Kg Of Initial BW Research Articles

How neonatal diet affects the long-term development of rumination behavior, rumen fermentation and feed digestion in dairy calves fed a high milk level?

This study was to investigate growth performance, rumination development, rumen fermentation and feed digestion in young calves provided high volumes (about 20% of calf birth weight) of milk with or without forage inclusion and how these parameters correlate with each other. Immediately after birth, 160 newborn Holstein female calves (41.6 ± 4.2 kg of initial BW) were randomly divided into 2 treatments: 1) starter (CON, only starter) and 2) starter and hay (HAY, both starter and hay). The calves were fed their respective experimental diets from d 4 to 84, after which they were all introduced to similar diets until the end of the experiment on d 196. Treatment had no effect on growth and structural measurements throughout the experimental period. However, treatment had an effect on the other parameters, mainly during the post-weaning period. Forage supplementation tended to reduce starter dry matter intake (P = 0.05), while increasing the forage intake (P < 0.01) and the feed-to-gain ratio (P < 0.01). HAY calves had increased neutral detergent fiber (NDF) and physically effective NDF (peNDF) intakes (P < 0.05) and tended to lower (P < 0.01) starch intake compared to CON calves. The HAY calves had a higher rumination time (P < 0.01), ruminal pH (P < 0.01), and acetate-to-propionate ratio (P = 0.05) compared to the CON calves. Spearman correlation analysis showed that rumination time was positively related to the ruminal pH at d 84 (P = 0.01) and 196 (P = 0.02). The HAY calves had similar apparent total-tract digestibility of dry matter (DM), NDF and ether extract (EE), but lower digestibility of organic matter (OM, P = 0.03), crude protein (CP, P < 0.01) and starch (P < 0.01) compared to those of the CON calves at week 12. Furthermore, there were no positive relationships between rumination time and nutrient digestibility or between rumination time per kilogram DM and nutrient digestibility. In conclusion, feeding hay to calves fed a high milk level improved rumination during the post-weaning period only, without a concomitant effect on growth performance throughout the experimental period, suggesting no detrimental effect of feeding forage in calves fed high milk level.

Orange molasses as a new energy ingredient for feedlot lambs in Brazil.

The objectives of this experiment were to evaluate the effects of increasing levels of orange molasses in replacement of flint corn grain in high-concentrate diets on dry matter intake (DMI), average daily gain (ADG), and feed efficiency (FE) of feedlot lambs. Thirty male lambs without defined racial pattern (30.3 ± 5.3 kg of initial BW; mean ± SD) were used in a randomized complete block design with 10 blocks and 3 treatments. The treatments were defined by partial replacement of flint corn by orange molasses in the diet with 90% of concentrate and 10% of Cynodon spp. hay, as follows: 0OM-control diet without orange molasses; 20OM-20% of orange molasses replacing flint corn; and 40OM-40% of orange molasses replacing flint corn (DM basis). The experiment lasted 72 days divided into 3 subperiods, with 1 subperiod of 16 days and 2 subperiods of 28 days. Animals were weighed after a 16-h fast on days 1, 16, 44, and 72 of the experimental periods to determine the ADG and FE. The DMI, ADG, and FE showed an interaction between treatments and experimental periods. The DMI in the first period decreased linearly (P < 0.01); in the third period, there was no effect of treatments (P > 0.05) on DMI. The ADG decreased linearly (P < 0.01) in the first period as the orange molasses increased. Otherwise, in the third period, ADG increased linearly (P = 0.05) as flint corn was replacement by orange molasses. The FE showed an interaction between treatment and period (P = 0.09). The first period had a decreased linear effect; in the third period, there was a trend (P = 0.07) of increased linear effect. There was no difference between the diets regarding the final BW of the lambs. In conclusion, the orange molasses can replace up to 40% of flint corn in diets for feedlot lambs without affecting final BW. However, it is important to consider the adaptation time proved to be very important for better use of orange molasses as a source of energy in diets for lambs.

Ingestive behaviour, physiological parameters and carcase traits of lambs fed diets containing greasy babassu by-product

ABSTRACT This experiment was conducted to evaluate the effect of increasing levels of greasy babassu by-product (GBB) effects on ingestive behaviour, physiological parameters and carcase traits. Twenty-eight lambs (20.6 ± 4.1 kg of initial BW) were distributed in a completely randomised design being confined for 60 days. The treatments were GBB inclusion levels (0, 50, 100 and 150 g kg-1, in DM basis) in diets with 20% roughage and 80% concentrate (DM basis). Physiological parameters and ingestive behaviour did not change with the inclusion of GBB in the diets (P > 0.05); however, the time of ruminating tended to decrease as well as the time of ruminating chews per bolus, and number of ruminating chews per bolus (P < 0.10). Additionally, inclusion of GBB did not change the carcase traits and commercial meat cuts (P > 0.05). Thus, the addition of GBB up to 150 g kg-1 in the diet for finishing lambs represents an attractive alternative feed for corn and soybean meal, which does not modify the physiological parameters, ingestive behaviour and carcase traits.

