Digestible Organic Matter Intake Research Articles

ENERGY REQUIREMENTS OF YOUNG EWES FED GUINEA GRASS (PANICUM MAXIMUM) FOR MAINTENANCE AND GAIN

Energy requirement for maintenance and weight gain of non-lactating, non-pregnant West African Dwarf ewes were determined by using equation of the form DOMI = aw0.75 + bG........ (1) where, DOMI = Digestible Organic matter intake (kg/day), W = Liveweight of ewe (kg), G = Liveweight gain of ewe (kg/day), a = DOMI requirement per kg of Wkg0.75, b = DOMI requirement for each kilogram liveweight gain. The regression equation obtained was DOMI = 0.0385Wkg 0.75 + 1.54G........(2). The values of DOM required per kilogram of Wkg0.75 and for each kilogram of liveweight gain, were 0.0385 and 1.54kg respectively. In terms of Metabolizable energy (ME) equation (2) can be written as follows: ME = 523.50Wkg0.75 + 20940.92G........(3) Values of ME required per kilogram of Wkg0.75 and each kilogram of liveweight gain were 523.5 and 20940.92 KJ from equation 3. These results are comparable to those obtained for other breeds of sheep of both temperate and tropical origin.

Nutrient intake, digestibility and growth performance of Yankasa sheep fed urea-treated or untreated rice straw with supplements

A study was conducted at the Abubakar Tafawa Balewa University (ATBU) Research and Teaching Farm between December and May 2006 to determine nutrient intake, digestibility and growth performance in Yankasa rams fed urea-treated (UTRS) and untreated rice straw (URS) with supplementation. Thirty-two (32) Yankasa rams with an average weigh of 17.5kg, and aged 1.5 to 2 years old were alloted to eight (8) dietary treatments with four (4) rams per treatment in a 2 x 4 factorial design. The two basal feeds were urea0treated rice straw (UTRS) and untreated rice straw (URS). The supplements were maize bran (MB), MB + sun-dried poultry litter (MB + SDPL), MB + ensiled poultry litter (MB+ EPL) and MB + cotton seed cake (MB + CSC). Total dry matter intake (TDMI), daily basal feed intake (DBFI) were significant (P<0.05) across dietary treatments. Animals on supplements MB and MB+CSC for both UTRS and URS recorded the lowest and highest DBFI. The digestible crude protein intake (DCPI) and digestible organic matter intake (DOMI) were high for rams on UTRS and the values ranged from 17.72 to 28.36g/d and 288.81 to 482.66g/d for DCPI and DOMI respectively. Nutrient digestibility was improved by treatment of straw and supplementation. However, crude protein digestibility was similar for animals fed URS but, significantly (P<0.05) lower compared to those fed UTRS which were also similar across supplements. Average daily weight gain ranged from 53.58 to 91.18g/d across dietary treatment with animals on supplement MB recording the lowest (53.58 and 61.43g/d for URS and UTRs respectively) and those fed supplement MB+CSC the highest (81.38 and 91.18g/d fro URS and UTRS respectively) irrespective of straw treatment. Feed conversion ratio (FCR) was least for animals on supplement MB+CSC for both URS and UTRs, indicating that this supplement (MB+CSC) influenced feed utilization more positively. From the results of this trial, it may be concluded that straw treatment and/or supplementation can enhance crop residue utilization by sheep. however, mixed supplements especially MB+CSC were more efficient in enhancing the utilization of the straw and consequently animal performance.

Effect of dietary supplementation of Emblica officinalis fruit pomace on methane emission, ruminal fermentation, nutrient utilization, and milk production performance in buffaloes.

