Evaluation of tropically adapted straightbred and crossbred cattle: postweaning gain and feed efficiency when finished in a temperate climate     

Coleman SW  Chase CC  Phillips WA  Riley DG  Olson TA 《Journal of animal science》2012,90(6):1955-1965

Beef cows in the subtropical USA must be adapted to the stressors of the environment, typically supplied by using Brahman (Br) breeding. Calves produced in the region, however, are usually grown and finished in more temperate regions, and have a perceived reputation for poor ADG and feed efficiency during finishing. Compromised fertility and carcass quality often associated with the Br have increased interest in tropically adapted Bos taurus breed types. The objective of this study was to evaluate 3 breeds [An = Angus (Bos taurus, temperate); Br (B. indicus, tropical); and Ro = Romosinuano (B. taurus, tropical)] and all possible crosses during various segments of post-weaning growth, and for feed efficiency during the finishing phase. Steer calves (n = 473) born over 3 yr were weaned in late September, backgrounded for at least 21 d (BKG), shipped 2,025 km to El Reno, OK, in October, fed a preconditioning diet for 28 d (RCV), grazed wheat (Triticum aestivum L.) pasture from November to May (WHT), finished on a conventional feedlot diet (FIN), and serially harvested after approximately 95, 125, and 150 d on feed. Body weight and ADG during each segment were tested using a mixed model that included calf age at weaning, year (Y), breed of sire (SB), breed of dam (DB), and interactions. In addition, winter treatment (continuous wheat or reduced grazing of wheat with supplement) was included for the wheat and feedlot phases. Sire within SB × SB [and pen (barn × year) for feedlot phase] were considered random. The SB × DB interaction was significant for all traits (P < 0.01) except exit velocity taken at weaning and ADG during FIN, but both traits were affected by 3-way interactions with Y or harvest group. Tropically-adapted purebred steers had greater (P < 0.01) ADG than AnAn through weaning and BKG in FL but the reverse was true during the RCV and WHT segments. Similar, but less pronounced results were noted for F(1) steers with 100% tropical influence compared with those with only 50%. Heterosis was numerically greater for most traits for An × Br (11 to 64%) compared with An × Ro and Br × Ro (3 to 42%), which were similar. In a subset of the steers (n = 261), G:F was not influenced by level of tropical breeding, but tropically adapted steers were more efficient (P < 0.05) by residual feed intake. No heterosis was evident. These data show that in temperate zones, winter is the period when productivity of tropically adapted cattle is compromised.  相似文献   

Genetic effects on carcass quantity, quality, and palatability traits in straightbred and crossbred Romosinuano steers     

DG Riley  CC Chase  SW Coleman  WA Phillips  MF Miller  JC Brooks  DD Johnson  TA Olson 《Journal of animal science》2012,90(7):2159-2166

The objectives of this work were to estimate heterosis and breed genetic effects for carcass quantity, quality, and palatability traits of steers (Bos spp.) produced from matings of Romosinuano, Brahman, and Angus cattle. Steers (n = 464) were weaned at 7 mo of age and transported to the Southern Great Plains where they grazed winter wheat for 6 mo and were then fed a finishing diet until serial slaughter after different days on feed (average 130 d). Carcass quality and quantity traits were measured; steaks (aged 7 d) were obtained for palatability evaluation. Heterosis was detected for BW, HCW, dressing percentage, LM area, and yield grade for all pairs of breeds. Generally, Romosinuano-Angus heterosis estimates were smallest, Romosinuano-Brahman estimates were intermediate, and Brahman-Angus heterosis estimates were largest. The direct Romosinuano effect was to decrease (P < 0.05) BW (-67 ± 16 kg), HCW (-48 ± 10 kg), dressing percentage (-1.4 ± 0.5 units), 12th rib fat thickness (-5.2 ± 0.8 mm), and yield grade (-0.9 ± 0.1), and to increase LM area per 100 kg HCW (3.6 ± 0.3 cm(2)/100 kg). Significant Brahman direct effects were detected for BW (34 ± 17 kg), HCW (29 ± 10 kg), dressing percentage (1.6 ± 0.6 %), LM area per 100 kg HCW (-3.3 ± 0.4 cm(2)/100 kg), and yield grade (0.6 ± 0.1). Significant Angus direct effects were to increase 12th rib fat thickness (3.8 ± 1 mm). Among sire breed means, Romosinuano had reduced (P = 0.002) marbling score (393 ± 9) than Angus, but greater mean sensory tenderness scores (5.8 ± 0.1), and reduced percentage Standard carcasses (10 ± 2%) than Brahman (P < 0.002). Angus sire breed means for marbling score (475 ± 10), overall tenderness (5.8 ± 0.1), and percentage Choice carcasses (75 ± 5%) were greater (P < 0.05) than Brahman sire breed means (360 ± 11, 5.4 ± 0.1, 31 ± 5%). From consideration only of characteristics of the end product of beef production, Romosinuano did not provide a clearly superior alternative to Brahman for U.S. producers, as they had some quality and palatability advantages relative to Brahman, but at lighter HCW.  相似文献   

