Effects of age, weight, and fat slaughter end points on estimates of breed and retained heterosis effects for carcass traits     

Ríos-Utrera A  Cundiff LV  Gregory KE  Koch RM  Dikeman ME  Koohmaraie M  Van Vleck LD 《Journal of animal science》2006,84(1):63-87

The influence of different levels of adjusted fat thickness (AFT) and HCW slaughter end points (covariates) on estimates of breed and retained heterosis effects was studied for 14 carcass traits from serially slaughtered purebred and composite steers from the US Meat Animal Research Center (MARC). Contrasts among breed solutions were estimated at 0.7, 1.1, and 1.5 cm of AFT, and at 295.1, 340.5, and 385.9 kg of HCW. For constant slaughter age, contrasts were adjusted to the overall mean (432.5 d). Breed effects for Red Poll, Hereford, Limousin, Braunvieh, Pinzgauer, Gelbvieh, Simmental, Charolais, MARC I, MARC II, and MARC III were estimated as deviations from Angus. In addition, purebreds were pooled into 3 groups based on lean-to-fat ratio, and then differences were estimated among groups. Retention of combined individual and maternal heterosis was estimated for each composite. Mean retained heterosis for the 3 composites also was estimated. Breed rankings and expression of heterosis varied within and among end points. For example, Charolais had greater (P < 0.05) dressing percentages than Angus at the 2 largest levels of AFT and smaller (P < 0.01) percentages at the 2 largest levels of HCW, whereas the 2 breeds did not differ (P > or = 0.05) at a constant age. The MARC III composite produced 9.7 kg more (P < 0.01) fat than Angus at AFT of 0.7 cm, but 7.9 kg less (P < 0.05) at AFT of 1.5 cm. For MARC III, the estimate of retained heterosis for HCW was significant (P < 0.05) at the lowest level of AFT, but at the intermediate and greatest levels estimates were nil. The pattern was the same for MARC I and MARC III for LM area. Adjustment for age resulted in near zero estimates of retained heterosis for AFT, and similarly, adjustment for HCW resulted in nil estimates of retained heterosis for LM area. For actual retail product as a percentage of HCW, the estimate of retained heterosis for MARC III was negative (-1.27%; P < 0.05) at 0.7 cm but was significantly positive (2.55%; P < 0.05) at 1.5 cm of AFT. Furthermore, for MARC III, estimates of heterosis for some traits (fat as a percentage of HCW as another example) also doubled in magnitude depending on different levels of AFT end point. Rational exploitation of breeds requires special attention to use of different end points and levels of those end points, mainly for fat thickness.  相似文献   

Relationship between Prenatal Survival Rate at 70 days of Gestation and Morphometric Parameters of Vagina, Uterus and Placenta in Gilts     

WL Vianna  ME Pinese  A de  Campos Rosseto  PP Bombonato  PHM Rodrigues  A de  Sant''Anna Moretti 《Reproduction in domestic animals》2004,39(6):381-384

Swine uterine capacity affects litter size, and it could be used as a selection parameter of reproductive performance. Although there are some controversial results, evidences show that the catheter penetration length is positively correlated with litter size, and it could be used as a tool for predicting selection methods. The aim of this study was to determine whether there is any association between the prenatal survival rate and placental size at 70 days of gestation, the vaginal length [catheter penetration length during artificial insemination (AI)] and the uterine capacity in a homogeneous group of gilts. Sixty-six commercial-line gilts in pre-pubertal phase had their oestrus induced by hormonal treatment [600 UI of Equine Chorionic Gonadtrophin (eCG) i.m. and after a 72-h period 5 mg of luteinizing hormone (LH) i.m.], but only 40 gilts showed cyclicity after induction. The AI catheter penetration length was tested on these 40 gilts at the moment of AI using a calibrated AI catheter. Four gilts returned to oestrus and the other 36 were killed at around day 69 of pregnancy. The uterine length and weight showed a significant and positive correlation with the prenatal survival rate (p <0.05). The catheter penetration length was unable to predict the conceptus survival rate on 70 days of gestation; however, the uterine size influenced the survival rate positively. The mean placental area was positively correlated with the mean placental weight (p <0.0001), and both with the mean foetal weight (p <0.0001 and p <0.001, respectively). The analysis of the results obtained showed that neither did the catheter penetration length measurement during AI, nor the prenatal survival rate on day 70 of pregnancy predict the uterine capacity, but the uterine and placental size had a significant influence on the prenatal survival and foetus weight, respectively.  相似文献   

