Effect of diet composition and feed intake level on diet digestibility and ruminal metabolism in growing lambs.

Lambs (29 +/- 2.5 kg) were fed three diets at various intakes to determine whether diet composition or level of intake was reflected in changes in diet digestibility or ruminal fluid characteristics. In Exp. 1, a 90% concentrated, pelleted diet or a whole shelled corn diet with a pelleted protein supplement was fed at three levels of intake: ad libitum and 92.5 and 85% of ad libitum (n = 15). Exp. 2 compared the 90% concentrate diet with diets in which the energy density was diluted to 55 or 72.5% concentrate by including alfalfa hay as a possible method of restricting energy intake (n = 6). Lambs were adapted to diets for 13 d; feces were collected for 6 d and ruminal fluid was collected 0, 3, and 6 h after feeding on the day following fecal collection. Restricting intake in Exp. 1 did not affect DM digestibility or digestibility of CP or starch. Digestibility of ADF was increased (P less than .10) by restricting intake. Ruminal fluid pH, ammonia concentration and VFA concentrations were affected little by either restricted intake level. Digestibility of DM was 4% higher (P less than .001) and starch 5% higher (P less than .001) for the whole shelled corn diet than for the pelleted, high-concentrate diet. Ruminal pH of lambs fed the whole shelled corn diet was higher and fluctuated less than the ruminal pH of lambs fed the high-concentrate, pelleted diet. In Exp. 2, diet digestibility was reduced (P less than .01) and ruminal pH was increased (P less than .002) by addition of hay. Restricted feeding of lambs did not seem to increase diet digestibility or alter ruminal conditions.     

Effects of breed and intake level on growth and feed efficiency in ram lambs

Effects of breed and intake level on growth and feed efficiency in ram lambs were tested with 52 Rambouillet, 46 Dorset and 53 Finnish Landrace (Finn) rams. Rams were individually fed at 100, 85 or 70% of ad libitum or at maintenance. The experimental diet contained 79% digestible dry matter (DM), 3.28% N and 2.95 Mcal metabolizable energy/kg DM. Rams were serially slaughtered every 35 d for 175 d. The efficiency of deposition of body weight, protein, energy and trimmed cuts was determined by breed and intake level over constant time, weight, fat and maturity intervals. Ranking of the breeds for feed efficiency depended upon both the interval and the criterion of evaluation. Efficiency of protein and trimmed cut gain was positively related to mature size in the time and weight intervals, but all differences in efficiency were small in the fat or maturity intervals. Gross energetic efficiency did not differ greatly among breeds in any interval. Dorsets appeared to have a somewhat greater propensity to fatten than the other breeds and to be less able to retain N at a fixed N intake. In the constant time interval, maintenance requirements were estimated to be 115 kcal/kg.75, and the estimated partial efficiencies of energy deposition in fat and protein were .49 and .26, respectively.     

Effect of diet quality and shearing on feed and water intake,in vitro ruminal methane production,and blood parameters of Omani sheep

Tropical Animal Health and Production - The aim of this study was to evaluate the effect of diet and animal shearing on the feed and nutrient intakes, water intake, in vitro ruminal methane...     

Phenotypic and genetic relationships between residual energy intake and growth, feed intake, and carcass traits of young bulls.

Residual energy intake, defined as actual minus predicted energy intake during a production period, was estimated for each of 650 bull calves of 31 Holstein Friesian or Brown Swiss sires. Residual energy intake, measured under ad libitum feeding, had heritabilities similar to those of growth rate and energy conversion ratio with an estimate of approximately .3. Residual energy intake was related to average daily energy intake both phenotypically and genetically such that selection for decreased residual energy intake would lead to a decrease in daily feed intake. Such selection would also tend to increase carcass fatness (i.e., genetically fat animals are the most efficient). Residual energy intake estimated with and without correction for carcass composition were closely correlated. Thus, residual energy intake may be estimated without the knowledge of carcass composition in growing bulls of dual-purpose breeds.     

