Digestible Organic Matter Intake Research Articles

Apparent digestibility and microbial protein yield of Desmodium uncinatum, Mucuna pruriens and Vigna unguiculata forage legumes in goats

This study examined the effects of adding forage legumes as protein supplements to poor-quality natural pasture (veld) hay offered to goats on microbial protein yield and nitrogen metabolism. Four indigenous Nguni-type goats were used in a 4×4 Latin cross-over design experiment. Goats were randomly allocated to four dietary treatments comprising commercial goat feed (GF), veld hay supplemented with cowpea (CW), velvetbean (VB) or silverleaf desmodium (SD). Microbial protein yields were determined using the purine derivatives technique and nitrogen retention was calculated from the digestible organic matter intake. Total nitrogen intake was significantly higher in the GF followed by CW, SD and VB, respectively. Microbial protein supply, calculated microbial true protein and digestible microbial true protein were affected (P<0.05) by legume supplementation. Animals on poor-quality forages had the most efficient microbial protein synthesis. However, supplementation of hay failed to meet the maintenance requirements of animals as evidenced by negative nitrogen balances in VB and SD. The efficiency of utilisation of nitrogen in the supplements could have been limited by unavailable fermentable metabolisable energy in the diets. Supplementation of poor-quality veld hay with legume forages could improve utilisation, especially in the dry season.

Effects of nitrogen fertilisation rate and maturity of grass silage on methane emission by lactating dairy cows

Grass silage is typically fed to dairy cows in temperate regions. However, in vivo information on methane (CH4) emission from grass silage of varying quality is limited. We evaluated the effect of two rates of nitrogen (N) fertilisation of grassland (low fertilisation (LF), 65 kg of N/ha; and high fertilisation (HF), 150 kg of N/ha) and of three stages of maturity of grass at cutting: early maturity (EM; 28 days of regrowth), mid maturity (MM; 41 days of regrowth) and late maturity (LM; 62 days of regrowth) on CH4 production by lactating dairy cows. In a randomised block design, 54 lactating Holstein–Friesian dairy cows (168±11 days in milk; mean±standard error of mean) received grass silage (mainly ryegrass) and compound feed at 80 : 20 on dry matter basis. Cows were adapted to the diet for 12 days and CH4 production was measured in climate respiration chambers for 5 days. Dry matter intake (DMI; 14.9±0.56 kg/day) decreased with increasing N fertilisation and grass maturity. Production of fat- and protein-corrected milk (FPCM; 24.0±1.57 kg/day) decreased with advancing grass maturity but was not affected by N fertilisation. Apparent total-tract feed digestibility decreased with advancing grass maturity but was unaffected by N fertilisation except for an increase and decrease in N and fat digestibility with increasing N fertilisation, respectively. Total CH4 production per cow (347±13.6 g/day) decreased with increasing N fertilisation by 4% and grass maturity by 6%. The smaller CH4 production with advancing grass maturity was offset by a smaller FPCM and lower feed digestibility. As a result, with advancing grass maturity CH4 emission intensity increased per units of FPCM (15.0±1.00 g CH4/kg) by 31% and digestible organic matter intake (33.1±0.78 g CH4/kg) by 15%. In addition, emission intensity increased per units of DMI (23.5±0.43 g CH4/kg) by 7% and gross energy intake (7.0±0.14% CH4) by 9%, implying an increased loss of dietary energy with advancing grass maturity. Rate of N fertilisation had no effect on CH4 emissions per units of FPCM, DMI and gross energy intake. These results suggest that despite a lower absolute daily CH4 production with a higher N fertilisation rate, CH4 emission intensity remains unchanged. A significant reduction of CH4 emission intensity can be achieved by feeding dairy cows silage of grass harvested at an earlier stage of maturity.

Effects of Feeding Ficus polita Foliage-based Complete Rations with Varying Forage: concentrate Ratio on Performance and Ruminal Fermentation in Growing Goats

A study was conducted to investigate the effects of forage to concentrate ratio (F: C) on voluntary feed intake, total tract digestibility, N utilization, ruminal fermentation, microbial protein supply and growth in goats in a 91-day experiment excluding the adjustment period. Twenty-one goats, with an initial similar body weight of 12.3±0.59 kg, were randomly assigned to one of three F: C ratio diets containing 70: 30, 60: 40 or 50: 50 in a completely randomized design. Dry matter and nutrient intakes, apparent digestibility of fibre fractions, digestible crude protein (DCP) and digestible organic matter (DOM), digestible energy (DE) and metabolizable energy (ME), ruminal total N, N retention, feed conversion ratio and average daily gain were not (P>0.05) affected by the treatments. Intakes of DCP, DOM, DE and ME, organic matter digested in the rumen, microbial protein supply, total volatile fatty acids, apparent digestibility of crude protein and organic matter, and N absorbed linearly increased (P<0.05) with decreasing F: C ratio. Apparent DM digestibility, digestible DM, digestible DM intake, ruminal pH and NH3-N had a positive linear increase (P<0.01) with increasing level of concentrate. The results indicate that tannin-containing Ficus polita forage can be included in complete diet of goats up to 700 g/kg DM without compromising the performance of the animals.

