Effects of sun-drying and exogenous enzymes on nutrients intake,digestibility and nitrogen utilization in sheep fed Atriplex halimus foliages

This study was conducted to assess effects of sun-drying and/or addition of an exogenous enzyme (ENZ) preparation on intake, digestibility of nutrients and recovery values of secondary metabolites (SM) in the gastrointestinal tract of sheep fed Atriplex halimus (AH) foliages. A randomized block design for 28 d was used for four experimental treatments based on either fresh (AH-F) or sun-dried (AH-S) A. halimus foliages in the absence (?ENZ) or presence (+ENZ) of 10 g/sheep/d of the exogenous of ZADO^® enzyme preparation. Three adult sheep weighing 51 ± 2.7 kg were fed for each experimental treatment. The ENZ was added daily with a small amount of concentrate to help balance the dietary metabolizable energy concentration. Nutrient intake and digestibility, N balance and recovery of SM (i.e., total phenolics (TP), saponins (SP), alkaloids (AK), aqueous fraction (AF)) in the gastrointestinal tract were determined. Levels of most nutrients did not differ between AH-F and AH-S foliages, but the AH-S contained less than half of the SM in AH-F. Drying of A. halimus and ENZ addition increased (P=0.001) intake as well as OM and NDFom digestibility (P=0.02). Feed intake and digestibility were higher (P=0.01) in AH-S with ENZ addition. Intake of N by sheep fed the treatment diets depended on DM intake as the dietary concentration of N in the diets was similar. Thus AH-S sheep supplemented with ENZ had higher (P=0.001) N intake. Digestibility of N was similar to DM and OM digestibility, and was higher (P=0.03) in AH-S sheep supplemented with ENZ. Drying and ENZ addition to the diet increased (P=0.004) recovery of all SM. The fate of these compounds in the rumen needs to be evaluated considering that SM have been implicated in fiber and protein degradation in the rumen. The study showed that there are beneficial impacts of sun-drying and/or dietary exogenous enzyme addition for sheep fed A. halimus.     

Influence of undegraded intake protein on intake,digestion, serum hormones and metabolites,and nitrogen balance in sheep

In Exp. 1, 20 ewes of mixed breeding were fed grass hay : straw mixtures, assigned to one of four supplemental treatments and evaluated during six collection periods. Supplemental treatments were control (no supplement), and low, medium, and high levels (5.2%, 22.1%, and 41.3% of DM, respectively) of undegraded intake protein (UIP). Supplements were formulated to be similar in degraded intake protein (DIP; 21%). Digestibilities of DM, OM, and CP were increased (P < 0.10) with protein supplementation and in medium and high compared with low UIP supplemented ewes. Digestibility of CP also was increased (P < 0.10) in ewes on high compared with medium treatments. Serum insulin was not influenced (P > 0.10) by UIP treatment, except in collection period four. In contrast, serum glucose and growth hormone were not influenced (P > 0.10) by UIP treatment. In Exp. 2, four wether lambs fed the same treatments as in Exp. 1, were used in two 4 × 4 Latin squares trials. In trial 1 lambs received a grass hay diet (6.7% CP) and in trial 2 lambs were fed 40 : 60 blend (6.6% CP) of grass hay and spring wheat straw. In both trials, N intake, urinary N, N digestion, apparent N absorption, and N retention were increased (P < 0.10) with protein supplementation. In addition, in trial 1, urinary N, N digestion, and apparent N absorption were increased (P < 0.10) in medium and high compared with low UIP and also in high compared with medium UIP treatments. In trial 2 of Exp. 2, total feed intake (g/kg BW), digestibility of DM and OM, BW, and fecal N were increased (P < 0.10) with protein supplementation. Organic matter digestion, BW, N intake, and N retention were increased by medium and high compared with low UIP. Fecal N, BW, N intake, and N retention were increased (P < 0.10) in high compared with medium UIP. These data indicate that increasing levels of UIP supplementation increases DM, OM, and CP (N) digestibility, serum urea N concentration, and N retention in sheep fed low quality forage.     

Effects of sodium bicarbonate and yeast on nutrient intake,digestibility, and ruminal fermentation of light-weight lambs fed finishing diets

This study was conducted to determine the effects of adding yeast culture and sodium bicarbonate to the finishing diets for lambs on intake, digestibility, rumina1 parameters and nitrogen retention. Twenty Pelibuey male lambs, weighing an average of 23 kg, were assigned to one of four treatment groups according to a completely randomized design with a 2 × 2 factorial arrangement. Treatments were: (1) no additive (NA); (2) 0.12% yeast culture (YC); (3) 0.5% sodium bicarbonate (SB); and (4) 0.12% YC and 0.5% SB. During the 7-day collection period, SB increased DM intake (P < 0.05), while YC had no effect (P > 0.05) on intake. Intake of non-fibrous carbohydrates (NFC) was increased (P < 0.05) with SB in the ration, but not by supplementing YC (P > 0.05). The YC had no effect (P > 0.05) on dry matter (DM), neutral detergent fiber (NDF) or non-fibrous carbohydrates digestibility. A higher intake of NFC with the SB treatments was associated with a lower (P < 0.05) digestibility. SB increased excretion of NDF (P < 0.05), which reduced its digestibility (P < 0.05) by more than 9 percentage units. Lambs consuming diets with SB had 27% more N retained, in contrast with those fed the basal diet without additives. Rumen pH was greater than the minimum considered to cause acidosis (≤pH 5.5). The SB reduced (P < 0.05) percent molar acetate and increased (P < 0.05) percent molar propionate, which is in contrast to what has been normally observed with dairy cattle research. A lower acetate to propionate ratio with the SB rations may be a result of a lower digestibility and a higher intake of NDF, which may have increased the rate of passage of fiber particles through the gastrointestinal tract.     

