Supplements Containing Escape Protein Improve Redberry Juniper Intake by Goats

Redberry juniper (Juniperus pinchotii Sudw.) is a common invasive plant species in west-central Texas. Goats will consume redberry juniper, but intake is limited by monoterpenoids found in the plant. Previous research has shown that goats will increase juniper intake through 1) conditioning and 2) protein supplementation. This study compared intake of juniper when goats received different protein supplements either with or without protein sources that are high in amino acids that escape digestion in the rumen. Recently weaned Boer-cross goats (n = 47) were randomly placed into five treatments. Treatments 1, 2, 3, and 4 received a protein supplement and juniper for 1 h daily for 14 d, along with a basal diet of alfalfa pellets (2% body weight). Treatment 5 received only a basal diet of alfalfa pellets and juniper. All supplements were formulated to be isonitrogenous (37% crude protein [CP]). Treatment 1 contained cottonseed meal (high CP escape value), treatment 2 contained cottonseed meal and distiller’s dried grain (higher CP escape value), treatment 3 contained soybean meal (low CP escape value), and treatment 4 contained soybean meal and distiller’s dried grain (moderate CP escape value). Refusals of juniper, supplements, and alfalfa were weighed daily to determine intake. Supplementation with 1) cottonseed meal, 2) soybean meal, or 3) soybean meal and distillers dried grain did not influence (P > 0.05) juniper intake. Conversely, goats supplemented with cottonseed meal and distiller’s dried grain ate more (P < 0.05) juniper than goats receiving only alfalfa, possibly because of increased escape of glucogenic amino acids. We contend that supplementation with feeds high in protein escape values should increase juniper intake on rangelands.     

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.     

烷基多糖苷添加水平对山羊瘤胃发酵特性的影响

本试验通过研究日粮中添加不同水平的烷基多糖苷(alkyl polyglycoside,APG)对山羊瘤胃发酵特性的影响,考察APG在饲料添加剂领域的潜在用途.试验选用4头体重为(19.5±0.8)kg装有瘤胃瘘管的黑山羊,按4×4拉丁方设计,分别在山羊标准精料中添加0、5、10和20 mL/kg的APG,试验期48 d.试验结果表明,APG对山羊瘤胃pH没有显著影响(P>0.05);APG极显著地增高了山羊瘤胃氨氮浓度、总挥发性脂肪酸(TVFA)、乙酸含量以及乙酸与丙酸含量的比值(P<0.01),还使戊酸含量和乙酸摩尔百分比显著增高(P<0.05),但是对丙酸、丁酸、异丁酸、异戊酸含量以及除乙酸外其他各酸的摩尔百分比皆无显著影响(P>0.05).由此可知,添加APG不影响山羊瘤胃pH,极显著提高氨氮浓度,提高TVFA和乙酸含量,改善了山羊瘤胃发酵特性.     

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.     

Juniper Consumption Does Not Adversely Affect Meat Quality in Boer-Cross Goats

Goat browsing can be used as an alternative brush management option for redberry (Juniperus pinchotii Sudw.) and ashe (Juniperus asheii Buch) juniper instead of more expensive and invasive brush control methods, assuming consumption of juniper does not adversely affect the marketability of offspring. Some wildlife species reportedly retain juniper flavor when consumed. We determined if juniper consumption affected meat quality or flavoring of Boer-cross kid carcasses. Twenty recently weaned, Boer-cross wethers were randomly assigned to one of four treatments with treatments fed different amounts of juniper (0%, 10%, 20%, 30% juniper in the diet). All goats were fed juniper for 28 d at the Angelo State University (ASU) Management, Instruction, and Research Center. All goats were also fed a feedlot ration to meet maintenance requirements (2% body weight). Juniper intake varied (P < 0.05) between all treatments (0%, 10%, 20%, 30%) primarily because treatments were fed different amounts of juniper. Following a 28-d trial, goats were harvested at the ASU Food Safety and Product Development Laboratory. Carcass characteristics including live weight, hot carcass weight, dressing percentage, loineye area, body wall fat thickness, and leg circumference were similar (P > 0.05) among treatments. Sensory characteristics including tenderness, juiciness, flavor intensity, off-flavor, and overall acceptability were also similar (P > 0.05) among treatments. Landowners can utilize goats as a biological management tool without adversely affecting goat meat quality or flavoring.     

