Performance and total-tract digestibility responses to exogenous xylanase and phytase in diets for growing pigs

Sixty individually housed male pigs (Large White X Landrace, average weight 19.7±0.56 kg) were used in a completely randomised block design having five wheat-based dietary treatments (n=12 pigs per treatment) to study the interactive effects between added xylanase (XYL) and phytase (PHY), either alone or in combination, and days on trial on coefficient of total-tract digestibility (CTTAD) and performance. The diets used were: (i) positive control (PC); (ii) negative control with reduced energy and mineral content (NC); (iii) NC with added XYL (NCX); (iv) NC with added PHY (NCP); and (v) NC with added XYL plus PHY (NCXP). The performance response and CTTAD of dietary components were measured 3 and 7 weeks after commencement of feeding, with the experiment finishing when pigs reached approximately 65 kg live weight.Pigs fed the NC diet decreased average daily gain (ADG) by 13% (P<0.01) and increased feed conversion ratio (FCR) by 11% (P<0.01) compared to pigs fed the PC diet. Addition of PHY in the NC diet increased ADG by 9% (P<0.05) and decreased FCR by 5% (P=0.065), whilst addition of XYL in the NC diet had no effect on the performance indices. Combined addition of XYL and PHY in the NC diet did not improve performance of pigs for the first 21 days but improved FCR by 8% (P=0.008) during the days 22–49. Digestibility measurements showed that combined use of XYL and PHY in the NC diet improved CTTAD of dry matter (DM, P<0.05), gross energy (GE, P<0.05) and crude protein (CP, P<0.01) only during the days 22–49. Independent supplementation of PHY in the NC diet tended to improve CTTAD of GE (P=0.09) only during the days 22–49. In contrast, supplementation of PHY immediately improved CTTAD of P and maintained it to similar levels at 49 days. Results suggested that supplementation of PHY plus XYL in combination in the NC diet improved FCR and CTTAD of DM, GE, CP and P but the beneficial effects other than CTTAD of P were derived mainly during days 22–49.     

The potential of Commelina benghalensis as a forage for ruminants

To evaluate the potential of Commelina benghalensis as a forage for ruminants, effects of plant maturity on chemical composition, rumen degradability as well as its increased dietary inclusion level on intake, digestibility and N balance in sheep fed Sorghum almum were investigated with forage obtained from the wild, re-established and harvested at 6, 10 and 14 weeks of growth. Composite herbage samples were analyzed for dry matter (DM), chemical components, total extractable phenolics (TEP) and amino acid content. In sacco rumen degradability measurements used six individually confined wethers (8 ± 0.5 months of age; 21 ± 2.6 kg live-weight (LW)) fitted with rumen cannulae and fed a ration of 3:1 fresh S. almum and Medicago sativa hay (about 1:2 on a DM basis). In sacco bags containing 5 g each of dry herbage were inserted into the rumen and withdrawn sequentially after 0, 12, 24, 36 and 48 h. Metabolizable energy (ME) was estimated from 24 h in vitro gas production. In the digestibility study, 12 wethers fitted with rumen canula were housed in metabolic crates and allotted to four treatment diets (i. e., D0, D10, D20 and D30) constituted from fresh S. almum and pre-wilted C. benghalensis in a randomized complete block design. The control diet (D0) was 3 kg fresh S. almum (≈535.5 g DM/wether/d about 30 g/kg LW), whereas D10, D20 and D30 were D0 +300, 600 or 900 g of wilted C. benghalensis (≈34, 68 or about 102 g DM/wether/d), respectively. The study lasted for 21 d. Dry matter, fibre and TEP content increased (P<0.001) with maturity of the forage, whereas those of CP and EE decreased (P<0.0001) over the same period. Amino acids (AA) also declined with maturity (P<0.05). Rumen degradability of DM and OM were unaffected, but DM intake increased linearly (P<0.0001) at a decreasing rate (Q: P<0.05) and DM digestibility (DMD) and N intake increased linearly (P<0.01 and P<0.0001, respectively) as level of C. benghalensis in the diet increased. Results indicate that advancing maturity affected chemical composition, but not rumen degradability, of C. benghalensis and also demonstrated that inclusion of C. benghalensis in S. almum diet improved intake, digestibility and N intake, suggesting its potential use as a feed supplement.     