Effects of dietary supplementation of Emblica officinalis fruit (Indian gooseberry) pomace (EFP), a waste from fruit processing plants and rich in polyphenolic compounds, were investigated for ruminal fermentation, nutrient utilization, methane production, and milk production performance in buffaloes. An in vitro experiment was conducted using 0 to 50g/kg of EFP (six treatments) to select an optimum dose for feeding of buffaloes. Organic matter (OM) degradability, total volatile fatty acid concentration, and acetate proportion decreased, but propionate proportion increased at the higher doses (> 30g/kg). Methane production also decreased at the higher doses (≥ 20g/kg). In the in vivo study, ten lactating buffaloes were randomly allotted into control and EFP groups (n = 5/group). The control group was fed a total mixed ration, whereas the EFP group was fed the control ration along with EFP at 20g/kg of dry matter (DM) intake for 120days. Feeding of EFP to buffaloes improved milk yield (P < 0.01) and milk production efficiency (P < 0.01). Concentration of milk protein tended (P = 0.071) to increase and that of solid not fat increased (P = 0.032) due to the EFP feeding. Yields (kg/day) of milk fat (P = 0.026), solid not fat (P = 0.011), and protein (P = 0.002) were greater in the EFP group than the control group. Somatic cell count in milk decreased (P = 0.032) due to EFP feeding. Digestibility of ether extract (P < 0.001) increased and OM (P = 0.051) tended to increase by EFP feeding. Methane production (g/d), yield (g/kg DM intake or g/kg digestible organic matter intake), and intensity (g/kg milk, g/kg milk fat, or g/kg milk protein), and methane conversion rate (percentage of gross energy intake) were lower (P < 0.01) in the EFP group than the control group. For milk fatty acid (FA) profiles, total saturated FA proportion tended to be greater (P = 0.057) in the EFP group than the control group, which was due to increased (P = 0.045) proportion of total short- and medium-chain FA (C4 to C14). Feed intake, digestibility of crude protein and fiber, and total n-6, n-3, mono-unsaturated FA, poly-unsaturated FA, and long-chain FA (C18 to C24) proportions were similar between the groups. This study suggests that feeding of EFP at 20g/kg DM intake increases milk production and decreases methane production and intensity without impacting health of buffaloes and FA profiles of milk. This is a win-win situation for sustainable and cleaner buffalo production by improving milk production and decreasing environmental burdens of greenhouse gas emission and EFP residue disposal problems.

Nutrient intake, digestibility and rumen metabolites in bulls fed rice straw with or without supplements

Nutrient intake, digestibility and rumen metabolites were determined in rumen - cannulated bulls fed rice straw or straw supplemented with urea, groundnut hay or cotton seed cake. Total dry matter intake (DMI) ranged from 7.55 10 8.29kg/d or 3.66 to 4.04% of liveweight and from 6.48 to 7.21kg/d for organic matter. Total DMI was increased by supplementation with urea and groundnut hay by about 7.6%. However, supplementation with groundnut hay and cotton seed cake reduced straw intake. Digestible organic matter intake (DOMI) was highest on straw supplemented with groundnut hay. There were no dietary differences in the digestibility of dry matter (DMD), organic matter (OMD), cellulose (CD) and hemicellulose (HCD). Digestibility of crude protein (CPD) was higher on the supplemented diets than on basal rice straw. The rumen pa ranged from 6.42 - 8.28; ammonia-N (RAN), 6.74 - 27.70mg/100ml; volatile fatty acids (VFA), 8.79 - 12.40mmol/100ml and bacterial count, 5.73-16.10 (x 10s)/ml and those values were affected by diets (D), period of sampling (P) and their interactions (D x P).

Post-extraction algal residue as a protein supplement for beef steers consuming forage: Palatability and nutrient utilization

Post-extraction algal residue (PEAR), the co-product of algal biofuel production, has potential to be incorporated as an ingredient in ruminant diets. Market value of PEAR will be driven by its ability to compete with commonly fed protein sources, such as cottonseed meal (CSM) and dried distillers’ grains (DDG). Two experiments were conducted to evaluate the potential for PEAR to be incorporated in existing protein supplementation strategies of the beef industry. In Experiment 1, 12 steers were used in a 12 × 12 Latin square experiment consisting of 12, 4-d periods to evaluate the palatability of PEAR at divergent inclusion levels and with differing carriers (DDG; CSM; liquid supplement, LS) as a supplement to cattle consuming a basal diet of Bermudagrass hay. Each period included 3-d where steers were fed a test supplement followed by a 1-d washout where steers were fed DDG. Blends were formulated with carrier ingredients (CSM, DDG, or liquid supplement, LS) at varying levels of PEAR inclusion; PEAR and carrier ingredients were also offered as stand-alone supplements. Completion rate and consumption rate (g supplement consumed/min) were recorded daily. In Experiment 2, six steers were used in concurrent 3 × 3 Latin Square experiments to determine the effect of PEAR on nutrient utilization and mineral intake in steers consuming low-quality forage. Treatments included no supplemental protein (CON) and isonitrogenous levels of PEAR or CSM (100 mg N/kg BW). In Experiment 1, completion rate was ≥90 % for DDG- and CSM-based blends, which was greater (P < 0.05) than when PEAR was offered alone (56 %). Consumption rate of 100 % PEAR was similar (P ≥ 0.05) to that of most CSM-based supplements, approximately 148–154 g supplement consumed/min. In Experiment 2, provision of isonitrogenous levels of PEAR and CSM stimulated (P ≤ 0.05) total digestible OM intake to a similar extent (P = 0.98), from 2.35 (CON) to 2.82 kg/d (PEAR and CSM). OM and NDF digestion were similar for all treatments (P ≥ 0.23), ranging from 56 to 59% (OM) and 49–54 % (NDF). Supplemented steers retained and absorbed more N (P ≤ 0.02) than CON. Supplementation of PEAR (100 mg N/kg BW) to steers consuming low-quality forage resulted in a Ca:P ratio of 8:1, which was the only mineral imbalance observed. Overall, our results suggest PEAR can be blended up to 60 % with existing ingredients (e.g., CSM, DDG) to create suitable protein supplements for grazing beef cattle.