Supplementation of isonitrogenous oil seed cakes in cactus (Opuntia ficus-indica)–tef straw (Eragrostis tef) based feeding of Tigray Highland sheep

The experiment was conducted at Maichew Agricultural Technical Vocational Education and Training College, Ethiopia. Twenty four male yearling Tigray Highland sheep with mean body weight (BW) of 21 ± 2.6 kg (mean ± S.D.) were used to investigate the effect of different protein sources on feed intake, nutrient digestibility, BW change and carcass parameters in a study comprising of 90 days feeding trial, followed by 7 days of digestibility trial and evaluation of carcass parameters. Six individually fed animals were used per treatment in a randomized complete block design. The treatments consisted of ad libitum feeding of tef (Eragrostis tef) straw plus 172 g dry matter (DM) of cactus (Opuntia ficus-indica) pear (T1, control) and supplementation with 145 g DM cotton seed cake (CSC) (T2), 195 g DM noug seed cake (NSC) (T3) or 149 g DM peanut cake (PNC) (T4) per head per day. The quantity of the supplements was set to supply 62.5 g crude protein (CP). Tef straw DM intake was depressed (P<0.01) as the result of NSC supplementation. Sheep supplemented with CSC and PNC had higher (P<0.001) total DM intake than the control and NSC supplemented ones. Supplementation with NSC and PNC also resulted in higher (P<0.01) apparent digestibility of DM and OM compared to the control treatment. Supplementation with CSC and PNC resulted in better daily BW gain (P<0.001), feed conversion efficiency (FCE) and dressed carcass weight (P<0.01) compared to the non-supplemented diet. Dressing percentage on slaughter weight base was higher (P<0.01) in supplemented sheep than in the non-supplemented ones. Supplementation with PNC also promoted higher (P<0.05) rib-eye muscle area than in the non-supplemented ones. It was concluded that supplementation with 145 g DM CSC and 149 g DM PNC resulted in better feed intake, BW gain and carcass traits in cactus–tef straw based feeding of sheep.     

Feed digestion,rumen fermentation and blood biochemical constituents in Malpura rams fed a complete feed-block diet with the inclusion of tree leaves

This experiment assayed the influence of the inclusion of dried Azardirachta indica, Albizzia lebbek or Ailanthus excelsa leaves in pearl millet stover-based complete feed block diets on feed intake, nutrient utilization, rumen fermentation characteristics, ciliate protozoa population and blood biochemical constituents in adult Malpura sheep. Complete feed blocks were formulated to have roughage-to-concentrate ratio of 70:30. Pearl millet stover (PMS) was used as basal roughage; 30 parts of pearl millet stover was replaced with dried leaves either of Azardirachta indica (NL), Albizzia lebbek (SL) or Ailanthus excelsa (AL). Twelve hogget Malpura rams, divided into four equal groups, were offered one of the four dietary treatments. A feeding-cum-metabolic trial was conducted to assess nutrient utilization. Rumen liquor samples were collected at 0, 3, 6, 12, 18 and 24 h post-feeding to assess rumen fermentation pattern and ciliate protozoa population. Inclusion of dried leaves in PMS-based diets improved CP and DCP content. Dietary DCP was low (P < 0.01) in PMS (8.52%) compared to tree leaves (9.77–11.59%) diets. AL and NL diets had higher (P < 0.05) DCP than the SL diet. The inclusion of tree leaves did not influence organic matter, crude protein or cellulose digestibility, but depressed dry matter, NDF, ADF and energy digestibility. DE content was also lower in tree leave diets. Inclusion of tree leaves improved CP and DCP intake, but DE intake and nitrogen utilization did not change. The pH of rumen liquor (SRL) was low (6.99, P < 0.05), but total nitrogen (52.9 mg/dl SRL) and NH₃-nitrogen (9.34 mg/dl SRL) concentrations were higher (P < 0.01) in the AL diet. TVFA concentrations and ciliate protozoa population were similar on the four diets. Animals in the four groups had the desired concentration of rumen metabolites required for fibrous diets. Complete feed-block feeding provided a constant nutrient supply to rumen microbes that optimise rumen fermentation. Blood biochemical constituents did not change due to the inclusion of tree leaves. Therefore, tree leaves can be included with roughage-based feeding to improve the protein nutrition status of ruminants. Further studies are required to assess the negative influence of tree leaves on digestibility.     