丝兰提取物对三角鲂摄食、生长、饲料利用及废物排放的影响

在室外养殖桶中进行8周饲养实验以评估丝兰提取物对三角鲂(Megalobrama terminalis)摄食、生长、饲料利用、鱼体组成及废物排放的影响。在三角鲂基础饲料中分别添加0%(Y0)、0.05%(Y1)、0.15%(Y2)、0.25%(Y3)、0.35%(Y4)和0.45%(Y5)的丝兰提取物,每天饱食投喂实验鱼(16.0±0.8)g两次。研究结果显示,随着丝兰提取物添加水平的增加,实验鱼的终末体重、增重率和特定生长率呈先上升后下降趋势。与对照组Y0相比,实验组Y3具有最高的终末体重、增重率、特定生长率、饲料氮储积效率,最低的饲料系数和磷废物排放量(P0.05)。实验组Y2的FI显著高于对照组Y0(P0.05),而各实验组与对照组Y0之间的饲料磷储积效率、肥满度、肝体指数、鱼体组成(水分、粗蛋白质、粗脂肪、灰分、磷和氨基酸)均无显著差异(P0.05)。研究表明,在三角鲂饲料中添加0.25%的丝兰提取物可显著提高三角鲂的生长和饲料利用效率,并降低养殖废物排放。     

Influence of realimentation diet on recovery of rumen activity and feed intake in beef steers

Two trials were conducted to determine the influence of realimentation diet energy, protein, B-vitamin (BV) and Lactobacillus acidophilus (LAC) content on recovery of rumen activity and feed consumption in beef steers. In trial 1, ruminal-fistulated steers were fasted and refed 1) prairie hay, 2) 10% protein (LCP), 3) 12.5% protein (MCP), 4) LCP + BV or 5) LCP + LAC. In trial 2, calves were fasted and refed 1) 60% cottonseed hulls-40% alfalfa dehy (high roughage), 2) LCP, 3) 15% protein (HCP), 4) LCP + BV or 5) LCP + LAC. Rumen fermentative capacity declined 74% (P less than .05) during feed and water deprivation, but returned to control levels by d 7 of realimentation. On d 3 of realimentation, steers fed the LCP and MCP diets had molar proportions of ruminal butyrate in excess of 35%. Steers fed the hay, LAC and BV diets did not have a high butyrate fermentation. In trial 2, calves lost about 15% of their body weight during feed and water deprivation. Calves fed the high roughage diet appeared to return to prefast feed and energy intakes more slowly than steers fed the medium roughage diets. Results of this study indicate that rumen fermentative capacity is a factor limiting feed intake in fasted calves for 7 to 14 after the reintroduction of feed and water.     

Associative effects of supplementing rice straw‐based diet with cornstarch on intake,digestion, rumen microbes and growth performance of Huzhou lambs

Thirty‐six male Hu lambs consuming a rice straw‐based diet were used in a 60‐day trial to study the associative effects of cornstarch supplementation on intake, digestion, ruminal microbial population and growth performance. All animals were fed rice straw ad libitum together with 160 g/day of rapeseed meal and supplemented with cornstarch at levels of 0 (control), 60, 120 or 180 g/day, respectively. Increment of supplementary cornstarch showed little influence on rice straw intake. Optimal growth performance and highest apparent digestibility of organic matter was achieved in the 120 g/day cornstarch group (P < 0.05), while the digestibilities of neutral detergent fiber and crude protein were significantly decreased by 180 g/day cornstarch (P < 0.05). Similar results were observed for carboxymethyl cellulose activity and relative populations of cellulolytic bacteria (Ruminococcus albus, Ruminococcus flavefaciens and Fibrobacter succinogene). Blood urea nitrogen was reduced by supplementary cornstarch, indicating enhanced protein utilization efficiency. Carcass traits were all significantly improved by supplementary cornstarch. These results suggested that proper amounts of starch supplementation (within 0.5% BW) has little adverse effect on forage utilization, but could effectively improve growth performance. High levels of cornstarch, however, would decrease cellulase activity and populations of cellulolytic bacteria, and hence the digestibility of forage.     