How does herbage mass effect voluntary dry matter intake and in vivo organic matter digestibility in sheep and the in vitro gas production of perennial ryegrass?

It is essential to have accurate data relating sward herbage mass (HM) to voluntary dry matter intake (VDMI) and in vivo organic matter digestibility (OMDIV) across the year. This will ensure that the production performance of animals grazing differing HM swards can be accurately predicted using in vitro and in situ methods. The objectives of this experiment were to (i) determine the OMDIV and VDMI of sheep offered perennial ryegrass differing in HM throughout the growing season and (ii) evaluate in vitro gas production (IVGP) and in situ indigestible neutral detergent fibre (iNDFIS) as methods of predicting OMDIV. A 3 × 3 Latin square design was used to investigate three HM treatments. The target HM (measured > 4 cm) of perennial ryegrass for the three HM treatments was 1200 kg dry matter (DM)/ha (Low), 2500 kg DM/ha (Medium) and 4000 kg DM/ha (High). The experiment was a Latin square design repeated in three time stages (TS) in 2013 (TS1, TS2 and TS3). A 3 × 2 incomplete Latin square design was used in early spring 2014 (TS4). In TS4 the HM were lower than in the previous TS at 1000 kg DM/ha (Low), 1800 kg DM/ha (Medium) and 2500 kg DM/ha (High). Each experimental period within each TS consisted of a 6 day adaptation phase and 6 day measurement phase; with 12 Texel wether sheep used. Sheep were fed ad libitum to ensure a 10% refusal rate. The interaction between TS and HM treatment had the greatest effect on chemical composition, VDMI and OMDIV. Low HM swards had the greatest VDMI and OMDIV. For each 1000 kg DM/ha increase in HM, OMDIV was reduced by 2.3% on average. This varied from 0.9% in TS4 to 2.7% in TS3. There was no difference between HM treatments in the rate of digestion of digestible NDF using the IVGP technique. In situ indigestible NDF concentration and OMD derived from IVGP (OMDGP) were highly correlated with OMDIV (r2 = 0.901 and 0.895 respectively) and moderately correlated with digestible organic matter intake (DOMI) (r2 = 0.633 and 0.652 respectively). It can be concluded that the interaction between HM and TS will greatly affect OMDIV and VDMI. Secondly OMDIV can be predicted by both iNDFIS and OMDGP with acceptable accuracy to allow for their use in future feed evaluations.

Sustainable utilization of Aloe vera waste in the diet of lactating cows for improvement of milk production performance and reduction of carbon footprint

Aloe vera is a medicinal plant cultivated for various applications in medical, food and health products. During the extraction of aloe vera gel from leaves of this plant, a substantial proportion of Aloe vera waste (AVW) is produced. The AVW is a great environmental concern for its disposal; however, it is rich in various bioactive compounds, which could be valorised as an ingredient of feeds in dairy cattle to reduce enteric methane production and consequently carbon footprint of milk production. Therefore, this study investigated the effects of dietary supplementation of AVW on ruminal fermentation, methane production, nutrient utilization, and milk production performance in lactating cows. First, an in vitro experiment was performed using 0, 10, 20, 30 and 40 g/kg of AVW in substrate (five treatments) to select an optimum dose for feeding of dairy cows. Inclusion of AVW at 20 g/kg substrate decreased methane production, increased feed digestibility and total volatile fatty acid concentration in vitro. In the in vivo study, 16 lactating cows were randomly allotted into control and AVW groups (n = 8/group). The control group was fed a total mixed ration, whereas the AVW group was fed the control ration along with AVW at 20 g/kg of dry matter intake for 90 days. Feed intake was slightly greater in the AVW group than that of the control group. Milk production increased due to feeding of AVW. In vivo nutrient digestibility and concentrations of fat, protein, and lactose in milk were not affected, but yields of these milk components increased due to AVW feeding. Supplementation of AVW significantly decreased methane production (g/day), methane yield (g/kg dry matter intake or g/kg digestible organic matter intake), methane intensity (g/kg milk production) or methane conversion ratio. Feeding of AVW improved delayed type of hypersensitivity without affecting other blood variables adversely. This study demonstrates that feeding of AVW at 20 g/kg dry matter intake to dairy cows increased milk production and decreased methane production, which combinedly decreased methane production per unit of milk production substantially without health effects. Thus, feeding of AVW could be beneficial for sustainable and cleaner milk production decreasing environmental burdens of residue disposal problems and ruminal methane production.