Intake,digestibility and nitrogen utilization of Robinia pseudoacacia foliage fed to growing goat wethers

Black locust (BL; Robinia pseudoacacia L.), a native tree of southeastern USA known to contain substantial levels of condensed tannins (CT), was fed to 32, 4 month old (20.4 kg BW) Boer cross wether goats in two randomized complete block design trials. The objectives were to examine the effects of feeding hay diets containing several levels of fresh BL foliage on intake, digestibility, and N metabolism. First year (1999) diets were H_E (100% Eastern gamagrass [EGH; Tripsacum dactyloides L.] hay), H_EG (70% EGH and a 30% mixture of 59% ground corn [GC; Zea mays L.], 36% soybean meal [SBM; Glycine max L.], and 5% minerals), 25BL99 (75% EGH and 25% BL leaves), and 50BL99 (50% EGH and 50% BL leaves). Second year (2000) diets were H_O (100% orchardgrass [OGH; Dactylis glomerata L.] hay), H_OG (70% OGH and a 30% mixture of 63% GC, 37% SBM, and 5% minerals), 50BL00 (50% OGH and 50% BL leaves), and 75BL00 (25% OGH and 75% BL leaves). In 1999, apparent digestibilities of the diets in the order listed above were 62.4, 68.2, 58.0, and 60.6% (P = 0.001) for DM and 62.8, 72.5, 56.0, and 59.1% (P = 0.001) for crude protein (CP). Acid detergent lignin digestibilities were negative for diets 25BL99 (−56.7%) and 50BL99 (−49.3%), apparently due to the formation of insoluble tannin and lignin complexes during passage through the digestive tract. Intakes of DM were similar across diets. In 2000, apparent digestibilities of diet DM (64.4, 71.7, 64.8 and 65.4%) and CP (70.0, 76.0, 66.6, and 66.5%) did not differ. Lignin digestibilities were positive for diets 50BL00 (9.4%) and 75BL00 (29.6%) unlike those for year 1999. Overall, BL contained 10% CT and 18–34% hydrolyzable tannins. In 1999, N intake, urinary N (UN) excretion and N retained were higher for diet H_EG (P = 0.01) than diet H_E whereas fecal N excretion (FN) was similar for diets H_EG, 25BL99 and 50BL99. In 1999, FN excretion as a percentage of N intake was higher (P < 0.02) in the BL diets, although UN as a percentage of N intake did not differ among diets. In 2000, N intake and FN output were higher for BL diets compared to diets H_O (P = 0.01) and H_OG (P = 0.02). Fecal N as a percentage of N intake was lower (P = 0.01) for diet H_OG (24.0%) than for diets 50BL00 (33.4%) and 75BL00 (33.5%). Conversely, urinary N as a percentage of N intake was higher for diets H_O and H_OG compared to the BL diets (P = 0.02). Increased levels of dietary BL increased FN, suggesting that tannins formed insoluble protein complexes thus hindering digestibility.     

Clinical profile of sheep fed non-conventional feeds containing phenols and condensed tannins

A study was carried out to investigate the effects of feeding low quality non-conventional feeds (NCF) containing phenols and condensed tannins on the clinical profiles of sheep. Thirty-two Omani sheep were fed one of four diets with two base roughages, urea-treated palm frond (UTPF) and Rhodesgrass hay (RGH) and two concentrates, commercial concentrate (CC) and a by-products concentrate (BC) for 120 days. Haematological, serum biochemical and urine analyses were used to assess sheep health. Non-conventional feeds (urea-treated palm frond and by-products concentrate) contained higher levels of polyphenols and condensed tannins than conventional feeds (Rhodesgrass hay and commercial cubes). Feeds based on urea-treated palm frond had lower dry matter, crude protein, acid detergent fibre, neutral detergent fibre, gross energy (P < 0.001) and ash (P < 0.05) digestibility coefficients than those based on Rhodesgrass hay. Animals fed NCF had lower feed intake (P < 0.001) and lower body gain (P < 0.001) than those fed conventional ones. They also produced larger volumes of faeces (P < 0.01) which contained higher levels of nitrogen (P < 0.001) and had lower viscosity values of intestinal content (P < 0.001). Rumen liquor of NCF-fed animals had higher pH and lower ammonia–nitrogen levels (P < 0.01). Animals fed urea-treated palm frond plus by-products concentrate had lower lymphocyte (P < 0.01), monocyte (P < 0.05) and eosinophil (P < 0.05) counts by the end of the trial than those fed Rhodesgrass hay based diets. The urea-treated palm frond and by-products concentrate fed animals had lower blood urea nitrogen (BUN) levels (P < 0.05), higher (P < 0.01) alanine aminotransferase (ALT) and lower serum iron (P < 0.001) than those fed Rhodesgrass hay based diets. There was a trend of increasing blood, leukocytes and specific gravity in the urine of NCF-fed animals. This experiment implies that feeding low quality non-conventional feeds containing antinutritional factors for relatively long periods might produce subtle negative effects on the physiology and chemistry of the digestive system and blood parameters which might negatively affect sheep health and make them more susceptible to diseases.     