二次制粒颗粒饲料对仔猪培育的影响

选用360头21日龄断奶仔猪,按制粒工艺、原料预处理不同设计2因素2水平试验,研究二次制粒颗粒饲料对断奶仔猪培育阶段生长性能的影响。结果:试验全期,采用二次制粒工艺及膨化玉米、膨化豆粕原料的处理组4,仔猪体重、平均日增重、饲料转化效率显著优于(P<0.05)其他3组。处理组4仔猪42日龄的血清尿素氮和皮质醇浓度显著低于其他3个处理组。试验表明,在选择膨化玉米与膨化豆粕优质饲料原料的基础上,采用二次制粒工艺,尤其先将鱼粉与膨化玉米、膨化豆粕进行第一次高温制粒,对降低应激、改善仔猪培育阶段的生长性能有良好的效果。     

Effect of sex and feeding system on feed intake, growth, and meat and carcass characteristics of fattening Assaf lambs

The effect of feeding system and sex on intake, growth and carcass and meat characteristics of Assaf fattening lambs was studied. Twenty four weaned Assaf lambs, half males and half females were used. After an adaptation period, lambs were randomly assigned to one of the two feeding systems studied. Control lambs received ad libitum commercial concentrate (70% barley, 22% soybean meal, 4.8% wheat, 0.5% bicarbonate, 2.7% mineral–vitamin premix) and barley straw. Free Choice lambs had ad libitum and separate access to whole barley grain and a protein supplement (73.3% soyabean meal, 16% wheat, 1.7% bicarbonate, 9% mineral–vitamin premix). Lambs were slaughtered at 25 kg LBW. Feed intake was not significantly affected by sex (P > 0.05) but Free Choice lambs showed higher dry mater intake than the Control lambs. Nevertheless, only males from the Free Choice group showed an improvement in feed efficiency rate (P < 0.05) and average daily gain (P < 0.01) relating to the Control lambs. Neither feeding system nor feeding system × sex interaction significantly affected non-carcass weight, fat depots, cold carcass weight, dressing percentage, main proportions of commercial cuts and meat characteristics (P < 0.05). As it was expected, female lambs showed a lower average daily gain and a higher feed conversion efficiency than male lambs (P < 0.001) which was related to a greater fat deposition. Meat characteristics were unaffected by sex, with the exception of longissimus lumborum fat content, which was higher in female lambs.The present results suggest that Free Choice feeding system might be suitable for intensively reared male lambs since improvements in daily weight gain and feed conversion rate were achieved, with no adverse effect on carcass and meat quality. Despite the selected diet of both, males and females, did not differ in the crude protein content, the use of Free Choice feeding system for female lambs did not improve performance compared to the Control group.     

Effect of ractopamine hydrochloride and zilpaterol hydrochloride on growth,diet digestibility,intake and carcass characteristics of feedlot lambs

The effects of the β-adrenergic agonists ractopamine hydrochloride (RH; 0.35, 0.70 and 1.05 mg kg^− 1 of BW d^− 1) and zilpaterol hydrochloride (ZH; 0.10, 0.20 and 0.30 mg kg^− 1 of BW d^− 1) on growth performance and carcass characteristics were determined in 84 Dorper × Katahdin lambs (12 lambs per treatment), that were randomly assigned to a complete block design during a 42-day feeding trial. Lambs were fed a corn grain-based diet (18.71% CP and 12.9 MJ/kg ME). Nutrient digestibility of diets and blood serum metabolites were also determined. There were no significant (P > 0.05) differences in growth characteristics by effect of ZH or RH administration. However, lambs final weight, total weight gain and ADG increased linearly (P < 0.05) as levels of both β-adrenergic agonist increased. RH or ZH administration did not affect feed efficiency, diet digestibility or particular blood serum metabolites of lambs. Carcass characteristics of lambs consuming ZH were significantly better (P < 0.01) than RH or control lambs; RH produced significant linear response on carcass weight, dressing percentage, longissimus muscle area, carcass conformation and quality grade, and improved quadratically (P < 0.05) fat thickness and USDA yield grade of lamb carcasses. On the other hand, increasing levels of ZH decreased linearly (P > 0.01) fat thickness and improved (P > 0.05) USDA yield grade and carcass quality grade. Both β-adrenergic agonists improved carcass characteristics; although greater improvements were obtained with ZH than RH for most carcass characteristics.     

