Effects of Supplementation on Juniper Intake by Goats

The potential for winter supplementation to increase juniper intake by goats on rangelands in the Edwards Plateau region of Texas was assessed in two experiments. The first experiment evaluated the effect on juniper intake of either no supplementation (negative control) or supplementation with corn, alfalfa, or cottonseed meal fed at an isonitrogenous protein level of 1.5 g · kg body weight^-1 for 12 days. Redberry juniper (Juniperus pinchotii Sudw.) consumption by individually penned Spanish, Boer × Spanish, Spanish × Angora, and Angora goats was measured on days 11 and 12. Each goat received each supplement in a complete 4 × 4 Latin square design. Juniper intake increased for goats supplemented with alfalfa and cottonseed meal (P = 0.001), but not for those supplemented with corn (P = 0.944). Boer × Spanish goats did not differ in levels of consumption (P = 0.085) from the other breeds. A second study investigated the effect of either no supplementation or soybean meal supplementation on juniper consumption by free grazing Angora and Boer × Spanish goats. Forty goats were assigned to four pasture groups by breed and previous juniper intake, and randomly allocated to either the treatment (supplementation) or control (no supplementation) regime in a complete block design. After 4 days of grazing and supplementation, fecal samples were collected to estimate percent of juniper in the diet using near-infrared spectroscopy. Goats were then rotated to another pasture. Juniper intake was highest for goats supplemented with soybean meal (P = 0.034). Breed of goat did not affect intake (P = 0.240). Goats previously categorized as high juniper consumers based upon prior measurements of juniper intake ate more juniper (P = 0.003) than those classified as low consumers. This research indicates that the effectiveness of goats for biological control of juniper can be improved with a high protein, low starch supplement.     

Simultaneous measures of rates of ruminal digestion and passage of feeds for prediction of ruminal nitrogen and dry matter digestion in lactating dairy cows

Three ruminal-cannulated Holstein cows in early lactation were fed three diets, each containing different energy and protein supplements in two consecutive 3 X 3 Latin squares. Each supplement contained a combination of three different feedstuffs (ground corn, soybean meal and wheat mids; corn gluten feed, rolled oats and distiller's dried grains; ground barley, brewer's grains and cottonseed meal). Diets consisted of 30% corn silage, 10% alfalfa hay, 10% alfalfa haylage, 17.7% ground corn plus minerals and vitamins, with the remainder as supplemental feedstuffs individually marked for measurement of ruminal turnover and in situ digestion rates. An extra period at the end of each Latin square was used to measure ruminal turnover and in situ digestion of individual forages. Diet had no effect on dry matter intake or milk yield. Mean fractional turnover (per hour) rate, measured by labeling feedstuffs with cerium, samarium or lanthanum was .044, .048, .049, .043, .047, .046, .050, .047, .049, .037, .046 and .045 for corn, soybean meal, wheat mids, corn gluten feed, oats, distiller's dried grains with solubles, barley, brewer's dried grains, cottonseed meal, alfalfa hay, corn silage and alfalfa haylage (P greater than .1), respectively. In situ-predicted ruminal degradation of N weighted for rate of passage was 61.4, 67.0, 81.5, 74.8, 86.3, 71.0, 75.7, 52.1, 54.2, 60.8, 71.7 and 70.9% for respective feedstuffs (P less than .05). In comparison with mean literature values for in vivo-measured N degradability, mean literature value = 1.172 (in situ predicted) -9.73 (P less than .05, R2 = .51). Results are interpreted to indicate a tendency for overestimating ruminal N degradability by in situ methods in feedstuffs of low degradability, while underestimating degradability in more highly degraded feedstuffs. Estimates were 11 to 17 percentage units lower than literature values for alfalfa hay and haylage and 17 units lower than literature values for distiller's dried grains.     

