Effects of ethanol extraction and duration of heat treatment of soybean flakes on the utilization of soybean protein by growing rats and pigs

Three experiments were conducted to determine the effects of ethanol extraction and duration of heat treatment of soybean flakes on the utilization of soybean protein by growing rats and pigs. In the first experiment, the treatments were no extraction or extraction with a 55% ethanol-water mixture (v/v), and heat treatments of 0, 5, 10, 20 and 40 min in an autoclave. Ethanol extraction improved rate (P less than .002) and efficiency of gain (P less than .001) of rats. As heat treatment was increased from 0 to 20 min, rate of gain increased, but it decreased again as heating time was increased from 20 to 40 min (P less than .03). In Exp. 2 and 3, 45 pigs were used in a growth assay and 54 were used in a N balance experiment to determine the effects of ethanol extraction on under-, intermediate- and over-processed soybean flakes (i.e., 5, 20 and 60 min of autoclaving). The heat treatments were applied either without, before or after extraction with ethanol. Responses in rate and efficiency of gain to ethanol extraction were greater for soybean flakes heated for either 5 or 60 min than for the soybean flakes heated for 20 min. When pooled across heat treatment, pigs fed the soybean flakes heated before or after extraction with ethanol gained faster (P less than .001), had greater gain:feed (P less than .001) and lower plasma urea concentrations (P less than .002) than pigs fed soybean flakes heated without extraction. Feeding soybean flakes heated and extracted with ethanol also resulted in greater apparent N retention (P less than .003), apparent N digestibility (P less than .001) and apparent biological value (P less than .03) than soybean flakes that were heated without extraction. Ethanol extraction improved the protein quality of soybean flakes, especially when the flakes were under- or overprocessed with heat.     

Antiepithelial autoantibodies associated with the feline eosinophilic granuloma complex

A retrospective study of banked sera from 19 cats with the eosinophilic granuloma complex revealed that 68% of affected cats had circulating antibodies to components of normal cat epithelium. Seemingly, the eosinophilic granuloma complex of cats may be an autoimmune disease; however, epidermal damage caused by the eosinophilic granuloma complex may release altered self-antigens to which the cat's immune system responds.     

Effect of source of dietary energy and energy restriction during lactation on sow and litter performance

The effects of source of energy and energy restriction during lactation on sow and litter performance were investigated in an experiment with 90 primiparous sows. At parturition, the sows were randomly assigned to diets containing either tallow or cornstarch as a major energy source. Energy intake was restricted to 8 Mcal of metabolizable energy X sow-1 X d-1 during a 28-d lactation. All sows received equal amounts of crude protein, vitamins and minerals daily, which met or exceeded standard recommendations. Sows fed the diet with tallow lost more weight (P less than .05) during lactation than those fed the diet with cornstarch. Litter size at d 28 was greater (P less than .07) for sows fed cornstarch than for sows fed tallow. However, pig and litter weights on d 14 and 28 of lactation were similar between dietary treatments. Sows were bled on d 110 of gestation and d 14 and 28 of lactation and blood plasma was analyzed for urea. A significant treatment X time interaction was found for plasma urea. Sows fed the diet with tallow appeared to catabolize more protein than those fed the diet with cornstarch. Energy digestibility was lower (P less than .01) in the diet containing tallow, but protein digestibility was not affected by source of energy. Percentages of sows in estrus by 7, 14 and 70 d post-weaning were not different between treatments.     

Effects of sodium pentobarbital on release of gonadotropins in ewes immediately after ovariectomy and after treatment with gonadotropin-releas ing hormone

Two experiments were conducted with ewes 9 to 11 days after estrus to determine whether the secretion of luteinizing hormone (LH) and follicle-stimulating hormone (FSH) are controlled differentially. In experiment 1, gonadotropin-releasing hormone (GnRH) was injected (100 (μg/ewe) at time = 0 min into ewes in four treatment groups. The treatment groups (9 ewes/group) were: 1) periodic iv sodium pentobarbital (NaPen) vehicle from 0 min; 2) periodic iv NaPen from 0 min; 3) vehicle iv for 120 min then iv NaPen from 120 min; 4) vehicle iv for 150 min then iv NaPen from 150 min. A surgical plane of anesthesia was maintained from the initiation of NaPen injection until the experiment ended. Jugular blood was sampled at 30-min intervals from ?30 to + 210 min for LH and FSH assays, and profiles of hormone concentrations were compared by time-trend analyses. GnRH released LH (P<.001) and FSH (P<.001), but NaPen did not affect the profiles of hormone concentrations; this indicated that NaPen did not reduce the ability of the pituitary to secrete gonadotropins in response to GnRH. Experiment 2 was a 2x2 factorial with ovariectomy (time = 0 hr) and NaPen as the main effects. One group of ovariectomized (n = 6) and one group of sham ovariectomized (n = 6) ewes were anesthetized only during surgery, while a group of ovariectomized (n = 7) and a group of sham ovariectomized (n = 6) ewes were kept at a surgical plane of anesthesia until 10 hr after surgery. Patterns of LH and FSH were compared in jugular blood collected hourly from 0 hr until 10 hr after surgery and in samples collected at 24 hr intervals from -24 to +72 hr of surgery. After ovariectomy, LH increased (P<.001) hourly and daily, but anesthesia suppressed (hourly, <.001 and daily, P<.005) these increases, which resulted in an interaction (hourly, P<.001 and daily, P<.01) of ovariectomy and anesthesia. FSH after ovariectomy increased hourly and daily (hourly, P<.02 and daily, P<.001), but the effect of anesthesia and interaction of ovariectomy and anesthesia were not significant. Because NaPen did not alter secretion of LH or FSH after exogenous GnRH in experiment 1 while it blocked the postovariectomy increase in LH but not FSH in experiment 2, we concluded that the postovariectomy increase in LH resulted from increased hypothalamic secretion of GnRH. The mechanisms responsible for the postovariectomy increase in FSH secretion are not identical to those for LH. The mechanisms that control the postovariectomy secretion of FSH might involve factors that are not suppressible by NaPen or, alternatively, the differences in LH and FSH release after ovariectomy might reflect the removal of ovarian factors that suppress FSH but not LH secretion in intact ewes.     

