Availability Of Crude Protein Research Articles

Pineapple stem-derived bromelain based priming improves pepper seed protein reserve mobilization, germination, emergence and plant growth.

Pepper seeds are slow to germinate and emergence is often non-uniform and incomplete, reducing gains from this cash crop. This study investigated the effects of pineapple stem- derived protease (stem bromelain) based priming on pepper seed germination in relation to reserve mobilization (specifically, proteins and aminoacids), germination, emergence and plant growth. These parameters were compared across two controls, (1) unsoaked seeds and (2) seeds soaked in deionized water, and seeds soaked in pineapple stem bromelain crude extract (treatment). Seeds were soaked in bromelain crude extract possessing a proteolytic activity of 6.25 tU or deionized water (first control) for 3h at 35°C. Light microscopy revealed an abundance of protein bodies in the endosperm of the seeds prior to imbibition. When observed for a period of 96h, these bodies were progressively degraded, with the rate of this degradation being fastest in bromelain-treated seeds. Quantitative analysis of protein levels confirmed this observation: 17.2mg proteins/g FW at 120h after priming in bromelain-treated seeds compared with 22.1mg/g FW in controls (average). The bromelain treatment also increased levels of free amino acids from 3.9mg/g FW in the controls to 4.6mg/g FW after 120h of imbibition. Germination and emergence percentages were initially higher in bromelain-treated seeds: 92.0% germination in bromelain-treated seeds vs. ~ 52.2% in the controls at 18 d; 100% emergence in protease-treated seeds vs. ~ 72.2% in the controls at 18 d. However, these parameters were comparable across the treatment and the controls at 28 d. Importantly, plant fresh and dry weights were significantly higher when seeds were primed with bromelain. The results suggest the use of bromelain extracts for priming pepper seeds based on their proteolytic activity, since germination is dependent on the availability of crude protein and essential aminoacids. The benefits of bromelain seed priming appear to translate into improved seedling growth as well.

In vivo foregut digestion of protein from 6 fibre feeds in horses using the mobile bag technique

It is now widely recognised that feeding high levels of cereal-based concentrate feeds to horses can precipitate episodes of colic, laminitis and developmental orthopaedic disease. However, when feeding performance horses or fast-growing young stock, particularly Thoroughbreds, traditional feeding regimes still persist whereby animals are fed high-cereal, low-fibre diets. When considering the knowledge to-date on the digestibility and availability of crude protein, this feeding regime is not surprising as previous work by Gibbs et al (1988 and 1996) and Potter et al (1992), have reported that the large intestine was the major site for crude protein degradation in hay. Protein is held within the cell wall matrix in fibre feeds and is fermented by microbes to NH3, which may be subsequently processed in the liver to urea, recycled or excreted via the urine. Moreover, a high proportion of the protein passing through the ileo-caecal junction is excreted with the faeces as intact microbial protein and therefore is unavailable for metabolic purposes in the horse.

Estimation of ruminal degradation and intestinal availability of crude protein in the animal-origin feedstuffs using mobile nylon bag technique

Estimation of ruminal degradation and intestinal availability of crude protein in the animal-origin feedstuffs using mobile nylon bag technique

Urinary Cortisol and Urea Nitrogen Responses to Winter Stress in Mule Deer

We investigated the urinary cortisol and urea nitrogen responses of mule deer (Odocoileus hemionus) to winter population densities. We collected urine samples from 14 hand-reared mule deer fawns and 14 hand-reared mule dder yearlings placed in 2 pastures (66 and 169 ha) stocked with wild deer at high (133 deer/km 2 ) and low (44 deer/km 2 ) densities, respectively. Levels of urinary cortisol: creatinine ratios increased exponentially as winter progressed and with pasture density and were correlated with wild fawn survival in the pastures. Animals larger at the start of winter had lower cortisol: creatinine ratios during the winter. Weather conditions and date of birth for fawns, and snow depths for yearlings, exerted minor effects. Urea nitrogen: creatinine ratios declined as winter progressed and increased with cortisol levels. Rate of mass loss increased over time in fawns, was constant in yearlings, and was weakly correated to cortisol: creatinine ratios. Urine cortisol, assumed to reflect energy deficit, allows researchers to distinguish high levels of urea nitrogen caused by the availability of crude protein from those caused by muscle catabolism. By reflecting both environmental and animal condition, urine cortisol provides a tool for assessing population condition and ecological density