Intake, performance, and carcass characteristics of lambs fed spineless cactus replacing wheat bran.

To assess the intake, digestibility of nutrients, ingestive behavior, performance, and carcass characteristics of feedlot lambs, 36 F1 Santa Ines × Dorper male lambs with an initial average weight of 19.5 ± 0.27kg were fed with different levels of spineless cactus (0, 33, 66, and 100%) as a replacement of the wheat bran. The replacement diets had no effect on the intake of dry matter (DM) or crude protein (CP), whose average values were 962 and 140g/day, respectively. There was a quadratic effect on the intake of digestible organic matter (OM) and the digestibility of DM, CP, neutral detergent fiber (NDF), and non-fiber carbohydrates (NFC). The highest average daily gain (ADG) of 168g/day was achieved at 58.7% replacement level. The highest hot and cold carcass weights of 15.4 and 14.5kg were achieved at 62.4 and 56.9% replacement levels. For lambs in the feedlot, we recommend replacing wheat bran with up to 58.7% spineless cactus.

Potential of tannin-rich plants, Leucaena leucocephala, Glyricidia sepium and Manihot esculenta, to reduce enteric methane emissions in sheep.

An invivo trial was conducted in sheep to investigate the effect of three tropical tannin-rich plants (TRP) on methane emission, intake and digestibility. The TRP used were leaves of Glyricidia sepium, Leucaena leucocephala and Manihot esculenta that contained, respectively, 39, 75 and 92g condensed tannins/kg DM. Methane was determined with the sulphur hexafluoride tracer technique. Eight rumen-cannulated sheep of two breeds (four Texel, four Blackbelly) were used in two 4×4 Latin square designs. Four experimental diets were tested. They consisted in a tropical natural grassland hay based on Dichanthium spp. fed alone (C) or in association with G. sepium (G), L. leucocephala (L) or M. esculenta (M) given as pellets at 44% of the daily ration. Daily organic matter intake was higher in TRP diets (686, 984, 1054 and 1186g/day for C, G, L and M respectively; p<0.05) while apparent organic matter total tract digestibility was not affected (69.9%, 62.8%, 65.3% and 64.7% for C, G, L and M respectively; p>0.05). Methane emission was 47.1, 44.9, 33.3 and 33.5g/kg digestible organic matter intake for C, G, L and M, respectively, and was significantly lower (p<0.05) for L and M than for G and C. Our results confirm the potential of some TRP to reduce methane production. The strong decrease in methane and the increase in intake with TRPs may be due to their presentation as pellets.

Effects of forage source and extruded linseed supplementation on methane emissions from growing dairy cattle of differing body weights

Changes in diet carbohydrate amount and type (i.e., starch vs. fiber) and dietary oil supplements can affect ruminant methane emissions. Our objectives were to measure methane emissions, whole-tract digestibility, and energy and nitrogen utilization from growing dairy cattle at 2 body weight (BW) ranges, fed diets containing either high maize silage (MS) or high grass silage (GS), without or with supplemental oil from extruded linseed (ELS). Four Holstein-Friesian heifers aged 13mo (BW range from start to finish of 382 to 526kg) were used in experiment 1, whereas 4 lighter heifers aged 12mo (BW range from start to finish of 292 to 419kg) were used in experiment 2. Diets were fed as total mixed rations with forage dry matter (DM) containing high MS or high GS and concentrates in proportions (forage:concentrate, DM basis) of either 75:25 (experiment 1) or 60:40 (experiment 2), respectively. Diets were supplemented without or with ELS (Lintec, BOCM Pauls Ltd., Wherstead, UK; 260g of oil/kg of DM) at 6% of ration DM. Each experiment was a 4×4 Latin square design with 33-d periods, with measurements during d 29 to 33 while animals were housed in respiration chambers. Heifers fed MS at a heavier BW (experiment 1) emitted 20% less methane per unit of DM intake (yield) compared with GS (21.4 vs. 26.6, respectively). However, when repeated with heifers of a lower BW (experiment 2), methane yield did not differ between the 2 diets (26.6g/kg of DM intake). Differences in heifer BW had no overall effect on methane emissions, except when expressed as grams per kilogram of digestible organic matter (OMD) intake (32.4 vs. 36.6, heavy vs. light heifers). Heavier heifers fed MS in experiment 1 had a greater DM intake (9.4kg/d) and lower OMD (755g/kg), but no difference in N utilization (31% of N intake) compared with heifers fed GS (7.9kg/d and 799g/kg, respectively). Tissue energy retention was nearly double for heifers fed MS compared with GS in experiment 1 (15 vs. 8% of energy intake, respectively). Heifers fed MS in experiment 2 had similar DM intake (7.2kg/d) and retention of energy (5% of intake energy) and N (28% of N intake), compared with GS-fed heifers, but OMD was lower (741 vs. 765g/kg, respectively). No effect of ELS was noted on any of the variables measured, irrespective of animal BW, and this was likely due to the relatively low amount of supplemental oil provided. Differences in heifer BW did not markedly influence dietary effects on methane emissions. Differences in methane yield were attributable to differences in dietary starch and fiber composition associated with forage type and source.