Wet brewers’ grains as a source of protein for feedlot lambs: Impacts on intake, apparent nutrient digestibility, ruminal fermentation, and nitrogen balance

The aim of this study was to evaluate the effect of wet brewers’ grain (WBG) as an alternative ingredient replacing soybean meal (SBM) and ground corn (GC) on nutrient intake and apparent digestibility, ruminal fermentation characteristics, and nitrogen balance in feedlot lambs. Five ruminally cannulated ½ Dorper × ½ Santa Inês lambs, castrated with 48.3 ± 2.0 kg of initial BW and 8.3 ± 0.68-month-old (mean ± SD), were assigned in a 5 × 5 Latin square design. The experimental diets were composed of 10% roughage (Coastcross hay) and 90% concentrates, in which 85.9% of the diet was composed of GC (71.3%) plus SBM (14.6%) in the control diet. Treatments consisted in WBG inclusion levels of 7.6%, 15%, 23% and 30% replacing GC+SBM in control diet with the aim to maintain isonitrogenous concentrations. The data were analyzed using a linear or quadratic polynomial contrast in SAS. There was no effect of WBG inclusion on DMI, OM nor CP intake, but a linear increase was observed for NDF (P < 0.001), ADF (P < 0.001), EE intake (P < 0.01), and linear decrease (P < 0.001) on NFC intake. Inclusion of WBG decrease linearly NFC, while DM, OM, and CP digestibility were being lower for lambs fed a diet contained 23% WBG (quadratic component, p < 0.05). The replacement of SBM and corn grain by WBG, linearly increased the molar ratio of acetate (P < 0.01), and linearly decreased propionate (P < 0.01), resulting in a linear increase in the acetate:propionate ratio (P = 0.04). In addition, increasing the inclusion of WBG linearly increased the molar proportion of isovalerate (P < 0.05). Ruminal pH increased linearly (P < 0.001) by dietary WBG inclusion, as consequence, ruminal pH was maintained less time below 5.5 as WBG inclusion increased. Although nitrogen excretion was greater with 23% inclusion of WBG in diet (quadratic component, P < 0.05), there was no effect (P > 0.10) on retained N. Based on diet acceptability, digestibility, N retention, and ruminal fermentation parameters, it is concluded that, WBG can be used as feed ingredient up to 7.6% in diets, replacing partially SBM and GC in finishing diets for lambs. Inclusion WBG replacing SBM and partially GC, minimize the risk of acidosis in lambs fed high-concentrate diets during fattening. Inclusions beyond 23% decreased significant diet digestibility and increased ruminal acetate: propionate molar ratio, decreasing energy efficiency, increasing methane losses.

Association between chitosan and unsaturated fatty acids supplementation on ruminal fermentation, digestive metabolism, and ruminal kinetics in beef heifers

This study evaluated the effects of supplementation of chitosan and unsaturated fatty acid (UFAs) sources on intake, digestibility, ruminal and nitrogen metabolism, blood metabolites, and feeding behavior of beef heifers. Five crossbred Simental x Zebu heifers (335 ± 53.2 kg of initial BW), ruminally cannulated, were randomly assigned according to a 5 × 5 Latin square design containing the following treatments: 1) CON, the control diet without supplementation; 2) SO, control diet supplemented with 25.3 g/kg of soybean oil; 3) WRS, control diet supplemented with 160 g/kg of whole raw soybean (WRS); 4) SOCHI, SO diet plus 14 g/kg of CHI; 5) WRSCHI, WRS diet plus 14 g/kg of CHI. No interaction effects between CHI and WRS were observed on nutrient intakes and digestibilities. Heifers fed SO, or WRS diets with or without CHI had lower enteric methane (CH4) emissions (P < 0.01) than those fed CON. Moreover, animals fed SO and WRS had higher CH4 emissions than those fed SOCHI and WRSCHI. No interaction between CHI and WRS was observed on nitrogen balance. However, heifers fed SO or WRS diets with or without CHI had lower nitrogen (N) intake (P = 0.001) and fecal N (P = 0.015) than those fed CON. Besides, animals fed SO and WRS diets showed lower retained N (P = 0.010) and efficiency (P = 0.005) than those fed SOCHI and WRSCHI. Heifers fed SO, or WRS diets with or without CHI showed lower rumination efficiencies of dry matter (DM; P < 0.01) and neutral detergent fiber (NDF; P = 0.013) than those fed CON. Heifers fed SO or WRS with or without CHI, showed lower reticular flows of DM (P = 0.049), NDF (P = 0.002), and potentially digestible NDF (P = 0.002) than those fed CON. In addition, animals fed SO or WRS diets with or without CHI showed a lower rumen digestion rate of DM, turnover rates of DM and NDF, and passage rates of DM and pdNDF than those fed CON. The supply of CHI to beef heifers fed diets with SO and WRS alters ruminal fermentation, methane production, nitrogen balance, feeding behavior, and ruminal dynamics. Nevertheless, the results strengthen the evidence that the provision of CHI in beef cattle diets can positively influence the effect of fatty acid sources. Besides, fatty acids sources provided alone have a negative influence on most metabolism parameters in beef heifers.