Digestibility,nitrogen balance,and blood metabolites in llama (Lama glama) and alpaca (lama pacos) fed barley or barley alfalfa diets

To determine the effect of barley diets on digestibility, nitrogen balance, and blood metabolites, mature gelded llamas and alpacas (n = 8; 4 llamas, 36 ± 4 months, 90 ± 10.7 kg; 4 alpacas, 24–36 months, 50 ± 4 kg) were randomly fed 100% barley (B) and 20% alfalfa/80% barley (BA) hay. Animals were housed in metabolism crates and diets were fed for a 7 days adjustment period followed by a 5 days collection period. Feed, feed refusal, feces and urine were collected, dried and N content determined by combustion analysis. Blood samples were collected on day 12 at 30 min intervals over a 6 h period. Plasma was harvested and analyzed for electrolytes (Na, K, Cl, Ca, Ca²⁺, P, Mg), metabolites glucose, non-esterified fatty acids (NEFAs), urea N, creatinine, albumin, total protein (TPP), osmolality (Osm). Plasma glucose, urea N, albumin, osmolality, electrolyte and metabolite levels were similar between species, and were unaffected by diet. On a metabolic weight basis, only diet was significant for N intake, urinary and fecal N, and total N excreted. Dry matter intake was not significantly different; however, BA consumption was greater than B, (B) 1272 g N/day and (BA) 1636 g N/day for llamas, and for alpacas (B) 835 g N/day and (BA) 1034 g N/day, respectively. Nitrogen intake followed the same pattern, (B) 21.4 g N/day and (BA) 33.9 g N/day, respectively for llamas, and (B) 13.6 g N/day and (BA) 20.6 g N/day, respectively for alpacas (diet, P < 0.002). Diet affects were significant for urine N excretion (P < 0.02), (B) 11.2 g/day and (BA) 18.2 g/day for llamas, and (B) 6.8 and (BA) 10.8 g N/day for alpacas. Fecal N excretion was different for diet (P < 0.03), with fecal excreted N of 9.0 g N/day and 11.9 g N/day for B and BA in llamas, and 5.9 g N/day and 9.1 g N/day for B and BA respectively in for alpacas, respectively. Nitrogen retention, DM digestibility and N digestibility were unaffected by diet or species. However, the llamas in this study displayed an increase in nitrogen intake of 64.6% between the B and BA diets with a 381% increase in N retention. Alpacas increased their N intake by 57.4% when they consumed the BA forage, which only increased N retention by 22.2%. These species differences indicate that alpacas have a lower N requirement to meet metabolic needs than llamas, which are likely related to the smaller body size of the alpaca. When examining the biological value of N from the respective diets, alpacas and llamas had a value of 56.2% when consuming barley. The BA diet had a higher biological value of 65.0% in llamas compared to 57.4% in alpacas. Therefore, on the basis of this study, extrapolations between llamas and alpacas with respect to nitrogen requirement and balance are not valid.     

Fecal nitrogen to estimate intake and digestibility in grazing ruminants

This study aimed at evaluating forage intake and digestibility in ruminants using fecal nitrogen content, as well as validating a non-linear model to estimate digestibility in ruminants. A total of 58 conventional metabolism trials, carried out with sheep fed 27 forages (offered pure or in mixture) used in Rio Grande do Sul (RS) during the period 1969–1989 was analyzed. OM intake and OM digestibility (OMD) results were regressed linearly against fecal N, and OMD was also estimated from fecal crude protein (N × 6.25) content by a non-linear regression model. Fecal nitrogen excretion estimated forage intake in sheep with an R² = 0.73, whereas a low R² value of 0.36 was observed for OMD estimates. The equation obtained using the non-linear model was OMD = 0.7326 ? 0.3598 exp [(?0.9052 CP (g/kg OM))/100]. The parameters a (0.7326) and b (0.3598) estimated by the equation for all forages were significant (P<0.00001) and there was no effect of type of forage (P=0.38). The mean prediction error (MSPE), was 0.2379, indicating that the equation fit well to the data. The difference between estimated and observed organic matter digestibility was mainly caused by random variation (0.9765). The results indicated that the equation using the non-linear model developed with all forages can be used with enough precision to estimate the OM digestibility of forage consumed by sheep in Rio Grande do Sul.     

Nutrient composition,digestion and rumen fermentation in sheep of wheat straw treated with calcium oxide,sodium hydroxide and alkaline hydrogen peroxide

This study tested the effect of calcium oxide (CaO), sodium hydroxide (NaOH) and NaOH plus hydrogen peroxide (H₂O₂; AHP) on cell wall composition, digestion and fermentation of wheat straw (straw) in sheep. Treated straws were prepared by mixing straw either with water followed by dusting with CaO at 160 g kg⁻¹ DM or with a NaOH solution alone at 3 l kg⁻¹ DM to supply 80 g NaOH kg⁻¹ DM (Na) or pre-soaked with Na exactly as in the previous treatment for 27 h followed by mixing with 130 g H₂O₂ kg⁻¹ DM (AHP) for 6 h. After 14 days of storage, the treated straws and an untreated straw (U) were fed automatically every 2 h to four individually housed sheep together with a supplement in a 4×4 latin square experiment. Each kilogram supplement DM contained 422 g CP and 10.8 MJ ME. NDF (p<0.001) and hemicellulose (p<0.01) contents were significantly reduced whereas cellulose was increased (p<0.001) in treated compared to untreated straw. ADL was reduced in Ca (p<0.05) but increased (p<0.05) in Na and AHP compared with U. The rumen and total tract digestibility were significantly (p<0.001) greater in sheep fed treated compared with untreated straw. Significant differences (p<0.05) between treatments for pH, NH₃ and VFA were also observed. All treatments improved the nutritive value of straws compared with untreated through modification of cell wall with a subsequent increase in digestibility by sheep. Although the digestibility for Ca was lower than that for Na despite reduction in cell wall, its use to treat straws may be more safe and cost effective than Na. AHP was the most effective and could also improve the energy value of other low quality forages for ruminants. However, the need of AHP for a large amount of NaOH to achieve highly alkaline pH limits its farm scale application. Therefore, further studies should either consider reducing the amount of NaOH or finding alternative alkalis that are cost effective and user-friendly.     

