Effect of Different Levels of Copper and Molybdenum Supplements on Performance,Nutrient Digestibility,and Follicle Characteristics in Cashmere Goats

A 2 × 3 factorial arrangement of treatments was used to investigate the effects of different levels of copper (Cu, 0, 19, and 38 mg/kg, dry matter (DM)) and molybdenum (Mo, 0 and 5 mg/kg, DM) supplements and an interaction of these two factors on growth performance, nutrient digestibility, and cashmere and follicle characteristics in cashmere goats. Thirty-six Liaoning cashmere goats (approximately 1.5 years of age; 27.53 ± 1.38 kg of body weight) were assigned randomly to one of six treatments and fed with Chinese wildrye- and alfalfa hay-based treatment diets (the basal diet contained 4.72 mg Cu/kg, 1.65 mg Mo/kg, and 0.21% S.). Body weight was measured on two consecutive days at the start and the end of the 70-day experimental period. On day 30, the metabolism trial was conducted to study the effects of dietary Cu and Mo on nutrient digestibility. The cashmere and skin samples were collected on day 70. Copper supplementation increased (P < 0.05) growth performance and fiber digestion, but there were no differences (P > 0.05) between Cu-supplemented groups. Addition of 19 mg Cu/kg DM increased (P < 0.05) cashmere growth length or growth rate by increasing the number of active secondary follicles. Molybdenum supplementation decreased (P < 0.05) growth, but did not affect (P > 0.05) nutrient digestion, cashmere, and follicle characteristics. There is a tendency or significant interaction effect of Cu and Mo on growth performance (P = 0.057), cashmere growth (P = 0.076), or diameter (P < 0.05) which might be accomplished by changing the number of secondary follicle and active secondary follicle, and secondary to primary follicle ratio. In conclusion, the optimal supplemental Cu level for Liaoning cashmere goats fed with the basal diet was 19 mg/kg DM (the total dietary Cu level of 23.72 mg/kg DM), while 38 mg Cu/kg DM supplementation was found to be needed when 5 mg Mo/kg was added in the basal diet during the cashmere growing period.     

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.     

Influence of Dietary Copper Methionine Concentrations on Growth Performance,Digestibility of Nutrients,Serum Lipid Profiles,and Immune Defenses in Broilers

A 42-day experiment was conducted to evaluate the influence of dietary copper (Cu) concentrations on growth performance, nutrient digestibility, and serum parameters in broilers aged from 1 to 42 days. Five hundred forty 1-day-old broilers were randomly assigned into 1 of the following 6 dietary treatments: (1) control (basal diet without supplemental Cu), (2) 15 mg/kg supplemental Cu (Cu15), (3) 30 mg/kg supplemental Cu (Cu30), (4) 60 mg/kg supplemental Cu (Cu60), (5) 120 mg/kg supplemental Cu (Cu120), and (6) 240 mg/kg supplemental Cu (Cu240), Cu as copper methionine. A 4-day metabolism trial was conducted during the last week of the experiment feeding. The results showed that dietary Cu supplementation increased the average daily gain and the average daily feed intake (P < 0.01). The feed gain ratio, however, was not affected by dietary Cu (P > 0.10). Additionally, dietary Cu supplementation increased the digestibility of fat and energy (P < 0.05). The concentration of serum cholesterol, triglycerides, and high-density lipoprotein cholesterol decreased with dietary Cu supplementation (P < 0.05). The activities of serum Cu-Zn superoxide dismutase (P < 0.05), glutathione peroxidase (P < 0.05), and ceruloplasmin (P = 0.09), on the contrary, were increased by Cu addition. For immune indexes, dietary Cu supplementation increased serum IgA and IgM (P < 0.05). In addition, the activities of serum ALT increased with increasing dietary Cu supplementation (P < 0.05). In conclusion, our data suggest that Cu supplementation can increase fat digestibility and promote growth. Additionally, dietary Cu supplementation can reduce serum cholesterol and enhance antioxidant capacity in broilers.

