Effects of age, castration, and season on difficulty of pelt removal in lambs

Sixty-four white-faced rams and wethers were dressed with the aid of a commercial pelt puller. The effects of age, castration, and season on difficulty of pelt removal and pelt damage were evaluated. Lambs were divided into two age groups (5 and 12 mo) within gender (ram and whether) and season (spring and fall). A greater force (P less than .05) was required to remove pelts from rams than from wethers in both 5- and 12-mo-old groups. Older lambs slaughtered in the fall required more force (P less than .05) to remove their pelts than did those slaughtered in the spring, but differences by season did not exist for 5-mo-old lambs. The difference between rams and wethers in percentage of live weight that was closely shorn pelt weight was not significant (P greater than .05). The area of grain crack in the flank expressed as a percentage of total area of the skin was lower (P less than .05) for skins from 5-mo-old lambs and ram lambs than it was for skins from 12-mo-old lambs and wether lambs, respectively. Factors involved in difficulty of pelt removal in ram lambs included crosscut shoulder weight, fat firmness, and carcass weight. Difficulty of pelt removal in wether lambs was best predicted by including crosscut shoulder weight and bodywall thickness in multiple regression equations.     

Estimating the mass of asteroid 253 mathilde from tracking data during the NEAR flyby

The terminal navigation of the Near Earth Asteroid Rendezvous (NEAR) spacecraft during its close flyby of asteroid 253 Mathilde involved coordinated efforts to determine the heliocentric orbits of the spacecraft and Mathilde and then to determine the relative trajectory of the spacecraft with respect to Mathilde. The gravitational perturbation of Mathilde on the passing spacecraft was apparent in the spacecraft tracking data. As a result of the accurate targeting achieved, these data could be used to determine Mathilde's mass as 1.033 (+/- 0.044) x 10(20) grams. Coupled with a volume estimate provided by the NEAR imaging team, this mass suggests a low bulk density for Mathilde of 1.3 grams per cubic centimeter.     

Cross-polarization/magic angle spinning NMR to study glucose mobility in a model intermediate-moisture food system

Theories for the chemical stability of foods cite the role of moisture content or water activity in reactant mobility, though mobility has been variously defined. One theory, based on plasticization by moisture, is limited by a lack of research directly linking the mobility of a matrix to the mobility and reactivity of small solute molecules in foods. A cross-polarization/magic angle spinning technique was developed to study glucose rotational mobility in the solid state over a range of water activities and in matrixes with different glass transition temperatures. Data analysis stressed the significance of separating molecular mobility from relaxation time. Results showed that, in a caseinate matrix, compared to a control, adding glycerol yielded the highest glucose mobility and lowest glass transition temperature (T(g)), while adding sorbitol also increased mobility and lowered T(g). Consequently, plasticization by either moisture or these humectants increases the mobility of small solute molecules such as glucose.     

Evaluation of nutritive value and in vitro rumen fermentation gas accumulation of de-oiled algal residues

Background：Algae are widely recognized for their high oil content and for exponentially accumulating biomass with particular potential to provide single cell protein for human consumption or animal feed.It is believed that along with biodiesel from algae,the high protein de-oiled algal residue may become an alternative feed supplement option in the future.This study was conducted to investigate de-oiled algal residue obtained from the common Chlorella species,Thalassiosira weissflogii,Selenarstrum capricornutum,Scenedesmus sp.,and Scenedesmus dimorphus for assessment as potential feed supplements for ruminants by comparing with soybean（Glycine max） meal and alfalfa（Medicago sativa） hay.Results：With the exception of T.weissflogii,algal residue had higher concentrations of Cu,Zn,and Mn and lower concentration of Ca,Mg,and K than soybean meal and alfalfa hay.The algal residue CP（crude protein）concentrations ranged from 140 to 445 g/kg DM and varied among the de-oiled residues.In vitro rumen fermentation gas accumulation curves indicated that algal biomass degradation potential was less than that of soybean meal or alfalfa hay by up to 41.7%.The gas production curve,interpreted with a dual pool logistic model,confirmed that the fraction sizes for fast fermenting and slow fermenting of de-oiled algal residues were smaller than those in soybean meal and alfalfa hay,and the fermenting rate of the fractions was also low.Conclusions：Inferior in vitro rumen gas accumulation from the five de-oiled algal residues suggests that these algal byproducts are less degradable in the rumen.     

Evaluation of nutritive value and in vitro rumen fermentation gas accumulation of de-oiled algal residues

Background

Algae are widely recognized for their high oil content and for exponentially accumulating biomass with particular potential to provide single cell protein for human consumption or animal feed. It is believed that along with biodiesel from algae, the high protein de-oiled algal residue may become an alternative feed supplement option in the future. This study was conducted to investigate de-oiled algal residue obtained from the common Chlorella species, Thalassiosira weissflogii, Selenarstrum capricornutum, Scenedesmus sp., and Scenedesmus dimorphus for assessment as potential feed supplements for ruminants by comparing with soybean (Glycine max) meal and alfalfa (Medicago sativa) hay.

Results

With the exception of T. weissflogii, algal residue had higher concentrations of Cu, Zn, and Mn and lower concentration of Ca, Mg, and K than soybean meal and alfalfa hay. The algal residue CP (crude protein) concentrations ranged from 140 to 445 g/kg DM and varied among the de-oiled residues. In vitro rumen fermentation gas accumulation curves indicated that algal biomass degradation potential was less than that of soybean meal or alfalfa hay by up to 41.7%.The gas production curve, interpreted with a dual pool logistic model, confirmed that the fraction sizes for fast fermenting and slow fermenting of de-oiled algal residues were smaller than those in soybean meal and alfalfa hay, and the fermenting rate of the fractions was also low.

Conclusions

Inferior in vitro rumen gas accumulation from the five de-oiled algal residues suggests that these algal byproducts are less degradable in the rumen.