Essential oil from Arnica montana alters the protein metabolism in lambs fed with high-concentrate diets

The objective of this study was to evaluate the effect of essential oil (EO) from Arnica montana as an additive on nutrient intake and digestibility, nitrogen balance, and rumen fermentation characteristics in feedlot lambs. Five ruminally cannulated Dorper × Santa Inês ram lambs, castrated, with 50.6 ± 1.19 kg of initial BW and 14.6 ± 1.28 month-old were distributed in a 5 × 5 Latin square design. All lambs were fed a basal diet (160.5 ± 3.06 g/kg DM of CP) containing 90 % concentrate and 10 % forage (Coastcross hay) to which the following 5 treatments were applied: 1. 0 mg/kg DM of OE from Arnica montana (A0), 2. 450 mg/kg DM of OE from Arnica montana (A450), 3. 900 mg/kg DM of OE from Arnica montana (A900), 4. 1350 mg/kg DM of OE from Arnica montana (A1350), 5. diet with 25 mg/kg DM of sodium monensin (positive control – MON). The levels of EO from Arnica montana did not alter the dry matter intake (DMI) and nutrient intake (DM, OM, CP, EE, NDF, ADF, NFC, and TDN). There was higher DM and nutrient intake for the EO from Arnica montana diets compared to MON (P < 0.05). For the comparison between MON vs. A0, there was a lower DMI and nutrients intake for MON (P < 0.05). Crude protein digestibility increased linearly (P = 0.03) in response to increasing levels of EO from Arnica montana in the diets. However, the digestibility of the other nutrients was not altered by the inclusion of EO from Arnica montana. There was no difference in nutrient digestibility for comparison between diets containing EO from Arnica montana vs. MON; and MON vs. A0. The inclusion of EO from Arnica montana in the diet linearly decreased (P = 0.03) nitrogen (N) in the urine, which was associated with a linear decrease (P = 0.03) in rumen ammonia concentration. The EO from Arnica montana contents linearly increased N retention (g/kg N intake and g/kg N absorption; P < 0.05). Diets with EO from Arnica montana had higher N intake and N excretion in urine compared to MON (P < 0.05). There was increased N retention for the diets with EO from Arnica montana when compared to MON (P = 0.02). In the contrast between MON vs. A0, there was lower N intake and lower N excretion via urine for MON (P < 0.05). The EO from Arnica montana contents conferred a quadratic effect (P = 0.03) on the molar ratio of acetate, with a lower concentration for A450. The total and individual concentrations of the other short-chain fatty acids (SCFA) were not affected by the inclusion of EO from Arnica montana. Total and individual SCFA concentrations did not differ between diets containing EO from Arnica montana vs. MON, nor between MON vs. A0. Rumen pH was not influenced by the inclusion of EO from Arnica montana in the diet, but there was a quadratic effect (P = 0.02) on the area under pH 5.5, with a greater area under 5.5 for A450. Diets with EO from Arnica montana had lower rumen pH when compared to MON (P = 0.01). The MON diet increased rumen pH compared to A0 (P < 0.01), this result contributed to a lower area under pH 5.5 and a higher total pH area for MON (P < 0.05). In conclusion, the 1350 mg/kg DM of EO from Arnica montana was the most promising, especially for the increased dietary N use efficiency, even when compared with sodium monensin.

PSXVI-5 Rumen Parameters and Microbial Population Changes in Fattening Holstein Heifers fed with Nitrate-Contaminated Water

Abstract The aim of this study was to evaluate the effect of drinking water nitrate concentration on rumen parameters and its microbial population that may affect greenhouse gases in fattening cattle. Holstein heifers (n = 24; 161 ± 19.9 kg of initial BW, and 183 ± 25.3 d of age) were housed individually and fed ad libitum. Animals were assigned to 4 treatments according to nitrate concentration in drinking water: 1) Control (n=6), without NO3-; 2) Low (n=6), with 44 mg/L of NO3-; 3) Moderate (n=6), with 110 mg/L of NO3-, and 4) High (n=6), with 220 mg/L of NO3-. After 14 and 168 days the ruminal content was sampled to determine pH, volatile fatty acids (VFA), nitrate and nitrite concentration, and rumen microbiota (except for Moderate). To assess the rumen microbiota, DNA-based qPCR of total bacterial population (16S rRNA), dissimilatory sulfate-reducing prokaryotes (aprA), ammonia-oxidizing bacteria and archaea (amoA-AOB and amoA-AOA), typical complete denitrifiers (nosZ-clade I linked to the transformation of N2O to N2), and anammox bacteria (hzo) was determined. Rumen pH, VFA, nitrate and nitrite were analyzed with a mixed effects model. Rumen microbial populations were statistically treated by analysis of variance applying pairwise comparisons (Fisher's least). Rumen pH, VFA, nitrate and nitrite were not affected by nitrate concentration in drinking water; however, rumen nitrite concentrations were greater (P &amp;lt; 0.01) in d 14 than in d 168 (32.1 vs. 6.3 ± 4.20 mg/L, respectively). Nitrate drinking water concentration did not affect rumen microbial populations, except for complete-denitrifying population (nosZ-clade I) which were slightly greater (P=0.01) in High than in Control in d 168. In conclusion, nitrate-contaminated water did not show a significant impact on rumen parameters and microbial populations but increased the bacterial denitrifying potential after a long term, which could decrease ruminal N2O emissions and nitrite ruminal accumulation in fattening heifers.