Dried poultry waste for cows grazing low-quality winter forage

Two trials conducted in 1996-97 measured BW and body condition score changes of cows fed different sources of degradable intake protein, including dried poultry waste and soybean meal, while grazing low-quality winter forages. In Trial 1, 60 spring-calving cows (5 yr; 555 kg) were used in an individual supplementation trial. Cows were gathered three times a week, sorted into individual pens, and fed their respective supplement. Cows grazed dormant native Sandhills winter range (common pasture) and were assigned to one of six supplemental treatments: 1) no supplement, 2) urea, 3) 22% dried poultry waste + urea, 4) soybean meal, 5) 22% dried poultry waste + soybean meal, or 6) 44% dried poultry waste. All supplements were based on wheat middlings and soybean hulls and were formulated to contain 44% CP. Thirty-six cows were selected randomly (six per treatment) for a 5-d measurement of forage intake from December 16 through December 20, 1996. Cows receiving supplements gained more weight (P < 0.001) and maintained greater body condition (P < 0.001) than unsupplemented cows. Cows receiving urea gained less (P < 0.10) than cows receiving a source of natural protein, but body condition remained similar. No differences were found in daily forage or total organic matter intake (P > 0.10). In Trial 2, cows grazed corn residues. Forty-eight spring-calving cows were group-fed supplements in one of six 4-ha paddocks. Cows received supplements containing either soybean meal or dried poultry waste that were the same as the soybean meal and 44% dried poultry waste supplements fed in Trial 1; gains were not different (P > 0.10). Under the economic conditions that existed at the time of these experiments, the supplement containing dried poultry waste resulted in a savings of $.04 per cow per day and a total savings of $3.20 per cow over an 80-d period. Feeding a supplement containing dried poultry waste resulted in performance similar to that when feeding a more conventional supplement containing soybean meal.     

Using Experience and Supplementation to Increase Juniper Consumption by Three Different Breeds of Sheep

In the southwestern United States, redberry (Juniperus pinchotii Sudw.) and ashe (Juniperus ashei Buchholz) juniper are two invasive species that dominate some rangelands. Goats will consume up to 30% of their diet in juniper, but it is unknown if sheep will accept juniper to the same extent. The objectives of this study were to determine if sheep can be conditioned to consume juniper and to compare intake among different breeds. Rambouillet (n = 10), Suffolk (n = 10), and Dorper-cross (n = 10) lambs were randomly placed in individual pens for 31 d. A basal diet of alfalfa pellets (2.5% body weight [BW]) and juniper were fed. Juniper was fed each morning from 0800 to 0830 hours. The basal diet was fed for the remainder of the day. Intake of each was measured daily. Following the first 17 d, the basal diet was reduced to 2% BW for 7 d and then reduced to 1.5% BW for the final 7 d. Serum aspartate transaminase (AST), gamma glutamyltransferase (GGT), blood urea nitrogen (BUN), creatinine, and bilirubin levels, and live body weight were measured to assess any adverse physiological effects from juniper consumption. In a second trial, lambs were again fed alfalfa (2.5% BW) and juniper. One half of the lambs were also fed a 36% protein supplement to determine if supplementation with protein sources that escape rumen degradation would improve juniper consumption. Lambs received alfalfa, juniper, and protein supplement for 22 d with intake of each recorded daily. Intake of juniper was similar (P > 0.05) among breeds of sheep. Lambs readily consumed juniper and increased (P < 0.05) intake of juniper as the amount of alfalfa fed was reduced. Weight change was also similar among treatments. Protein supplementation did not improve juniper consumption. We contend that sheep will consume a diet consisting of 24% juniper without experiencing any adverse effects.     

Effects of Feeding Distiller's Dried Grains with Solubles on Growth and Feed Efficiency of Weanling Horses

The effects of replacing corn and soybean meal with distiller's dried grains and solubles in the weanling horse diet were examined. Sixteen weanling horses, 12 fillies and four colts, were fed completely pelleted diets consisting of 50% alfalfa in addition to 50% of a concentrate containing either corn and soybean meal (CS), or 30% of the concentrate replaced with distiller's dried grains with solubles (DDGS). There were no significant differences (P > .05) between the two diets in either average daily gain or gain-to-feed ratio. The CS diet had a higher apparent dry matter digestibility (P < .0001), and higher apparent digestibility of crude protein (CP), acid detergent fiber (ADF), and neutral detergent fiber (NDF) (P < .01). It was concluded that replacing a portion of the corn and soybean meal with distiller's dried grains with solubles in the weanling horse diet did not lead to significant growth depression. However, the diet containing DDGS had reduced apparent digestibility of dry matter, CP, and fiber. Therefore, it was concluded that it may not be advisable to replace more than 30% of the concentrate portion or 15% of the total diet with distiller's dried grains and solubles when alfalfa is used as the forage source constituting 50% of the weanling diet. Even less DDGS may be desirable to substitute for corn and soybean meal in weanling horse diets if the forage source is one with lower protein quality than alfalfa. It is possible that using DDGS for less than 30% of the concentrate portion of the diet along with high-quality alfalfa forage may produce comparable gain and feed efficiency results with less depression of apparent digestibility of dry matter, crude protein, and fiber.     

