大豆皮替代奶牛日粮中玉米与小麦麸对瘤胃干物质与纤维消化的影响

采用尼龙袋消化试验研究大豆皮替代奶牛日粮中玉米与小麦麸对瘤胃干物质与纤维消化特性的影响,试验处理为大豆皮分别替代精料中0（对照）,25％,50％,75％和100％玉米与小麦麸的5个替代水平的产奶牛饲粮,饲粮的精料和粗料比为50：50,利用2头装有永久性瘤胃瘘管的本地黄牛测定5种大豆皮替代水平饲粮的干物质（DM）和中性洗涤纤维（NDF）的尼龙袋消化率与动态消化参数。所用数学模型为：Y＝a b(1-e^-c(t-L)。大豆皮DM与NDF的每小时消化速度分别为0．072和0．063,DM和NDF中潜在可消化组分比例（a b)分别为925和89％,提高大豆皮替代水平,饲粮DM中慢速消化组分b直线提高（P＝0．023）,快速消化组分a趋于下降（P＝0．140）,消化延滞期趋于延长（P＝．0127）.提高大豆皮替代水平,对饲粮DM中其他动态消化参数没有影响（P＝0．360－0．903）。随着大豆皮替代玉米与小麦麸水平的提高,饲粮NDF中慢速消化组分的比例b,潜在可消化组分（a b)呈二次曲线规律提高（P＝0．001－0．006）,快速消化组分a的比例趋于线性提高（P＝0．082）,而慢速消化组的消化速度c不受大豆皮替代水平的影响（P＝0．688）。从本试验得出结论：以大豆皮替代奶牛饲粮中0,25％,50％,75％和100％的玉米与小麦麸,对饲粮干物质潜在可消化组分比例和消化速度无明显影响,但对纤维消化具有促进作用。     

Ultrasonographic studies on the reproductive tract of mares after parturition: effect of involution and uterine fluid on pregnancy rates in mares with normal and delayed first postpartum ovulatory cycles

During breeding of mares, ultrasonographic detection of uterine fluid accumulations in the first postpartum ovulatory period was associated with significantly decreased pregnancy rates, when compared with rates in control mares (P less than 0.005). The previously gravid uterine horn was recognized as the larger horn, when assessed for size by ultrasonography, for a mean of 21 days (range, 15 to 25 days) after parturition. On the basis of similar measurements obtained during 3 ultrasonographic scans (5-day period), uterine involution was determined to be completed in a mean of 23 days (range, 13 to 29 days). Progestin treatment did not affect uterine size, fluid accumulation, or rate of involution after parturition. However, delaying the first postpartum ovulation with 8 days of progestin treatment significantly improved pregnancy rates (P less than 0.05). More (P less than 0.05) mares became pregnant (23 of 28, 82%) when ovulation occurred after day 15 in the first postpartum ovulatory period, compared with those mares that ovulated before day 15 (6 of 12, 50%). We concluded that ultrasonographic detection of uterine fluid and postpartum progestin treatment can be used to manipulate breeding strategies and to improve pregnancy rates in mares bred during the first postpartum ovulatory period.     

Gonadotropin response by postpartum mares to gonadotropin-releasing hormone

We hypothesized that the LH response to GnRH would be greater as the interval from foaling increases, whereas the FSH response would decrease, and that corpus luteum function after the first ovulation would be similar to that after the second ovulation. At parturition, mares were assigned to receive GnRH (2 micrograms/kg) intravenously on 1) d 3 postpartum (n = 6); 2) d 6 postpartum (n = 6); 3) d 1 of first postpartum estrus (foal estrus) and again on d 1 of second postpartum estrus (n = 8). Blood was collected through an indwelling cannula at -2, -1 and 0 h relative to GnRH stimulation (basal concentrations) and at .25, .5, .75, 1.0, 1.5, 2.0, 2.5, 3.0, 3.5 and 4.0 h post-GnRH. Samples were assayed for concentrations of LH and FSH. Basal concentrations of LH were lower (P less than .05) for mares given GnRH on d 3 postpartum than for mares on d 1 of foal estrus. A rise in concentrations of LH was noted within 30 min in all groups, but the response to GnRH on d 1 of the first estrus was less (P less than .05) than on d 1 of second postpartum estrus. As the interval from parturition increased, the amount of LH secreted in response to GnRH increased. The maximum response to GnRH was greater (P less than .05) during d 1 of the first estrus than on d 3 or 6 postpartum and was greater on d 1 of cycle 2 than on d 1 of cycle 1.(ABSTRACT TRUNCATED AT 250 WORDS)     