Effects of medium-chain fatty acid supplementation on performance and rumen fermentation of lactating Holstein dairy cows

Medium-chain fatty acids (MCFAs) have antimicrobial properties and cause negative or positive effects on animal performance depending on its dosage. We hypothesized that MCFA supplementation at a lower dose (i.e., 0.05–0.2% of dietary DM) would increase rumen pH and milk production without decreasing nutrient digestibility which is typically observed with the higher inclusion rates (i.e., >1% of dietary DM). The objective of this study was to evaluate the effects of MCFA supplementation at a lower dose on productivity, plasma energy metabolite concentrations, apparent total tract nutrient digestibility, rumen fermentation, and rumen microbial profile of lactating dairy cows. Thirty (n = 8 primiparous, n = 22 multiparous) Holstein cows in mid-lactation (637 ± 68.5 kg of initial BW, 98.5 ± 27.4 d in milk; mean ± standard deviation) were used in a crossover design with two 28-d periods. The MCFA supplement, consisted of 25% MCFA (containing 32% C8:0, 21% C10:0, 47% C12:0 on DM basis) and 75% carrier ingredients, was fed at 0.25% of dietary DM replacing dry ground corn in control (CON). Total inclusion of MCFA was 0.063% of dietary DM. No differences were observed in DM intake, apparent total tract nutrient digestibility and BW change between MCFA and CON. Milk and milk component yields did not differ between treatment groups. The MCFA supplementation tended to have higher minimum rumen pH (5.66 vs. 5.54), and decreased daily fluctuation range of rumen pH (1.17 vs. 1.40) compared to CON. However, the duration of acidosis (pH < 5.8, min/d) did not differ between treatment groups and ruminal total volatile fatty acid concentration and its profile did not differ between treatment groups. For rumen microbiota, the Chao1 index of bacterial community tended to be lower (10.9 vs. 11.6) whereas the Shannon index did not differ (0.91 vs. 0.93) in MCFA compared to CON, and both indices did not differ for archaeal and protozoan communities between treatment groups. The relative abundance of Methanobrevibacter gottschalkii increased when supplemented with MCFA (5.14 vs. 4.92%). These results suggest that supplementation of MCFA at 0.063% dietary DM may not affect overall animal performance or total tract nutrient digestibility, but decrease the daily range of pH and the bacterial richness in the rumen.

Whole corn grain-based diet and levels of physically effective neutral detergent fiber from forage (pefNDF) for feedlot lambs: Digestibility, ruminal fermentation, nitrogen balance and ruminal pH

The present study evaluates the increasing levels of physically effective neutral detergent fiber of forage (pefNDF) in a whole corn grain-based diet on DMI, the apparent digestibility of nutrients, the nitrogen balance, and ruminal fermentation. Thirty ruminally cannulated Dorper × Santa Inês ram lambs, castrated, with 30.14 ± 3.01 kg of initial BW and approximately 3-month-old were used. The experimental design was in a randomized complete block (5 treatments and 6 blocks), defined by BW and age at the beginning of the experiment. The experimental diets were: CONT (positive control) – ground corn-based diet with 72 g/kg of pefNDF; 0pefNDF – whole corn grain-based diet without forage; 36pefNDF – whole corn grain-based diet with 36 g/kg of pefNDF; 72pefNDF – whole corn grain-based diet with 72 g/kg of pefNDF; 108pefNDF – whole corn grain-based diet with 108 g/kg of pefNDF (DM basis). The experimental diets were formulated to be isonitrogenous. The treatments did not affect the DMI. The increasing levels of pefNDF decreased the digestibility of DM, OM (P = 0.03) and TDN (P < 0.001). Whole corn grain-based diets associated or not with pefNDF showed higher digestibility of DM and OM (P < 0.01) than CONT. On the other hand, 0pefNDF showed higher digestibility of TDN (P < 0.01) than CONT. Ruminal propionate concentration of lambs fed CONT was lower than 0pefNDF (P = 0.04), while the isobutyrate concentration was higher (P = 0.01) for lambs on the CONT compared to lambs that received the other diets. The CONT had a lower ruminal pH (hour 9, P = 0.04; hour 12, P < 0.01) and ruminal pH area under the curve (hour 9, P = 0.03; hour 12, P < 0.02) when compared to the 0pefNDF. Additionally, at hours 9 (P < 0.02), 12 (P < 0.001) and 16 (P = 0.001) the lambs of the CONT had lower ruminal pH and pH area under the curve compared to lambs fed diets with whole corn with pefNDF. At hour 24, there was a linear increase in ruminal pH (P = 0.02) and ruminal pH area under the curve (P < 0.01) according to the increase in pefNDF levels in the diets. In diets with whole corn, the addition of pefNDF is not recommended, considering that no benefits were observed for nutrient digestibility, ruminal fermentation or nitrogen balance. The diet consisting of whole corn proved to be suitable for finishing lambs, as it enhanced DM and OM digestibility without clinical evidence of ruminal acidosis.

