Case study: effects of low-stress weaning on calf growth performance and carcass characteristics.

The objective of this study was to compare the influence of two low-stress weaning methods with conventional weaning on post-weaning performance and carcass characteristics of beef steers. Single-sourced steer calves ( = 89) were stratified by body weight (BW) and dam age into three groups in a completely randomized design ( = 29 or 30 steers/treatment): ABRUPT (calves isolated from dams on the day of weaning), FENCE (calves separated from dams via a fence for 7 d prior to completely weaning), and NOSE (nose-flap inserted and calves remained with dams for 7 d prior to completely weaning). At day +7 post-weaning, calves were transported to a commercial feedlot where they received standard step-up and finishing rations typical for a Northern Plains feedlot.

Effects of long-term postgastric infusion of casein or glutamic acid on small intestinal starch digestion and energy balance in cattle.

The objective of this experiment was to evaluate effects of postruminal flows of casein or glutamic acid on small intestinal starch digestion and to quantify changes in energy and nutrient balance. Twenty-four steers (body weight = 179 ± 4 kg) were duodenally infused with raw cornstarch (1.46 ± 0.

Influence of Maternal Carbohydrate Source (Concentrate-Based vs. Forage-Based) on Growth Performance, Carcass Characteristics, and Meat Quality of Progeny.

The objective of this research was to investigate the influence of maternal prepartum dietary carbohydrate source on growth performance, carcass characteristics, and meat quality of offspring. Angus-based cows were assigned to either a concentrate-based diet or forage-based diet during mid- and late-gestation. A subset of calves was selected for evaluation of progeny performance.

Transcriptome profiles of the skeletal muscle of mature cows during feed restriction and realimentation.

Objective: Realimentation can compensate for weight loss from poor-quality feedstuffs or drought. Mature cows fluctuate in body weight throughout the year due to nutrient availability. The objective of this study was to determine whether cows that differ in weight gain during realimentation also differ in the abundance of transcripts for enzymes associated with energy utilization in skeletal muscle.

Predicting residual feed intake status using rumen microbial profiles in ewe lambs1.

Including feed efficiency as a trait for selection has gained interest in the sheep industry because it can result in reduced feed inputs or improve stocking rates, both of which translate into increased profitability for the producer. It is of interest whether the feed efficiency status of a testing population of sheep could be predicted using rumen microbial profiles associated with divergent feed efficiency status in a training population of sheep. Two populations of ewes were fed the same diet, and each group was evaluated for feed efficiency.

Poor feed efficiency in sheep is associated with several structural abnormalities in the community metabolic network of their ruminal microbes.

Ruminant animals have a symbiotic relationship with the microorganisms in their rumens. In this relationship, rumen microbes efficiently degrade complex plant-derived compounds into smaller digestible compounds, a process that is very likely associated with host animal feed efficiency. The resulting simpler metabolites can then be absorbed by the host and converted into other compounds by host enzymes.

Differential transcript abundance in adipose tissue of mature beef cows during feed restriction and realimentation.

Feed costs account for over 70% of the annual expenditures in cow/calf production. During the production year the cow uses nutrients to support conceptus growth, milk production, work (grazing and locomotion), and maintenance requirements. The majority of the nutrients are used to support maintenance.

RUMINANT NUTRITION SYMPOSIUM: Tiny but mighty: the role of the rumen microbes in livestock production.

The microbes inhabiting the rumen convert low-quality, fibrous, plant material into useable energy for the host ruminant. Consisting of bacteria, protozoa, fungi, archaea, and viruses, the rumen microbiome composes a sophisticated network of symbiosis essential to maintenance, immune function, and overall production efficiency of the host ruminant. Robert Hungate laid the foundation for rumen microbiome research.

Diet shifts provoke complex and variable changes in the metabolic networks of the ruminal microbiome.

Background: Grazing mammals rely on their ruminal microbial symbionts to convert plant structural biomass into metabolites they can assimilate. To explore how this complex metabolic system adapts to the host animal's diet, we inferred a microbiome-level metabolic network from shotgun metagenomic data.

Results: Using comparative genomics, we then linked this microbial network to that of the host animal using a set of interface metabolites likely to be transferred to the host.

Comparison of the humoral response between sheep vaccinated with a killed-virus vaccine and those vaccinated with a modified-live virus vaccine against bluetongue virus serotype 17.

OBJECTIVE To compare the humoral response between sheep vaccinated with a killed-virus (KV) vaccine and those vaccinated with a modified-live virus (MLV) vaccine against bluetongue virus (BTV) serotype 17. DESIGN Randomized clinical trial followed by a field trial. ANIMALS 30 yearling crossbred ewes (phase 1) and 344 sheep from 7 Wyoming farms (phase 2).

Diet alters both the structure and taxonomy of the ovine gut microbial ecosystem.

We surveyed the ruminal metagenomes of 16 sheep under two different diets using Illumina pair-end DNA sequencing of raw microbial DNA extracted from rumen samples. The resulting sequence data were bioinformatically mapped to known prokaryotic 16S rDNA sequences to identify the taxa present in the samples and then analysed for the presence of potentially new taxa. Strikingly, the majority of the microbial individuals found did not map to known taxa from 16S sequence databases.

Right ventricular hypertrophy with heart failure in Holstein heifers at elevation of 1,600 meters.

A syndrome of progressive right-sided heart failure occurred among yearling Holsteins at a heifer-raising facility and 2 dairies on the Colorado Front Range between 2007 and 2011. Most cases were seen at the heifer-raising facility, where the disease ranked second only to pneumonia as a major cause of death in animals aged <1.5 years.

Effect of maternal fatness on fetal steroids and semi-quantitative real-time PCR expression of receptor genes in sheep.

Sexual differentiation of the brain occurs between d 30 and 70 in the fetal lamb. The objective of this experiment was to determine if maternal fatness affects fetal steroid production and expression of their receptors which may ultimately alter endocrine systems postnatally. Fetuses were collected from ewes fed at either 100% (Control; n=5) or 150% (Fat; n=6) of NRC recommendations from 60 d prior to breeding until collection at 75 d of gestation.