添喂葵花籽油对山羊瘤胃消化代谢与瘤胃液脂肪酸组成的影响

为研究亚油酸底物葵花籽油对山羊瘤胃消化代谢和瘤胃液脂肪酸组成的影响,以5只装有永久性瘤胃瘘管的雌性成年徐淮白山羊为试验动物,采用自身对照设计,对照期和试验期（添喂葵花籽油7 mL/d）各15 d,低精料日粮常规饲养。每期结束后采集瘤胃液进行分析。结果表明,添喂葵花籽油后,瘤胃液pH无显著变化;而氨氮（NH3-N）水平和TVFA显著升高（P〈0.05）;乙、丙酸含量显著增加（P〈0.05）,而乙、丙、丁酸比例（C2＋C4）/C3比值和微生物粗蛋白（MCP）均无明显变化;（C18∶1）和c9,t11-CLA（P〈0.05）浓度均明显升高。表明在山羊日粮中添加一定量的葵花籽油,可在不改变瘤胃发酵类型和不影响瘤胃微生物本身的情况下促进瘤胃消化代谢,调节瘤胃液脂肪酸组成。     

Effect of Supplementation of a Basal Diet of Maize Stover with Erythrina variegata,Gliricidia sepium or Leucaena leucocephala on Feed Intake and Digestibility by Goats

Two 4 x 4 Latin square design experiments were carried out. In experiment 1, four mature Anglo-Nubian x Fiji local goats, pre-experimental body weight 25.0 +/- 0.6 kg, 22-24 months old, were used to study the effect of supplementation of a basal diet of maize stover with Erythrina variegata (EV), Gliricidia sepium (GS) and Leucaena leucocephala (LL) on dry matter intake (DMI) and nutrient digestibility. Maize stover treated with urea was used as a control diet. E. variegata was higher in crude protein content than LL or GS. The DMI of the urea treated stover diet was significantly lower (p < 0.05) than that of the diets of untreated stover supplemented with forage legumes. The DMI was significantly lower (p < 0.05) in the GS diet than in the EV or LL diets. Significant (p < 0.05) differences existed between the urea-treated stover and the diets of stover supplemented with forage legumes in the digestibility of dry matter (DM), crude protein (CP), neutral detergent fibre (NDF), organic matter (OM) and energy. In experiment 2, four mature goats, pre-experimental body weight 27.0 +/- 0.3 kg, 24-28 months old, were used to measure their response when the urea-treated maize stover and the maize stover and forage legume diets were sprayed with molasses. The intake of the urea-treated stover diet sprayed with molasses was significantly lower (p < 0.05) that that of the maize stover/forage legume diets sprayed with molasses. The DMI of the diets improved with the addition of molasses. The DMI among the goats offered the maize stover/forage legume diets + molasses did not differ significantly. (p > 0.05). Statistically significant (p < 0.05) differences were obtained in this second study between the urea-treated stover and the stover supplemented with forage legumes in the digestibility of DM, CP, NDF, OM and energy. The stover supplemented with forage legumes had a higher (p < 0.05) nutrient digestibility. The present studies demonstrated that the use of forage legumes as protein supplements improved the feed quality of maize stover in the diets of mature goats. It is suggested that molasses should be sprayed on fresh leaves of Gliricicia sepium and other forage legumes that are initially rejected, in order to improve acceptance and DMI when fed to ruminant animals in confinement or in a cut-and-carry system of production.     