Cashew processing product as alternative energy feedstuff for grazing beef cattle under tropical conditions

The aim of this study was to examine the effect of replacing corn with dried cashew processing product (CPP) in dietary supplements on the intake, digestibility and nitrogen (N) metabolism of grazing beef cattle. Five Nellore bulls with an average initial weight of 359 ± 34.8 kg were used in a 5 × 5 Latin square design. The animals were kept in five 0.32-ha paddocks of marandu grass (Urochloa brizantha cv. Marandu). Five isonitrogenous protein-energy supplements (310 g crude protein [CP]/kg of supplement) were formulated with CPP replacing corn at different levels (0, 0.25, 0.50, 0.75 or 1.00 g/g). The diets were supplied daily in the amount of 1.0 kg/animal. The replacement of corn with CPP caused a linear decrease in the intakes of supplement DM, total DM, CP and digestible organic matter, but did not influence forage DM intake. On the other hand, the substitution resulted in a linear increase in the intakes of indigestible neutral detergent fiber and total tannins. The replacement of corn with CPP caused a linear decrease in the digestibility coefficients of total DM, organic matter, CP and neutral detergent fiber and in the dietary concentration of OM. A linear decrease was also noted for N retention, microbial N synthesis, rumen ammonia N and blood urea N, while no changes were detected in fecal or urinary N excretion or microbial efficiency. Replacing corn with cashew processing product reduces intake, apparent diet digestibility, microbial nitrogen synthesis and nitrogen retention in grazing cattle.

Effect of ammoniation and harvest method on waste and consumption of corn residue bales fed to cows in a round bale feeder.

To determine the effects of harvest method and ammoniation (3.7% of dry matter) on consumption and waste of baled corn residue, a 6 × 6 Latin square with a 3 × 2 factorial treatment structure was conducted. Six treatments consisted of either nonammoniated or ammoniated residue, harvested one of three ways: conventional rake and bale (CONV), New Holland Cornrower with two rows of stem chopped into the windrow with tailings (2ROW), or EZBale system (EZB) with a disengaged combine spreader and tailings dropped in a windrow. Open cows were grouped by body weight to produce a light block of two pens (448 kg ± 49.6) and a heavy block of four pens (649 kg ± 65.9). One bale was fed to each pen during each of six 7-d periods using round bale ring feeders with closed bottom panels. Residue falling around (waste) and remaining in (refusals) the feeder was collected. The daily nutrient intake was estimated as the difference between what was offered and what remained (waste plus refusals). Crude protein (CP) of residue offered did not differ (P = 0.58) among harvest methods. The digestible organic matter (DOM) content of residue offered in 2ROW and EZB bales did not differ (P = 0.86) and was greater (P < 0.01) than CONV. Ammoniation increased (P < 0.01) CP and DOM content of the residue offered. Total wasted and refused residue did not differ (P = 0.12) between 2ROW (29%) and EZB (37%), while CONV (42%) was greater (P = 0.02) than 2ROW but did not differ (P = 0.34) from EZB. Ammoniation reduced (P = 0.03) total waste and refusals from 41% to 32%. The nutrient content of both waste and refusals did not differ (P ≥ 0.34) among harvest methods and, with the exception of CP, was not affected (P ≥ 0.15) by ammoniation. The CP content of the waste was greater (P = 0.02) and refusals tended to be greater (P = 0.08) from ammoniated bales. The CP intake of 2ROW was greater (P ≤ 0.02) than both EZB and CONV, while EZB tended (P = 0.06) to be greater than CONV. The CP intake of all ammoniated residues was greater (P < 0.01) than the nonammoniated residue. The DOM intake of nonammoniated 2ROW and EZB did not differ (P = 0.61) but was greater than nonammoniated CONV (P < 0.01). Ammoniation increased (P < 0.01) DOM intake. Overall, ammoniation had much larger effects than harvest method, resulting in reduced waste and refusals and greater intake of DOM and CP. However, the combination of both ammoniation and selective harvest (2ROW or EZB) was needed to result in energy and protein intakes that would meet the needs of a mature cow in mid-gestation.

Effect of including functional oils in ovine diets on ruminal fermentation and performance

Abstract The objective of this study was to evaluate the effects that different levels of functional oil (FO) extracted from castor bean (CO) and cashew nut shell liquid (CNSL) have on nutrient intake and digestibility, rumen fermentation, N-use efficiency, and microbial protein synthesis in sheep. Four castrated male sheep of no defined breed, with rumen cannulation (49.1 kg ± 7 kg live weight), were used in a 4 × 4 Latin square. The animals were randomly assigned one of the following four treatments: control (0; without additives; and 2, 4, and 6 g/animal/day FO (commercial mix of CNSL and CO). The intake of digestible organic matter decreased linearly with the inclusion of FO. The treatments did not affect nutrient digestibility. Neither N use nor microbial protein synthesis were affected by the levels of FO in the diet. Rumen pH and parameters were similar among FO levels. The inclusion of a CNSL and CO mix in sheep diets can be considered a natural food supplement that decreases intake without negatively affecting nutrient fermentation and usage.