Intake, digestibility, rumen fermentation and performance of beef cattle fed diets based on whole-crop wheat or barley harvested at two cutting heights relative to maize silage or ad libitum concentrates

This experiment aimed to quantify the relative intake, digestibility, rumen fermentation, performance and carcass characteristics of beef cattle fed diets based on good quality whole-crop wheat and barley silages, each harvested at two cutting heights, and to rank these relative to good quality maize silage and an ad libitum concentrates-based diet. Ninety beef steers, initial live-weight 438 ± 31.0 kg, were allocated to one of the following dietary treatments in a randomised complete block design: maize silage (MS), whole-crop wheat harvested at a normal cutting height (WCW) (stubble height 0.12 m) or an elevated cutting height (HCW) (stubble height 0.29 m), whole-crop barley harvested at a normal cutting height (WCB) (stubble height 0.13 m) or an elevated cutting height (HCB) (stubble height 0.30 m), each being supplemented with 3 kg concentrates/head/day, and ad libitum concentrates (ALC) supplemented with 5 kg grass silage/head/day for the duration of the 160-day study. Mean dry matter (DM) of the maize silage, whole-crop wheat, head-cut wheat, whole-crop barley and head-cut barley was 301, 488, 520, 491 and 499 g/kg, respectively. There were no differences in total DM intake among treatments, or in rumen fermentation characteristics (except ammonia), or in DM digestibility among the forage-based treatments. Neutral detergent fibre digestibility was lower (P<0.05) for whole-crop wheat than head-cut barley, and starch digestibility was lower (P<0.05) for whole-crop barley and head-cut barley than maize silage. Steers fed ALC had a higher carcass gain (P<0.001) and carcass weight (P<0.05) than all other treatments, but there were no differences between any of the forage-based treatments. Steers fed MS had a better feed conversion efficiency (FCE) than those on WCW or WCB (P<0.05) but were similar to HCW and HCB. The FCE was better for ALC versus any of the other treatments, particularly compared to WCW or WCB (P<0.001). Subcutaneous fat from steers fed ALC was more yellow (P<0.01) than that from steers fed the other treatments. Neither intake nor performance were altered by raising the cutting height of cereals or by replacing whole-crop wheat by barley. However, head-cut cereals numerically favoured DM intake, carcass gain and feed conversion efficiency values nearer to that of maize than whole-crop cereal silages. Ad libitum concentrates supported superior levels of growth by steers compared to all other treatments.     

Assessment of a brown midrib (BMR) mutant gene on the nutritive value of sudangrass using in vitro and in vivo techniques

The brown midrib (BMR) gene has been reported to reduce the lignin concentration in plants, which contributed to increased fiber digestion in ruminants. Three studies were completed to compare the digestibility of a BMR mutant of sudangrass (sorghum bicolor subsp. Drummondii) versus a non-BMR (‘Piper’) variety when included in diets fed to sheep (Study 1), to complete a rumen in vitro assessment of sheep and lactating cow diets (Study 2), and to compare digestibility when included in the diet fed to lactating dairy cows (Study 3). Four wether sheep were used in a 2 × 2 Latin square experiment (Study 1) with total fecal collection to determine total tract apparent digestibility of pelleted Piper (P) and BMR (P-BMR) sudangrass hays. Forage pellets consisted of either P-BMR or P hay with added urea to meet the maintenance crude protein (CP) requirement of the sheep. Digestibility of organic matter (OM; P<0.01), dry matter (DM; P<0.01), acid detergent fiber (ADF; P<0.05), and neutral detergent fiber (aNDFom; P<0.07) was higher for P-BMR than P sudangrass. In vitro rumen digestibility of aNDFom using cattle rumen fluid was higher at 24 (P<0.01), 48 (P<0.01) and 72 h (P<0.01) of fermentation for P-BMR versus P (Study 2). Four lactating Holstein dairy cows (251 ± 30 days in milk) and fitted with ruminal and duodenal cannulae were used in a 4 × 4 Latin square experiment. Total mixed rations (TMR) contained 180 g/kg DM shredded sudangrass hay and 180 g/kg sliced alfalfa hay, but the proportion of P to P-BMR sudangrass varied as 100:0, 66:34, 34:66, or 0:100. Yields of milk and milk protein were highest at the 66:34 level (Quadratic: P=0.06 and 0.07, respectively), but composition of milk fat, protein and lactose, as well as DM intake, did not differ (Study 3), probably because forestomach and total tract apparent digestion of aNDFom and OM did not differ due to sudangrass source.     