复合营养素对扎布耶盐山羊育肥效果和肉品质的影响

研究复合营养素对育肥扎布耶盐山羊的产肉性能和肉品质的影响。选取60只体重相近的2岁龄扎布耶盐山羊羯羊,随机分为空白对照组、试验Ⅰ组、试验Ⅱ组和试验Ⅲ组。在试验期间,每组每日均按照农牧民放牧习惯自由放牧,晚上补饲精料颗粒料,添加量为280 g/d,燕麦青干草为自由采食;试验Ⅰ组、试验Ⅱ组和试验Ⅲ组分别添加复合营养素Ⅰ、复合营养素Ⅱ和复合营养素Ⅲ各20 g/只;分别在试验第56天的早晨测定所有实验羊活重,计算其在育肥期间的增重率;从各试验组和对照组中分别随机选取10只羊进行屠宰,测定其产肉性能指标以及背最长肌肉品质指标。结果显示,育肥扎布耶盐山羊的补饲日粮中添加复合营养素可使其生长速度加快,3个复合营养素添加组的活体增重和增重率极显著高于对照组（P〈0.01）,屠宰率显著或极显著高于对照组（P〈0.05或P〈0.01）。3个复合营养素添加组的背最长肌水分含量降低（P〉0.05）,但脂肪含量增加（P〈0.01）,剪切力下降（P〉0.05）,表明肌肉的口感明显提升;多不饱和脂肪酸、必需氨基酸、VA、VB_1、VB_（12）含量显著或极显著增加（P〈0.05或P〈0.01）,胆固醇含量降低（P〉0.05）,表明其营养价值明显提高。研究结果为今后在饲草料相对缺乏的藏北牧区开展扎布耶盐山羊的短期育肥提供了技术支撑。     

One-Seed Juniper Sapling Use by Goats in Relation to Stocking Density and Mixed Grazing With Sheep

Suppression of one-seed juniper (Juniper monosperma [Englem.] Sarg.) reinvasion with goats requires achieving levels of defoliation of newly established saplings that eventually kill or suppress plant growth. We tested the effects of stocking density and mixed grazing with sheep on the level of use of one-seed juniper saplings by goats. In summer and spring, groups of 10 does (goats alone, GA) or 5 does and 4 ewes (mixed grazing, MG), grazed 20 × 30 m cells infested with saplings (500–533 · ha^?1; mean: 0.8 m tall), either continuously for 6 d (low stocking density, LD) or with daily rotation through 10 × 10 m cells during the 6-d period (high stocking density, HD) in a block design. Feeding activity; juniper in feces; utilization of herbaceous vegetation; frequency of saplings with light, moderate, and heavy foliage and bark use; and branch utilization were determined. Goats in HD spent more time feeding on saplings, less time feeding on herbaceous forages, and tended to consume more juniper than goats in LD. Utilization of herbaceous vegetation ranged from 52% to 73% and was higher for MG than GA and for LD than HD. The MG–HD treatment resulted in the highest frequency of short saplings (< 0.5 m) with heavy defoliation in summer and spring, and lowest frequency of saplings with light debarking in spring. Heavy defoliation was more frequent in short saplings, whereas heavy debarking was more frequent in tall (> 1 m) saplings. Sapling mortality was not affected by treatments (P > 0.05) and averaged 5% across treatments. Branch debarking was greater in spring (P = 0.02) and explained approximately 80% of branch mortality and 62% and 52% of the reduction in sapling live crown height and volume. Branch utilization (percent length) was not affected by grazing treatments (range: 45–48%), but was influenced by the length and diameter of branches. This study suggests that high stocking density and mixed grazing stimulate feeding behaviors that increase utilization of juniper saplings by goats. Susceptibility of saplings to defoliation and debarking varies with sapling size, branch structure, and season. Targeted grazing in spring appears to have a greater impact on sapling suppression and branch mortality due to higher debarking frequency.     

Age and Body Condition of Goats Influence Consumption of Juniper and Monoterpene-Treated Feed