Relationship of Milk Odd- and Branched-Chain Fatty Acids with Urine Parameters and Ruminal Microbial Protein Synthesis in Dairy Cows Fed Different Proportions of Maize Silage and Red Clover Silage.

Simple SummaryThe purpose of this study is to assess the relationship of milk odd- and branched-chain fatty acids (OBCFA) with urinary purine derivates (PD) and estimated ruminal microbial crude protein (MCP). The correlations and regressions demonstrate that yields and concentrations of individual or total OBCFA are weakly related to urinary PD and are low to moderate markers of MCP synthesis. Nevertheless, milk OBCFA can still be seen as a promising method for predicting rumen function and microbial protein supply to the duodenum in dairy cows because MCP flow was not directly measured in this study but instead indirectly estimated probably comprising considerable deviations of the assumed values from the true ones.The aim of this study was to evaluate the relationship of milk odd- and branched-chain fatty acids (OBCFA) with urinary purine derivates and estimated ruminal microbial crude protein (MCP) synthesis. Forty-four lactating Holstein cows were used in a 4 × 4 Latin square design with 21-day periods comprised of a 13-day adaptation phase to diet followed by an 8-day sampling phase. Differences in estimated MCP yield and milk OBCFA composition were found by feeding total mixed rations containing forage (maize silage, MS; red clover silage, RCS) and concentrates (0.75:0.25) with targeted proportions of RCS to MS of 0.15:0.60, 0.30:0.45, 0.45:0.30, and 0.60:0.15 on a dry matter basis. The MCP was estimated from the total urinary purine derivate (PD) excretion (MCPPD) and intakes of metabolizable energy (MCPME) or digestible organic matter (MCPdOM). The Pearson correlations of individual OBCFA with urinary parameters (uric acid, allantoin, PD and nitrogen) were generally weak (r = −0.37 to 0.55). Yields of individual OBCFA correlated positively with MCPME and MCPdOM (r = 0.21 to 0.55). The prediction of urinary PD concentration was moderate (R2 = 0.64) when including the proportion of iso-C17:0. The prediction of total PD excretion was low (R2 = 0.21) with yields of iso-C15:0, anteiso-C17:0, and iso-C16:0. The prediction of MCPPD was high (R2 = 0.99) when including the iso-C16:0 and cis-9 C17:1 concentrations, while those of MCPME and MCPdOM were low (R2 = 0.37 and 0.36, respectively) when including yields of iso-C15:0, cis-9 C17:1, and iso-C18:0. The correlations and regression analyses demonstrate that the estimated MCP synthesis and urinary PD excretion can be only moderately predicted by yields and concentrations of individual or total OBCFA in cow’s milk. However, milk OBCFA can still be seen as a promising, non-invasive method for predicting rumen function and microbial protein supply in dairy cows because MCP flow was not directly measured in this study but instead indirectly estimated probably comprising considerable deviations of the assumed values from the true ones.

Indirect measures of methane emissions of Sahelian zebu cattle in West Africa, role of environment and management.

In Northern Senegal, traditional cattle management systems (TRAD) which depend on natural forages coexist with intensified systems (INT) which rely on periodic supplementation with crop residues and local concentrates. This study aims to estimate the effects of seasons and management systems on the methane emissions of Gobra zebu, in relation to the diet's chemical composition and feed intake. Six Gobra zebu cows per management system were individually monitored over 10months, diet and faeces were sampled each season and their chemical composition and dry matter intake (DMI) were predicted by near infrared spectroscopy. Each diet was fermented in vitro to assess methane production and volatile fatty acid concentration. The DMI and digestible organic matter intake (DOMI) decreased (P < 0.0001) during the dry seasons for both systems in the same range, but INT improved the crude protein of the diets (P < 0.0001). Enteric methane production (mmol.g-1 dry matter) was lower for TRAD than INT, except during the rainy season when TRAD cows experienced a higher increase (P = 0.002). The methanogenic potential (methane production in vitro × DMI) varied with the seasons and the system with more accentuated variations for TRAD (P< 0.0001). Methanogenic potential shows true reflection of the effects of the seasons and management systems. The results highlight that enteric methane emissions varied with seasonal changes and that intensifying the diet induced no mitigating effect.