Methane emission by goats consuming different sources of condensed tannins

Twenty-four yearling Boer × Spanish wethers (7/8 Boer; initial body weight (BW) of 37.5 ± 0.91 kg) were used to assess effects of different condensed tannin (CT) sources on methane (CH₄) emission. Diets were Kobe lespedeza (Lespedeza striata; K), K plus quebracho providing CT at 50 g/kg dry matter (DM) intake (KQ), Sericea lespedeza (Lespedeza cuneata; S), and a 1:1 mixture of K and S (KS). Forages harvested daily were fed at 1.3 times the maintenance metabolizable energy requirement. The experiment was 51 days divided into two phases. In phase A forage diets were fed alone, and in phase B, 25 g/day of polyethylene glycol (PEG) was given mixed with 50 g/day of ground maize grain. Adaptation periods were 28 and 7 days in phases A and B, respectively. After adaptation there were 8 days for feces and urine collections, with gas exchange measured on the last 2 days. Ruminal fluid was collected at the end of the experiment via stomach tube for microbiology assays. The N concentration was 22.8 and 23.6 g/kg DM, in vitro true DM digestibility was 0.698 and 0.648, and the level of CT was 140 and 151 g/kg DM for S and K, respectively. DM intake was similar among treatments in both phases (phase A: 720, 611, 745, and 719 g/day (S.E. = 59.0); phase B: 832, 822, 867, and 880 g/day (S.E. = 55.3) for K, KQ, S, and KS, respectively). N digestibility was affected by treatment in phase A (P<0.05) but not in phase B (phase A: 0.514, 0.492, 0.280, and 0.413 (S.E. = 0.0376); phase B: 0.683, 0.650, 0.638, and 0.662 (S.E. = 0.0203) for K, KQ, S, and KS, respectively). Gross energy digestibility was similar among treatments in phase A (0.475, 0.407, 0.393, and 0.411 (S.E. = 0.0353)) but differed among treatments in phase B (0.449, 0.373, 0.353, and 0.409 for K, KQ, S, and KS, respectively (S.E. = 0.0221)) CH₄ emission was 9.6, 6.8, 10.6, and 8.9 l/day (S.E. = 1.44) in phase A and 19.0, 16.6, 21.8, and 19.2 l/day (S.E. = 1.51) in phase B for K, KQ, S, and KS, respectively (S.E. = 1.25). When data of both phases were pooled, supplementation with PEG in phase B markedly increased (P<0.05) CH₄ emission (9.0 l/day versus 19.1 l/day). In accordance, there was a substantial difference (P<0.05) between phases in in vitro CH₄ emission by ruminal fluid incubated for 3 weeks in a methanogenic medium and with other conditions promoting activity by methanogens (11.5 and 22.9 ml in phases A and B, respectively). Counts of total bacteria and protozoa were similar among treatments in both phases, but values were greater (P<0.05) in phase B versus phase A. In summary, CT from different sources had a disparate influence on N digestion, but similar effects on ruminal microbial CH₄ emission by goats, possibly by altering activity of ruminal methanogenic bacteria though change in actions of other bacteria and/or protozoa may also be involved.     

Ensiling and subsequent ruminal degradation characteristics of barley tea grounds treated with contrasting additives

The objective of this experiment was to determine the ensiling characteristics and in situ degradation of barley tea grounds (BTG) treated with contrasting additives. The BTG was ensiled without additive (control), or with mixtures of lactic acid bacteria and Acremonium cellulase (LAB + AUS), formic acid (FA), and sodium hydroxide (NaOH) for a period of 60 days. Three ruminal-fistulated steers were used to determine in situ degradabilities of dry matter (DM), crude protein (CP) in the BTG and its silages. In the LAB + AUS treated silage, the pH value (P<0.001) and ammonia-N content (P=0.007) were lower and the lactic acid content (P<0.001) was higher than the control. The FA and NaOH treated silages were well preserved as indicated by low ammonia-N content (P=0.007), no propionic acid and butyric acid. The LAB + AUS treated silage had higher rapidly degradable fraction of DM and CP than the control and BTG (P<0.001). The NaOH treated silage had higher contents of rapidly degradable fraction, slowly degradable fraction and effective degradability of DM and CP than control and BTG (P<0.01).     

