCD1. O uso de gordura protegida aumenta o desempenho dos animais no início do confinamento, e a monensina proporciona maior rendimento de carcaça.

Changes in blood profile in sheep receiving raw garlic, garlic oil or monensin

This study aimed to evaluate the effects of supplementing a basal diet (CTR) with raw garlic (GAR) or garlic oil (GAO) on blood profile in sheep. Monensin (MON, 33 mg/kg DM) was used as positive control. Four ruminally fistulated rams were used in three experiments each arranged in a 4 × 4 Latin square design with 28-day periods. Experiments 1 and 2 differed in the dose of GAR (75 vs. 100 g/kg DM) and GAO (500 vs. 750 mg/kg DM), while experiment 3 was designed to compare the two doses of each additive (GAR and GAO). The animals were fed a basal diet as TMR consisting of 77.83% forage (alfalfa hay and corn silage) and 22.17% concentrate, providing 10.50 MJ/kg DM (metabolizable energy) and 16.5% crude protein to cover maintenance energy and protein requirements. Supplementation of monensin decreased (P < 0.05) β-hydroxybutyrate (BHB) and non-esterified fatty acid (NEFA) concentrations in the blood compared with other treatments. There was no significant effect of additives on serum concentration of glucose, total triglycerides, cholesterol, total protein, albumin and blood urea nitrogen (BUN). Although the serum insulin concentration was elevated in sheep receiving MON and GAO (P < 0.01), no change was observed in blood glucose concentration. No significant effect of GAO and GAR was observed in key energy and protein-related blood metabolites. However, administration of monensin had a positive influence on energy indices. In conclusion, whereas parameters characterizing the energy balance did not show a significant effect of GAR supplementation, a higher insulin concentration in GAO-treated animals was observed.