Ericaceous species reduce methane emissions in sheep and red deer: Respiration chamber measurements and predictions at the scale of European heathlands

Despite the importance of atmospheric methane as a potent greenhouse gas and the significant contribution from ruminant enteric fermentation on methane emissions at a global scale, little effort has been made to consider the influence that different plant-based natural diets have on methane emissions in grazing systems. Heathland is an ericaceous dwarf-shrub-dominated habitat widespread across the northern hemisphere, in Europe, provides valuable ecosystem services in areas with poor soils, such as water flow regulation, land-based carbon skin, energy reservoir and habitat of key game species. We (i) measured methane emissions from red deer (Cervus elaphus) and sheep (Ovis aries) fed mixed diets of natural grass plus ericaceous species (either Calluna vulgaris or Vaccinium myrtillus) using open-circuit respiration chambers; and (ii) modelled the results to estimate methane emissions from red deer and sheep populations inhabiting heathland habitats across Europe under different scenarios of grass-based mixed diets with varying proportions of ericaceous species. Our results indicated that methane emissions per unit of digestible organic matter intake decreased as the proportion of ericaceous species in diet increased, but this relationship was complex because of the significant interaction between the proportion of ericaceous species in the diet and digestible organic matter intake. According to our estimates red deer and sheep populations across European heathlands produce 129.7 kt·y−1 methane (se = 1.79) based on a hypothetical grass-ericaceous species mixed diet containing 30% of ericaceous species; this is 0.5% of total methane emissions from human activity across Europe (24,755 kt·y−1), and a reduction in methane emissions of 63.8 kt·y−1 against the same deer and sheep populations, if assumed to consume a grass-only diet. We suggest the implementation of carbon credits as a measure to value the relevance of heathland systems to promote biodiversity and its potential contribution to reduce methane emissions in ruminant grazing systems.

Methane emission, nutrient utilization, microbial protein synthesis and growth performance in finisher lambs fed complete feed blocks containing phytochemical-rich forages of semi-arid region

Tree leaves of Ailanthus excelsa, Ziziphus nummularia and Prosopis cineraria were fed in complete feed block (CFB) to 36 weaner (91 d) lambs distributed equally (20.6 ± 0.55 kg) in three groups (T1, T2 and T3). The CFB of T1 consisted of 40% A. excelsa leaves, which was replaced at 50% level with phytochemical rich Z. nummularia leaves in T2 and P. cineraria leaves in T3. There was decline (p < 0.05) in methane emission per kg digestible OM intake by 10.7 and 15.5% in T2 and T3 compared to T1. Rumen fermentation pattern showed an increased trichloroacetic acid precipitable N with decreased ammonia N and ciliate protozoa population in T3 compared to other two groups. Ruminal microbial protein synthesis as assessed from urinary purine derivatives excretion was higher (p = 0.012) in T3 than T1, while T2 had an intermediate value. There was decreased (p < 0.05) digestibility of dry matter, organic matter (OM) and ADF in T3, and that of crude protein (CP) and NDF in both T2 and T3. Lambs in T1 and T2 had higher (p < 0.05) intake of digestible OM, metabolizable energy (ME) and digestible CP than T3. There was improved (p = 0.038) N utilization efficiency with a reduced (p = 0.041) excretion through urine, but increased (p = 0.004) excretion through feces in T2 and T3 compared to T1. The live weight gain was lower in T3 compared to T1 with an intermediate performance in T2, but feed conversion ratio with respect to digestible OM and ME intake was similar in all the three groups. It is inferred that inclusion of Z. nummularia and P. cineraria leaves in CFB reduced methane emission, improved ruminal attributes including microbial protein synthesis and N utilization, but lower digestibility and ME intake lead to lower gain. Thus, ration with phytochemicals-rich tree forages would support finished lamb production under greener environment.

254 Digestibility of sheep offered tall fescue, meadow fescue and orchardgrass grasses ensiled with slurry or commercial urea fertilization

Abstract Silage intake by ruminants can be affected by both fertilization and forage type. The objective of this study was to evaluate digestion by sheep offered three different grasses fertilized with either urea (C) or dairy slurry (S). Plots of meadow fescue (MF), tall fescue (TF) or orchardgrass (OG) were planted on 25 July 2017, and first harvested on 29 June 2018. Plots were then fertilized with urea (52 kg N/ha) or slurry (71,150 L/ha). A second harvest was baled 6 August at approximately 57% moisture and wrapped in plastic. Eighteen lambs (59 ± 1.5 kg) were allocated randomly to one of the 6 treatment combinations to provide 3 lambs per treatment within each of 3 periods consisting of a 10-d adaptation and 7-d total fecal and urine collection. Data were analyzed as a 2 × 3 factorial arrangement using PROC MIXED of SAS. Dry matter (DM) and organic matter (OM) intakes (g/kg BW) were greater (P &amp;lt; 0.05) from MF fertilized with C than from the other forage-fertility combinations. Digestibility of DM and OM were greater (P &amp;lt; 0.05) from MF vs. OG, and OG vs. TF. Digestibility of OM also was greater (P &amp;lt; 0.05) from C vs. S. Digestible DM and OM intakes (g/kg BW) were greatest (P &amp;lt; 0.05) from MF fertilized with C. In addition, digestible DM intake (g/kg BW) was greater (P &amp;lt; 0.05) for MF fertilized with S compared to TF fertilized with C, and digestible OM intake was greater (P &amp;lt; 0.05) for MF fertilized with S compared to OG fertilized with S. Therefore, urea-fertilized meadow fescue may improve energy intake compared with that from orchardgrass or tall fescue, but fertilization of meadow fescue with slurry may reduce this advantage. The study was supported in part by USDA-ARS specific cooperative agreement 58-3655-4-052.