A pilot study to investigate the measurement of immunoglobulin A in Welsh Cob and Welsh Pony foals’ faeces and their dam’s milk     

CB Riley  CJ Jenvey  FJ Baker  A Corripio 《New Zealand veterinary journal》2020,68(4):225-230

ABSTRACT

Aims: To determine if an ELISA for measurement of IgA in equine serum could be used to measure concentrations of IgA in foal faeces and to determine correlations with concentrations in the milk of the dam.

Methods: Faeces from 20 Welsh Cob and Welsh Pony foals and milk from their dams were collected within 12?hours (Day 0) and at 6 days after parturition (Day 6). On Day 6, faeces could not be collected from 2/20 foals, and milk samples could not be collected from 3/20 mares. An equine IgA ELISA validated for serum and plasma was used to measure concentrations of IgA in all samples in triplicate. The precision of the assay for each sample type was determined using modified CV.

Results: IgA was not detectable in 7/20 Day 0 faecal samples and in 2/18 Day 6 faecal samples. For samples with detectable IgA, the mean modified CV was 10.5 (95% CI?=?6.0–15.0)% for Day 0 faecal samples, and was 6.8 (95% CI?=?4.3–9.4)% for Day 6 faecal samples. Median concentrations of IgA in faeces on Day 0 were lower than concentrations on Day 6 (0.7?mg/g vs. 37?mg/g dry matter; p?=?0.003). Concentrations of IgA in milk and faeces on Day 6 were statistically correlated (r?=?0.59; p?=?0.006).

Conclusions and clinical relevance: The IgA ELISA showed acceptable precision when used to estimate concentrations of IgA in foal faeces during the first week of life, but IgA could not be detected in 37% of meconium samples collected on Day 0. This assay may be useful for investigation of the role of maternal milk IgA in the gastrointestinal tract of neonatal foals, but further assessment of both accuracy and precision of the ELISA is required.  相似文献   

Wild-Harvested Venison Yields and Sharing by Michigan Deer Hunters     

Amber D. Goguen  Shawn J. Riley  John F. Organ  Brent A. Rudolph 《Human Dimensions of Wildlife》2018,23(3):197-212

An increased societal focus on wildlife as food and recent policy deliberations regarding legal markets for wild-harvested meat are encouraging wildlife managers and researchers to examine the amount, use, and distribution of meat yielded through recreational hunting. We used responses to questions on the Michigan Deer Harvest Study to estimate the maximum yield of edible venison and assess hunters’ sharing behaviors. We estimated 11,402–14,473 metric tons of edible venison were procured during the 2013 hunting season. Of hunters who harvested a deer, 85% shared their venison. Hunters who shared did so with an average of 5.6 people (SD = 4.5). Sharing occurred most frequently within tight social networks: members of hunters’ households (69%), relatives (52%), and friends, neighbors, or coworkers (50%). In the absence of legal markets, venison is distributed widely by hunters and greatly amplifies the number of people benefiting from hunting. Nonetheless, we also identified the potential breadth of exposure to disease or contaminants from wild-harvested meat.  相似文献   

Statistical aspects of aquaculture research: pond variability and pseudoreplication     

J Riley  P Edwards 《Aquaculture Research》1998,29(4):281-288

Pond experiments with one treatment per pond are discussed for their sources of variability. Replication of treated ponds, randomization of treatment allocation to ponds and the importance of independence between ponds are emphasized for efficient estimation of both treatment and inherent pond differences. Appropriate models are given for the analysis of data for pond experiments with whole-pond treatments. Corresponding analyses of variance are given to illustrate the estimation of differences between treatments, between ponds and between fish within ponds. Appropriate significance tests for treatment effects are demonstrated to avoid pseudoreplication, the incorrect use of within-pond variation. Using a fertilizer experiment, simple graphical methods are presented for examining between- and within-pond variation to identify ponds with unusual data, and to determine adequacy of design and appropriate analyses.  相似文献   