Effect of tree leaves with or without urea as a feed supplement on nutrient digestion and nitrogen balance in sheep

Two nitrogen balance experiments in a 4 × 4 Latin square design were conducted to compare leaves of Grewia oppositifolia and Ziziphus mauritiana containing condensed tannins (CT) 0.08 g and 34.7 g per kg DM, respectively as supplement on feed intake, nutrients digestibility and nitrogen (N) retention in adult wethers and to examine the benefits of adding urea to Z. mauritiana leaves containing higher level of CT on N utilization in the animals. In experiment 1, the basal diet of oat hay was fed to sheep either un-supplemented or supplemented with 320 g dried leaves of Z. mauritiana or 320 g dried leaves of G. oppositifolia or 160 g dried leaves each of Z. mauritiana and G. oppositifolia. In vivo dry matter (DM) digestibility was not different among the four diets while N digestibility remained significantly lower (P<0.05) in Z. mauritiana supplemented diets. Daily intake of oat hay reduced (P<0.05) and that of total diet DM increased (P<0.001) with feeding of the leave supplements. Mean N retention on control diet was 4.39 g/d and increased to 7.51 g/d with inclusion of G. oppositifolia leaves but did not change with the other two supplements. In experiment 2, a basal diet of sorghum hay was fed ad libitum without any supplement (control diet) and the other three diets were supplemented with 320 g dried leaves of Z. mauritiana with no urea, 5 g urea/d or 10 g urea/d. Daily intake (g/d) of sorghum hay or total DM intake did not respond to inclusion of urea in the diets. Supplementation of Z. mauritiana with or without urea did not affect digestibility of DM, organic matter and acid detergent fiber. Nitrogen retention increased (P<0.05) from 0.57 g/d on control diet to 3.72 g/d with supplementation of Z. mauritiana leaves. Addition of urea 5 g/d did not further increase the N retention (4.78 g/d) but was significantly increased to 7.16 g/d in response to 10 g urea/d in the diet. It was concluded that response to urea feeding in the presence of tannin rich Z. mauritiana leaves was dose-dependant and that feeding 10 g urea/d increased the capacity of sheep to consume more feed and retain more N in the body.     

Poor Glycemic Control of Diabetes Mellitus Is Associated with Higher Risk of Prostate Cancer Detection in a Biopsy Population

Objectives

To evaluate the impact of glycemic control of diabetes mellitus (DM) on prostate cancer detection in a biopsy population.

Patients and Methods

We retrospectively reviewed the records of 1,368 men who underwent prostate biopsy at our institution. We divided our biopsy population into three groups according to their history of DM, and their Hemoglobin A1c (HbA1c) level: a no-DM (DM−) group; a good glycemic control (DM+GC) group (HbA1c <6.5%); and a poor glycemic control (DM+PC) group (HbA1c ≥6.5%). For sub-analyses, the DM+PC group was divided into a moderately poor glycemic control (DM+mPC) group (6.5≤ HbA1c <7.5%) and a severely poor glycemic control (DM+sPC) group (HbA1c ≥7.5%).

Results

Among 1,368 men, 338 (24.7%) had a history of DM, and 393 (28.7%) had a positive biopsy. There was a significant difference in prostatic specific antigen density (PSAD) (P = 0.037) and the frequency of abnormal DRE findings (P = 0.031) among three groups. The occurrence rate of overall prostate cancer (P<0.001) and high-grade prostate cancer (P = 0.016) also presented with a significantly difference. In the multivariate analysis, the DM+PC group was significantly associated with a higher rate of overall prostate cancer detection in biopsy subjects compared to the DM− group (OR = 2.313, P = 0.001) but the DM+PC group was not associated with a higher rate of high-grade (Gleason score ≥7) diseases detected during the biopsy (OR = 1.297, P = 0.376). However, in subgroup analysis, DM+sPC group was significantly related to a higher risk of high-grade diseases compared to the DM− group (OR = 2.446, P = 0.048).

Conclusions

Poor glycemic control of DM was associated with a higher risk of prostate cancer detection, including high-grade disease, in the biopsy population.     

Effects of exogenous fibrolytic enzymes on ruminal fermentation and digestibility of total mixed rations fed to lambs

This experiment was designed to study effects of exogenous fibrolytic enzymes on digestibility and ruminal fermentation of total mixed rations (TMR) with different forage:concentrate (F:C) ratios. The experimental design was a 6×6 Latin square with six ruminally cannulated Ramboulliet lambs (58 ± 7.4 kg body weight) used in a 3×2 factorial arrangement of treatments using three forage:concentrate (F:C) ratios (400:600, 500:500, 600:400 kg/kg) and two (0 or 2 g) levels of fibrolytic enzymes/kg TMR dry matter (DM). Exogenous fibrolytic enzymes increased the soluble fraction of DM (P<0.01) and ruminal in situ disappearance rate of DM and neutral detergent fibre (aNDF; P<0.001). However, there were no differences among treatments in DM and aNDF in vivo digestibility due to enzyme addition to the diet. Feed intake and N balance were also not affected by enzymes, and ruminal fermentation patterns were unchanged. Exogenous fibrolytic enzymes improved ruminal disappearance rates of DM and aNDF, but had no impact on lamb performance or ruminal fermentation.     