PSX-33 Effect of supplementing different proportions of sericea lespedeza with alfalfa silage on intake, digestibility, and nitrogen balance in sheep

Abstract Dietary manipulations to include tannins can change the proportion and amounts of N excreted in the urine and feces as well as improve N-use efficiency in ruminants. This study was conducted to investigate effects on animal digestion parameters of adding different proportions of sericea lespedeza hay (SL) to alfalfa silage. Alfalfa was harvested in June 2018 at 75% bloom, chopped, and then packed at 55% moisture into plastic-lined bins and allowed to ensile for 3 months. Alfalfa silage was either offered alone or mixed with 9, 18, or 27% SL on a DM basis. These diets were offered randomly for ad libitum consumption to 16 ewes (41.8 ± 4.61 kg BW) in a randomized complete block design experiment with 2 periods to provide 4 observations per treatment per experimental period, each consisting of a 14-d dietary adaptation period followed by 5 d of total fecal and urine collection. Data were analyzed using PROC MIXED of SAS and orthogonal linear and quadratic trend analyses were tested. Digestibility (%) of DM and OM and digestible DM and OM intake (g/kg BW) decreased linearly (P &amp;lt; 0.05) with increasing SL addition to the diet. Digestibility of NDF and ADF decreased linearly (P &amp;lt; 0.01) with increasing SL, and apparent absorption (%) of N decreased linearly (P &amp;lt; 0.05) with increasing SL in the diet. Urinary N excretions (g/d) tended (P = 0.10) to decrease linearly while fecal N (g/day) tended to increase (P = 0.10) linearly with increasing SL proportion in the diet. In this study, supplementation with sericea lespedeza as a tannin source to alfalfa silage decreased forage digestibility and digestible organic matter intake and did not positively influence nitrogen use. The study was supported in part by USDA-ARS specific cooperative agreement 58-3655-4-052 and by USDA NIFA grant 2018-67019-27804.

258 Intake, digestibility and rumen fermentation in sheep offered alfalfa silage alone or alfalfa and tall fescue-mixtures harvested after a killing frost

Abstract The objective of this study was to determine the effect of harvesting alfalfa and fescue after frost and ensiling mixtures of these forages on silage fermentation characteristics, intake, digestibility and ruminal fermentation by ewes. Forages were harvested in October of 2018, wilted, and blended as either alfalfa alone, 67% alfalfa +33% fescue, 33% alfalfa + 67% fescue, or 100% fescue. Twenty bins were lined with 2 plastic bags, packed (n = 5/trt), stored for 3 months, and then randomly assigned to ewes (n = 20; mean BW = 34.7 ± 6.65 kg) for ad libitum consumption, using 5 animals per treatment. Ewes were given 17 d of adaptation followed by 5 d of total feces and urine collection. Data were analyzed using PROC-MIXED of SAS and orthogonal polynomial trends were used to identify the effects of different proportions of fescue-to-alfalfa silage. Silage total acids, lactate, and acetate increased linearly (P &amp;lt; 0.01) while silage moisture and ammonia decreased linearly (P &amp;lt; 0.01) with increasing proportions of fescue in the diet. The proportions of lactate to total acids (mole/100 moles) increased linearly (P &amp;lt; 0.01) and quadratically (P &amp;lt; 0.05) by adding more fescue to alfalfa. Intake (g/kg BW), digestibility (%), and intake of digestible DM and OM (g/kg BW) decreased linearly (P &amp;lt; 0.05) as fescue proportion was increased in the silages. Ruminal acetate and butyrate (%) increased linearly (P &amp;lt; 0.01) with increasing fescue concentrations in the diet. Ensiling alfalfa with fescue may improve forage fermentation characteristics, but may reduce intake and digestibility in sheep compared to feeding alfalfa silage alone. This study was supported in part by USDA-ARS specific cooperative agreement 58-3655-4-052.