Predation by invasive signal crayfish on early life stages of European barbel may be limited          下载免费PDF全文

Gordon H. Copp  Lorenzo Vilizzi  William D. Riley 《水产资源保护:海洋与淡水生态系统》2017,27(5):1056-1060

High-temperature-tolerant mungbean (Vigna radiata L.) lines produce better yields when exposed to higher CO2 levels     

H. Bindumadhava  L. Sharma  R. M. Nair  H. Nayyar  J.J Riley  W Easdown 《Journal of Crop Improvement》2018,32(3):418-430

Increasing global air temperatures, along with rising CO₂ levels, are causing concerns about reducing available freshwater resources and altering cropping patterns. They may influence overall growth and production pattern of crop plants. These likely changes would become major limiting factors for future sustainable food production largely in the tropics and subtropics. Thus, understanding physiological responses hold the key to determining the functional relationship between the environment and crop performance. We explore here the impact of rising CO₂ on the growth and yield traits of a few selected high-temperature (HT)-tolerant mungbean lines, which we earlier screened for HT tolerance using a physiological assay under managed growth conditions. The HT-tolerant lines grown under elevated CO₂ levels (550 and 700 μL L^?1) showed a considerable improvement in growth rates (13.5%, 67.8%, and 46.5% in plant height, leaf area, and total dry matter, respectively) and pod and seed yield (48.7% and 31.7%, respectively), compared to local checks under the same environments. Interestingly, the symptoms of accelerated pod maturity were also observed in most of these lines. The outcome of the study would undoubtedly open up opportunities for increased yield potentials of legumes under the conditions of the warming climate and elevated levels of carbon dioxide.  相似文献   

Increased expression of GAPDH protein is not indicative of nitrosative stress or apoptosis in liver of starved rainbow trout (Oncorhynchus mykiss)     

Baumgarner BL  Riley CP  Sepulveda MS  Brown PB  Meyer JL  Adamec J 《Fish physiology and biochemistry》2012,38(2):319-327

Short-term starvation has been linked to in vivo protein degradation in liver of rainbow trout (Oncorhynchus mykiss). However, it is unclear whether this proposed increase in protein degradation is followed by programmed cell death (apoptosis) in liver of starved trout. A preliminary study in our laboratory revealed an isoform of glyceraldehyde-3-phosphate dehydrogenase (GAPDH) protein that increased 4.5-fold in liver of starved trout. GAPDH is a glycolytic enzyme involved in other cellular functions, including apoptosis. Increased intracellular nitric oxide (NO) promotes nuclear translocation of GAPDH that is associated with increased apoptosis in mammals. If GAPDH protein is associated with apoptosis in rainbow trout, it could potentially be used as a biomarker of cellular stress in liver of teleost fish species. The purpose of this study was to determine whether increased GAPDH protein expression in liver of starved rainbow trout is associated with NO-induced apoptosis. Targeted proteomic analysis using multiple reaction monitoring (MRM) was used to determine the level of GAPDH in nuclear and cytoplasmic fractions and inducible nitric oxide synthase (iNOS) in cell lysates. Dot blot and DNA fragmentation analyses were conducted to evaluate protein S-nitrosylation and apoptosis, respectively. Results showed that cytoplasmic GAPDH was 3.4-fold higher in liver of starved versus fed rainbow trout but could not be detected in nuclear fractions. Starvation significantly reduced hepato-somatic index but had no effect on iNOS protein expression, protein S-nitrosylation, or apoptosis. Our results indicate that starvation promoted significant reduction in liver mass that was not associated with increased apoptosis or NO-induced stress and that greater GAPDH concentration in liver of starved rainbow trout was located primarily in the cytoplasm.  相似文献   

Characterization of the horseweed (Conyza canadensis) transcriptome using GS‐FLX 454 pyrosequencing and its application for expression analysis of candidate non‐target herbicide resistance genes     

Yanhui Peng  Laura LG Abercrombie  Joshua S Yuan  Chance W Riggins  R Douglas Sammons  Patrick J Tranel  C Neal Stewart Jr 《Pest management science》2010,66(10):1053-1062

  相似文献   

Home Care for Horses with Chronic Laminitis     

James A. Orsini  Jennifer WrigleyPatrick Riley 《Veterinary Clinics of North America: Equine Practice》2010

  相似文献