奶牛常用蛋白质饲料和粗饲料的瘤胃降解特性研究

本研究旨在评定不同蛋白质饲料(豆粕、双低菜籽粕、膨化大豆、玉米蛋白粉、棉籽粕)和粗饲料(苜蓿干草、全株玉米青贮、燕麦草、苜蓿青贮、羊草)的营养价值,并研究其奶牛瘤胃降解特性.选择5头安装永久性瘤胃瘘管的健康荷斯坦牛,采用尼龙袋评定法评定饲料瘤胃有效降解率和动态降解率.结果表明:1)各蛋白质饲料干物质(DM)含量差异不显...     

Renal energy excretion of horses depends on renal hippuric acid and nitrogen excretion

The prediction of renal energy excretion is crucial in a metabolizable energy system for horses. Phenolic acids from forage cell walls may affect renal energy losses by increasing hippuric acid excretion. Therefore, the relationships were investigated between renal energy, nitrogen (N) and hippuric acid excretion of four adult ponies (230–384 kg body weight (BW)) consuming diets based on fresh grass, grass silage, grass cobs (heat‐dried, finely chopped, pressed grass), alfalfa hay, straw, extruded straw and soybean meal. Feed intake was measured; urine and faeces were quantitatively collected for three days. Feed was analysed for crude nutrients, gross energy, amino acids and neutral‐detergent‐insoluble crude protein (CP); faeces were analysed for crude nutrients and cross energy; urine was analysed for N, hippuric acid, creatinine and gross energy. Renal energy excretion (y; kJ/kg BW^0.75) correlated with renal N excretion (x₁; g/kg BW^0.75) and renal hippuric acid excretion (x₂; g/kg BW^0.75): y = 14.4 + 30.2x₁+20.7x₂ (r = .95; n = 30; p < .05). Renal hippuric acid excretion was highest after intake of fresh grass and lowest after intake of soybean meal. The ratio of hippuric acid to creatinine in urine and the excretion of hippuric acid per gram of dry matter intake was significantly higher for fresh grass than for all other rations. There was no relationship between aromatic amino acid intake and renal hippuric acid excretion. The results of the present study and literature data suggest that feed can be categorized into four groups with regard to the energy losses per gram CP intake: (i) protein supplements (e.g., soybean meal): 4.2–4.9 kJ/g CP intake (ii) alfalfa hay, grains, dried sugar beet pulp: 6.4 kJ/g CP intake, (iii) hay, preserved grass products, straw: 5.2–12.3 kJ/g CP intake (mean 8) and (iv) fresh grass. For group (iii) a negative relationship was observed between renal energy losses per gram of CP and the content of CP or neutral‐detergent‐insoluble CP in dry matter.     

Comparison of soybean meal/sorghum grain, alfalfa hay and dehydrated alfalfa pellets as supplemental protein sources for beef cattle consuming dormant tallgrass-prairie forage

Three experiments were conducted to compare soybean meal/sorghum grain (SBM/SG), alfalfa hay or dehydrated alfalfa pellets (DEHY) as supplemental protein sources for beef cattle grazing dormant range forage. In Exp. 1 (35-d digestion study), 16 ruminally cannulated steers were stratified by weight (average BW 259 kg) and assigned randomly within stratification to: 1) control, no supplement; 2) SBM/SG (25% CP) fed at .48% BW; 3) alfalfa hay (17% CP) fed at .70% BW; or 4) DEHY (17.4% CP) fed at .67% BW. Steers receiving protein supplements displayed at least a twofold increase in forage intake (P less than .10). In addition, steers supplemented with DEHY consumed approximately 15% more forage (P less than .10) than SBM/SG- or alfalfa hay-supplemented steers. Digestible DM intake (kg/d), however, was similar between alfalfa hay- and DEHY-supplemented steers and 20% greater (P less than .10) than for SBM/SG-supplemented steers. In Exp. 2, 82 mature, nonlactating Hereford x Angus cows (average BW 489 kg) were assigned randomly to SBM/SG, alfalfa hay or DEHY supplement treatments, which were replicated in three pastures. Cows supplemented with DEHY gained more weight (P less than .05) during the first 84 d of supplementation and displayed the least amount of weight loss at calving (d 127; P less than .05) and just prior to breeding (P less than .10). In contrast, calving interval (361 d) and pregnancy rate (94%) were unaffected (P greater than .10) by dam's previous supplemental treatment. In Exp. 3, one block (pasture) of cows from Exp. 2 was selected at random and grazing behavior was monitored during week-long periods in January and February. A treatment X time interaction (P less than .05) occurred for total time spent grazing; treatments did not differ in January, but cows supplemented with alfalfa hay spent less time grazing in the February grazing period. In conclusion, DEHY and alfalfa hay appear to be at least as effective as SBM/SG as a supplemental protein source for pregnant grazing cows when supplements are fed on an equal CP and ME basis.     