Effect of combined herbal feed additives on methane,total gas production and rumen fermentation

The present study was to evaluate effect of herbal feed additives on methane and total gas production during the rumen fermentation for environment and animal health concern. Different parts of the five medicinal plants were selected such as leaf and small stems of Ocimum sanctum (Tulsi), roots of Curcuma longa (Haldi), fruits of Emblica officinalis (Amla), leaves of Azadirachta indica (Neem) and leaves and small stem of Clerodendrum phlomidis (Arni) for our study. Addition of different herbal additive combinations did not influence IVDMD and total gas production however methane production (mg/g of substrate DM) was significantly (P<0.05) reduced in Amla: Neem and Neem: Arni combinations. Total nitrogen significantly (P<0.01) increased in the combinations of Tulsi: Haldi and Amla: Neem. TCA–ppt-N is significantly (P<0.01) increased in Tulsi: Haldi, Haldi: Amla, Amla: Neem and Neem: Arni however NH₃-N (mg/dl) significantly decreased in all treatments. We conclude that the screening of plant combinations, Amla: Neem and Neem: Arni have potential to decrease methane production and our herbal feed supplements have no side-effects on the ruminant in small amount.     

A new in vitro system to study the effect of liquid phase turnover and pH on microbial fermentation of concentrate diets for ruminants

A simple and inexpensive in vitro feed evaluation system which estimates microbial fermentation by measuring gas production and allows for adjustment of liquid dilution rate has been design. Working conditions, in terms of substrate and inoculum proportions (experiment 1, EXP 1) and the liquid replacement schedule (experiment 2, EXP 2) were initially set. In EXP 1, three substrate concentrations (10, 20 and 30 mg/ml: S1, S2 and S3) and three inoculum proportions (0.10, 0.20 and 0.30; I10, I20 and I30) were assayed in a 3 × 3 factorial design, in three incubations of 24 h. Gas production (ml/g organic matter) with S1 was the highest, avoiding to be in excess for microbial colonisation and activity and inoculum I20 limited inoculum contribution by self-fermentation; they were hence considered for further trials. In EXP 2, two liquid replacement schedules (every hour from 0 to 12 h and every 3 h from 12 to 24 h, HF, and every 2 h from 0 to 12 h and every 4 h from 12 to 24 h, LF) were compared with a non-replacement (NR) treatment, using three bottles per treatment. No differences among treatments were detected, and thus the LF schedule was chosen because it was easier to carry out. Once these working conditions were adjusted in EXP 1 and 2, the effect of fluid turnover and incubation pH on the extent of microbial fermentation in a mixed diet (experiment 3, EXP 3) was studied in two incubations. Two liquid turnover rates (0.06 and 0.10 h⁻¹) were compared with a non-replacement treatment at two different pH (6.8 and 6.1) in a 3 × 2 factorial design. Liquid outflow increased gas production, dry matter disappearance (DMd) and total volatile fatty acid (VFA) concentration at both pH (P>0.01), but protozoal numbers were unaffected. Liquid replacement at pH 6.8 did not affect the VFA profile, but the acetate proportion diminished (P=0.04) and the propionate increased (P<0.001), with replacement at pH 6.1. Increasing the fluid turnover rate from 0.06 to 0.10 h⁻¹ reduced gas production from 8 to 20 h of incubation (P<0.05) but it did not alter the VFA profile. The volume of gas produced decreased (P<0.05) with incubation pH, as did DMd (P=0.04) and protozoal (P=0.03) and total VFA (P=0.002) concentration. The acetate proportion was lower (P<0.001) and that of propionate and butyrate was higher (P<0.001) at pH 6.1 than at pH 6.8. Both liquid turnover and pH must be taken into consideration for in vitro evaluation of mixed and concentrate diets for ruminants and this system provides a simple and inexpensive method for doing this.     

Chemical composition, in situ ruminal degradability and post-ruminal disappearance of dry matter and crude protein from the halophytic plants Kochia scoparia, Atriplex dimorphostegia, Suaeda arcuata and Gamanthus gamacarpus