Clostridial cellulitis in the horse: a report of five cases

Five horses with fatal clostridial cellulitis are described. The characteristic findings were the rapid development of a crepitant swelling with an associated toxemia, which in four cases followed intramuscular injections. The clinical features, diagnostic techniques and pathogenesis are discussed. The importance of an early diagnosis is emphasized.     

Induction of abortion during midgestation in mares

Four standardbred mares, 99 to 153 days pregnant, were treated with a synthetic prostaglandin analogue, prostalene, in an attempt to induce abortion. The mares received subcutaneous injection of either 2 mg prostalene (recommended luteolytic dose); 4 mg prostalene (double luteolytic dose) or 4 mg twice at intervals of 12 hours or 24 hours. The prostalene treatment resulted in cervical relaxation, increased tone of the uterus and decreased plasma concentrations of progesterone. None of the pregnant mares aborted within seven days after the first prostalene treatment. Abortions were subsequently induced by single or multiple intrauterine infusions using warm hypertonic saline. There were no postabortion complications.     

Enzootic nasal adenocarcinoma of sheep in Canada

A survey of veterinary diagnostic laboratories revealed that intranasal tumors occur in sheep in most provinces of Canada. Tumors were diagnosed in 44 sheep of several breeds including Polled Dorset, Suffolk, Cheviot, Rambouillet and various crossbreeds. Twenty-seven percent of tumors occurred in sheep that were less than two years old. Most tumors were sporadic but 33% of cases occurred in six related flocks, indicating that this disease can be an enzootic problem. The clinical signs were persistent serous, mucous or mucopurulent nasal discharge and stridor. Affected sheep progressively developed anorexia, dyspnea and mouth breathing and most died from effects of asphyxia and inanition within 90 days of the onset of clinical signs. Tumors originated unilaterally or occasionally bilaterally in the olfactory mucosa of the ethmoid turbinates. They were expansive and sometimes locally invasive but metastases were not found. Histologically, the tumors were classified as adenomas or, more frequently, adenocarcinomas. The etiology was not established but retrovirus like particles were observed in tumor tissue from one affected sheep.     

Laminitis-like changes in the claws of feedlot cattle

The purpose of this study was to observe and quantitate changes in the claws of two groups of feedlot cattle (calves and backgrounded yearlings) fed diets that varied in energy (73.5 or 78.5% TDN) and crude protein (11, 13, 15, 16, 17, or 19%) content. At slaughter, the thickness of sole horn and the prevalence of toe and heel hemorrhages were greater in calves than in yearlings (p<0.02). Feeding the high-energy ration increased the prevalence of toe and heel hemorrhages in calves (p<0.02) and heel hemorrhages in yearlings (p<0.02). In yearlings, rotation of the distal phalanx and ridging of the dorsal wall of the claw were the most prominent pathological features. Osteopathy of the apex of the distal phalanx occurred more frequently in calves than in yearlings (p<0.01). This study suggests that intensive feeding of beef cattle before they reach 14 months of age has a deleterious effect on digital health.     