339 Effects of a Blend of Mannan and Glucan on Growth Performance and Immunocompetence of Newly Weaned Beef Steers

Abstract We examined the effects of dietary supplementation of a blend of mannan and glucan on the growth performance, diet digestibility, and whole-blood immune gene expression of newly weaned beef steers during a 42-d receiving period. Forty-eight newly weaned Angus crossbred steers (2 d post-weaning; 199 ± 13 kg of initial BW) were randomly assigned to 1 of 2 treatments: basal diet with no additive (CON; n = 24) or a basal diet top-dressed with 5 g of a blend of mannan and glucan (MANGLU; n = 24). Average daily gain (ADG) was calculated from weekly BW. Blood samples were collected on days 0, 14, and 42 for measurement of plasma glucose and NEFA. Expression of 84 immune-related genes was analyzed on blood samples collected on day 42. Beginning on days 37 to 42, total mixed ration, refusals, and fecal samples were collected once daily to determine apparent total tract digestibility of DM, CP, NDF, and ADF using indigestible NDF as an internal marker. Immune gene expression data was analyzed using a GeneGlobe Data Analysis Center. All other data were analyzed as a randomized complete block design using the GLIMMIX procedure of SAS. Over the 42-d feeding trial, MANGLU tended to increase final BW (P = 0.07) and ADG (P = 0.06). Compared to CON, beef steers fed supplemental MANGLU had greater DM digestibility (P = 0.03) and tended to have greater NDF digestibility (P = 0.09). No treatment effects (P &amp;gt; 0.10) on plasma glucose and NEFA on d 14 and 42 were detected. Compared with CON, MANGLU increased (P ≤ 0.05) the expression of five immune-related genes involved in recognition of and mounting immune defense against microbial pathogens. In conclusion, this study demonstrated that supplemental MANGLU enhances beef cattle immunocompetence and productivity during feedlot receiving period.

PSIX-8 Drinking water acidification and chlorination improves microbiological water quality without detrimental effects on performance or hazard side-effects in bulls fed high-concentrate diets

Abstract The aim of this study was to evaluate the effect of drinking water disinfection (chlorination) and conditioning (acidification) on microbiological water quality, water and feed consumption, total tract apparent digestibility and its potential hazard effects on animal health in Holstein bulls fed high-concentrate diets. Twenty-four Holstein bulls (221 ± 20.9 kg of initial BW, and 184 ± 9.9 d of age) were housed individually and fed ad libitum. Animals were assigned to 4 treatments with a 2 x 2 factorial design: drinking water conditioning (with or without acidification) and disinfection (absence or chlorination). Every 28 d, water samples from the tank and drinker were collected to analyze pH, residual chlorine and microbial load. Water consumption was recorded daily, and every 2 wks feed consumption and BW were recorded. At d 0, 14, 98 and 196 blood samples were collected to hematology and clinical chemistry analysis. At d 42 and 147 total tract apparent digestibility was estimated. Data were analyzed with a mixed effects model. In the tank, acidification increased residual free chlorine (0.58 vs. 0.33 ± 0.081 ppm, interaction, P = 0.10) and chlorination reduced (P &amp;lt; 0.01) total coliform count (0.8 vs. 392.7 ± 0.30 CFU / 100 ml) and Clostridium perfringens count (0.0 vs. 9.0 ± 0.13 CFU / 100 ml). In the drinkers, chlorination only tended (P = 0.10) to decrease total coliform count (967.5 vs. 994.7 ± 0.01 CFU / 100 ml). Treatments did not affect daily water consumption, total DMI nor blood parameters. At the end of the study, chlorination tended (P = 0.07) to improve starch total apparent digestibility (98.2 vs 97.7 ± 0.28 %). In fattening bulls’, the conditioning (acidification) and disinfection (chlorination) of drinking water improved its microbiological quality without detrimental effects on water and feed consumption, ruminal digestibility or hazard side-effects.

PSXIII-10 Effects of nitrate concentration in drinking water on water and feed consumption, total tract digestibility and health implications in Holstein bulls fed high-concentrate diets

Abstract The aim of this study was to evaluate the effect of nitrate concentration in drinking water on water and feed consumption, total tract apparent digestibility and its potential toxicity on animal health in fattening Holstein bulls. Twenty-four Holstein bulls (161 ± 19.9 kg of initial BW, and 183 ± 25.3 d of age) were housed individually and fed ad libitum. Animals were assigned to 4 treatments according to nitrate concentration in drinking water: 0, 44, 110 and 220 mg / L. The different nitrate concentrations were achieved by the addition of different potassium nitrate 0.22 M doses. Water consumption and animal health status was recorded daily. Every 2 wks feed consumption, BW were recorded, and nitrate concentration in drinking water was analyzed by photometry. At d 0, 14, 112 and 168 blood samples were collected to determine ammonia and methemoglobin concentrations. At d 14 and 168 total tract apparent digestibility was estimated. Data were analyzed with a mixed effects model. Water consumption decreased (P &amp;lt; 0.05) when nitrate concentration in water was above ≥ 110 mg / L (30.2, 27.4, 24.4 and 26.4 ± 1.38 L/d for 0, 44, 110 and 220 mg/L nitrates in water, respectively). Water nitrate concentration did not affect serum ammonia and methemoglobin concentration (58.0 ± 2.17 µmol / L and 2.4 0.09 %, respectively). In addition, water nitrate concentration did not affect performance, total DMI, and nutrient digestibility. Drinking water for a long period with nitrate concentrations up to 110 mg/L did not have detrimental effects on performance and health. Beyond this threshold a reduction of water consumption of 16 % was observed and blood parameters (methemoglobin) and health registers did not indicate that the concentration of 220 mg/L of nitrates in drinking water may have health side-effects in fattening bulls fed high-concentrate diets.