Samples of Kochia (K. scoparia), Atriplex (A. dimorphostegia), Suaeda (S. arcuata) and Gamanthus (G. gamacarpus) were collected and analyzed for chemical composition including crude protein (CP), ether extract (EE), ash, neutral detergent fiber (NDFom), acid detergent fiber (ADFom), non-protein N (NPN), Ca, P, Na, K, Cl, Mg, Fe, Cu and Se. In addition, in situ ruminal degradability and post-ruminal disappearance of dry matter (DM) and CP of the samples using a mobile bag technique were determined. Results indicate that the chemical composition of Kochia and Atriplex was notably different from those of Suaeda and Gamanthus. All of these halophytic plants had high concentrations of Na, K, Cl, Cu and Se, and low levels of Ca, P and Mg. The rapidly degradable fractions of DM and CP (g/g) of Kochia (0.31 and 0.35, respectively) and Atriplex (0.39 and 0.50, respectively) were lower than for Suaeda (0.53 and 0.55, respectively) and Gamanthus (0.56 and 0.66, respectively). Ruminal DM and CP disappearance of Kochia (444 and 517 g/kg, respectively) and Atriplex (472 and 529 g/kg, respectively) were lower (P<0.05) than those of Suaeda (553 and 577 g/kg, respectively) and Gamanthus (663 and 677 g/kg, respectively) (P<0.05) using the mobile bag technique. Suaeda had the lowest (P<0.05) NDFom and ADFom disappearance (214 and 232 g/kg, respectively) in the rumen. Kochia scoparia and Atriplex dimorphostegia have more beneficial chemical nutritive components and digestible values versus Suaeda arcuata and Gamanthus gamacarpus.     

Effects of dietary zinc on performance, nutrient digestibility and plasma zinc status in Cashmere goats

Thirty-six 1.0-year-old Liao Ning Cashmere goat wethers (BW = 22.01 ± 0.59 kg) were used to determine the effects of dietary zinc (Zn) level on the performance, nutrient digestibility and plasma Zn status during the cashmere fiber growing period. The goats were randomly divided into four groups that were fed a basal diet containing 22.3 mg Zn/kg dry matter (DM) with 0, 15, 30 or 45 mg Zn/kg DM as reagent grade ZnSO₄·7H₂O. The experiment lasted 60 days including a 7-day metabolism trial. Both average daily gain (ADG) and feed efficiency were improved (P < 0.05) by Zn supplementation and were higher (P < 0.05) for the treatment groups supplemented with 30 and 45 mg Zn/kg DM compared with 15 mg Zn/kg DM. Zn supplementation had no influence on the length and diameter of cashmere fiber (P > 0.05). Digestibility of DM, crude protein (CP), neutral detergent fiber (NDF) and acid detergent fiber (ADF) did not differ among treatments (P > 0.05). Plasma Zn concentrations were increased (P < 0.01) by Zn supplementation and were higher (P < 0.05) for the treatment groups supplemented with 30 and 45 mg Zn/kg DM compared with 15 mg Zn/kg DM. Zn apparent absorption rate and apparent retention rate were decreased (P < 0.05) by Zn supplementation, but did not differ among Zn supplemented treatments (P > 0.05). In conclusion, a control diet containing 22.3 mg Zn/kg DM was inadequate for achieving optimal growth performance in Cashmere goats, and the recommended level of dietary Zn for such goats is 52.3 mg/kg DM during the cashmere fiber growing period.     

Effects of Brosimum alicastrum and Lysiloma latisiliquum mixtures on voluntary intake, nutrient digestibility and nitrogen balance in sheep fed tropical pastures

Effects of supplementing tree foliage mixtures on voluntary intake, apparent digestibility and N balance was evaluated using Pelibuey sheep fed low quality diets. Five treatments were examined in a 5 × 5 Latin square design, which consisted of a basal diet of grass (Sorghum halepense) hay supplemented with Brosimum alicastrum (B) and Lysiloma latisiliquum (L) at the following rates (g DM/kg diet): B264, L0; B198, L66; B132, L132; B66, L198 and B0, L264. Additionally, an in situ degradability evaluation was completed with two ruminally cannulated cows. Neutral detergent fibre (NDF), acid detergent insoluble N (ADIN), lignin(sa) and total phenols (TP) were higher (P<0.01) in L. latisiliquum versus B. alicastrum. Daily intake (g/kg LW^0.75/day) of DM (from 98 to 73) and OM (from 88 to 66) decreased quadratically (P<0.01), whereas CP (from 8.0 to 5.6) and ME (from 7.7 to 5.2, MJ/sheep/day) reduced linearly (P<0.01), as L. latisiliquum increased in the diet. Apparent digestibility of DM (from 0.486 to 0.445), OM (from 0.511 to 0.458) and CP (from 0.417 to 0.198) decreased linearly (P<0.01) and was associated with a low ruminal in situ CP degradability of L. latisiliquum. The decrease in N intake and digestibility induced lower (P<0.01) N retention (from 2.7 to 0.1 g/sheep/day). Although the incremental substitution of B. alicastrum with L. latisiliquum negatively affected intake, rumen degradation, digestibility and N balance, results indicate that this foliage mixture, but with no more than 132 g DM/kg diet of L. latisiliquum, could be used as a supplementation strategy to sheep fed low quality forage without negative effects on voluntary intake.     