体外法研究总挥发性脂肪酸和产气量与饲料营养成分的关系

本试验旨在通过测定青贮玉米、苜蓿、玉米秸、豆秸、羊草、稻草、专用青贮玉米秸7种粗饲料的总挥发性脂肪酸(TVFA)与产气量(GAS)及饲料营养成分[干物质(DM)、粗友分(ASH)、粗蛋白质(CP)和中性洗涤纤维(NDF)],研究三者之间的相关性.结果表明:不同时间点的TVFA与GAS及饲料营养成分之间的关系式为:TVFA=1.07×GAS-1.41×CP-0.90×NDF-6.80×NDS/CP-2.33x(NDS-ASH)/CP+113.70,R2=0.7431.本试验R2值较大,表明本试验所得的关系式具有更好的应用价值.     

Effect of adding crude glycerine to diets with feed additives on the feed intake,ruminal degradability,volatile fatty acid concentrations and in vitro gas production of feedlot Nellore cattle

The effects of adding crude glycerine with sodium monensin or essential oils to beef cattle diets on the intake, degradability of DM and nutrients, rumen concentration of volatile fatty acids (VFA) and in vitro gas production were evaluated. Five ruminally cannulated Nellore steers were randomly assigned to a 5 × 5 Latin square design. The treatments were as follows: CONT, without crude glycerine and additives; EO, with essential oils and without crude glycerine; MON, with sodium monensin and without crude glycerine; EOG, with essential oils and crude glycerine; MONG, with sodium monensin and crude glycerine. Treatments with essential oil and sodium monensin increased the NDF and STC intake and the DM degradability. When crude glycerine was combined with either sodium monensin or essential oil, there was a reduction in DM, NDF and STC intake and an increase in DM and CP degradability of the diets. The adding crude glycerine to essential oil diets reduced the CH₄ production. Sodium monensin treatments reduced DM and NDF intake and the production of total gas, CH₄, total VFA and acetic acid concentration. In conclusion, the adding crude glycerine (200 g/kg DM) with either sodium monensin (0.03 g/kg DM) or essential oil (0.5 g/kg DM) can be utilized in diets for Nellore cattle without causing detrimental effects on feed intake and improving the DM degradability.     

Effect of growth hormone-secreting tumors on body composition and feed intake in young female Wistar-Furth rats

Growth hormone (GH) was elevated in young growing, intact female Wistar-Furth rats bearing growth hormone (GH1) or growth hormone and prolactin (GH3) secreting tumors. Animals were injected with GH1 or GH3 cells at 1 wk of age. Total feed intake was measured for the 8-wk period from weaning until killed at 11 wk of age. Animals were fed a commercial chow diet throughout the trial. Body composition and composition of the liver and tibialis anterior muscle were determined. Tumor-bearing rats were about 65% heavier than control rats at 11 wk of age: most of the difference in body weight gain was obtained during the last 4 wk of the trial. Total feed intake during the 8 wk after weaning was increased in both GH1 and GH3 tumor-bearing rats when compared with controls. Overall feed efficiency (grams feed consumed/gram body weight gain) was improved in tumor-bearing animals when compared with controls. The GH1 tumor-bearing rats were slightly hyperphagic during wk 8, 9 and 10 (grams feed consumed/gram body weight) when compared with controls. The total amount of body dry matter, protein and ash was increased in tumor-bearing rats when compared with controls. There was no effect on total body fat. Tumor-bearing rats had increased liver weight and increased fat, protein, RNA, DNA and dry matter content when compared with controls. Tumor induction increased the weight, total RNA and total fat content of the tibialis anterior muscle when compared with controls. There was no effect on muscle protein content.(ABSTRACT TRUNCATED AT 250 WORDS)     

The effects of vomitoxin and feed intake on the performance and blood characteristics of young pigs