Effects of fibre level and dietary mannanoligosaccharides on digestibility,caecal volatile fatty acids and performances of growing rabbits

The current experiment with 3 trials aimed to study the effect of two levels of dietary fibre – high fibre (HF; 323 g aNDFom/kg) and low fibre (LF; 248 g aNDFom/kg) – and the effect of mannanoligosaccharides (MOS) addition (1 g/kg) to the LF diet (LFM) on the performances and health status of growing rabbits, digestibility and caecal fermentative characteristics. In the growth trial 132 rabbits of both sexes were used (11 cages with 4 rabbits per treatment) from weaning (32 days of age) to slaughter (67 days of age). Rabbits fed HF diet showed a significantly higher weight gain and live weight at 67 days than rabbits fed LF diet (2032 g vs. 1935 g) (P<0.05). Feed and digestible energy intake increased with dietary fibre level (P<0.05). During the growing period rabbits fed HF diet had a feed intake 26% higher than those fed LF diet. Feed efficiency ratio was worse in HF animals (0.334 vs. 0.385; P<0.05). Addition of MOS to LF diet did not affect growth performance parameters (P>0.05). Mortality and morbidity rate were not affected by treatments. In the digestibility 24 rabbits from 46 to 51 days of age trial were used. The HF diet resulted in a significant (P<0.05) decrease in digestibility of dry matter, organic matter and protein while the aNDFom digestibility was not significantly different between diets (P>0.05). Supplementation with MOS had no effects on digestibility (P>0.05). In the 3rd trial the caecal traits were measured in 30 rabbits with 46 days of age that received the experimental diets in the previous 14 days. Caecal production of total volatile fatty acids (VFA), acetate and propionate were significantly higher (P>0.05) on rabbits fed HF diets than on rabbits fed LF diets. The total VFA concentration increased 64% (from 5.01 to 8.20 mmol/100 ml) and acetate increased 73% (from 3.73 to 6.44 mmol/100 ml). Butyrate production was not different between diets (P>0.05). Fibre level did not affect proportions of VFA and caecal contents and caecal weights. Addition of MOS to LF diet did not affect any caecal trait (P>0.05). It was concluded that the reduction of dietary fibre level increases feed digestibility but worsens rabbit growth performances. Supplementation of low fibre diet with 1 g MOS/kg is not enough to reduce its negative effects on growth performances.     

Effects of diets of differing fiber contents on digestibility,passage rate of digesta and heat production in lesser mouse deer (Tragulus javanicus)

The effects of different levels of dietary fiber on feed intake, digestibility, mean retention times of solute and particle and heat production were studied in twelve male lesser mouse deer (Tragulus javanicus). The animals were randomly assigned into four groups of three mouse deer each and fed on individual basis. Four diets, namely A, B, C and D were prepared in pellet forms. Each diet contained ～14% crude protein and ～18 kJ/g gross energy. The crude fiber contents of diet A, B, C and D were 4.2, 11.3, 16.8 and 22.5%, respectively. The results showed that the crude fiber intake of mouse deer was 1.4 ± 0.04, 3.8 ± 0.4, 5.8 ± 0.7 and 6.0 ± 0.6 g/kg W^0.75/d fed diet A, B, C and D, respectively. Mouse deer fed diet D had significantly lower DM intake than those fed lower levels of fiber. The digestibility values of DM decreased gradually with increasing levels of fiber in the diet. The mean retention times (MRTs) of particles (～1.5 mm) in the reticulorumen were in the range of (19.0–22.9 h), with the shortest time for mouse deer fed diet D. However mouse deer fed diet C and D showed significant shorter solute MRT in the reticulorumen (17.1–18.5 h) when compared to mouse deer fed lower fiber diets (21.4–21.9 h). The selectivity factor in the reticulorumen was in the range of 1.04–1.18, indicating the mouse deer to be a ‘moose-type’ ruminant. Fiber levels had no significant effect on water intake of mouse deer. Heat production tended to decrease with increasing levels of fiber (448.3–435.7 kJ/kg W^0.75/d) but differences among the mouse deer fed the four diets were not significant.     

Rumen degradable nitrogen requirements for optimum microbial protein synthesis and nutrient utilization in sheep fed on finger millet straw (Eleucine coracana) based diet

Studies were conducted to determine the rumen degradable nitrogen (RDN) requirement levels for optimum microbial protein synthesis and nutrient utilization in Nellore rams fed on finger millet straw (FMS) based diet. Thirty six Nellore sheep were randomly divided into four groups of nine animals each using the balanced completely randomized design. Animals in all the groups were fed finger millet straw as a basal roughage and groundnut cake (GNC) was offered daily in two equal halves in the morning (8.00 AM) and evening (4.00 PM) as RDN source. The animals in group I (GI) were fed with ad libitum FMS. Animals in group II, III and IV (GII, GIII, and IV) were offered GNC @ 12.4, 16.6, and 21.1 g RDN/kg digestible organic matter (DOM) along with FMS. The daily total dry matter (DM) and organic matter (OM) intakes linearly increased (P<0.05) with increasing level of RDN supplementation while there was no difference in total DM and OM intake/kg W^0.75 among different experimental groups. The digestibility coefficients of DM (P<0.001), OM (P<0.001), crude protein (CP) (P<0.001), ether extract (EE) (P<0.001), neutral detergent fibre (NDF) (P<0.01) and acid detergent fibre (ADF) (P<0.03) increased quadratically with increasing level of RDN supplementation from GI to GIV. The purine derivatives (PD) excretion, microbial purine absorption and microbial nitrogen supply (MNS g/day) linearly increased (P<0.001) as the level of RDN supplementation increased. There was no difference in nitrogen capture efficiency (NCE) and microbial nitrogen to total urinary nitrogen ratio (MN:UN) among the RDN supplemented groups. This study indicated that 12 g RDN/kg digestible organic matter intake (RDN g/kg DOMI) or 18 g RDN/kg OM apparently digested in the rumen (RDN g/kg DOMR) may be adequate for optimum microbial protein synthesis and digestibility of nutrients, there by improved plane of nutrition in sheep fed on finger millet straw based diet.     