Effect of organic zinc supplementation on growth, nutrient utilization and mineral profile in lambs

To study the efficacy of organic zinc (Zn) supplementation on growth, nutrient utilization and mineral profile as compared to inorganic source [zinc sulphate (ZnSO₄)], 18 Muzaffarnagari male lambs of 11.30 ± 0.45 kg mean body weight (4–5 months of age) were divided into three groups of six animals in each in a randomized block design. Lambs in the control group were fed a standard total mixed ration (TMR) consisted of 60 kg/100 kg of concentrate mixture (CM) and 40 kg/100 kg of wheat straw. CM was consisted of 300 g/kg crushed maize grain, 270 g/kg soybean meal, 400 g/kg wheat bran, 20 g/kg mineral mixture (without Zn) and 10 g/kg common salt. Animals in the experimental groups were additionally supplemented with 20 mg Zn/kg of diet either through inorganic (ZnSO₄) or organic [Zn-methionine AA complex (Zn-meth)] sources. Experimental feeding was done for a period of 150 days including a 6 days metabolism trial. The intake of dry matter (DM), organic matter (OM), crude protein (CP), digestible CP and total digestible nutrients and digestibility of DM, OM, CP, ether extract, neutral detergent fibre and hemicellulose were comparable (P>0.05) among the three groups. However, digestibility of cellulose and acid detergent fibre was significantly (P<0.05) higher in Zn-meth group as compared to control group. Though the balance of calcium was adversely affected (P<0.01) in both the Zn supplemented groups, but it was significantly higher in Zn-meth group compared to ZnSO₄ group. While apparent absorption and retention of nitrogen, phosphorus, copper, iron and manganese were similar (P>0.05) among different groups, retention of Zn (P<0.05) as well as its concentration in the serum (P<0.01) were highest in Zn-meth group, followed by ZnSO₄ group and lowest in the control group, suggesting higher bioavailability of Zn from Zn-meth as compared to ZnSO₄. Average daily gain of the lambs and feed conversion efficiency were also significantly (P<0.05) higher in Zn-meth group as compared to control and ZnSO₄ groups, suggesting a positive role of organic zinc supplementation on the performance of lambs.     

Nutritional value of fermented olive wastes in growing lamb rations

In an experiment with 40 growing Florina (Pelagonia) lambs, effects of replacing barley grain, sugar beet pulp, and alfalfa meal with fermented olive wastes (FOW) and soybean meal on productivity and meat composition was determined. In the 45-day experiment, lambs were allocated to one of the four treatments of 10 lambs (5 male and 5 female) each. Male and female lambs had an initial body weight (BW) of 19.7 ± 0.8 and 19.5 ± 0.8 kg, respectively, and were individually fed a concentrate mixture ad libitum and alfalfa hay (0.18 kg/lamb/day, dry matter (DM) basis). The FOW was added to the concentrate mixtures at inclusion levels (as fed basis) of 0, 50, 100, and 150 kg/t for treatments FOW0, FOW50, FOW100, and FOW150, respectively. Male lambs grew faster (P<0.01) than female lambs, but no differences (P>0.05) occurred among FOW treatments in final BW, BW gain, DM intake, or feed conversion ratio. Males had heavier (P<0.01) fasted BW and cold carcass weight, and lower (P=0.04) carcass yield than females, but no differences in carcass components among treatments were detected. FOW can be incorporated into concentrates for growing lambs, at levels up to 150 kg/t, with no adverse effects on performance or carcass characteristics.     

A thermophilic and acid stable family-10 xylanase from the acidophilic fungus Bispora sp. MEY-1