     

Effect of ruminally protected fat on in vitro fermentation and apparent nutrient digestibility in buffaloes (Bubalus bubalis)

Experiments were conducted to evaluate effects of supplementation of calcium salts of long chain fatty acids (Ca-LCFA) as a rumen inert fat (PF) on in vitro fermentation and apparent nutrient digestion in adult buffaloes fed wheat straw based diets. For the in vitro fermentation study, five total mixed rations (TMR) consisting of a concentrate mixture (CM), green Sorghum bicolor, WS and supplemented without (C) or with 30 g/kg dry matter (DM) rice bran fatty acid oil (RBO) (30 RBO) or 20 g/kg RBO + 10 g/kg PF (20 RBO/10 PF) or 10 g/kg RBO + 20 g/kg PF (10 RBO/20 PF) or 30 g/kg PF in the DM in the ratio of 340:50:580:30 were prepared. The in vitro DM degradability (IVDMD), TN, trichloro acetic acid precipitable N (TCA-N), non-protein N (NPN) and ammonia N (NH₃-N) were similar among groups. Within the fat supplemented groups, total volatile fatty acid (TVFA) concentration increased linearly (P=0.025) with PF supplementation. Apparent nutrient digestibility was determined on 20 adult buffaloes divided into five equal groups fed CM supplemented without (C) or with 300 g RBO (30 RBO) or 200 g RBO + 100 g PF (20 RBO/10 PF) or 100 g RBO + 200 g PF (10 RBO/20 PF) or 300 g PF (30 PF) along with limited green S. bicolor and WS maintaining forage: concentrate ratio of 650:350. Fat supplementation had no effect on the DM intake and apparent digestibilities of DM, organic matter (OM), crude protein (CP), total carbohydrate (TCHO) and neutral detergent fiber (aNDF). Within fat supplemented groups, inclusion of PF increased digestibilities of DM, OM, ether extract (EE), TCHO, aNDF and ADF. Supplemental fat also increased the digestible energy (DE) and metabolizable energy (ME) content of the diet, which also increased linearly with PF supplementation. All buffaloes were in positive N, Ca and P balances. We conclude that 200–300 g supplemental PF in the form of Ca-LCFA can be included in straw based diets fed to buffaloes to increase its energy density without adversely affecting DM intake and digestibility.     

Effects of Dietary Iodine and Selenium on Nutrient Digestibility,Serum Thyroid Hormones,and Antioxidant Status of Liaoning Cashmere Goats

Forty-eight 2-year-old Liaoning Cashmere goats (body weight = 38.0 ± 2.94 kg) were used to investigate the effects of dietary iodine (I) and selenium (Se) supplementation on nutrient digestibility, serum thyroid hormones, and antioxidant status during the cashmere telogen period to learn more about the effects of dietary I and Se on nutrition or health status of Cashmere goats. The goats were equally divided into six groups of eight animals each that were treated with 0, 2, or 4 mg of supplemental I/kg dry matter (DM) and 0 or 1 mg of supplemental Se/kg DM in a 2 × 3 factorial arrangement of treatments. The six treatments were I₀Se₀, I₂Se₀, I₄Se₀, I₀Se₁, I₂Se₁, and I₄Se₁. The concentrations of I and Se in the basal diet were 0.67 and 0.09 mg/kg DM, respectively. The study started in March and proceeded for 45 days. Supplemental I or Se alone had no effect on nutrient digestibility and nitrogen metabolism. However, the interaction between I and Se was significant regarding the digestibility of acid detergent fiber (ADF; P < 0.05), and compared with group I₄Se₁, the digestibility of ADF was significantly increased in group I₄Se₀ (P < 0.05). Selenium supplementation did not affect serum triiodothyronine (T₃) or thyroxine (T₄) concentrations. However, the concentration of serum T₄ but not that of T₃ was significantly increased with I supplementation (P < 0.05). In addition, serum superoxide dismutase (SOD) activity was not affected (P > 0.05), but serum glutathione peroxidase (GSH-Px) activity was significantly decreased by I supplementation (P < 0.05). The antioxidant status was improved by Se supplementation, and the activities of SOD and GSH-Px were significantly increased (P < 0.05).     

Effect of copper sources and levels on serum lipid profiles in Black Bengal (Capra hircus) kids