森林资源时态GIS数据存储与时空分析方法研究     

谢绍锋  肖化顺 《西北林学院学报》2011,26(1):181-186

在分析时态数据库的研究与应用现状基础上,针对森林资源数据特点,在对象—关系Oracle数据库上,扩展基本数据类型和函数集,实现森林资源时空数据的有效储存,对森林资源数据的现状及变化等基本信息进行空间拓扑、时态拓扑和时空拓扑操作,提供完善的时序分析功能,高效地回答与时间相关的各类问题,准确地描述森林资源信息,完整地反映森林资源演变过程,为森林资源数据管理提供服务,对森林资源数据库的建设提供新的思路和方法。  相似文献   

Mechanical measures of uncooked beef longissimus muscle can predict sensory panel tenderness and Warner-Bratzler shear force of cooked steaks     

Timm RR  Unruh JA  Dikeman ME  Hunt MC  Lawrence TE  Boyer JE  Marsden JL 《Journal of animal science》2003,81(7):1721-1727

Two experiments were conducted to investigate mechanical measures of tenderness on uncooked USDA Select longissimus muscle as a means to predict Warner-Bratzler shear force (WBSF) and trained sensory panel tenderness (SPT) of cooked steaks. In Exp. 1, strip loins (n = 24) were aged 14 d postmortem and fabricated into steaks (2.54 cm). Medial, center, and lateral locations within uncooked steaks were evaluated by a plumb bob device and correlated with WBSF and SPT of cooked steaks. In Exp. 2, 24 strip loins were used to evaluate how well plumb bob and needle probe devices used on uncooked steaks predicted WBSF and SPT of cooked steaks. At 2 d postmortem, two steaks were fabricated from the anterior end. One uncooked steak (2.54 cm) was assigned to the plumb bob treatment and the other uncooked steak (5.08 cm) was assigned to needle probe treatment. At 14 d postmortem, one uncooked steak (5.08 cm) was assigned to needle probe treatment, a second uncooked steak (2.54 cm) was assigned to plumb bob treatment, whereas the remaining steaks (2.54 cm) were cooked and evaluated by a trained sensory panel and WBSF device. In Exp. 1, average plumb bob values were negatively correlated (P < 0.05) to average SPT scores (r = -0.48). However, correlations between WBSF and plumb bob values for medial, lateral, and average of all sections were not significant (P > 0.05). In Exp. 2, regression models to predict SPT from needle probe and plumb bob measurements individually taken at 2 d postmortem had R2 of 0.54 and 0.51, respectively. Combining needle probe and plumb bob measurements resulted in an R2 of 0.76; when quadratic terms for both variables were in the model, the R2 was 0.80. Regressing needle probe and plumb bob measurements at 2 d postmortem with WBSF produced R2 values of 0.51 and 0.45, respectively. If linear terms of both probes were combined to predict WBSF, the R2 increased to 0.77. An equation to predict WBSF, including both the linear and quadratic terms of needle probe and plumb bob measurements, resulted in an R2 of 0.84. Using plumb bob and needle probe devices on uncooked longissimus muscle at 2 d postmortem can predict cooked WBSF and SPT of USDA Select Grade steaks at 14 d postmortem.  相似文献   

Performance, carcass, cartilage calcium, sensory and collagen traits of longissimus muscles of open versus 30-month-old heifers that produced one calf     

A W Waggoner  M E Dikeman  J R Brethour  K E Kemp 《Journal of animal science》1990,68(8):2380-2386