Liquid residue of cassava as a replacement for corn in the diets of sheep.

The effect of the replacement of corn with the liquid residue of cassava was evaluated at levels of 0, 25, 50, 75, and 100% in the diets of sheep on the intake and nutrient digestibility, weight gain, and carcass characteristics. Forty non-castrated crossbred Santa Ines sheep at 4 months of age and an initial body weight of 19.5 ± 2.5 kg were slaughtered after 90 days at the feedlot. A quadratic effect was found for intake of dry matter (DM), organic matter (OM), non-fiber carbohydrates (NFC), and digestible OM, with estimated values of 1130, 1080, 558, and 777 g/day at 11.2, 11.9, 30.8, and 2.18% of replacing corn with liquid residue of cassava, respectively. However, the intake of crude protein (CP) and neutral detergent fiber (NDF) decreased linearly around 105 to 45.3 g CP/day and 413 to 284 g NDF/day. The same effect was found for digestibility of DM (715 to 649 g/kg), OM (725 to 669 g/kg), CP (801 to 759 g/kg), and NDF (486 to 379 g/kg), which decreased linearly as the dietary liquid residue of cassava increased. The maximum average daily gain (174 g/day) was estimated with a 22.4% replacement level. Liquid residue of cassava can replace up to 25% of the corn in the diets of sheep, since it was possible to obtain a gain above 100 g/day, which is considered to be satisfactory.

Impact of a tannin extract on digestibility, ruminal fermentation and duodenal flow of amino acids in steers fed maize silage and concentrate containing soybean meal or canola meal as protein source

SUMMARYFour Holstein steers (297 ± 56 kg of body weight (BW)) fitted with duodenal cannula and rumen catheter, were housed in metabolism cages and used in a 4 × 4 Latin Square trial to evaluate the effect of both protein source andAcacia mearnsiitannin extract on digestibility, ruminal fermentation, rumen microbial protein synthesis, N utilization and on duodenal flow of individual amino acids. The diet was offered at restricted amount of 25 g of dry matter (DM)/kg BW and consisted of maize silage plus concentrate, in a proportion of 0·7:0·3 (DM basis) respectively. Concentrate was formulated with either soybean meal or canola meal as protein source, with or without 50 g/kg ofA. mearnsiitannin extract (i.e. 15 g/kg of total dietary DM). There was no effect of protein source on most variables. The apparent and true organic matter (OM) digestibilities, as well as neutral detergent fibre (NDF) digestibility were negatively affected by tannin extract inclusion without, however, affecting digestible OM intake. The amount of nitrogen (N) excreted in faeces increased whereas the urinary N excretion decreased in tannin extract treatments. No interaction time × treatment was detected for any rumen variable and no treatment effect was observed for rumen fluid pH and reducing sugars concentration. Rumen fluid concentration of ammonia N was lower for the canola meal plus tannin extract treatment. Rumen concentration ofα-amino compounds was not affected by tannin extract but was higher when canola meal was the protein source. The duodenal flow of OM, total N,α-amino N and non-ammonia non-microbial N increased with tannin extract inclusion, whereas the duodenal flow of microbial N was not affected by treatment. For both protein sources, the amount of most individual amino acids flowing to the duodenum increased due to tannin extract addition. In conclusion, the dietary inclusion of 15 g/kg DM of tannin extract fromA. mearnsiiimproved the amino acid supply independently of whether the protein source was canola meal or soybean meal, without affecting the amino acid profile, to steers fed maize silage plus concentrate, with a minor but significant impact on OM digestibility.