PSXIII-5 Effects of B vitamins and hydroxy trace minerals supplementation on hepatic metabolism of beef cattle at finishing phase in pasture

Abstract Vitamin B and trace minerals are crucial molecular signals involved in many biological pathways of energy metabolism and their bioavailability is compromised in high-producing ruminant animals. Despite the current knowledge of the effects of vitamin B complex and trace minerals on animal performance, their use as a rumen-protected form and its impact on liver metabolism in finishing beef cattle is poorly known. The present study aimed to assess the effects of ruminally protected B-vitamin blend (Trouw Nutrition, Italy) and hydroxy trace minerals (Cu and Zn; Micronutrients Inc., Indianapolis, IN) on hepatic proteome. A total of 20 non-castrated Nellore males with 353 ± 43 kg of initial BW were submitted in a high supplementation (1.7% of BW) in pasture and randomly assigned to one of the following treatments: CTRL – inorganic trace minerals without supplementation of vitamin B blend; SUP – supplementation of hydroxy trace minerals (Cu and Zn) and vitamin B blend (B5, B6, B7, B9, and B12). All animals were fed the same level of the experimental diet for 106 days and liver biopsy was performed at the end of the experimental period. We use shotgun proteomics combined with biological and network analyses of the protein differentially abundant between treatments, showing 37 proteins differentially abundant (P &amp;lt; 0.10) between treatment groups, where all proteins were up-regulated in the SUP treatment. These proteins were related to protein folding (P = 0.0456), oxidoreductase complex (P = 0.0155), mitochondrial respiratory chain complex IV (P = 0.0132), chaperonin-containing T-complex 2 (P = 0.0132), glutathione metabolism (P = 0.00026) and other linked to oxidative stress regulation. These results indicate that ruminal-protected vitamin B and hydroxy trace minerals supplementation during the finishing phase cause positive changes in the abundance of proteins related to oxidative metabolism and response to oxidative damage.

Effects of feeding growing-finishing lambs with cashew nut shell liquid on the growth performance, physicochemical attributes, lipid peroxidation and sensorial parameters of burger

This study evaluated the optimum inclusion of a feed oil additive chemically extracted from cashew nuts in lamb diets on the physicochemical and sensory attributes of burgers produced from their meat. Forty lambs (26 ± 2.4 kg of initial BW and 5 months of age) were used in a block randomized design with ten experimental units per treatment. Lambs were fed a total mixed ration containing cashew nut shell liquid (tCNSL) at levels of 0, 7.5, 15 and 22.5 g/kg g/kg of dietary dry matter. Lambs were slaughtered, and the meat was processed for burger production. The addition of tCNSL to the diets promoted a quadratic increase in DMI (P = 0.034), ADG (P = 0.016) and slaughter BW (P = 0.002). However, the addition of tCNSL to the lamb diet did not change (P >0.05) the concentrations of moisture, protein, lipids, crude ash and cooking losses; water holding capacity or hardness and color index a* of the lamb meat burgers. There was a linear decrease (P <0.001) with lower formations of peroxides and metomyoglobins in lamb meat burger when dietary levels 15 and 22.5 g/kg of tCNSL were added in diets. The pH of the lamb meat burgers increased linearly (P = 0.0196), due to the inclusion of tCNSL in the lamb diets. The L* color index reduced linearly (P = 0.0179) while b* and C* color increased linearly (P ≤ 0.05) with the addition of tCNSL in the diet. The inclusion of tCNSL did not change (P > 0.05) in the sensory attributes of the lamb meat burgers. All variables scored between 7 and 8, being considered by the tasters as moderately liked and very liked, obtaining a good overall acceptance. However, the preference (P = 0.042) ranking of the panellists was for burgers from the meat of lambs fed with tCNSL, regardless of the level of inclusion, compared to treatment without tCNSL. It is recommended to include up to 15 g tCNSL/kg DM as antioxidant in the lamb’s diet because it improves growth performance, color index and physical quality, and reduces the elasticity, chewability, lipid peroxidation and metmyoglobins, and increasing the preference of lamb meat burgers.

Evaluation of whole corn substitution in diets based on steam-flaked corn containing different concentrations of wet distillers grains with solubles for beef cattle

Our objective was to determine effects of substituting steam-flaked corn (SFC) with whole shelled corn (WSC) in finishing diets containing wet distillers grains with solubles (WDGS) on cattle performance, carcass characteristics, digestion, and rumen microbial ecology. The study used 642 Angus-cross heifers (411.7 ± 18.0 kg of initial BW) assigned to 36 pens. Treatments (2 × 3 factorial) were 6 SFC-based finishing diets with 0 or 20% WSC and 0, 15, or 30% WDGS (DM basis). Ruminal fluid was collected to evaluate ruminal characteristics, and feces and manure were collected to determine nutrient digestion and losses. Heifers fed 20% WSC diets had greater ( P < 0.01) DMI, but ADG and G:F were not affected ( P ≥ 0.11) by WSC concentration. The percentage of carcasses grading USDA Choice tended to be lower ( P = 0.07) for cattle fed diets with 20 versus 0% WSC. Increasing dietary WDGS decreased G:F ( P < 0.01) and tended to decrease ADG ( P = 0.10), increased DMI ( P = 0.08), and decreased hot carcass weight ( P = 0.09). Dietary WSC affected ruminal pH ( P < 0.01) and VFA molar concentrations ( P = 0.05). Ruminal acetate:propionate decreased (quadratic, P < 0.03) with increasing WDGS. Bacterial diversity was not affected by WSC ( P = 0.63) but increased with increasing WDGS ( P = 0.01). Substituting SFC with 20% WSC in cattle finishing diets did not affect animal performance but decreased carcass quality. In contrast, increasing dietary WDGS decreased animal performance but did not affect carcass characteristics.