A complete gene, xyl10C, encoding a thermophilic endo-1,4-β-xylanase (XYL10C), was cloned from the acidophilic fungus Bispora sp. MEY-1 and expressed in Pichia pastoris. XYL10C shares highest nucleotide and amino acid sequence identities of 57.3 and 49.7%, respectively, with a putative xylanase from Aspergillus fumigatus Af293 of glycoside hydrolase family 10. A high expression level in P. pastoris (73,400 U ml⁻¹) was achieved in a 3.7–l fermenter. The purified recombinant XYL10C was thermophilic, exhibiting maximum activity at 85°C, which is higher than that reported from any fungal xylanase. The enzyme was also highly thermostable, exhibiting ~100% of the initial activity after incubation at 80°C for 60 min and >87% of activity at 90°C for 10 min. The half lives of XYL10C at 80 and 85°C were approximately 45 and 3 h, respectively. It had two activity peaks at pH 3.0 and 4.5–5.0 (maximum), respectively, and was very acid stable, retaining more than 80% activity after incubation at pH 1.5−6.0 for 1 h. The enzyme was resistant to Co²⁺, Mn²⁺, Cr³⁺ and Ag⁺. The specific activity of XYL10C for oat spelt xylan was 18,831 U mg⁻¹. It also had wide substrate specificity and produced simple products (65.1% xylose, 25.0% xylobiose and 9.9% xylan polymer) from oat spelt xylan.     

Effects of lanthanum on rumen fermentation, urinary excretion of purine derivatives and digestibility in steers

The objective of this study was to evaluate the effects of LaCl₃ supplementation on rumen fermentation, urinary excretion of purine derivatives and feed digestibility in the total tract of steers. Eight ruminally cannulated Simmental steers (420 ± 20 kg) were used in a replicated 4 × 4 Latin square experiment. The treatments were control (without LaCl₃); La-low; La-medium and La-high with 450, 900 and 1800 mg LaCl₃ per steer per day, respectively. Diet consisted of 600 g/kg corn stover and 400 g/kg concentrate (dry matter [DM] basis). Dry matter intake (averaged 9 kg/day) was restricted to a maximum of 90% of ad libitum intake. Ruminal pH (range of 6.59–6.42) was quadratically (P<0.04) changed, whereas total volatile fatty acids (VFA) concentration (range of 74.16–88.61 mM) was linearly (P<0.01) and quadratically (P<0.01) increased with increasing La supplementation. Ratio of acetate to propionate decreased linearly (P<0.01) from 3.28 to 1.79 as La supplementation increased due to the increased in propionate production. In situ ruminal neutral detergent fibre (aNDF) degradation of corn stover was improved but the crude protein (CP) degradability of soybean meal was decreased with increasing La supplementation. Urinary excretion of purine derivatives was quadratically (P<0.01) changed with altering La supplementation (75.5, 81.0, 82.4 and 70.6 mmol/day for control, low-, medium- and high-LaCl₃ supplementation, respectively). Similarly, digestibilities of organic matter, aNDF and CP in the total tract were also linearly and quadratically increased with increasing La supplementation. The present results indicate that supplementation of diet with LaCl₃ improved rumen fermentation and feed digestion in beef cattle. It was suggested that the La stimulated the digestive microorganisms or enzymes in a dose-dependent manner. In the experimental conditions of this trial, the optimum La dose was about 900 mg LaCl₃ per steer per day.     

Chemical characterization,in vitro dry matter and ruminal crude protein degradability and microbial protein synthesis of some cowpea (Vigna unguiculata L. Walp) haulm varieties

A study was carried out to evaluate the chemical composition, in vitro apparently and truly degraded dry matter (DM), utilizable crude protein at the duodenum (uCP) (total CP at the duodenum minus endogenous CP), methane production, and short chain fatty acid production of haulms of six cowpea varieties. The study was arranged in a 2 × 2 × 2 factorial design, with three replicates. Three improved (ITA2, ITA6 and ITA8) and three commercial (Oloyin, Peu and Sokoto) cowpea varieties harvested during wet and dry seasons were used for the study. After an initial gas test to evaluate 96 h gas production profiles of haulms with and without polyethylene glycol (PEG), the time to half maximal gas production was calculated and a second incubation conducted with fermentation stopped at substrate specific half time (t_1/2) and 24 h for each substrate. True DM degradability was measured from incubated residues and combined with gas volume to estimate the partitioning factor. Crude protein flow to the duodenum was estimated by combining gas volume with the measured ammonia nitrogen in the incubated fluid. Addition of PEG did not have any effect (P>0.05) on all the variables determined. Interaction between group (improved vs. commercial) and season was observed for CP (P=0.002), lignin (P=0.003) and hemicellulose (P=0.030) contents of the haulms. A group × season interaction was also observed for some of the variables at both substrate specific t_1/2 and 24 h. Commercial cowpea haulms had greater (P=0.002) microbial mass and produced less (P<0.05) methane than the improved cowpea haulms. The improved cowpea haulms were less (P<0.001) degraded in the rumen and as a result ensured greater (P<0.001) amount of uCP. The results validated that cowpea haulm is an important agro-based by-product that is adequate in protein and energy to sustain ruminant animal production in Nigeria and other Sub-Saharan African countries during the extended dry season.