Response of lactating cows to live yeast supplementation during summer

Dairy cows experiencing heat stress have reduced intake and increased reliance on glucose, making feeding strategies capable of improving diet digestibility plausible for improving postrumen nutrient flow and performance. The effect of yeast on digestion and performance of lactating cows during the warm summer months of southeastern Brazil was evaluated. Cows were individually fed in tie stalls and temperature-humidity index was above 68 during 75.6% of the experiment. Twenty-eight Holstein cows (207±87 d in milk) received a standard diet for 14 d and then a treatment for 70 d, in a covariate-adjusted, randomized block design with repeated measures over time. Treatments were yeast (Saccharomyces cerevisiae) or control. Yeast was top dressed to the diet in the morning, equivalent to 25×1010 cfu of live cells and 5×1010 cfu of dead cells. The diet contained corn silage (37.7%), Tifton silage (7.1%), raw soybeans (4.1%), soybean meal (16.5%), finely ground corn (20.7%), and citrus pulp (11.9%). Yeast increased milk (26.7 vs. 25.4kg/d) and solids yield (3.06 vs. 2.92kg/d), especially lactose. Response in milk yield was consistent over time and started at d 5. The daily intake of digestible OM, total-tract digestibility of nutrients, urinary allantoin excretion, chewing pattern throughout the day, and dry matter intake did not respond to yeast. A trend was observed for increased plasma glucose with yeast (62.9 vs. 57.3mg/dL), lowered respiratory frequency (48 vs. 56 breaths/min), and increased plasma niacin content (1.31 vs. 1.22 µg/mL), though cows had similar rectal temperature. Ruminal lactate and butyrate as proportions of ruminal organic acids were reduced by yeast, but no effects on other organic acids, ruminal pH, or protozoa content were detected. Plasma urea N over 24h was increased by yeast. On d 72 to 74, citrus pulp was abruptly replaced with finely ground corn to induce acidosis. The increased load of starch increased dry matter intake between 0700 and 1300h, jugular blood partial pressure of CO2, HCO3−, and base excess, and decreased blood pH for both treatments. The yeast treatment had a higher blood pH compared with the control, 7.34, and 7.31, respectively. Yeast supplementation improved lactation performance of dairy cows under heat stress. Improvement in lactation performance apparently involved the regulation of body homeothermia, rather than improved digestibility.

Effect of nitrogen fertilization rate and regrowth interval of grass herbage on methane emission of zero-grazing lactating dairy cows

Dairy cattle farming in temperate regions often relies on grass herbage (GH)-based diets but the effect of several grass management options on enteric CH4 emission has not been fully investigated yet. We investigated the combined effect of N fertilization rate and length of regrowth period of GH (predominantly ryegrass) on CH4 emission from lactating dairy cows. In a randomized block design, 28 lactating Holstein-Friesian dairy cows received a basal diet of GH and compound feed [85:15; dry matter (DM) basis]. Treatments consisted of GH cut after 3 or 5 weeks of regrowth, after receiving either a low (20kg of N/ha) or a high (90kg of N/ha) fertilization rate after initial cut. Feed intake, digestibility, milk production and composition, N and energy balance, and CH4 emission were measured during a 5-d period in climate respiration chambers after an adaptation to the diet for 12d. Cows were restricted-fed during measurements and mean DM intake was 15.0±0.16kg/d. Herbage crude protein content varied between 76 and 161g/kg of DM, and sugar content between 186 and 303g/kg of DM. Fat- and protein-corrected milk (FPCM) and feed digestibility increased with increased N fertilization rates and a shorter regrowth interval. Increasing the N fertilization rate increased daily CH4 emission per cow (+10%) and per unit of DM intake (+9%), tended to increase the fraction of gross energy intake emitted as CH4 (+7%), and (partly because of the low crude protein content for the low fertilized GH) only numerically reduced CH4 per unit of FPCM. The longer regrowth interval increased CH4 emission per unit of FPCM (+14%) compared with the shorter regrowth interval, but did not affect CH4 emission expressed in any other unit. With increasing N fertilization CH4 emission decreased per unit of digestible neutral detergent fiber intake (−13%) but not per unit of digestible organic matter intake. There was no interaction of the effect of N fertilization rate and regrowth interval on CH4 emission, but effects of N fertilization were generally most distinct with GH of 5 wk regrowth. The present results suggest that altering grass quality through an increase of N fertilization and a shorter regrowth interval can reduce CH4 emission in zero-grazing dairy cows, depending on the unit in which it is expressed. The larger amount of CH4 produced per day and cow with the more intensively managed GH is compensated by a higher feed digestibility and FPCM yield.