Thirty barrows (average weight 8.4 kg) were used in a 3-wk experiment to determine the effects of the ingestion of vomitoxin (deoxynivalenol)-contaminated feed on performance and blood chemistry. The barrows were assigned randomly to consume either: 1) a control diet (C), fed ad libitum, 2) a vomitoxin contaminated diet (V; 10.5 ppm), fed ad libitum, or 3) a vomitoxin contaminated pair-fed at levels equal to those consumed by V animals (PF). The V and PF pigs had similar daily gains (.19 vs .20 kg) and feed intakes (.40 and .39 kg), but both of these were lower (P less than .01) than those for the C-fed pigs (.38 kg daily gain and .72 kg feed intake). The V-fed pigs had lower (P less than .05) hematocrit, hemoglobin, serum glucose and serum phosphorus and tended to have lower serum calcium (P less than .06) than C-fed pigs. The V-fed pigs had higher (P less than .05) hemoglobin and tended to have higher (P less than .08) serum phosphorus and lower (P less than .07) serum calcium than PF animals. There was a high total- and free-bilirubin concentration in serum of C- and V-fed pigs in the last sampling period (3-wk), which may be due to fasting and not cholestasis. No differences among treatments were observed in any of the other blood parameters. These results suggest that the differences in animal performance and blood parameters observed between control-and vomitoxin-fed pigs are mainly due to differences in feed intake.     

A tryptophan-enriched diet improves feed intake and growth performance of susceptible weanling pigs orally challenged with Escherichia coli K88

We tested the effect of Trp addition to a standard weaning diet and oral challenge with enterotoxigenic Escherichia coli K88 (ETEC) on growth and health of piglets susceptible or nonsusceptible to the intestinal adhesion of ETEC. Sixty-four pigs weaned at 21 d of age were divided into 3 groups based on their ancestry and BW: a control group of 8 pigs fed a basal diet (B), the first challenged group of 28 pigs fed B diet (BCh), and the second challenged group of 28 pigs fed a diet with Trp (TrpCh). The Trp diet was produced by the addition of 1 g of l-Trp/kg to the basal diet. On d 5, pigs were orally challenged with 1.5 mL suspension containing 10(10) cfu ETEC/mL or placebo, and killed on d 9 or 23. Based on in vitro villus adhesion assay, the pigs (except the B group) were classified as susceptible (s(+)) or nonsusceptible (s(-)) to the intestinal ETEC adhesion. Thus, after the challenge, treatments were B, BChs(-), BChs(+), TrpChs(-), and TrpChs(+). Pigs susceptible to ETEC were 50.0% in the BChs(+) group (3 pigs lost included) and 46.4% in the TrpChs (+) group (1 pig lost included). During the first 4 d after challenge, the challenge reduced ADG (P < 0.05), and this reduction was greater in susceptible pigs (P < 0.05) than nonsusceptible ones. Tryptophan increased ADG and feed intake in susceptible pigs (P < 0.05) from challenge to d 4, but not thereafter. Tryptophan supplementation did not improve the fecal consistency and did not reduce the number of pigs positive for ETEC in feces on d 4 after the challenge. The K88-specific immunoglobulin A activity in blood serum tended to be greater in challenged pigs (P = 0.102) and was not affected by the addition of Trp. Villous height was affected by the addition of Trp and challenge in different ways, depending on the site of small intestine. The need to consider the phenotype for the adhesion of the ETEC in studies with different supply of Trp was clearly evident. When compared with practical weaning standard diets, Trp supplementation allowed susceptible pigs to partially compensate for the effects of ETEC challenge by increasing feed intake and maintaining an adequate BW growth. This is of practical importance for the formulation of diets for pigs selected for lean growth because of the presence of an association between this trait and the susceptibility to the intestinal adhesion of ETEC.     

饲喂代乳粉对羔羊生长性能和体组织参数的影响

研究饲喂代乳粉和母羊哺乳对羔羊生长性能和体组织参数的影响。选取18只日龄和体重相近、健康的杂交F1羔羊,随机分成试验组和对照组,每组9只。试验组饲喂代乳粉,对照组随母羊哺乳,饲养时间为90d。称取20、90日龄空腹体重,并于90日龄时每组随机选取4只屠宰,称量胴体、各胃室、小肠各段、内脏器官鲜重。结果表明:与对照组相比,试验组羔羊平均日增重提高18.61%(P0.05);宰前活体重、胴体重分别提高22.28%、32.44%(P0.05),屠宰率提高6.67%(P0.05);复胃总重增加13.25%(P0.05),其中瘤胃鲜重增加25.92%(P0.05),皱胃鲜重提高6.74%(P0.05),网胃和瓣胃鲜重则有降低的趋势;回肠鲜重和长度分别增长75.28%(P0.05)和35.50%(P0.05);肺、肾脏、肝脏和脾脏鲜重提高22.29%、30.10%、28.86%和38.22%(P0.05)。结论:饲喂代乳粉后可提高羔羊生长性能,但对屠宰率无显著影响,可促进其瘤胃的发育,并影响部分内脏器官发育。     