Reproductive efficiency of Thoroughbred and Standardbred horses in north-east Victoria

Objective To evaluate the reproductive efficiency of horse farms in north-east Victoria and identify aspects of management to be targeted for improving reproductive efficiency. Design Retrospective study. Procedure Records from seven Thoroughbred (TB) and four Standardbred (STB) studs in north-east Victoria from 1990 to 2001 were reviewed; 8813 cycles in 4455 mares were analysed. TB mares were inseminated by natural mating, whereas STB mares (89%) were artificially inseminated. Results The overall early pregnancy rate per cycle was 68.8% for TB mares and for STB mares, 68.3%. Multiple pregnancy per cycle was more frequent in TB (8.3%) than in STB (4.6%) mares (P < 0.001). Early embryonic death occurred in 7.1% of TB and 7.5% of STB pregnancies. TB mares had fewer inseminations per cycle (1.03) than STB mares (1.43) (P < 0.001). There was a significantly lower proportion of barren reproductive status within the TB than the STB mares. Pregnancy rate per cycle among stallions ranged from 48% to 79%. Conclusions On-farm pregnancy rates in both breeds were higher than previously reported and likely reflect improvements in reproductive management. The disparity between breeds in the inseminations per cycle and proportion of barren mares exposed the differing structures of the two industries, and presents a target for improving the reproductive efficiency in STBs. The difference between breeds in the multiple pregnancy rate per cycle likely reflects the higher ovulation rate of TB mares. The variability in pregnancy rate per cycle between the 22 stallions was associated with differences in individual inherent fertility and the quality of stallion management.     

大豆皮替代产奶牛日粮精料中玉米与小麦麸对产奶性能和干物质与纤维消化特性的影响(1)

用产奶牛饲喂试验(试验1)和尼龙袋消化试验(试验2)研究了大豆皮替代产奶牛日粮精料中玉米与小麦麸对产奶性能和干物质及纤维消化特性的影响。试验1条件下,以大豆皮替代精料中25%和50%玉米与小麦麸饲喂奶牛,每千克产奶的饲料成本平均减少0.045元和0.057元。试验2利用2头装有永久性瘤胃瘘管的本地黄牛测定了大豆皮及5种饲粮大豆皮替代水平(分别替代精料中玉米和小麦麸的0、25%、50%、75%和100%)的干物质(DM)和中性洗涤纤维(NDF)的尼龙袋消化率与动态消化参数。随着大豆皮替代玉米与小麦麸比例的提高,饲粮NDF中慢速消化组分的比例呈线性(P=0.002)和二次线性曲线(P=0.001)上升;快速消化组分趋于线性上升(P=0.082);NDF总体可消化组分呈线性上升(P=0.001)。     

Evaluation of wheat-based thin stillage as a water source for growing and finishing beef cattle.

Two trials were conducted to evaluate the nutritional value of wheat-based thin stillage as a water source for cattle. In Trial 1, 20 large-framed steers were fed a basal diet based primarily on barley grain and barley silage, with ad libitum access to water or thin stillage at one of three DM concentrations (2, 4, and 6.7%) in a completely randomized design. The trial consisted of a 70-d growing period and a finishing phase. In Trial 2, total-tract nutrient digestibility coefficients of the basal diet and water treatments fed in the growing period were determined in a randomized complete block design using 12 medium-framed steers. The results showed that when only DMI from the basal diet was considered, there was a linear reduction (P<.01) in DMI and a linear improvement (P<.01) in the gain:feed ratio with no effect on daily gain as thin stillage DM concentration increased. No differences were detected in DMI or efficiency of gain when total DMI (basal diet and thin stillage) was considered. Carcass traits indicated a trend toward increased (P<.06) carcass fat with increasing thin stillage DM concentration. Results of Trial 2 indicated a linear improvement (P<.05) in apparent digestibility of DM, CP, NDF, and energy of the total diet (basal diet and thin stillage) as thin stillage DM concentration increased. We concluded that supplementing growing and finishing cattle with thin stillage reduced the amount of the basal diet required for gain and improved nutrient utilization.