Glicerina bruta em suplementos para bovinos de corte a pasto no período seco

O objetivo deste trabalho foi avaliar o efeito da substituição do milho pela glicerina bruta (GB) sobre os parâmetros nutricionais e o desempenho de bovinos de corte em pastagem de Urochloa brizantha 'Marandu', no período seco. Para a avaliação dos parâmetros ruminais, foram utilizados cinco bovinos da raça Nelore não fistulados, com peso corporal (PC) inicial de 331,7±29,6 kg, distribuídos em delineamento em quadrado latino 5x5. Para a avaliação do desempenho, foram utilizados 30 bovinos, com PC médio de 312,4±23,3 kg, distribuídos em delineamento inteiramente casualizado. Avaliaram-se suplementos concentrados (20% de proteína bruta) com 0, 33, 66 e 100% de GB em substituição ao milho, fornecidos na quantidade de 4,0 kg por animal por dia. Os consumos de matéria seca (MS) de suplemento, total e de pasto, bem como o de matéria orgânica (MO) digestível, apresentaram comportamento quadrático frente aos níveis de substituição. As digestibilidades aparentes de MS, MO, fibra em detergente neutro e MO digerida, bem como o ganho médio diário, também apresentaram comportamento quadrático. Em suplementos concentrados fornecidos na quantidade de 10 g kg-1 de peso corporal, a substituição total do milho pela glicerina bruta reduz o consumo de suplemento e de matéria orgânica digerida, além do desempenho de bovinos de corte em pastejo.

Effect of camelina oil or live yeasts (Saccharomyces cerevisiae) on ruminal methane production, rumen fermentation, and milk fatty acid composition in lactating cows fed grass silage diets

The potential of dietary supplements of 2 live yeast strains (Saccharomyces cerevisiae) or camelina oil to lower ruminal methane (CH4) and carbon dioxide (CO2) production and the associated effects on animal performance, rumen fermentation, rumen microbial populations, nutrient metabolism, and milk fatty acid (FA) composition of cows fed grass silage-based diets were examined. Four Finnish Ayrshire cows (53±7 d in milk) fitted with rumen cannula were used in a 4×4 Latin square with four 42-d periods. Cows received a basal total mixed ration (control treatment) with a 50:50 forage-to-concentrate ratio [on a dry matter (DM) basis] containing grass silage, the same basal total mixed ration supplemented with 1 of 2 live yeasts, A or B, administered directly in the rumen at 1010 cfu/d (treatments A and B), or supplements of 60g of camelina oil/kg of diet DM that replaced concentrate ingredients in the basal total mixed ration (treatment CO). Relative to the control, treatments A and B had no effects on DM intake, rumen fermentation, ruminal gas production, or apparent total-tract nutrient digestibility. In contrast, treatment CO lowered DM intake and ruminal CH4 and CO2 production, responses associated with numerical nonsignificant decreases in total-tract organic matter digestibility, but no alterations in rumen fermentation characteristics or changes in the total numbers of rumen bacteria, methanogens, protozoa, and fungi. Compared with the control, treatment CO decreased the yields of milk, milk fat, lactose, and protein. Relative to treatment B, treatment CO improved nitrogen utilization due to a lower crude protein intake. Treatment A had no influence on milk FA composition, whereas treatment B increased cis-9 10:1 and decreased 11-cyclohexyl 11:0 and 24:0 concentrations. Treatment CO decreased milk fat 8:0 to 16:0 and total saturated FA, and increased 18:0, 18:1, 18:2, conjugated linoleic acid, 18:3n-3, and trans FA concentrations. Decreases in ruminal CH4 production to treatment CO were related, at least in part to lowered DM intake, whereas treatments had no effect on ruminal CH4 emission intensity (g/kg of digestible organic matter intake or milk yield). Results indicated that live yeasts A and B had no influence on animal performance, ruminal gas production, rumen fermentation, or nutrient utilization in cows fed grass silage-based diets. Dietary supplements of camelina oil decreased ruminal CH4 and CO2 production, but also lowered the yields of milk and milk constituents due to an adverse effect on intake.

Comparison of the alkane-based herbage intakes and the liveweight gains of young sheep grazing forage oats, dual-purpose wheat or phalaris-based pasture