Twenty eight 2–3 month old castrated male Black Bengal kids (Capra hircus) were used to determine the effects of dietary Cu concentration on lipid metabolism. These kids were randomly assigned to one of seven treatments in a ((2 × 3) + 1) factorial arrangement. Factors were two sources of Cu (CuSO₄ versus Cu proteinate) fed at three dietary levels (10, 20 or 30 mg/kg) and the control group, where neither CuSO₄ nor Cu proteinate were supplemented. Kids were fed a basal diet containing maize (19.5%), soybean (17.0%), deoiled rice bran (56.5%), molasses (4.0%), di-calcium phosphate and salt (1.0% each), and mineral and vitamin mixture (0.5% each) supplements, at 3.5% of BW to meet NRC requirements for protein, energy, macro minerals and micro minerals, excluding Cu. The basal diet (DM basis) contained 5.7 mg Cu/kg, 122.5 mg Fe/kg, 110 mg Zn/kg, 0.26 mg Mo/kg and 0.32% S. CuSO₄ or Cu proteinate (Cu-P) was added to the basal diet at the rate of 10, 20 and 30 mg/kg. Kids were housed in a well-ventilated shed with facilities for individual feeding in aluminum plated metabolic cages in an open-sided barn. Blood samples were collected on Days 0, 30, 60 and 90 to determine serum cholesterol, high density lipoprotein (HDL), total lipid and phospholipids. Kids were slaughtered after metabolism trial and liver tissues were collected to determine the copper and zinc concentrations. Kids receiving Cu-P showed higher (P < 0.05) HDL, total lipid and phospholipid concentrations. Increase in dietary level of Cu significantly decreased (P < 0.05) serum cholesterol and increased serum HDL, total lipid and phospholipid concentrations. There was an increasing (P < 0.05) trend in liver Cu with the increased dietary level of Cu supplementation irrespective of source, but the increasing rate was greater with CuSO₄ than Cu-P supplementation. Kids’ diet containing 30 mg/kg CuSO₄ had 26% more liver Cu than those fed iso-amounts of Cu-P. Fecal Cu excretion was increased with the increasing dietary level of Cu, and excretion was reduced by the use of Cu-P in the diet. In conclusion, dietary supplementation of organic Cu in the form of copper proteinate had significant effects on lipid metabolism in goat kids. There was an increase in accumulation of Cu in the liver and excretion of Cu in feces with the increase of dietary level of Cu in the diet of Black Bengal kids.     

Effects of different forms of Acacia saligna leaves inclusion on feed intake, digestibility and body weight gain in lambs fed grass hay basal diet

The study was undertaken to determine the effects of different forms of Acacia saligna leaves inclusion on feed intake, digestibility and body weight gain in lambs fed grass hay basal diet. Twenty local ‘Farta’ yearling male lambs weighing 17.4 ± 0.10 kg (mean ± SD) were randomly allocated to four dietary treatments consisting of daily feeding of lambs in T1 with 700 g grass hay (dry matter basis), and daily free choice feeding of lambs in T2, T3, and T4 with 700 g grass hay + 700 g fresh, wilted, and dried A. saligna leaves, respectively. Inclusion of different forms of A. saligna leaves improved (P<0.01) the daily intake of total DM by 8–9% and that of OM and CP by 7 and 38%, respectively compared to the control. The daily intake of NDFom was lower (P<0.01) by 1–2.3%, whereas that of the ADFom intake declined (P<0.01) by 1.3–3.4% for lambs on wilted and dried forms of A. saligna leaves. Inclusion of A. saligna leaves replaced the intake of the grass hay by 26–27% of the total diet and reduced (P<0.05) apparent digestibility coefficient of the total DM by 9, 7, and 4%, OM by 7, 6 and 4%, and CP by 12, 12, and 9%, but improved (P<0.05) apparent digestibility coefficient of NDFom by 3–4% compared to the control diet. Dried A. saligna leaves improved (P<0.05) apparent digestibility of DM, OM and CP compared to fresh A. saligna leaves. Lambs fed on hay alone lost (P<0.05) body weight, while the lambs supplemented with A. saligna leaves gained (P<0.05) weight. The results of this study revealed that A. saligna leaves could be best included in the grass hay based feeding in dried form at the rate of 265 g/kg DM for improved nutrient utilization and growth performance of yearling lambs.     

Performance,rumen fermentation,blood minerals,leukocyte and antioxidant capacity of young Holstein calves receiving high-surface ZnO instead of common ZnO