Effect of feeding different levels of wilted cassava foliage (Manihot esculenta,Crantz) on the performance of growing goats

The effects of feeding different levels of wilted cassava foliage (Manihot esculenta, Crantz) on growth and diet digestibility were studied using local male growing goats with an average body weight of 14.5 kg. Thirty-two animals were randomly allocated to four groups of eight animals in a growth experiment, and four animals were assigned to a 4 × 4 Latin Square design to study digestibility. The four diets in both the growth and the digestibility studies were Gamba grass (Andropogon gayanus) as a sole diet offered ad libitum (control) or supplemented with wilted cassava foliage (WCF) at 20%, 30% and 40% of an expected daily DM intake of 3% of BW. Dry matter (DM) intake was significantly lower in the control group and increased with the level of WCF in the diet, while the DM intake of Gamba grass was not significantly changed. Total DM intake and DM intakes from Gamba grass were 472, 546, 584 and 616 g/d and 472, 457, 457 and 470 g/d for the control and treatments with 20%, 30% and 40% of WCF in the diet, respectively. The inclusion of WCF in the diet increased the apparent digestibility of DM, organic matter, N, Neutral detergent Fibre and Acid Detergent Fibre, and resulted in a higher N-retention. The average daily gains of animals fed diets with WCF were significantly higher than in the control group. The highest gain was recorded in goats with 40% of WCF in the diet (55.0 g/d) and lowest for the control (28.9 g/d). In conclusion, supplementing a basal diet of Gamba grass (Andropogon gayanus) with WCF improved DM intake, digestibility, N-retention and weight gain. The inclusion level of WCF in the diet can be up to 30%–40% of diet DM (21%–24% of total DM intake).     

Effects of feed intake on enteric methane emissions from sheep fed fresh white clover (Trifolium repens) and perennial ryegrass (Lolium perenne) forages

Published analyses of enteric methane (CH₄) emissions from sheep and cattle show an inverse relationship between feed intake and CH₄ yield (g CH₄/kg dry matter (DM) intake), which suggests opportunities for reducing CH₄ emissions from feed eaten and per unit of animal production. Most relationships between feed intake and CH₄ yield have been based on animals fed conserved feeds, especially silages and grains. Our research is a series of experiments with fresh white clover (Trifolium repens) and perennial ryegrass (Lolium perenne; ryegrass) forages fed to sheep at a range of feed intake levels. This study was comprised of four experiments where good quality freshly harvested white clover or ryegrass were fed to sheep over a three-fold range in DM intake, and CH₄ emissions were measured in respiration chambers for two consecutive days in each experiment. Measurements were made from 16 sheep in Experiment 1 (fed at 1.6 × metabolizable energy requirements for maintenance; ME_m), 28 sheep in Experiment 2 (at 0.8 and 2.0 × ME_m), eight sheep and two measurement periods in Experiment 3 (at 1.6 × ME_m), and 30 sheep in Experiment 4 (fed at 0.8, 1.2, 1.6, 2.0 and 2.5 × ME_m). Prior to each experiment, sheep had a 10 d acclimatization period to diets. Apparent digestibility was measured over 7 d from sheep in Experiments 1, 3 and 4, along with collection of rumen digesta for volatile fatty acid (VFA) determination. Although CH₄ yields differed when sheep were fed white clover or ryegrass at similar intakes, the differences were inconsistent and mean values similar across all experiments. This, and a similar structure of all experiments, enabled combined analysis of data from all four experiments using the restricted maximum likelihood (REML) procedure to estimate effects of feed intake level on digestibility, digestible nutrient intake, gas emissions, and VFA concentrations in the rumen. The REML analysis showed that when DM intake increased from 0.40 to 1.60 kg/d, the predicted responses were an increase in CH₄ production (g/d) of 187% (12.4–35.6 g/d; P<0.001), and a decline in CH₄ yield of 21% (25.6–20.2 g/kg DM intake; P<0.001). High feed intake levels were associated with increased molar proportions (mM of total VFA) of propionate from 0.17 to 0.21 (P=0.038). Single and multiple regressions were completed on the data from all experiments, with organic matter (OM) intake predicting 0.87 of the variation in CH₄ production, and molar proportion of propionate predicting 0.60 of the variation in CH₄ yield. Increasing feed intakes by 1 kg/d of DM reduced CH₄ yield by 4.5 g/kg DM intake. Plant chemical composition was weakly related to CH₄ yield. High intakes of fresh forages will lower CH₄ yield from fermentation, but effects of feed composition on CH₄ emissions were minor. The interaction between effects of feed intake and rumen function requires further investigation to understand relationships with CH₄ emissions.     