Two experiments were conducted between 2004 and 2006 near Canberra, Australia, to provide information about herbage intake and liveweight gains of young sheep grazing dual-purpose crop cf. pasture. In an indoor feeding trial (2004–2005), dual-purpose wheat (cv. Mackellar) and oats (cv. Blackbutt) had estimated organic matter (OM) digestibilities of 0.849 ± 0.0070 and 0.847 ± 0.0001, respectively. The indoor trial also provided data for the concentrations and faecal recoveries of the cuticular wax alkane and long-chain alcohol (LCOH) markers used to estimate diet composition and intake in the grazing trial. The faecal recoveries of both alkanes and LCOH were well described by asymptotic regressions. Alkane recovery differed between crops, though not between years. Faecal LCOH recovery did not differ between crops or years. Under grazing conditions in 2004–2005, the OM digestibility (OMD) of crop herbage was 0.825–0.871, significantly higher than the OMD of phalaris-based pasture (0.752–0.758). The estimated OMD of wheat in 2006 (0.792) was lower than in the earlier years. Sheep consumed ~1 kg/day digestible OM intake (DOMI) from crop in 2004–2005. In 2004 this was significantly higher than the DOMI of sheep grazing pasture (0.75 kg/day) whereas in 2005 the DOMI from pasture was slightly (1.15 kg/day) but significantly higher than that from crop (mean 0.97 kg/day). Regardless of the source of herbage consumed, sheep daily liveweight gains were in the range 200–250 g/kg DOMI. Liveweight gains of sheep grazing crop were also predicted from their calculated metabolisable energy intakes and requirements for maintenance and were within 1% of the observed liveweight gains. Our results demonstrate that in high-rainfall areas, the quantity and quality of the herbage provided by sowing dual-purpose crops, and the resultant increased animal liveweight gains, justify the inclusion of dual-purpose crops in grazing systems.

Effect of Kinnow Mandarin (Citrus Nobilis Lour × Citrus Deliciosa Tenora) Fruit Waste Silage on Nutrient Intake, Digestibility and Performance of Goat Bucks

The objective of this study was to evaluate the effect of the feeding Kinnow mandarin fruit waste (KMW) silage viś-a- viśoat silage on nutrient intake, nutrient digestibility, utilization and general performance of adult male goats. Twelve local adult male goats were randomly allotted into two equal groups namely oat silage (OS) and Kinnow silage (KS) group. Animals were offered weighed quantities of respective silage (Oat silage to OS and KMW silage to KS) on ad lib. Silage intake (g/d), DM intake (DMI), digestible DMI, digestible organic matter (OMI) and digestible CP intake was comparable (P>0.05) among the two dietary groups. The per cent digestibility of all the analysed nutrients was analogous (P>0.05) in both the groups irrespective of the diet. Total digestible nutrient (TDN) intake (g/d) of goats kept on KMW silage was significantly (P<0.05) higher than OS group animals. Balance of nitrogen and phosphorus was positive in both the groups without any significant (P>0.05) difference between dietary groups. There was no significant difference in analysed blood bio-chemicals and serum enzymes level between different periods and groups, suggesting general well-being of goats. On the basis of results of present study, it can be concluded adult male goats can be maintained on the silage of Kinnow waste without affecting nutrient intake, utilization and general performance of animals.

Effects of nitrate and fumarate in tree leaves-based diets on nutrient utilization, rumen fermentation, microbial protein supply and blood profiles in sheep

This experiment was conducted to study the effects of nitrate and fumarate on nutrient utilization, rumen fermentation and blood biochemical profile in sheep fed on tree leaves-based diet. Thirty two matured male Chokla breed of sheep (2–3 years old and 46.9±0.95kg average body weight) were equally distributed in a randomized block design in four groups with similar average age and mean body weight. All groups were fed diets containing roughage and concentrate in a 70:30 ratio. Control group (C) was fed with cenchrus (Cenchrus ciliaris) straw as an only roughage source, whereas other three groups (T1, T2 and T3) were fed with cenchrus straw, ardu (Ailanthus excelsa) leaves and khejri (Prosopis cineraria) leaves (50:25:25) as roughage sources. Animals in the T1 group were not supplemented with any feed additive; whereas, animals in the T2 and T3 groups were added with 2% potassium nitrate of the concentrate mixture and 2% fumarate of the dry matter (DM) intake, respectively. There were no effects (P>0.10) of any treatments on DM intake, BW change or nutrient utilization. N retention increased in treatment groups compared with control due to greater amount of N intake. Concentrations of glucose, haemoglobin, albumin, blood urea nitrogen and creatinine, and different blood enzyme concentrations were not affected (P>0.10) by any treatments, but concentrations of total protein, globulin and cholesterol in blood were higher for T1 and T3 than for C and T2 treatments. Microbial N supply in terms of digestible OM intake or digestible OM retained in the rumen did not differ among treatments. Total amylase and carboxymethyl cellulase concentrations were similar among the groups. However, total xylanase activity increased in T3 group than other groups. A reduction in average propionate concentration (P=0.020) was observed for the T2 treatment in comparison with the C and T1 groups. Concentrations of ammonia N, total N and trichloroacetate-perceptible N were lower in control than other treatments, but concentrations of soluble N were not affected (P>0.05) by any treatments. In conclusion, fumarate (2% of DM) may be included in the diet of sheep fed with ardu–khejri leaves without affecting nutrient utilization and rumen fermentation, whereas ardu–khejri leaves diet containing nitrate (0.6% of DM) may affect rumen fermentation.