Effects of supplemental energy and/or degradable intake protein on performance,grazing behavior,intake, digestibility,and fecal and blood indices by beef steers grazed on dormant native tallgrass prairie

To evaluate the effects of balancing total diet degradable intake protein with dietary total digestible nutrients (TDN), we conducted two studies during 2 yr with 100 (302 +/- 8 kg initial BW) mixed-breed yearling steers and 12 ruminally cannulated steers (526 +/- 28 kg). Steers individually received one of four supplements 5 d/wk while grazing dormant native tallgrass prairie. Supplements included: 1) corn and soybean meal, balanced for total diet degradable intake protein in relation to total diet TDN (CRSBM), 2) corn and soybean hulls, equal in supplemental TDN to CRSBM (CORN), 3) soybean meal, equal in supplemental degradable intake protein to CRSBM (SBM), or 4) a cottonseed hull-based control supplement (CONT). At each feeding (5 d/wk), steers consumed 13.6, 13.6, or 4.2 g of dry matter/kg of body weight, or 178 g of DM, respectively, of supplement. Steers fed CRSBM had greater (P < 0.01) average daily gain than cattle fed CORN or SBM. Feeding soybean meal (CRSBM, SBM) resulted in improved (P < 0.01) efficiency of supplement. Grazing time, intensity, and harvesting efficiency were reduced (P < 0.05) by corn supplementation (CRSBM and CORN), whereas the number of grazing bouts per day was increased (P < 0.08). Intake and digestibility of forage organic matter were reduced (P < 0.01) for steers supplemented with corn (CORN and CRSBM) vs cattle not fed corn (SBM and CONT). Total diet digestibility (P < 0.12) and digestible organic matter intake (P < 0.01) were greater for CRSBM-fed steers than for cattle fed either CORN or SBM. Steers fed CRSBM had greater (P < 0.01) fecal nitrogen and serum insulin than cattle fed CORN or SBM. Corn-fed cattle had lesser (P < 0.01) fecal pH and ADF concentrations than steers not consuming grain. Cattle fed supplements with soybean meal (CRSBM and SBM) had greater (P < 0.01) serum urea nitrogen than steers fed supplements without soybean meal (CORN, CONT). Supplemented steers grazing dormant tallgrass prairie had a greater rate of gain, with the greatest response in animal performance occurring when grain supplements were balanced for total diet degradable intake protein in relation to total diet TDN. These results lead us to suggest that grain-supplemented cattle grazing dormant tallgrass prairie require a balance of total diet degradable intake protein in relation to total diet TDN to optimize animal performance.     

肉牛常见饲料干物质和蛋白质瘤胃降解特性和小肠消化率研究

[方法]选用装有瘤胃瘘管和小肠瘘管的肉牛作为试验动物,尼龙袋法测定肉牛常见饲料干物质(DM)和粗蛋白(CP)的瘤胃降解特性和小肠消化率。[结果]结果表明,DM瘤胃有效降解率由高到低为玉米粉、麦麸、苜蓿干草、豆粕、菜籽粕、玉米青贮、醋糟、白酒糟;CP瘤胃有效降解率由高到低为苜蓿干草、麦麸、豆粕、醋糟、玉米粉、玉米青贮、菜籽粕、白酒糟;DM小肠消化率由高到低为豆粕、菜籽粕、玉米粉、白酒糟、醋糟、麦麸、苜蓿干草、玉米青贮;CP小肠消化率由高到低为豆粕、菜籽粕、玉米粉、苜蓿干草、麦麸、白酒糟、玉米青贮、醋糟。[结论]试验表明,不同饲料瘤胃降解特性不同,为小肠提供过瘤胃可消化蛋白的能力不同,且饲料的DM小肠消化率小于CP小肠消化率。     