Redberry juniper (Juniperus pinchotii Sudworth) is an invasive, evergreen tree that is rapidly expanding throughout western and central Texas. Goats will consume some juniper on rangelands; however, intake is limited. The objective of our research was to determine how the age and body condition of goats influence their consumption of juniper and an artificial feed containing 4 monoterpenes. Two separate experiments were conducted. Experiment 1 examined the intake of redberry juniper foliage and used 39 goats either young (2 yr) or mature (> 6 yr). One-half of each age group was fed appropriate basal rations to reach either a high (HBC) or low body condition (LBC). Goats in LBC ate more (P < 0.01, 8.6 g · kg⁻¹ body weight [BW] ± 0.7 SE) juniper than those in HBC (2.3 g · kg⁻¹ BW ± 0.3 SE), and young animals consumed more (P < 0.05, 7.2 g · kg⁻¹ BW ± 0.7 SE) juniper than mature goats (3.9 g · kg⁻¹ BW ± 0.5 SE) across body condition treatments. In experiment 2, 36 goats, either young (2 yr) or mature (> 6 yr) and in either HBC or LBC, were offered a synthetic ration treated with 20.8 g · kg⁻¹ of 4 monoterpenes found in redberry juniper. Goats in LBC ate more (P < 0.01, 25.3 g · kg⁻¹ BW ± 1.0 SE) of the terpene-treated feed than those in HBC (17.5 g · kg⁻¹ BW ± 0.7 SE), and young animals ate more (P < 0.05, 22.5 g · kg⁻¹ BW ± 0.8 SE) than mature goats (20.3 g · kg⁻¹ BW ± 0.8 SE) across body condition treatments. Total intake as a proportion of body weight was also affected by body condition. Age and body condition are important factors that influence intake of chemically defended plants. A better understanding of how these attributes affect diet selection will aid livestock producers in improving grazing management.     

Effects of Stocking Rate and Heather Supplementation on Gastrointestinal Nematode Infections and Host Performance in Naturally-Infected Cashmere Goats

The aim of this study, performed on 62 adult dry cashmere goats grazing upland perennial ryegrass–white clover pastures and naturally infected with gastrointestinal nematodes, was to investigate the effects of stocking rate (SR: 24 vs. 38 goats · ha^-1) and tannin-containing heather supplementation (H: Calluna vulgaris [L.] Hull, Erica spp.) vs. nonsupplementation on parasite burden, fecal egg counts (FEC), and live weight (LW) changes. Goats were randomly assigned to four treatments in a 2 × 2 factorial arrangement and grazed continuously from May to October. Six goats per treatment were slaughtered at the end of the grazing period, and adult worms in the abomasum and small and large intestines of each animal were recovered, counted, and identified. FEC was affected by SR (P < 0.01) but not by H. However, the SR × H interaction was significant (P < 0.05). FEC increased (P < 0.001) along the grazing season in all treatments, and the SR × time interaction was significant (P < 0.001). In general, mean total worm counts in abomasum and small intestine tended to be higher under high SR, although the differences were only significant (P < 0.01) in Trichostrongylus spp. counts. In goats managed under the high SR, the mean of total Teladorsagia circumcincta counts was lower (P < 0.01) in supplemented animals, but no differences were recorded for Trichostrongylus spp., Chabertia ovina, Oesophagostomum columbianum, and Trichuris ovis. The goats gained more LW (P < 0.001) under low SR and when they were heather-supplemented. No significant SR × H interaction was found for LW change. In conclusion, high stocking rate increases the infectivity risk of pasture and the supplementation of grazing goats with heather contributing to improve animals' performance. Notwithstanding, the effect of heather availability on nematode FEC reduction could be highly dependent on the climatic conditions.     

补饲粗蛋白对陇东绒山羊皮肤毛囊生长发育的影响

山羊绒生长期对陇东绒山羊母羊补饲不同水平的粗蛋白,试验期内每月中旬切取皮肤样品,实验室制作切片、观测研究。结果表明：试验组羊的次级毛囊直径、毛囊深度、毛囊密度、S/P及毛囊活性与对照组差异均不显著（P〉0.05）,毛囊深度、毛囊直径试验组略大于对照组;初级毛囊深度、毛囊直径差异显著（P〈0.05）,试验组间差异不显著（P〉0.05）,毛囊密度、S/P及毛囊活性与对照组差异均不显著（P〉0.05）。     