Effects of replacing soybean meal with dried rumen digesta on feed intake, digestibility of nutrients, rumen fermentation and nitrogen use efficiency in Thai cattle fed on rice straw

This study assessed the feed intake, nutrient intake, apparent digestibility of nutrient, rumen fermentation and nitrogen utilization of beef cattle fed with different soybean meal (SBM) replacement levels with dried rumen digesta (DRD) at 0, 33, 67 and 100%. Four 1.5-year-old Thai native beef cattle steers with initial body weight (BW±SD) of 92.1±4.59kg were used in a 4×4 Latin square design. All animals were fed rice straw ad libitum while additional concentrate was fed at 0.5% BW daily. Replacement of DRD for SBM were not altered (P>0.05) on total DM intake while the intake of rice straw of the 100% DRD diet was higher than that of the other diets, and it significantly increased with increase in the replacement level of SBM with DRD (P<0.05). Intakes of organic matter (OM), crude protein (CP), neutral detergent fiber (aNDF) and acid detergent fiber (ADF), digestible organic matter intake, digestible organic matter fermented in the rumen and metabolizable energy showed no difference when compared to those on the control diet (P>0.05). The experimental diets has no effect (P>0.05) on the apparent digestibilities of DM, OM, CP and ADF while aNDF digestibility increased with an increase of DRD in the diet and was highest when inclusion of 100% DRD. No differences (P>0.05) were found in ammonia nitrogen concentration, total volatile fatty acid (VFA) and VFAs profiles in the rumen fluid of cattle fed with DRD when compared to those on control diet. Similarly, N use efficiencies were not altered with level of DRD in the diet. Based on this study, it could be concluded that replacement of SBM by DRD as feed ingredient in cattle diets up to 100% dietary level resulted in improved rice straw intake and aNDF digestibility in beef cattle, without affecting the rumen fermentation or nitrogen use efficiency.

Effect of induced Fasciola gigantica infection during pre-patency on the performance of buffalo calves fed on different percentage of protein.

Thirty growing Murrah buffalo calves (8-12months of age, 109.85±2.43) were rearedin parasite free conditions and randomly divided into three equal groups as per CRD. They were fed on iso-caloric (2.01MEMcal/Kg diet) diets containing standard protein (SP) diet at 100%, 90% of SP (medium protein, MP) and 80% of SP (low protein, LP) of the protein requirements (Kearl 1982). After 21days of feeding, each group was further subdivided into two sub-groups (A & B). Animals in sub-groups 'A' served as non-infected control, while in sub group 'B' were orally infected with Fasciola gigantica metacercarie (mc; 1,000 each). A metabolic trial of 40days post infection was carried out in control and parasitized animals. Intake of digestible dry matter, organic matter and acid detergent fibre (ADF) was significantly higher (P<0.05) in SP group compared to LP group. The digestibility of crude protein (CP) and ADF was significantly higher in SP group compared to MP and LP groups. The digestible crude protein (DCP) and total digestible nutrients (TDN) intakes (g/kgW(0.75)) were also significantly (P<0.001) higher in SP than MP and LP groups. However, DCP intake was significantly (P<0.001) lower in infected subgroups compared to control subgroups. Intake and balance (g/d) of nitrogen, calcium and phosphorus were significantly (P<0.01) higher in SP than MP and LP groups. The average daily gain of buffalo calves fed on SP Uninfected (SPU), SP Infected (SPI), MPU, MPI and LPU, LPI groups was 333, 178, 356, 144, 222 and 144g and was significantly (P<0.01) lower in animals fed LP ration. The feed conversion ratio (FCR) was also significantly (P<0.01) higher in infected sub-groups as compared to respective control groups. The results showed that a SP diet substantially improved the overall performance of buffalo calves in control and infected groups and reduced adverse effect of F. gigantica infection.

Influence of monensin fed with a starch-based energy supplement on forage digestibility and intake by range cows during drought

Management strategies that maintain livestock performance while reducing intake in times of low forage availability, such as drought, are valuable. The hypotheses of this experiment were that a grain-based supplement would decrease forage intake and digestibility, whereas a grain-based supplement plus monensin would decrease forage intake and increase forage digestibility. Crossbred cows (n = 36) grazing native range pasture during the late summer were used in a randomized complete block design for 2 yr (average forage quality for yr 1 = 8.7% CP, 77% NDF, 47% ADF; for yr 2 = 8.0% CP, 76% NDF, 45% ADF). Treatments were control (no supplement; NS), cracked corn (S; 0.91 kg/cow per day, as-fed basis), and S with monensin added at 385 mg/kg of corn (SM). Diet samples were collected from 6 ruminally cannulated cows to calculate digestibility. Cows were dosed with Cr2O3 boluses to determine fecal output, OM intake, and digestible OM intake during 2 sampling periods each year. Forage intake and digestible OM intake as percentages of BW were greater (P 0.05) in yr 2. Starch-based supplement alone reduced OM and NDF digestibility in period 1 of both years compared with NS or SM treatments (P < 0.001). In period 2 of both years, OM digestibility was greatest for the SM treatment (P < 0.001). In period 2 of yr 1, NDF digestibility was greatest in SM (P < 0.001), but similar between SM and NS in yr 2. Under our experimental conditions, monensin fed with a starch-based energy supplement did not decrease forage intake during drought; however, moderate forage quality and type and amount of supplement provided may have affected responses.