Feed preference in pigs: effect of selected protein, fat, and fiber sources at different inclusion rates

Three double-choice feeding experiments were conducted to study the effect of different feedstuffs on feed preference in pigs. Fifteen protein sources, 6 fat sources, and 3 fiber sources were evaluated in Exp. 1, 2, and 3, respectively. Pigs were offered a series of double choices between a common reference diet and the diet with the ingredient under evaluation. The reference diet contained a soybean meal product with 56% CP (SBM-56), sunflower oil, and wheat bran, which were considered as the feedstuffs of reference for the protein, fat, and fiber sources, respectively. Preference, expressed as percentage of the tested diet to total feed intake, was affected by feedstuff nature and by its inclusion rate. In Exp. 1, feeds with fish meal at 50 and 100 g·kg?1, dried porcine hydrolyzed protein at 50 g·kg?1, and lupine, soybean meal with 44% CP, and dried skim milk at 100 g·kg?1 were preferred (P < 0.05) to the reference feed with SBM-56. On the contrary, relative to SBM-56, an avoidance (preference less than 50%) was observed for potato protein at all inclusion rates tested, rapeseed meal and acid milk whey at 100 and 200 g·kg?1, and dried porcine hydrolyzed protein, soybean protein concentrate, wheat gluten, and sunflower meal at 200 g·kg(-1). The storage of dried skim milk, soybean protein concentrate, and potato protein for 10 mo resulted in a reduction (P < 0.001) of their preference values. In Exp. 2, the feed with palm oil (at 30 g·kg?1) was preferred (P < 0.05), whereas feeds with linseed oil (at 30 and 100 g·kg?1) and soybean oil (at 100 g·kg?1) were avoided (P < 0.05) when contrasted with the reference feed with sunflower oil. Finally, in Exp. 3 diets with dehydrated alfalfa and sugar beet pulp at 130 g·kg?1 had a reduced (P < 0.05) preference compared with the reference diet with wheat bran. It is concluded that feedstuff nature, inclusion rate, and freshness affect feed preference in pigs. Feedstuff preferences should be taken into account during diet formulation, particularly at critical stages such as immediately after weaning.     

6种饲料原料瘤胃降解特性和瘤胃非降解蛋白质的小肠消化率

本试验旨在研究新疆地区玉米青贮、棉籽壳、苜蓿草粉、苜蓿干草、葡萄籽粕、蕃茄酱渣6种奶牛饲料原料的瘤胃降解特性和瘤胃非降解蛋白质(RUP)的小肠消化率(Idg)。选用3头装有永久性瘤胃瘘管的泌乳荷斯坦奶牛,采用尼龙袋法和改进三步体外法测定饲料原料的干物质(DM)、粗蛋白质(CP)、中性洗涤纤维(NDF)和酸性洗涤纤维(ADF)的瘤胃降解特性以及RUP的Idg和小肠可消化粗蛋白质(IDCP)含量。结果表明:1)苜蓿草粉和玉米青贮的DM有效降解率最高,显著高于次之的苜蓿干草、番茄酱渣(P0.05),葡萄籽粕、棉籽壳最低,显著低于其他原料(P0.05);CP有效降解率为番茄酱渣苜蓿草粉玉米青贮苜蓿干草棉籽壳葡萄籽粕,各原料间差异显著(P0.05);NDF有效降解率为玉米青贮苜蓿草粉棉籽壳苜蓿干草番茄酱渣葡萄籽粕,各组饲料原料间差异显著(P0.05);ADF有效降解率为玉米青贮棉籽壳苜蓿干草番茄酱渣苜蓿草粉葡萄籽粕,各组饲料原料间差异显著(P0.05)。2)苜蓿草粉RUP的Idg和IDCP含量最高,Idg显著高于依次降低的苜蓿干草、玉米青贮、番茄酱渣、葡萄籽粕、棉籽壳(P0.05),IDCP含量与苜蓿干草差异不显著(P0.05),显著高于依次降低的玉米青贮、番茄酱渣、葡萄籽粕、棉籽壳(P0.05)。综上所述,不同饲料原料具有不同的瘤胃降解特性,进入小肠IDCP的含量也不同。玉米青贮的DM、NDF和ADF在瘤胃的有效降解率较高,苜蓿草粉RUP的Idg较高,苜蓿草粉和苜蓿干草的IDCP含量较高。     