Effects of Fire and Neighboring Trees on Ashe Juniper

The survival of Ashe juniper (Juniperus ashei Buchh.) plants of all sizes was compared between paired burned and unburned plots in four savanna sites on the eastern Edwards Plateau. Smaller plants were less likely to survive a fire than larger plants, over the entire range of plant sizes. Overall fire survival rates varied from ∼45% (0- to 50-cm-tall plants) to ∼92% (&spigt; 2-m-tall plants). The high rate of survival of small plants indicates that fires like those typically used in this region are not likely to control even the early stages of the encroachment of Ashe juniper. If fire is to be used to maintain savannas in this region, multiple burns, more intense fires, or supplementary mechanical removal will probably be needed. Junipers 0 to 200 cm tall were significantly more likely to be growing under the canopy of a tree (defined as a plant &spigt; 2 m tall of any species) than in the open. Small (0 to 50 cm tall) junipers under a tree canopy were significantly more likely to be alive than plants in the same size class growing in the open, suggesting facilitation of small Ashe juniper by neighboring trees. There was, however, no significant effect of neighboring trees on the rate at which small Ashe juniper survived fire, contrary to our initial expectation.     

Intermediate Periodicities in Juniper Consumption and Sampling Strategies to Estimate the Diet of Free-Grazing Goats

We conducted this study to describe the intermediate-term periodicities in percentage juniper (Juniperus spp.) in goat diets and to develop optimal sampling schemes to estimate individual animal variation in juniper consumption. Fecal samples were collected from 12 multiparous female Angora goats on Monday and Thursday for a 24-mo period. Percentage juniper in the diet was determined using fecal near-infrared reflectance spectroscopy. Spectral analysis was used to determine the presence and length of cyclic variation in juniper consumption during growing and dormant season periods. Significant periodicities were found for 37% and 68% of the goats in the dormant and growing seasons, respectively. Cycle lengths varied from 9 d in the dormant season to 7 or 8 d in the growing season. The simple coefficient of determination between a two-sample moving average and the mean of all observations on individual goats was highest during a 3-mo period in the spring, which indicates that samples collected in the spring provided the best estimate of the yearlong percentage juniper in the diet. Monte Carlo simulations for 7-d cycles showed the root mean squared difference between estimated and population mean for two samples with 2 or 3 d between samples was only 1% greater than the root mean square difference for three or four samples collected every other day. The optimal sampling strategy for determining the dietary percentage of a species is to collect two samples separated by one-half of the cycle length.     

日粮铜钼水平对辽宁绒山羊瘤胃发酵指标的影响

试验研究日粮铜(Cu)、钼(Mo)添加水平对辽宁绒山羊瘤胃发酵指标的影响。选用18月龄体重相近,装有永久性瘤胃瘘管的辽宁绒山羊羯羊12只,采用完全随机分组试验设计,分成4组,每组3只。试验分为Mo 0处理和Mo5处理,Mo0处理日粮是在基础日粮中不加Mo,Mo5处理日粮是在基础日粮中加Mo(DM)5 mg/kg,每期设4个Cu水平,即0、20、30、40 mg/kg。结果表明:日粮中添加Mo 5 mg/kg显著降低了瘤胃液的pH,而显著提高了氨氮浓度、乙酸和总VFA浓度(P<0.05);日粮中添加不同水平的铜对瘤胃液pH和氨氮浓度影响差异不显著,但显著提高了乙酸、丙酸、总VFA的浓度(P<0.05);铜钼互作对氨氮浓度、乙酸、丙酸、丁酸及总VFA的浓度影响差异显著,对pH影响差异不显著。结果显示,当日粮中添加Mo为5 mg/kg,Cu为20 mg/kg时,有最适宜的瘤胃发酵水平。     