PSXIV-1 Effects of passage rate on forage intake and digestion in beef cattle

Abstract The objective was to evaluate treatments designed to increase passage rate on forage intake and digestion. Eight ruminally-cannulated steers were assigned to a replicated 4 × 4 Latin square design. All steers were fed an ad libitum diet of prairie grass hay (10.4% CP) with the following treatments designed to increase passage rate: no treatment (control; CON), pelleted (PEL), 7% Ca(OH)2 treated (CAOH), and six 2 kg weights inserted into the rumen (WTS). Molasses (3% of diet DM) was added to all treatments. Feed, orts, and total feces was collected on d 12–17 to determine total tract digestibility. On d 17–20, ruminal pH was recorded every 8 hr. Data were analyzed using the MIXED procedure of SAS 9.4 with treatment and period as fixed effects and steer as a random effect. A treatment effect (P &amp;lt; 0.01) was observed for ruminal pH; steers fed CAOH had the highest pH (6.97) with WTS and CON intermediate and PEL being the lowest (6.34). Organic matter intake (OMI) was affected (P &amp;lt; 0.01) by treatment with PEL steers consuming the most (7.86 kg). While steers consuming CON had greater OMI than CAOH (P = 0.04), WTS was not different from CON (P = 0.50). Organic matter digestibility (OMD) was also affected (P &amp;lt; 0.01) by treatment as WTS and CON were the greatest (62.8% and 61.7%, respectively) and CAOH (58.7%) tended (P = 0.08) to be greater than PEL (55.9%). Total digestible organic matter intake (TDOMI) was affected (P &amp;lt; 0.01) by treatment; PEL had the greatest TDOMI with CON being intermediate, and CAOH and WTS being the least. Treatments designed to increase passage rate did affect forage intake and digestion with the greatest effect resulting from pelleting grass hay due to the severe reduction in particle size.

Intake and digestibility by gestating sheep of alfalfa silage wrapped with or without an enhanced oxygen barrier plastic after time delays up to three days

Poor silage fermentation can affect its acceptance by livestock. Alfalfa from 3 field blocks were baled in large round bales (moisture concentration = 591 ± 43.0 g/kg) and then wrapped with 7 layers of plastic either with (EOB) or without (CW) an enhanced oxygen barrier on the day of baling, or 1, 2 or 3 d after baling in order to examine those effects on subsequent intake and digestibility by gestating sheep. Alfalfa was chopped after approximately 5 mo. of fermentation, and then offered for individual ad libitum consumption by 16 gestating ewes [63.5 ± 1.71 kg avg. body weight (BW)] in a 3-period (63-day) digestion study. Silage moisture and nitrogen (N) decreased linearly (P < 0.05), acid-detergent fiber (ADF) increased linearly (P < 0.05), and neutral-detergent fiber (aNDF) increased at a decreasing rate (linear; quadratic P < 0.05) with wrapping delay within EOB but not CW (P ≥ 0.23). Lactic acid expressed as g/kg of total silage acids decreased linearly (P < 0.05) within CW and decreased at an increasing rate (linear; quadratic P < 0.05) within EOB with increasing wrapping delay, likely because of aerobic deterioration. Digestible organic matter intake (DOMI) decreased linearly (P = 0.03) within EOB and quadratically (P = 0.02) within CW (wrap type × wrapping time after baling interaction; P = 0.04), but other intake and digestibility measurements were not affected (P ≥ 0.15) by wrap type or its interaction with wrapping time after baling. Intake of DM and OM (DMI and OMI, g/kg BW) as well as digestible DMI (g/kg BW) responded linearly and quadratically (P ≤ 0.03) with wrapping delay after baling by initially increasing to 1 d after baling, then declining sharply thereafter. Digestibility of aNDF increased linearly (P = 0.04) with wrapping delay which was likely related to reduced DMI. These values align somewhat closely with those for forage quality and fermentation profiles. Therefore, managing alfalfa silage to ensure more desirable fermentation should also result in higher digestible OMI, which will improve the overall energy status of ruminants.

Feed Value of Barn-Dried Hays from Permanent Grassland: A Comparison with Fresh Forage

In mountain areas, hays are the main forage in winter diets for livestock. Barn-dried hays can be an alternative to traditional hays, which are generally characterized by a low feed value. The aim of this study was to compare the feed value of barn-dried hays with that of the fresh forage from a permanent meadow. The study was carried out over three periods during the first growth cycle of the meadow’s vegetation (from 30 May to 3 June, from 13 to 17 June, and from 27 June to 1 July). Fresh forage and barn-dried hays of the same fresh forages were tested for dry matter digestibility (DMD), organic matter digestibility (OMD), and voluntary intake (VI). Both types of forage obtained each period were tested with an interval of 15 days. Chemical composition and OMD of forages did not change (p &gt; 0.05) according to the feeding method. However, the DMD values for barn-dried hays were higher (p &lt; 0.05) than for fresh forages at the end of the cycle. VI and digestible organic matter intake of barn-dried hays were higher (p &lt; 0.05) than that of fresh forages. In conclusion, barn-dried hays obtained from permanent grasslands presented a higher feed value than fresh forages.