Performance of Sheep and Goats Fed Arctostaphylos canescens With and Without Polyethylene Glycol Supplementation

Arctostaphylos canescens Eastw. is considered an important element in the chaparral fire matrix and an invasive plant in coniferous forest plantations in California. Previous studies reported that dry matter intake of Arctostaphylos was low, presumably because of its low nutritional quality and high condensed tannin (CT) content. We hypothesized that intake and digestibility of Arctostaphylos could be increased by the provision of a tannin-complexing agent polyethylene glycol (PEG). This study determined the effects of PEG (MW 4000) supplementation on intake (I) and digestibility (D) of Arctostaphylos in goats and sheep. Polyethylene glycol was added to drinking water at four levels (0.3%, 0.15%, 0.05%, and 0%) of body weight (BW). Alfalfa pellets were used as diet supplement at 1.5% of BW. Nutritional quality of Arctostaphylos was low as compared with alfalfa pellets. Arctostaphylos crude protein (CP) levels were low (4.5% vs. 17.9%) and CT concentration was high (23.1% vs. 0%), whereas estimates of in vitro organic matter digestibility (OMD, 36.6%) and metabolizable energy (5.1 MJ · kg^?1 dry matter [DM]) in Arctostaphylos were almost half of those found for alfalfa pellets (70.3% and 9.5 MJ · kg^?1 DM). A curvilinear increase (P < 0.05) in nutrient intake (per g · d^?1 and per kg BW^0.75) was observed in goats and sheep as PEG levels increased, although a linear increase (P < 0.001) was observed in CP intake (g · d^?1) of Arctostaphylos by goats. Addition of PEG curvilinearly increased (P < 0.05) digestibility of DM, CP, and neutral and acid detergent fiber, but quadratically increased (P < 0.05) that of OM in goats and sheep. Incorporation of PEG in drinking water at the level of 0.15% BW in sheep and goats was effective to maximize inactivation of CT in Arctostaphylos. However, the success in adopting this practice as a useful tool in vegetation management programs will depend on the cost–benefit ratio.     

Feeding Redberry Juniper (Juniperus pinchotii) at Weaning Increases Juniper Consumption by Goats on Pasture

Redberry (Juniperus pinchotii Sudw.) and ashe (Juniperus ashei Buchh.) juniper dominate rangelands throughout central Texas. Our objective was to attempt to improve the efficacy of goats as a biological control mechanism for juniper through behavioral training. Conditioning sheep and goats to increase the palatability of chemically defended plants can be a useful tool in brush control. Previous research illustrated that goats can be conditioned to consume more juniper while in individual pens when foraging choices are limited. To test whether this creates a longer-lasting increase in juniper preference, we determined if goats would continue to consume juniper on pasture for one year after being fed juniper in individual pens for 14 d. Female Boer-cross goats (n = 40) were randomly divided into two treatments: conditioned and naive to juniper. At approximately 12 mo of age, conditioned goats were placed in individual pens and fed redberry juniper 1 h daily for 14 d, while naive goats received only alfalfa pellets to meet maintenance requirements. After the pen-feeding phase of the study, goats were placed in one of four pastures (10 goats · pasture^?1) for 12 mo. Two pastures housed conditioned goats, and two pastures housed naive goats at a moderate stocking rate (1 animal unit · yr^?1 · 8 ha^?1). Bite count surveys were conducted twice per month, while herbaceous standing crop and monoterpene levels were measured once per month. Juniper preference varied monthly; however, conditioned goats consistently ate more (P < 0.05) juniper than naive goats except for April, when the study began, and March, when the study ended. When selection of herbaceous forages decreased, conditioned goats increased selection of juniper, while naive goats increased selection of other palatable shrubs. Seasonal changes of monoterpene levels in juniper had no apparent effect on juniper preference. We contend that feeding juniper at weaning will increase use of the plant in grazing situations.     