Nutritional characterization of Mucuna pruriens: 3. Effect of replacing soybean meal with Mucuna on intake,digestibility, N balance and microbial protein synthesis in sheep

Mucuna pruriens seeds have relatively high crude protein (CP) concentrations, but little is known about their potential to replace commonly used CP supplements in ruminant rations. The aim of this experiment was to determine effects of replacing soybean meal (SB) with Mucuna on the performance of lambs. Forty Rambouillet lambs (33.2 ± 5.73 kg) fed a basal diet of maize grain, cottonseed hulls and urea were randomly assigned to one of four supplements formulated by substituting 0 (SB), 330 (Lo), 670 (Med) or 1000 g/kg (Hi) of soybean meal with rolled Mucuna seeds. Lambs were housed individually in metabolic crates and allowed ad libitum access to isocaloric (metabolizable energy=11.7 MJ/kg dry matter, DM) and isonitrogenous (CP = 146 g/kg, DM) diets for 14 d of adaptation and 7 d of total fecal collection. Fecal egg counts and coccidian oocyst scores were determined on d 14. Dry matter intake (1.7 kg/d versus 1.5 kg/d; P<0.05), CP digestibility (774 g/kg versus 714 g/kg DM; P<0.05) and N retention (28.0 g/d versus 20.4 g/d; P<0.01) were higher and amylase-pretreated neutral detergent fiber digestibility (617 g/kg versus 686 g/kg DM) was lower (P<0.05) in sheep fed SB versus Mucuna diets. However, supplementary protein source did not affect rumen pH, blood urea N or glucose concentration, or fecal egg counts. Increasing the level of Mucuna supplementation increased (P<0.05) level and efficiency of microbial protein synthesis, ruminal fluid acidity, total volatile fatty acid concentration, decreased (P<0.05) coccidian oocyst scores, and tended (P<0.10) to increase N retention. Therefore, SB is a better supplement than Mucuna to support performance of lambs. Nevertheless, Mucuna seeds are a promising CP supplement for situations where cost or availability precludes use of SB in ruminant rations.     

Intake and digestion by lambs of dwarf elephant grass (Pennisetum purpureum Schum. cv. Mott) hay or hay supplemented with urea and different levels of cracked corn grain

This study was carried out to evaluate intake, digestibility, ruminal fermentation, nitrogen (N) retention and ruminal microbial protein synthesis in lambs fed dwarf elephant grass (Pennisetum purpureum Schum. cv. Mott) hay or hay supplemented with urea and 0, 5, 10 or 15 g/kg of live weight (LW) of cracked corn grain. Ten lambs (mean LW of 28 ± 0.9 kg), housed in metabolic cages, were used in a double 5 × 5 Latin Square experiment. Except fibre intake and digestibility, which was higher, the intake and digestibility of the others feed components, as well as ruminal microbial protein synthesis and N retention were lower in non-supplemented lambs. Corn supplementation increased total dry matter (DM) (P<0.05), organic matter (OM), non-structural carbohydrate (NSC) and energy intake (P<0.01) but decreased total neutral detergent fibre (aNDFom) (P<0.01) intake, as well as OM and aNDFom intake from the hay (P<0.01). Apparent DM, OM and energy digestibility, as well as OM true digestibility (OMTD) increased (P<0.01), and aNDFom digestibility decreased linearly (P<0.01) as corn supplementation increased. Total N intake was not influenced but, apparent and true N digestibility, as well as urinary N excretion decreased (P<0.01), and ruminal microbial N entering the small intestine increased linearly (P<0.01) as corn supplementation increased. However, the efficiency of ruminal microbial protein synthesis was similar for all treatments. Mean ruminal pH values and ammonia N concentrations decreased linearly (P<0.01) with level of corn supplementation. Ammonia N and amino acid, as well as peptide concentrations in ruminal fluid were quadratically related (P<0.01) with the time after feeding. Corn supplementation had a linear additive effect on total dry matter and digestible energy intake, as well as on N retention, but a linear negative effect on hay intake and on fibre digestibility. However, decreased forage digestibility by animals was probably neither related to lower ruminal pH, which values were always higher than 7.0, nor related to ruminal sugar concentrations, which were similar for all treatments.     

Effect of dietary inclusion of Ficus infectoria leaves as a protectant of proteins on the performance of lambs