Complete feed versus concentrate and straw fed separately: Effect of feeding method on eating and sorting behavior, rumen acidosis, and digestibility in crossbred Angus bulls fed high-concentrate diets

The aim of this study was to evaluate the effect of feeding method on eating and sorting behavior, rumen acidosis, and apparent total tract digestibility of crossbred Angus bulls fed a high-concentrate diet. Twenty-one Angus beef bulls (497 ± 7.7 kg of initial BW, and 324 ± 3.0 d of age) were housed individually and fed ad libitum. Three experimental treatments were tested: complete feed of pellet and chopped straw in a single feeder (TMR), pellet and chopped straw fed separately in two feeders (SS); pellet and long unprocessed straw fed separately in two feeders (LS). Feed consumption, fecal and bloat scoring were recorded daily. Every 2 wk TMR sorting, eating behavior, general activity, social and oral behaviors, and BW were recorded. At days 14 and 35 apparent total tract digestibility during one week was measured. At days 28 and 42 rumen samples were collected via rumenocentesis to measure rumen pH and determine ruminal volatile fatty acids (VFA) concentrations. At the study end (day 57) animals at slaughterhouse liver and rumen wall color and lesions were recorded by a macroscopic inspection. No differences among treatments in total DMI, and fecal and bloat scoring were observed. The straw to concentrate ratio was smaller in the SS and LS treatments (8–92) than in the TMR (15–85), and sorting analyses indicated that TMR bulls refused large particles (> 4 mm) and small particles (< 1.5 mm). TMR bulls spent less time eating (P < 0.01) and tended to perform more self-grooming (P = 0.06), oral non-nutritive behaviors (P < 0.01) and stereotypes (P < 0.01) than bulls fed straw separately. Animals fed TMR had a greater (P < 0.01) pH than SS and LS, however rumen pH was above 5.6 in all treatments and rumen wall lesions did not differ among treatments. Feeding TMR increased (P < 0.05) the rumen acetate to propionate ratio. Bulls fed LS had greater total apparent DM (P < 0.05) and CP digestibility (P < 0.01), but no differences among treatments were observed in starch digestibility. In conclusion, even if straw to concentrate ratio and NDF intake was smaller in the SS and LS treatments than in the TMR, feeding pellet and straw separately, independently of straw length, did not predispose animals to suffer rumen acidosis as indicated by rumen pH, feed consumption, animal behavior, fecal and bloat scoring and rumen wall macroscopic evaluation.

PSVI-5 Effects of exogenous glucoamylase enzymes or a combination with a neutral protease on total tract apparent digestibility and feces D-lactate in bulls fed a total mixed ration rich in rolled corn

Abstract The aim of this study was to evaluate the effect of 2 glucoamylases (GA) and the combination of one GA with a neutral protease on total tract apparent digestibility in bulls fed a total mixed ration (TMR) rich in rolled corn. Sixteen Angus beef bulls (266 ± 4.9 kg of initial BW, and 182 ± 1.7 d of age) were housed individually in pens and were distributed in 4 blocks of 4 animals balanced by BW. The experimental design was a 4 x 4 Latin square (4 blocks and 4 periods) with periods of 2 wks. Four treatments were tested; 1) control, a blank solution of 0.2% potassium sorbate and 0.6% sodium benzoate corresponding to the preservatives used in the enzyme preparation, 2) a GA preparation from Trichoderma reesei; 3) a GA preparation from Aspergillus fumigatus; 4) and a GA from Aspergillus fumigatus and a Bacillus amyloliquefaciens neutral protease preparation. These enzyme solutions were daily mixed was mixed in a dry TMR with 70% of rolled corn at a rate of 10 mL for 40 kg TMR. From day 8 to 14 chromium oxide (1 mg/kg) was mixed with the diet and from day 12 to 14 feces were collected to estimate total tract apparent digestibility and D-lactate concentration. Intake was recorded daily. Enzyme supplementation, regardless of enzyme type, increased (P &amp;lt; 0.05) DM (from 66.7% to 73.1% ± 2.01), OM (from 66.7% to 72.9% ± 2.03), and starch (from 74.7% to 81.8% ± 2.25) total tract apparent digestibility, and did not affect feces D-lactate concentration (1.26 vs 1.00 ± 0.200 mM for control and enzyme supplemented, respectively). So, any of the enzyme preparations tested (glucoamylases from Trichoderma reesei or Aspergillus fumigatus, or Aspergillus fumigatus glucoamylase n combination with the Bacillus amyloliquefaciens protease) increased by 9.5% starch digestibility.

Effects of Exogenous Glucoamylase Enzymes Alone or in Combination with a Neutral Protease on Apparent Total Tract Digestibility and Feces D-Lactate in Crossbred Angus Bulls Fed a Ration Rich in Rolled Corn.