日粮中添加富硒桑叶粉对陕南白山羊屠宰性状和肌肉脂肪酸的影响

[目的] 研究日粮中添加富硒蛋白桑叶粉对陕南白山羊屠宰性状指标、肌肉理化特性指标及肌肉脂肪酸和硒含量的影响。[方法] 将30只3月龄陕南白山羊羯羊随机分为对照组和富硒桑叶组,每组15只;对照组饲喂基础日粮,富硒桑叶组在基础日粮中添加15%的富硒蛋白桑叶粉;试验期为60 d,预饲期15 d,正饲期45 d;试验结束时进行屠宰试验,测定屠宰性状及肌肉理化特性指标;采集试验羊背最长肌,测定肌肉脂肪酸含量和硒含量。[结果] 日粮中添加15%的富硒蛋白桑叶粉可显著（P<0.05）提高陕南白山羊肌肉pH_{1 h}值和失水率;富硒桑叶组的眼肌面积和胴体重大于对照组,但差异不显著（P>0.05）。在2组山羊的背最长肌中检测到19种脂肪酸,其中饱和脂肪酸5种,不饱和脂肪酸14种;2组山羊肌肉中饱和脂肪酸、单不饱和脂肪酸及多不饱和脂肪酸含量占脂肪酸总含量的比例相似,分别约为28%、67%、5%;富硒桑叶组肌肉中的γ-亚麻酸含量显著（P<0.05）高于对照组,但脂肪酸总含量低于对照组。与对照组相比,富硒桑叶组肌肉中硒含量有所升高,但差异不显著（P>0.05）;富硒桑叶组（0.071 3 mg/kg）和对照组（0.066 0 mg/kg）背最长肌硒含量均达到陕西省含硒肉类食品标准。[结论] 在陕南白山羊日粮中添加15%桑叶粉可在一定程度上改善产肉量、促进硒在肌肉中的富集、减少胴体脂肪沉积,但由于肌肉失水率显著升高,需在储存和运输过程中尽量避免水分丢失。     

丙三醇对泌乳早期奶牛采食量、泌乳性能和代谢产物的影响

选用36头经产奶牛,根据泌乳期、上一泌乳期305天产奶量和预产期,采用随机区组设计分为4组,研究丙三醇（0、100、200和300 g.d-1）对泌乳早期奶牛采食量、泌乳性能、体质量变化、能量平衡、血液代谢产物和尿酮浓度的影响。结果表明：日粮添加丙三醇对奶牛的采食量、产奶量、乳蛋白率、乳糖率和乳干物质率无显著影响,200和300 g.d-1组饲料转化效率显著高于对照组（P〈0.05）,300 g.d-1组乳脂率显著低于对照组和100 g.d-1组（P〈0.05）。添加丙三醇后,和300 g.d-1组血浆葡萄糖浓度显著高于对照组（P〈0.05）,而血浆游离脂肪酸（NEFA）浓度显著低于对照组（P〈0.05）,300 g.d-1组β-羟丁酸浓度显著低于对照组（P〈0.05）;和300 g.d-1组尿酮浓度显著低于对照组（P〈0.05）。添加丙三醇200和300 g.d-1均显著改善了泌乳早期奶牛能量负平衡,减少了体质量下降。     

植物单宁对山羊的影响

由于植物单宁分子结构和化学性质的特殊性,使其对食草动物具有抗营养作用。作者综述了近几年植物单宁对山羊的影响的研究进展。     

日粮不同铜、钼水平对辽宁绒山羊机体抗氧化性能的影响

试验选用性别一致、年龄、体重相近的36只健康辽宁绒山羊,研究日粮中添加不同水平的铜(01、9mg/kgDM和38 mg/kg DM)和钼(0、5 mg/kg DM)对绒山羊机体抗氧化性能的影响。结果表明:日粮添加铜可显著增强绒山羊机体抗氧化性能,显著提高血铜浓度、铜蓝蛋白、铜-锌-SOD及谷胱甘肽过氧化物酶活性(P0.01),显著降低丙二醛含量(P0.01),但添加铜19 mg/kg DM和38 mg/kg DM差异不显著(P0.05)。日粮添加钼5 mg/kgDM显著提高谷胱甘肽过氧化物酶活性(P0.01),对其他指标无影响(P0.05)。铜钼对上述指标无显著互作效应(P0.05),但在铜蓝蛋白、铜-锌-SOD和谷胱甘肽过氧化物酶上存在互作趋势。     

胆固醇对山羊精液冷冻效果的影响

研究了胆固醇对山羊精液冷冻的影响。结果表明，胆固醇不影响冷冻后精子的活力，但影响精子的项体，添加胆固醇后，精子顶体部分脱落的比例增高，但全部脱落的比例降低。