This study examined the effects of dietary inclusion of tanniferous leaves of Ficus infectoria as a protectant of proteins on the performance of lambs. Twenty-four lambs were randomly divided into four groups of six each in a completely randomized block design and fed four iso-nitrogenous supplements formulated to contain 0, 1.0, 1.5 and 2.0% condensed tannins (CT) through dried and ground leaves of F. infectoria. The diets were designated as CT-1.0, CT-1.5 and CT-2.0, respectively, and fed to lambs on a basal diet of wheat straw to meet requirements for maintenance and growth. Blood-biochemical profile was monitored in all the lambs at 0, 45, 90, 135, 180 days of feeding. The average daily growth rate and wool growth for a period of 180 days showed a significant (P < 0.05) increase by the supplementation of CT at 1.5% through F. infectoria leaves. Although addition of CT up to 1.5% in the supplement did not interfere with the nutrient intake or digestibility, a depressing effect on DM, OM and ADF digestibility at 2.0% CT level was apparent without any detrimental affect on intake. Digestible crude protein (DCP) and total digestible nutrients (TDN) values of the composite diets were comparable, except for significantly (P < 0.05) lower TDN (%) in CT-2.0 than the control. Intake of DCP, digestible organic matter and TDN was comparable irrespective of dietary treatments, though lambs under CT-2.0 had significantly (P < 0.05) lower intake as compared to their counterparts given diet CT-1.0. Feeding of CT containing diets particularly at 1.5 and 2.0% levels significantly (P < 0.05) influenced N utilization and improved its retention, however, the microbial protein synthesis as estimated by urinary excretion of purine derivatives was not affected by the dietary treatments. Haematological (haemoglobin and packed cell volume) and biochemical parameters (serum glucose, total protein, albumin, globulin, A:G ratio, alanine aminotransferase and aspartate aminotransferase were similar among the dietary treatments except for significant (P < 0.05) reduction in serum urea concentration of lambs fed 1.5 and 2.0% CT in the supplement. It may be concluded that CT from F. infectoria leaves at 1.5% in supplement could be used as a protectant of proteins for improving the performance of lambs.     

Effect of harvesting period on the nutritive value of rice grass (Echinochloa sp.) hay given as sole diet to lambs

Data regarding the influence of maturity within the vegetative stage of tropical grasses on forage quality are limited and conflicting. The change in chemical composition of rice grass (Echinochloa sp.) hay harvested at 32, 46, 72 and 90 days of regrowth, and its effect on intake, digestibility, ruminal fermentation, rumen microbial protein synthesis (Experiment 1) and splanchnic oxygen uptake (Experiment 2) by lambs was evaluated. Except intake of indigestible neutral detergent fibre (NDF) which was similar for all treatments, intake of all hay components and the apparent digestibility of dry matter, organic matter (OM), NDF, N, as well as OM and N true digestibility, N retention and rumen microbial protein synthesis decreased linearly (P < 0.05) with increased regrowth age. Rumen fluid pH, ammonia N and peptide concentrations were similar for all treatments while sugars and amino acid concentrations decreased linearly with increased regrowth age of rice grass (P < 0.05). Passage rate of particles through reticulum-rumen (PRrr) was quadratically related (P < 0.05) to regrowth age. The highest PRrr and, consequently, the lowest retention time in the reticulum-rumen were obtained at 72 days of regrowth. There was a quadratic effect (P < 0.05) on net portal-drained viscera (PDV) flux of oxygen and heat production, while OM intake, portal blood flow and heat production as proportion of digestible energy (DE) intake were not affected by the increased regrowth age of rice grass. The highest means of oxygen uptake and heat production by PDV tissues were in 72 days treatment. In the whole splanchnic metabolism assay neither hay intake nor blood flow, oxygen uptake or heat production were affected by forage regrowth age. In conclusion, the nutritive value of rice grass hay decreased as regrowth age increased from 32 to 90 days due to decrease both OM intake and digestibility.     

In vivo and in situ digestibilities and nitrogen balance of Buddleia skutchii as a sole component and mixed with Pennisetum clandestinum in sheep diets

The objective of this work was to evaluate the intake (I) of all Buddleia skutchii foliage (BSF), collected from three different sites (places: A, B and C) in feeding sheep (phase 1), and in combination with Pennisetum clandestinum (Pc) (phase 2). Trials of feed intake, in vivo dry matter digestibility (IVDMD), and digestibilities of crude protein (CP), acid detergent fiber (ADF), neutral detergent fiber (NDF), and nitrogen balance were carried out during phase 1. Diet was given to nine Creole male lambs of 23(±3) kg body weight (BW), located in individual metabolism crates. During phase 2, four treatments were evaluated (T1 = 100% Pc, T2 = 20% BSF + 80% Pc, T3 = 40% BSF + 60% Pc and T4 = 60% BSF + 40% Pc) in a 4 × 4 Latin square design, using four ruminal cannulated Creole male rams of 50 ± 2 kg BW and remained in individual metabolism crates. In vivo digestibility (DM, CP and gross energy (GE)) and kinetics of in situ disappearance of DM were evaluated. The results in phase 1 indicated that BSF from Site B had relatively higher CP (14.9%), ADF (50.6%) content and nitrogen retention (1.93 g d⁻¹). On the other hand, the lambs showed intake levels of 376.29 g d⁻¹ DM, 56.21 g d⁻¹ CP, 206.24 g d⁻¹ ADF and 1418.21 kcal gross energy (P > 0.05); and digestibilities of 54.23% DM, 47.17% CP and 39.31% NDF. Therefore, BSF from Site B was selected for the second phase of this work as the best result. We observed that the nutrition quality of the diets was higher as a result of increasing BSF concentration in the diet. When sheep were fed on 40% BSF–60% Pc, DM intake levels of 900.6 g d⁻¹, and DM, CP and GE digestibility of 70.0, 52.82 and 55.1%, respectively, were observed. There were not significant differences among diets, and in situ disappearance, K_d and K_p, but the diet with 60% of BSF presented higher ruminal digestibility (42.3%). The results allowed to validate the local knowledge on BSF as a promising forage species, and showed that BSF should be incorporated in a sheep production system.