Simple SummaryDietary enzyme supplementation, as a feed additive, has been well adopted in monogastric production to increase feed efficiency. However, in ruminants, considerably fewer studies have been done and fewer, if any, commercial enzymes have been adopted as a feeding strategy. Feedlot cattle are commonly fed high-starch diets, with varying starch digestibilities depending on type of grain, and degree of grain processing. Improvement in starch digestibility in low processed grain diets will undoubtedly warrant economic benefits to feedlot producers and reduce environmental impact of intensive beef production. In this study, we have shown that dietary glucoamylase supplementation improved 7 to 13% apparent digestibility of dry matter and starch in bulls fed rolled corn-based diets, suggesting that enzyme (glucoamylase) supplementation could be a promising strategy to improve starch efficiency for finishing beef cattle.The aim of this study was to evaluate the effect of two glucoamylases (GA) and the combination of one GA with a neutral protease on apparent total tract digestibility in beef bulls fed a total mixed ration (TMR) rich in rolled corn. Sixteen Angus beef bulls (266 ± 4.9 kg of initial BW, and 182 ± 1.7 d of age) were distributed in 4 blocks, each block consisted of 4 animals balanced by BW. The experimental design was a 4 × 4 Latin square (4 blocks and 4 periods, 2 w per period). Four treatments were tested; (1) control, (2) GA preparation from Trichoderma reesei (TrGA); (3) GA from Aspergillus fumigatus (AfuGA); (4) AfuGA in combination with a neutral protease from Bacillus amyloliquefaciens (BamPro). Apparent total tract digestibility and fecal D-lactate concentration were analyzed. Enzyme supplementation, regardless of enzyme type, increased apparent total tract digestibility of dry matter (from 66.7% to 73.1% ± 2.01), and starch (from 74.7% to 81.8% ± 2.25), without affecting feces D-lactate concentration. Irrespective of glucoamylase type, glucoamylase supplementation improved apparent digestibility of dry matter and starch, and the addition of a protease did not have additional benefits on nutrient digestibility.

Use of narasin in diets for lactating ewes

ABSTRACT The objective of the present study was to evaluate the effect of different doses of narasin on dry matter intake (DMI), milk production and composition in ewes and growth performance of their lambs. Forty crossbred lactating ewes Dorper vs. Santa Ines (54.4 ± 1.7 kg of initial BW; mean ± SD) were penned individually with their lambs and used in a randomized complete block design with 10 blocks and 4 treatments. Ewes were fed a basal diet (168 ± 0.003 g/kg DM of CP) containing 50% concentrate and 50% Brachiaria brizantha hay. The treatments were as follows: 0 N - control diet (basal diet without addition narasin); 13 N - addition of 13 mg/kg DM of narasin; 20 N - addition of 20 mg/kg DM of narasin; 27 N - addition of 27 mg/kg DM of narasin. Once a week, from the second to tenth week of lactation (weaning time), ewes were separated from their lambs, injected with oxytocin, and mechanically milked to empty mammary gland. After 3 hours, the same procedure was repeated, milk production was recorded and samples collected for milk composition analysis. Ewes were weighed for 3 consecutive days at the beginning and end of the experiment. Lambs growth performance was evaluated weekly. The data were analyzed using a linear or quadratic polynomial contrast in SAS. There was a quadratic effect (P = 0.03) of narasin on milk production, in which ewes fed the diet containing 13 mg/kg DM had the highest production (194.9 g/3 hours) Narasin inclusion decreased linearly the percentage of protein (P = 0.01), non-fat solids (P = 0.03), and SCC (P = 0.04) in milk. The fat, lactose and total solids content were not affected by treatments. There was a quadratic effect (P = 0.05) of narasin doses on concentrate intake by the lambs, in which the lowest intake was observed for lambs from ewes fed N13. The supply of narasin did not affect the ADG and final BW of the lambs. In conclusion, the use of 13 mg/kg DM of narasin was the best concentration in diets containing 50% forage and 50% concentrate for lactating ewes, due to positive effect on milk production. The inclusion of values higher than 20 mg/kg DM of narasin is not recommended, because this content drastically reduced DMI and milk production, resulting in greater concentrate intake by lambs with no effect on ADG and final BW.

Chitosan associated with whole raw soybean in diets for Murrah buffaloes on ruminal fermentation, apparent digestibility and nutrients metabolism.

This study aimed to investigate the effects of chitosan and whole raw soybean on nutrient intake, apparent digestibility, nitrogen utilization, microbial protein synthesis, blood metabolites, feeding behavior, ruminal fermentation, digesta kinetics, and reticular flow of nutrients of buffaloes. Four ruminally-cannulated Murrah buffaloes (351±15kg of initial BW) were randomly assigned according to a 4×4 Latin square design. Treatments were arranged as 2×2 factorial arrangement: the first factor was whole raw soybean (WRS), and the second factor was chitosan (CHI) with or without their inclusion in diets. Intake and apparent digestibility of ether extract (p<.01; p=.04, respectively), non-fiber carbohydrates intake (p=.03) and apparent ruminal digestibility of dry matter (p=.01) were affected by diets. An interaction effect or tendency was observed for microbial nitrogen (p=.09), concentrations, ruminal ammonia nitrogen (p=.05), total volatile fatty acid (p=.03). Association of chitosan with whole raw soybean has potential effects as a modulator of rumen fermentation; therefore, chitosan can be applied as an alternative non-ionophore for Murrah buffaloes.