ABSTRACT

This study was conducted to assess the effect of feeding high-surface ZnO instead of common ZnO on the performance, rumen fermentation, blood minerals, leukocytes and antioxidant capacity of pre- and post-weaning calves. Thirty male suckling Holstein calves were allotted to one of three experimental groups (10 replicates) in a completely randomised design. Calves received: (1) a low Zn diet without Zn supplementation (control diet), (2) a high Zn diet containing 50 mg supplementary Zn/kg dry matter (DM) as common ZnO or (3) a high Zn diet containing 50 mg supplementary Zn/kg DM as high-surface ZnO (nano-ZnO). The control diet contained a native Zn content of 35.5, 34.7 or 33.7 mg/kg DM for the age periods of 7 to 30, 31 to 70 and 71 to 100 d, respectively. Supplementation of the diet with Zn did not change the dry matter intake (DMI) of calves during d 7 to 30 but increased the ADG in this period (p < 0.05). During age periods of 31 to 70 and 71 to 100 d, DMI and ADG of the Zn supplemented calves were higher (p < 0.05) than the control animals. The nutrient digestibility and the concentration of rumen volatile fatty acids were positively affected (p < 0.05) and the rumen ammonia-N concentration decreased (p < 0.05) by dietary Zn supplementation. Furthermore, the incidence of diarrhoea and pneumonia was lower in calves receiving the Zn supplemented diets. Irrespective of ZnO source, the blood total antioxidant capacity, leukocyte and haematocrit levels significantly increased (p < 0.05) with the ZnO supplemented diets. The post-weaning DMI, nutrient digestibility and blood haematocrit levels were higher in calves receiving high-surface ZnO, compared to those supplemented with common ZnO. With inclusion of the Zn sources in pre- and post-weaning diets, the blood Zn concentration increased (p < 0.05), but the blood Cu, Fe, Ca, P and Mg levels remained unchanged. Regardless of source, dietary supplementation of young calves with ZnO improved the performance and decreased rumen ammonia-N and the incidence of diseases. Moreover, high-surface ZnO had advantages over common ZnO in increasing the post-weaning feed intake, digestibility and blood Zn concentration.     

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.     

Effects of inclusion of neutral detergent soluble fibre sources in diets varying in forage particle size on feed intake, digestive processes, and performance of mid-lactation Holstein cows

The aim of this study was to evaluate effects of partial replacement of neutral detergent soluble fibre (NDSF) for starch in diets varying in particle size (PS) of alfalfa hay on chewing activities, ruminal fermentation, nutrient digestibility and performance in mid-lactation dairy cows. Eight multiparous Holstein cows (146 ± 6.0 d in milk; 36.7 ± 2.57 kg milk/d) were used in a replicated 4 × 4 Latin square design with four 21 d periods with the last 7 d for data collection. The experiment was a 2 × 2 factorial arrangement with 2 levels of NDSF (low = 85 g/kg or high = 130 g/kg diet dry matter) each combined with 2 PS (short = 20 mm or long = 40 mm) of alfalfa hay. Results show that forage PS alone, or in combination with NDSF inclusion, had no effect on dry matter (DM) intake. Although total chewing, eating and ruminating times were not affected by treatments, eating time per kg of neutral detergent fibre (NDF) ingested was higher in long versus short alfalfa hay-based diets (P<0.05). Feeding long forage PS increased sorting of the diet against particles >19 mm, and in favor of those <8 mm (P<0.05). Feeding diets high in NDSF lowered DM intake (P<0.05), but increased apparent digestibility of all nutrients including NDF (P<0.05) independent of forage PS. Ruminal pH and concentrations of total volatile fatty acids were unaffected by dietary treatments, however the proportion of butyrate was higher in ruminal fluid of cows fed high NDSF diets (P<0.05). Changes in milk composition included lower milk crude protein content in high NDSF diets and higher lactose content for short hay-based diets (P<0.05). That milk yield and milk energy output were similar in low versus high NDSF diets suggests that high NDSF-fed cows had higher energy efficiency due to lower DM intake. Results suggest that, independent of forage PS, NDSF sources can be successfully included to partly replace starchy grains in diets exceeding minimum fibre recommendations.     

Influence of exogenous enzymes on nutrient digestibility, extent of ruminal fermentation as well as milk production and composition in dairy cows