One hundred eleven Simmental x Hereford (3/8 to 5/8 Simmental) heifers were used to determine the effects of age, parturition and implantation on performance, carcass and meat-sensory traits, muscle-collagen characteristics and thoracic-button calcification. Eighty-five heifers that calved at about 2 yr of age, designated as single-calf heifers (SCH), were either implanted (I-SCH) with Synovex-H or not implanted (NI-SCH). The remaining 26, 2-yr-old non-pregnant heifers (2-OH) served as controls. Additionally, 24, 1-yr-old open heifers (1-OH) from the same genetic source were utilized as the standard heifer-production system. The 1-OH and 2-OH were slaughtered after being fed a high-grain diet for 137 and 112 d, respectively. The SCH were fed the same high-grain diet beginning about 1 mo after calving and were fed 137 d before slaughter. The 33 I-SCH were implanted when started on the high-grain diet. Calves were weaned about 5 wk before the SCH were slaughtered. The 2-OH had the highest (P less than .05) feedlot ADG, whereas no differences (P greater than .05) occurred among other treatments. Dressing percentages were higher (P less than .01) for I-SCH than for NI-SCH. Carcass weights were lowest (P less than .05) and percentage kidney, pelvic and heart fat was highest (P less than .01) for 1-OH. Fat thickness, yield grades, marbling scores and quality grades were similar (P greater than .05) and desirable for all treatments.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

Mechanical probes can predict tenderness of cooked beef longissimus using uncooked measurements     

Stephens JW  Unruh JA  Dikeman ME  Hunt MC  Lawrence TE  Loughin TM 《Journal of animal science》2004,82(7):2077-2086

Two experiments were conducted to determine the effectiveness of using mechanical probes and objective color measurement on beef LM to predict cooked tenderness. In Exp. 1, sharp needle (SN), sharp blade (SB), blunt needle (BN), blunt blade (BB), and plumb bob (PB) probes were used to measure uncooked LM (n = 29) at 2 d postmortem in both a perpendicular and parallel orientation to the long axis of the strip loin. Additionally, instrumental color measurements were measured on uncooked muscle at 2 d postmortem. Steaks for trained sensory panel (TSP) and Warner-Bratzler shear force (WBSF) measurements were aged 14 d postmortem before cooking. Probe measurements taken perpendicular to the long axis of the LM were not correlated (P = 0.22 to 0.82) to TSP tenderness. Probe measurements (BB, BN, SN, SB, and PB) taken parallel to the long axis were correlated to TSP tenderness (r = -0.57, -0.40, -0.77, -0.52, and -0.53, respectively). A regression equation using the SN probe to predict TSP tenderness had a R2 value of 0.74. The SB probe combined with L* accounted for 45% of the variation in TSP tenderness, whereas the PB probe combined with L* accounted for 56% of the variation in TSP tenderness. A second experiment (n = 24) was conducted using the SN, SB, and PB probes on uncooked sections at 2 d and on cooked steaks at 14 d postmortem. Probe measurements on cooked steaks were not correlated to TSP tenderness. New regression equations were calculated using the probe measurements on uncooked steaks from both experiments. Prediction equations formulated with L* values and either SN, SB, or PB probes accounted for 49, 50, and 47% of the variability in TSP tenderness scores, respectively. An equation using WBSF of cooked steaks to predict TSP tenderness had an R2 of 0.58. Of the steaks predicted to be tender (predicted tenderness > 5.0) by the equations using the SN, SB, and PB probes on uncooked steaks and WBSF on cooked steaks, 85, 88, 80, and 84%, respectively, were actually tender (TSP tenderness > 5.0). Mechanical probe measurements of uncooked steaks at 2 d postmortem can potentially classify strip loins into groups based on tenderness, as well as WBSF measurements, which are more costly and time consuming.  相似文献   

The relationship of calfhood morbidity with survival after calving in 25 New York Holstein herds     

LD Warnick  HN Erb  ME White 《Preventive veterinary medicine》1997,31(3-4):263-266