山东省羊常用粗饲料营养价值评定

试验旨在综合评价从山东省17个市采集的羊常用粗饲料原料的营养价值。试验测定了109个样本10种常用原料的常规营养成分及总能(GE),应用两级离体消化法测定干物质消化率(IVDMD),以计算消化能(DE)和代谢能(ME),并根据预测干物质随意采食量(DMI),进而计算出分级指数(GI)。结果表明,不同粗饲料间的常规养分的差异不能准确地评价饲料营养价值;以NDF、ADF所得GI综合评价粗饲料中营养价值得到苜蓿>冬牧70>地瓜秧>羊草>花生秧>青贮玉米秸>玉米秸>水稻秸>豆秸>麦秸;IVDMD与NDF、ADF均呈显著负相关,而与CP呈显著正相关;DE与NDF、ADF相关性较强,且均呈负相关。     

不同植物蛋白源日粮对山羊血液氮素代谢的影响

本试验旨在研究不同植物蛋白源日粮对山羊血液氮素代谢的影响。选择3头体况良好安装有颈动脉、门静脉和肠系膜静脉插管的徐淮白山羊,采用3×3拉丁方试验设计,以3种植物蛋白饲料-豆粕(A)、棉粕(B)和玉米干酒糟及其可溶物(C)作为蛋白源。结果表明:不同蛋白源日粮显著影响动脉和门静脉中尿素氮浓度(P<0.05);显著影响肠系膜静脉中总15N、蛋白态15N和氨基酸态15N丰度(P<0.05),且血液中15N丰度均为C组>A组>B组;各处理组间门静脉排流组织(PDV)和肠系膜排流组织(MDV)中总15N和蛋白态15N净流量差异均不显著(P>0.05),但不同蛋白源日粮显著影响PDV和MDV组织中游离氨基酸态15N净流量,且均以C组最高;各处理组中总游离氨基酸(TFAA)和总肽结合氨基酸(TPAA)浓度均存在显著差异(P<0.05)。综合上述,徐淮白山羊以玉米干酒糟及其可溶物作为植物蛋白源比豆粕和棉粕效果更好。     

Evaluation of nutritive value and in vitro rumen fermentation gas accumulation of de-oiled algal residues

Background

Algae are widely recognized for their high oil content and for exponentially accumulating biomass with particular potential to provide single cell protein for human consumption or animal feed. It is believed that along with biodiesel from algae, the high protein de-oiled algal residue may become an alternative feed supplement option in the future. This study was conducted to investigate de-oiled algal residue obtained from the common Chlorella species, Thalassiosira weissflogii, Selenarstrum capricornutum, Scenedesmus sp., and Scenedesmus dimorphus for assessment as potential feed supplements for ruminants by comparing with soybean (Glycine max) meal and alfalfa (Medicago sativa) hay.

Results

With the exception of T. weissflogii, algal residue had higher concentrations of Cu, Zn, and Mn and lower concentration of Ca, Mg, and K than soybean meal and alfalfa hay. The algal residue CP (crude protein) concentrations ranged from 140 to 445 g/kg DM and varied among the de-oiled residues. In vitro rumen fermentation gas accumulation curves indicated that algal biomass degradation potential was less than that of soybean meal or alfalfa hay by up to 41.7%.The gas production curve, interpreted with a dual pool logistic model, confirmed that the fraction sizes for fast fermenting and slow fermenting of de-oiled algal residues were smaller than those in soybean meal and alfalfa hay, and the fermenting rate of the fractions was also low.

Conclusions

Inferior in vitro rumen gas accumulation from the five de-oiled algal residues suggests that these algal byproducts are less degradable in the rumen.     

Intake and digestibility of low-quality native grass hay by beef cows supplemented with graded levels of soybean hulls