This experiment studied effects of a mixture of exogenous enzymes (ZADO^®) from anaerobic bacteria on ruminal fermentation, feed intake, digestibility, as well as milk production and composition in cows fed total mixed rations (TMRs; 0.7 corn silage and 0.3 of a concentrate mixture). Twenty lactating multiparous Brown Swiss cows (500 ± 12.4 kg live weight) were randomly assigned into two experimental groups of 10 immediately after calving and fed a TMR with or without (CTRL) addition of 40 g/cow/d of enzymes for 12 weeks. Addition of enzymes increased (P<0.05) rumen microbial N synthesis. Intake of dry matter (DM) and organic matter (OM) was positively influenced (P<0.05) by supplementation, and digestibility of all nutrients was higher (P<0.05) in the total tract of supplemented cows, although the magnitude of the improvement varied among nutrients, with the highest improvement in aNDFom and ADFom (418–584 and 401–532 g/kg respectively; P<0.05) than the other nutrients. Supplementation of enzymes also increased (P<0.05) rumen ammonia N and total short chain fatty acid (SCFA) concentrations, and individual SCFA proportions were also altered with an increase in acetate (61.0–64.8 mol/100 mol; P=0.05) before feeding, and acetate and propionate increased 3 h post-feeding (60.0–64.0 and 18.3–20.8 mol/100 mol respectively; P<0.05). Milk and milk protein production was higher (12.8–15.7 and 0.45–0.57 kg/d respectively; P<0.05) for cows fed the ZADO^® supplemented diet. This exogenous enzyme product, supplemented daily to the TMR of cows in early lactation, increased milk production due to positive effects on nutrient intake and digestibility, extent of ruminal fermentation and microbial protein synthesis.     

Intake, rumen fermentation and nutrient flow to the omasum in beef cattle fed grass silage fortified with sucrose and/or supplemented with concentrate

The objective was to determine the relative effects of a specific increase in grass silage sucrose concentration, or a specific supplement of a starch-based concentrate, on rumen fermentation and nutrient supply to the omasum in beef cattle. Four ruminally cannulated Holstein–Friesian steers were fed grass silage only (G), G plus 3 kg concentrates/day (GC), G plus 90 g sucrose/kg dry matter (DM) (GS) and G plus 90 g sucrose/kg DM plus 3 kg concentrates/day (GCS) in a 4 × 4 Latin Square design experiment. Omasal flow was estimated using Co-EDTA, Yb-acetate and indigestible neutral detergent fibre (INDF) as digesta flow markers and purine bases as microbial markers. Concentrate supplementation reduced (P < 0.01) silage and increased (P < 0.001) total DM intake whereas sucrose had no effect. There was a sucrose × concentrate interaction (P < 0.05) for rumen pH whereby addition of sucrose to grass silage alone decreased pH and to grass silage plus concentrate had no effect. Rumen ammonia N (P < 0.01), total volatile fatty acid (VFA) concentration (P < 0.05) and the molar proportions of valerate (P < 0.05) and butyrate (P < 0.001) increased with concentrate supplementation whereas, sucrose supplementation had no effect on rumen fermentation parameters. Organic matter (OM) intake, omasal OM flow, the quantities of OM apparently (OMAD) and truly digested (OMTD) in the rumen (P < 0.001) and total tract OM digestibility (P < 0.01) increased, and apparent and true ruminal OM digestibility decreased (P < 0.05) with concentrate supplementation. Supplementation with concentrate decreased (P < 0.05) ruminal neutral detergent fibre (aNDFom) digestibility and increased (P < 0.05) aNDFom omasal flow. There was a tendency for addition of sucrose to increase (P < 0.1) ruminal OMAD and OMTD, while there was no effect of sucrose addition on intake or digestion of aNDFom. Concentrate supplementation increased (P < 0.001) N intake, flows of N, non-ammonia N (NAN), microbial N (MN) (P < 0.05) and non-ammonia non-microbial N (NANMN) (P < 0.01) and apparent total tract digestibility of N (P < 0.01), whereas sucrose reduced (P < 0.05) N intake and apparent ruminal N digestibility. There was no effect of concentrate or sucrose on N use efficiency or efficiency of microbial protein synthesis. Concentrate supplementation increased (P < 0.001) plasma β-hydroxybutyrate levels. In comparison to supplementing unwilted, well preserved grass silage of moderate digestibility with 3 kg starch-based concentrate per day, the limited response to the rate of sucrose supplementation employed suggests that increasing the water-soluble carbohydrate (WSC) concentration of grass silage through agronomic and/or ensiling practices will have relatively little effect on intake, rumen digestion or efficiency of microbial N synthesis.     