The association of owner-diagnosed calfhood diseases with the length of herd life after calving was evaluated using data collected prospectively over a ten-year period in 25 New York Holstein dairy herds. Herds selected for the study were milking between 35 and 200 Holstein cows, used dairy herd improvement records, bred cows by artificial insemination unless they needed three or more services, and had regularly-scheduled herd health visits by clinicians from the Cornell University College of Veterinary Medicine. Owners recorded occurrences of dullness, respiratory disease, and scours from birth through 90 days of age for all heifer calves that lived at least 24 h and were to be kept as replacements. Milking herd life was measured as the difference between the age at first calving and the age at death or sale. Data on cows sold when the herd went out of business or still in the herd at the end of the study were censored observations. Cox's proportional hazards model was used for statistical analysis of the data. Controlling for age at first calving, study month of birth, and sire predicted difference for milk, there was no statistically significant association of calfhood morbidity with length of herd life. The estimated hazard rate ratios for leaving the milking herd and 95% confidence intervals for dullness, respiratory disease, and scours within 90 days of birth were 1.3 (0.9, 1.9), 0.9 (0.6, 1.3), and 1.0 (0.8, 1.3), respectively. Dullness was the only disease category with an estimated hazard rate ratio greater than 1, and although it was not statistically significant, may warrant evaluation in future studies of long term effects of calfhood morbidity.  相似文献   

Effects of florfenicol injection on the meat characteristics of the cervical muscles in cattle     

Hawkins LL  Perino LJ  Kennedy G  Dikeman M  Cole D 《American journal of veterinary research》2002,63(1):64-68

OBJECTIVE: To determine the effects of florfenicol injection on the meat characteristics of the cervical muscles in cattle. ANIMALS: 100 steers (mean weight, 380 kg). PROCEDURE: In 50 calves, florfenicol (25 ml, twice) was injected into the cervical muscles of 1 side of the neck, and saline (0.9% NaCI) solution (25 ml, twice) was injected into the cervical muscles of the other side of the neck. In the remaining 50 calves, florfenicol was injected into the cervical muscles of 1 side of the neck, and nothing was injected into the cervical muscles of the other side of the neck. Animals were slaughtered 132 days later, and samples of the cervical muscles were submitted for histologic evaluation and measurement of shear forces. RESULTS: 2 injection sites used in the present study had extensive lesions, and both of these were sites where florfenicol had been injected. However, histologic scores for the florfenicol injection sites were not significantly different from scores for the contralateral saline solution injection sites and uninjected control sites. In addition, shear force values were not significantly different between sites in which florfenicol had been injected and the contralateral sites. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that few reactions should be expected with injection of florfenicol into the cervical muscles in steers and that reactions that do occur will consist mainly of fibrosis and infiltration of adipose tissue. However, shear force values, a measure of tenderness of the meat, should not be affected.  相似文献   

Development of a method for the identification, using the polymerase chain reaction, of Aspergillus fumigatus isolated from ostriches     

ME KATZ  SC J. LOVE†  HS GILL‡  BF CHEETHAM 《Australian veterinary journal》1996,74(1):50-54

Objective To develop a method for identifying DNA of Aspergillus fumigatus from ostriches, using the polymerase chain reaction (PCR). A fumigatus is the principal causative agent of avian aspergillosis.
Design A biochemical trial.
Sample population Twelve Aspergillus fumigatus isolates and three other Aspergillus species.
Procedure PCR primers that were based on the sequence of the alkaline protease gene from human isolates of A fumigatus were used.
Results We successfully tested the method on ostrich isolates from five states and showed that the test is specific for A fumigatus.
Conclusions In most cases the DNA sequence of A fumigatus isolates from ostriches is similar to that of human isolates. DNA sequences vary significantly among A fumigatus isolates, including those from affected ostriches in the same flock. The genetic variation may be used to trace aspergillus infections in ostrich flocks and determine if the disease is transmitted by contact with infected birds.  相似文献   

Antibodies to bluetongue and related orbiviruses in sheep and goats in bluetongue virus-endemic areas of northern and central Queensland     

M. FLANAGAN  ME DASHORST  MP WARD  CM MORRIS 《Australian veterinary journal》1995,72(1):31-32

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