Twelve Hereford cows and four mature, ruminally cannulated Hereford x Angus heifers were fed supplements providing either 0 (control), 1, 2, or 3 kg/d of soybean hulls and including 440 g of protein/d (cottonseed meal was used to equalize protein intake) to determine the effects of supplementation on intake and utilization of low-quality native grass hay. Cattle were housed in individual pens and fed coarsely chopped (5-cm screen) native grass hay harvested in mid-November (4.1% CP, 76.9% NDF). Hay OM intake peaked (quadratic, P = .04) at 10.1 kg/d with 1 kg of soybean hulls and decreased when 2 kg (9.8 kg/d) or 3 kg (9.1 kg/d) of soybean hulls were fed. Although hay intake decreased when soybean hulls replaced cottonseed meal, feeding 3 kg soybean hulls decreased hay OM intake by only .64 kg. Total OM digestibility increased linearly (P = .009) with added increments of soybean hulls (45.8%, 46.2%, 46.6% and 48.6% for 0 through 3 kg soybean hulls/d, respectively), indicating that hulls were more digestible than the hay. Digestibility of NDF was not affected (P = .14) by level of soybean hull supplementation, although ADF digestibility increased (linear, P = .03). Increases in OM intake and digestibility with soybean hulls combined to increase digestible OM intake (linear, P = .0001). Soybean hull supplementation increased ruminal VFA concentrations (linear, P = .04) and the molar proportion of propionate (linear, P = .006).(ABSTRACT TRUNCATED AT 250 WORDS)     

Utilization of alternative protein meals with or without multiple-enzyme supplementation in broilers fed low-energy diets

An experiment was conducted to study the effect of different protein meals, with or without enzyme supplementation, on the performance of broilers. A diet based on a combination of protein meals (15% soybean meal, and 5% each of sunflower meal, canola meal, rapeseed meal, and cottonseed meal) was compared with 4 other diets containing 15% soybean meal and 20% of sunflower meal, canola meal, rapeseed meal, or cottonseed meal. Experimental diets were formulated to contain 2,630 kcal of ME/kg and 0.95% digestible lysine, with all other essential amino acids set to meet or exceed the ideal protein ratios. Each diet was fed with or without supplemental exogenous enzyme (Rovabio Excel at 500 g/metric ton of feed) to 6 replicate pens of 50 chicks from 1 to 35 d posthatch as coarse mash. In the cottonseed meal-based diet, supplemental enzyme resulted in high 35-d feed intake and FCR compared with the cottonseed meal-fed groups with no enzyme. There was a significant (P < 0.05) diet × enzyme interaction for 35-d feed intake and FCR. Birds fed the sunflower meal-based diet had significantly (P < 0.05) higher final BW gain and lower FCR as compared with those fed rapeseed meal- or cottonseed meal-based diets, whereas the BW gain of birds fed the rapeseed meal-based diet was significantly (P < 0.05) reduced compared with birds in all other groups. In conclusion, in low-ME broiler diets formulated on a digestible amino acid basis, up to 20% sunflower meal and canola meal can be safely incorporated into the diet. Supplementation of Rovabio failed to exert any positive effect on production parameters when used with diets containing high levels of each of the common protein meals.     

Effect of replacing soybean protein with protein from porcupine joint vetch (Aeschynomene histrix BRA 9690) and stylo (Stylosanthes guianensis Composite) leaf meal on growth performance of native (Moo Lath) Lao pigs

The effect of replacing soybean crude protein (CP) with legume leaf meal (LLM) CP on feed intake, growth performance and carcass traits was studied in native female Moo Lath Lao pigs. The diets comprised one traditional diet (T) without soybean meal, one control diet (C) with soybean meal and six diets iso-nitrogenous with diet C in which soybean protein was replaced (33, 66 and 100 % of CP) with LLM CP from porcupine joint vetch (PLM) or Stylosanthes (SLM). Feed and water were offered ad libitum. Replacing soybean CP with LLM CP reduced (P?<?0.05) intake of dry matter (DMI), CP (CPI), metabolisable energy (MEI), final body weight (BW) and average daily gain (ADG), but had no effect (P?>?0.05) on feed conversion ratio (FCR). Increasing the replacement rate of soybean CP with LLM CP had a negative linear effect (P?<?0.001) on DMI, CPI, MEI, final BW and ADG, and on all carcass traits except lean meat percentage. There were no differences in dressing percentage or organ weight and length between treatments. Supplementing diet T with soybean meal resulted in higher (P?<?0.05) DMI, CPI and MEI, lower (P?<?0.05) FCR, and higher (P?<?0.05) final BW and ADG. Slaughter weight, hot carcass weight, eye muscle thickness, back fat, fat in carcass and lean meat were lower (P?<?0.05) with diet T than diet C. In conclusion, LLM from stylo and porcupine joint vetch can be used as a CP source to partially replace soybean meal CP in the diet of growing native female Moo Lath Lao pigs.