Effects of Different Sources and Levels of Copper on Growth Performance,Nutrient Digestibility,and Elemental Balance in Young Female Mink (Mustela vison)

An experiment was conducted in a 3?×?3?+?1 factorial experiment based on a completely randomized design to evaluate the effects of different sources of copper on growth performance, nutrient digestibility and elemental balance in young female mink on a corn–fishmeal-based diet. Animals in the control group were fed a basal diet (containing 8.05 mg Cu/kg DM; control), which mainly consisted of corn, fish meal, meat bone meal, and soybean oil, with no copper supplementation. Minks in other nine treatments were fed basal diets supplemented with Cu from reagent-grade copper sulfate, tribasic copper chloride (TBCC) and copper methionate. Cu concentrations of experiment diets were 10, 25, and 40 mg/kg copper. A metabolism trial of 4 days was conducted during the last week of experimental feeding. Final body weight and average daily gain increased (linear and quadratic, P?<?0.05) as Cu increased in the diet; maximal growth was seen in the Cu25 group. Cu supplementation slightly improved the feed conversion rate (P?=?0.095). Apparent fat digestibility was increased by copper level (P?=?0.020). Retention nitrogen was increased by copper level (linear, P?=?0.003). Copper source had a significant effect on copper retention with Cu-Met and copper sulfate treatments retention more than TBCC treatments (P?<?0.05). Our results indicate that mink can efficiently utilize added dietary fat and that Cu plays an important role in the digestion of dietary fat in mink, and mink can efficiently utilize Cu-Met and CuSO₄.     

l-arginine supplementation of milk liquid or dry diets fed to pigs after weaning has a positive effect on production in the first three weeks after weaning at 21 days of age

A total of 48, 21-day-old weaned pigs, was used in a 2 × 2 factorial arrangement of treatments with the factors being diet type (milk liquid replacer vs. dry feed) and l-arginine (ARG) supplementation (0 vs. 6 g ARG/kg) to test the hypothesis that dietary supplementation with ARG would increase performance of pigs after weaning. Pigs were fed the experimental diets for 10 d (days) after weaning and then transitioned over a 3-d period to a dry Phase II diet fed in meal form devoid of supplemental ARG. The study ended at d 21. There were five replicates (pens) per treatment (a total of 12 pigs per treatment). Blood samples were collected from two pigs per replicate on d 7 and 16 of the experiment, and free amino acids (AA) and plasma urea nitrogen (PUN) levels analysed. Milk-fed pigs outperformed (P<0.001) dry-fed pigs for the first 10 d of the experiment as well as for the total 21-d period. At d 7, milk-fed pigs had higher (P<0.05) levels of most free indispensable and dispensable amino acids in their plasma. In both the milk-fed and dry-fed pigs supplemented with ARG, average daily feed intake (ADFI, P<0.05) and average daily gain (ADG, P<0.05) were increased during the dietary transition period (d 11–14), when pigs were being changed to the Phase II diet. The difference in production in the transition period caused a tendency for ARG-supplemented pigs to eat more feed (P<0.1) and grow faster (P<0.5) over the 21-d experimental period. Pigs supplemented with ARG had higher plasma ARG levels (P<0.05) at d 7 after weaning and lower plasma urea levels (P<0.05) at both d 7 and 16 after weaning. These data show the benefits of feeding a milk liquid diet as well as of ARG supplementation after weaning on production indices.     

Energy metabolism and protein balance in growing rats fed different levels of dietary fibre and protein

A study was performed to investigate the effect of different levels of dietary fibre (DF) and dietary protein on visceral organ size, digestibility, nitrogen balance and energy metabolism in rats. Thirty-six male Wistar rats, initial body weight about 76 g, were used in a factorial design consisting of three levels of DF (low, 100 g/kg DM; medium, 250 g/kg DM and high, 290 g/kg DM) and two levels of dietary protein (low, 120 g/kg DM and high, 223 g/kg DM). The added fibre source was soybean hulls and Danish fish meal was used as sole source of dietary protein. Measurements of gas-exchange were done on six rats (one group) while urine and faeces were collected individually. The ratio of food/empty body gain increased (P < 0.05) with increasing DF and decreasing levels of dietary protein. The weight of the digestive tract was larger (P < 0.05) in rats fed the high fibre diet than in those fed the low fibre diet. The digestibility of nutrients and energy decreased linearly with increasing level of soybean fibre (P < 0.05). An increased intake of DF was associated with a concomitant loss of protein and energy to faeces. The microbial degradation of NSP and other unabsorbed carbohydrates caused considerably changes in N metabolism of the colon. In rats fed the low protein diets increased levels of DF decreased N excretion in urine and increased N excretion in faeces, while the ratio of retained/digested protein remained constant. When rats were fed the high protein diet protein retention dropped in response to DF both absolute and relative to digested amount, indicating that energy intake could be a limiting factor. Heat production as a percentage of metabolizable energy (HP/ME) was higher (P < 0.05) in rats fed the low protein diet than in rats fed the high protein diet, but no significant difference was found among DF levels.     