Changes in hormonal profiles during the estrous cycle in old lactating beef cows

Patterns of concentrations of luteinizing hormone (LH), follicle stimulating hormone (FSH), progesterone (P4) and estradiol-17 beta (E2) during an estrous cycle were compared between 15 lactating beef cows 5 to 7 years of age (young) and 15 cows greater than or equal to 12 years of age (old). Length of estrous cycle did not differ between young and old cows (P = .06). No differences due to age were found for LH. Patterns of concentrations of P4 during the first 15 days of the cycle, of FSH during days 6 through 12 and of E2 during the follicular phase differed with age (P less than .05). An earlier (P less than .025) midcycle elevation of FSH was associated with an earlier rise and greater concentration of E2 (P less than .05) during the follicular phase in old than in young cows. Differences in FSH and P4, although subtle, were consistent with an earlier or more advanced follicular development in old cows, leading to greater secretion of E2 from the preovulatory follicle.     

Feline leukemia vaccine: efficacy, contents and probable mechanism

An effective subunit vaccine against feline leukemia virus infection and related diseases has been developed. The source of the vaccine immunogen is feline retrovirus persistently infected cells that continuously synthesize and shed virus polypeptides. Western blot analysis identifies FeLV-gp70, p27, p15, p12, and p10 in the subunit vaccine preparation. Cats immunized with the vaccine developed antibodies to a 70,000 MW protein of the vaccine that seems to be distinct from, but related to the FeLV-gp70 polypeptide.     

Leaf respiration at different canopy positions in sweetgum (Liquidambar styraciflua) grown in ambient and elevated concentrations of carbon dioxide in the field

Trees exposed to elevated CO2 partial pressure ([CO2]) generally show increased rates of photosynthesis and growth, but effects on leaf respiration are more variable. The causes of this variable response are unresolved. We grew 12-year-old sweetgum trees (Liquidambar styraciflua L.) in a Free-Air CO2 Enrichment (FACE) facility in ambient [CO2] (37/44 Pa daytime/nighttime) and elevated [CO2] (57/65 Pa daytime/nighttime) in native soil at Oak Ridge National Environmental Research Park. Nighttime respiration (R(N)) was measured on leaves in the upper and lower canopy in the second (1999) and third (2000) growing seasons of CO2 fumigation. Leaf respiration in the light (R(L)) was estimated by the technique of Brooks and Farquhar (1985) in the upper canopy during the third growing season. There were no significant short-term effects of elevated [CO2] on R(N) or long-term effects on R(N) or R(L), when expressed on an area, mass or nitrogen (N) basis. Upper-canopy leaves had 54% higher R(N) (area basis) than lower-canopy leaves, but this relationship was unaffected by CO2 growth treatment. In August 2000, R(L) was about 40% of R(N) in the upper canopy. Elevated [CO(2)] significantly increased the number of leaf mitochondria (62%), leaf mass per unit area (LMA; 9%), and leaf starch (31%) compared with leaves in ambient [CO(2)]. Upper-canopy leaves had a significantly higher number of mitochondria (73%), N (53%), LMA (38%), sugar (117%) and starch (23%) than lower-canopy leaves. Growth in elevated [CO2] did not affect the relationships (i.e., intercept and slope) between R(N) and the measured leaf characteristics. Although no factor explained more than 45% of the variation in R(N), leaf N and LMA were the best predictors for R(N). Therefore, the response of RN to CO2 treatment and canopy position was largely dependent on the magnitude of the effect of elevated [CO2] or canopy position on these characteristics. Because elevated [CO2] had little or no effect on N or LMA, there was no effect on R(N). Canopy position had large effects on these leaf characteristics, however, such that upper-canopy leaves exhibited higher R(N) than lower-canopy leaves. We conclude that elevated [CO2] does not directly impact leaf respiration in sweetgum and that barring changes in leaf nitrogen or leaf chemical composition, long-term effects of elevated [CO2] on respiration in this species will be minimal.     

评估调质时间和温度对猪颗粒饲料淀粉糊化度和维生素沉积的影响

本论文研究了饲料加工的两个关键参数(调质温度和时间)对育肥猪颗粒饲料淀粉糊化度和维生素沉积的影响。日粮配方为含30%干酒糟及其可溶物的玉米-豆粕型基础日粮。整个试验中配方保持不变。本试验采用2×3双因子设计,调质温度分别为77℃和88℃,调质时间分别15秒、30秒和60秒。此外,本试验还设置一个对照组,对照组饲料不采用调质制粒工艺,而是采用粉料饲喂。因此,本试验共有7个处理组。采集调质后制粒前(热干粉)、制粒后冷却前(热制粒)、以及制粒冷却后(冷制粒)的样品,并分析这三种样品的总淀粉率、淀粉糊化