Daily and alternate day supplementation of Moringa oleifera leaf meal or soyabean meal to lambs receiving oat hay

We hypothesized that Moringa oleifera foliage which is high in crude protein and almost free in main secondary compounds could replace soyabean meal used in supplementation strategies of livestock. Therefore, this experiment aimed to evaluate the effect of daily and alternate day supplementation of Moringa leaf meal (MLM) or soybean meal (SBM) to sheep on intake and digestion and glucose, protein and urea in blood plasma. Twenty Barbarine male lambs (average initial body weight, 27.3±3.0kg), were randomly divided into four groups of five lambs each. They were adapted for 22 days to dietary treatments before starting a 6-day total collection period. All animals consumed oat hay ad libitum supplemented with concentrates composed of barley grain only (C-BAR) or mixed with SBM (C-SBM), or MLM (C-MLM) as protein sources. Groups 1 and 2 received daily C-SBM and C-MLM, respectively. However, groups 3 and 4 had access to concentrates containing the protein sources (C-SBM and C-MLM) with alternate day that means they received for one day these concentrates and in the following day they received barley grain only (C-BAR). Soybean meal and MLM incorporation in concentrates had similar effects (P>0.05) on water, hay, and digestible organic matter (OM) intakes and DM, organic matter (OM) and neutral detergent fiber (NDF) digestibility. Daily substitution of SBM by MLM increased (P=0.024) crude protein (CP) intake and apparent total tract digestibility. However, the alternate day supplementation decreased apparent total tract CP digestibility but increased CP intake for SBM treatment. The concentration of ruminal ammonia nitrogen before feeding was higher (P=0.012) in groups 1 and 3 than in the other groups. The concentration of blood glucose was similar (P>0.05) among treatments. However, lambs receiving C-SBM exhibited highest concentrations of protein (P=0.039) and urea (P=0.001) in the blood. It is concluded that MLM administered at two day-intervals had similar effects on feed intake, digestion and blood metabolites to SBM incorporated in concentrate distributed to sheep receiving oat hay.

Corn bran versus corn grain at 2 levels of forage: Intake, apparent digestibility, and production responses by lactating dairy cows

The objective of this study was to determine the effect of substituting corn bran (CB) for dried ground corn grain (CG) in the nonforage portion of high-forage (HF) and low-forage (LF) diets. Twelve multiparous and 12 primiparous Holsteins were assigned to 4 diets using six 4× Latin squares with 3-wk periods. Forage was 64 or 38% of the total mixed ration (% of dry matter). On a dry matter basis, the HFCG diet had 20% CG, the LFCG diet had 39% CG, the HFCB diet had 19% CB, and the LFCB diet had 38% CB. Digestible organic matter intake (OMI) and milk energy yield were lower for CB compared with CG within forage level. Digestible OMI was greater (1.9kg/d) for the LFCG compared with the HFCG treatment. When CB replaced forage (LFCB vs. HFCB), digestible OMI was not different but milk energy yield was greater with the LFCB diet. The LFCG diet supported the greatest milk, milk protein, and milk energy yield. Decreased concentration of milk protein and increased concentration of milk urea nitrogen when feeding CB compared with CG suggests that lack of fermentable energy in the CB diets may have limited rumen microbial protein synthesis. Total substitution of CG with CB in the nonforage portion did not support maximum milk production, even when forage was reduced at the same time (HFCG vs. LFCB). Predicted neutral detergent fiber (NDF) digestibility at 1 times maintenance, based on chemical analysis of the individual feeds, was 22 percentage units greater for CB than for the forage mix (68.9 vs. 46.9%). In vitro NDF digestibility (30h) was 19.4 percentage units greater for CB than for the forage mix (68.9 vs. 49.5%). However, in vivo NDF digestibility of the diet when CB replaced forage (HFCB vs. LFCB) was similar (44.1 vs. 44.5%). Similarly, predicted total digestible nutrients at the production level of intake, based on chemical analysis, were greater for the CB treatments and lower for the CG treatments than those observed in vivo.