Effect of zinc supplementation from two sources on growth,nutrient utilization and immune response in male crossbred cattle (Bos indicus×Bos taurus) bulls

To investigate effects of Zn supplementation on performance, mineral balance and immune response, 15 male crossbred cattle (Bos indicus×Bos taurus) bulls of about 14 ± 0.4 months of age and weighing 226.0 ± 9.1 kg were divided in to three groups of five. Bulls in the control group were fed wheat straw and a concentrate mixture (basal diet with 32.5 mg Zn/kg dry matter (DM)), and in ZnSO₄ and ZnProp groups 35 mg Zn/kg DM was added through Zn sulphate and Zn propionate, respectively. All bulls were fed their respective treatment diets for 180 days. Daily feed intake was recorded and bulls were weighed at every 15 days to determine change in body weight (BW). After 120 days of feeding, bulls were vaccinated with Brucella abortus strain 19, and cell mediated and humoral immune responses were assessed between 120 and 148 days of experimental feeding. After 150 days of feeding, a metabolism study of 6 days duration was completed to determine nutrient digestibility and mineral balances (i.e., Ca, P, Zn, Cu, Fe and Mn). Intake of total DM, digestibility of DM, crude protein, ether extract, neutral detergent fibre and acid detergent fibre, N balance, average daily gain, feed: gain did not differ between the groups. Intake, excretion and balance of Ca, P, Zn, Cu, Fe and Mn also did not differ between the groups. However, retention of Zn was higher (P<0.001) in the ZnProp group. Bulls supplemented with Zn propionate had higher cell mediated (P<0.01) and humoral (P<0.05) immune response, while there was no alteration in immune response due to Zn sulphate supplementation. Results indicate that a diet containing about 32.5 mg Zn/kg DM was adequate to support normal growth and digestibility, but a better immune response occurred when Zn propionate was added to the diet at 35 mg/kg DM versus Zn sulphate.     

Effect of Different Levels of Copper and Molybdenum Supplements on Serum Lipid Profiles and Antioxidant Status in Cashmere Goats

An experiment was conducted to investigate on the effects of different levels of copper (Cu: 0, 19, and 38 mg/kg) and molybdenum (Mo: 0 and 5 mg/kg) supplements and the interaction of these two factors on serum lipid profiles and antioxidant status in cashmere goats during the cashmere fiber growing period. Thirty-six Liaoning cashmere goats (approximately 1.5 years of age; 27.53±1.38 kg of body weight) were assigned to one of six treatments in a completely randomized design involving a 2×3 factorial arrangement. Goats were housed in individual pens and fed with Chinese wild rye- and alfalfa hay-based diet containing 4.72 mg Cu/kg, 0.16 mg Mo/kg, and 0.21 % S for 84 days. Blood samples were collected on day 84. The triglyceride concentration did not differ among treatments (P>0.05). Supplemental Cu, regardless of Mo level, decreased (P<0.05) the concentrations of serum total cholesterol and low density lipoprotein cholesterol, and increased (P<0.05) the concentration of serum high density lipoprotein cholesterol, but there were no differences (P>0.05) in these values between Cu-supplemented groups. Supplemental Cu increased (P<0.05) the activities of serum ceruloplasmin (Cp), Cu-zinc superoxide dismutase (SOD), and glutathione peroxidase (GSH-Px), and decreased (P<0.05) the malondialdehyde content. The serum GSH-Px activity was also increased (P<0.05) by Mo supplementation. There was a tendency of the interaction effects of Cu and Mo on the activities of Cp (P=0.094), SOD (P=0.057), and GSH-Px (P=0.062), and goats fed with 19 mg Cu/kg in the absence of Mo tended to show the highest serum SOD activity, while goats fed with 38 mg Cu/kg with 5 mg Mo/kg tended to show the highest values of serum Cp and GSH-Px. Addition of Cu, Mo, or their interaction had no influence (P>0.05) on the activities of serum glutamate oxaloacetate transaminase, glutamate pyruvate transaminase, and lactate dehydrogenase, and the concentrations of serum glucose and total protein. In conclusion, addition of 19 mg Cu/kg in the absence of Mo (the total dietary Cu level of 23.72 mg/kg) was recommended for altering the fat metabolism and obtaining the optimal antioxidant activity of cashmere goats, while 38 mg Cu/kg should be supplemented when 5 mg Mo/kg was added in the basal diet (the total dietary level of 42.72 mg Cu/kg, 5.16 mg Mo/kg, and 0.21 % S) during the cashmere growing period.     