Effect of carprofen administration during banding or burdizzo castration of bulls on plasma cortisol, in vitro interferon-gamma production, acute-phase proteins, feed intake, and growth

The objective of this study was to determine the effect of carprofen (C) administration before banding or burdizzo castration of bulls on cortisol, in vitro interferon-gamma (IFN-gamma) production, acute-phase proteins, feed intake, and growth. Fifty Holstein Friesian bulls (5.5 mo old; 191 +/- 3.7 kg) were blocked by weight and assigned randomly to 1 of 5 treatments (n = 10/treatment): 1) untreated control (2) banding castration at 0 min (Band); 3) Band following an i.v. injection of 1.4 mg/kg of BW of C at -20 min (Band+C); 4) Burdizzo castration at 0 min (Burd); or 5) Burd following 1.4 mg/kg of BW of C at -20 min (Burd+C). Castration acutely increased plasma cortisol concentrations compared with control; no significant differences occurred in peak and interval to peak cortisol responses between Band and Band+C or Burd and Burd+C groups. The administration of C in Band+C reduced (P < 0.05) the cortisol concentration between 6 and 12 h postcastration compared with Band animals. Overall, the integrated cortisol response was greater (P < 0.05) in the castrates than in control, whereas C treatments tended to reduce this response compared with Band (P = 0.08) and Burd (P = 0.07), respectively. Plasma fibrinogen was elevated in Band animals on d 14 and in Burd animals on d 3 and 14. Carprofen administration reduced Band- and Burd-induced fibrinogen production on d 14 and 3, respectively. Plasma haptoglobin was elevated in Band animals on d 3 and 35 compared with control, and C administration was effective in reducing the haptoglobin elevation on d 35 in Band+C compared with Band. There were no differences among treatments in in vitro IFN-gamma production induced by concanavalin A and phytohemagglutinin on d 1 and 2. Overall from d -1 to 16, there were no DMI differences among treatments. From d -1 to 35, there were no ADG differences among treatments. In conclusion, banding and burdizzo castration increased plasma cortisol with no change in in vitro IFN-gamma production. Carprofen (1.4 mg/kg of BW) tended to reduce the integrated cortisol response, and it reduced cortisol secretion in banded animals between 6 and 12 h postcastration. There was an increased acute-phase protein production following castration; this response was effectively moderated by the administration of C before castration.     

Effects of Saccharomyces cerevisiae cell wall extract and poplar propolis ethanol extract supplementation on growth performance,digestibility, blood profile,fecal microbiota and fecal noxious gas emissions in growing pigs

A total of 105 growing pigs (24.91 ± 1.06 kg) were used in a 6‐week trial to investigate the effects of including Saccharomyces cerevisiae cell wall extract and poplar propolis ethanol extract (SPE) in the diet on growth performance, digestibility, blood profiles, fecal microbiota and fecal noxious gas emissions. Pigs were randomly allocated to one of three dietary treatments (seven pens/treatment, five pigs/pen) according to initial body weight and sex (two gilts and three barrows). Treatments consisted of a corn soybean meal basal diet supplemented with 0, 0.05 or 0.10% SPE. There was a significant linear improvement (P < 0.05) in average daily gain, gain/feed, the apparent total tract digestibility of dry matter, nitrogen, and gross energy, blood lymphocyte percentage, immunoglobulin G concentration, fecal Escherichia coli and Lactobacillus counts as well as fecal NH₃ and H₂S emissions associated with the inclusion of SPE in the diet. Average daily feed intake, red blood cells and white blood cells concentration were not significantly (P > 0.05) affected by SPE supplementation in the diets. In conclusion, results indicate that dietary SPE supplementation can improve growth performance, digestibility and fecal microbiota, and decrease fecal gas emissions in growing pigs.