Effect of Ascophyllum nodosum extract on growth performance, digestibility, carcass characteristics and selected intestinal microflora populations of grower–finisher pigs

The effects of an extract of the brown seaweed Ascophyllum nodosum (AN) in grower–finisher pigs are reported. In Experiment 1, the effect of dietary supplementation with increasing levels of AN extract (ANE) on growth performance, carcass characteristics and gastrointestinal microflora was investigated. A total of 360 pigs were randomly allocated, based on initial live-weight and sex, to one of four experimental treatments as follows; control diet (no ANE), control diet plus 3 g ANE/kg, control diet plus 6 g ANE/kg and control diet plus 9 g ANE/kg. These diets were fed ad libitum up to slaughter. In Experiment 2, eight male pigs were allocated to a control diet (no ANE) or the control diet plus 2.5 g ANE/kg to determine effects of ANE on coefficient of total tract apparent digestibility (CTTAD) of nutrients and nitrogen (N) balance. Supplementation with increasing levels of ANE in Experiment 1 resulted in reduced daily gain, carcass weight and kill-out yield during the combined grower–finisher period (P<0.05); however, there were no effects of treatment on feed intake, feed conversion ratio or carcass characteristics. Increasing levels of dietary ANE resulted in decreased ileal coliform counts (P<0.05). Increasing dietary ANE also tended to increase adherent lactobacilli in the colon (P=0.080) but caecal bifidobacteria declined (P<0.05). There were trends towards a linear reduction in colonic bifidobacteria (P=0.077) and towards a quadratic effect on rectal lactobacilli (P=0.077). Intestinal pH was unaffected by ANE supplementation (P>0.05). In Experiment 2, the CTTAD was unaffected by the inclusion of ANE (P>0.05). Overall, the intestinal coliform reductions obtained suggest that ANE may provide a dietary means to improve gut health and potentially reduce pathogen carriage in finishing pigs. However, the negative effects on growth performance observed in healthy animals will most likely limit the commercial use of dietary ANE as a feed additive.     

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.     

Growth and cashmere production by Spanish goats consuming ad libitum diets differing in protein and energy levels

Thirty-six Spanish goat wethers (196 ± 12.9 days of age and 17.5 ± 4.60 kg BW at experiment initiation) from a herd previously selected for cashmere growth were used to determine effects and interactions of ad libitum consumption of diets differing in concentrations of CP (10% and 15%) and ME (2.00, 2.35 and 2.70 Mcal/kg; DM basis) on growth and cashmere fiber production in an 84-day, fall-season experiment. DM intake was greater (P < 0.05) for diets with 15% vs. 10% CP (736 vs. 655 g/day) but similar among ME concentrations (P > 0.10). ADG was greater (P < 0.02) for 15% vs. 10% CP (79 vs. 53 g/day) and increased linearly (P < 0.10) as dietary ME level increased (58, 62 and 78 g/day for 2.00, 2.35 and 2.70 Mcal/kg ME, respectively). Total fleece weight at the end of the experiment was similar (P > 0.10) between CP levels but increased linearly (P < 0.03) as ME concentration in the diet increased (197, 239 and 227 g/day). Guard hair weight was not affected by dietary treatments (P > 0.10); cashmere length was similar among treatments (P > 0.10); and cashmere fiber diameter was not altered by dietary ME level (P > 0.10) but was greater (P < 0.05) for 15% vs. 10% CP (16.92 vs. 16.06 μm). Cashmere weight was influenced by an interaction between CP and ME levels (P < 0.05); cashmere fiber weight with 10% CP was 92, 82 and 95 g, and with 15% CP was 63, 115 and 99 g for 2.00, 2.35 and 2.70 Mcal ME/kg diets, respectively (SE = 10.2). However, the ranking of treatment means for initial cashmere fiber weight was similar to that at the end of the experiment, although differences at the beginning were non-significant and of lesser magnitude than at the end. In conclusion, further research with influences of concentrations of CP and ME in diets consumed ad libitum on cashmere fiber growth of growing US Spanish wether goats is required, and animal numbers and allocation to treatments deserve careful consideration in studies of cashmere fiber production.