The influence of diet on the distribution of nitrogen isotopes in animals was investigated by analyzing animals grown in the laboratory on diets of constant nitrogen isotopic composition. 
The isotopic composition of the nitrogen in an animal reflects the nitrogen isotopic composition of its diet. The δ^(15)N values of the whole bodies of animals are usually more positive than those of their diets. Different individuals of a species raised on the same diet can have significantly different δ^(15)N values. The variability of the relationship between the δ^(15)N values of animals and their diets is greater for different species raised on the same diet than for the same species raised on different diets. Different tissues of mice are also enriched in ^(15)N relative to the diet, with the difference between the δ^(15)N values of a tissue and the diet depending on both the kind of tissue and the diet involved. The δ^(15)N values of collagen and chitin, biochemical components that are often preserved in fossil animal remains, are also related to the δ^(15)N value of the diet. 
The dependence of the δ^(15)N values of whole animals and their tissues and biochemical components on the δ^(15)N value of diet indicates that the isotopic composition of animal nitrogen can be used to obtain information about an animal's diet if its potential food sources had different δ^(15)N values. The nitrogen isotopic method of dietary analysis probably can be used to estimate the relative use of legumes vs non-legumes or of aquatic vs terrestrial organisms as food sources for extant and fossil animals. However, the method probably will not be applicable in those modern ecosystems in which the use of chemical fertilizers has influenced the distribution of nitrogen isotopes in food sources. 
The isotopic method of dietary analysis was used to reconstruct changes in the diet of the human population that occupied the Tehuacan Valley of Mexico over a 7000 yr span. Variations in the δ^(15)C and δ^(15)N values of bone collagen suggest that C_4 and/or CAM plants (presumably mostly corn) and legumes (presumably mostly beans) were introduced into the diet much earlier than suggested by conventional archaeological analysis.

Influence of Diet On the Distribtion of Nitrogen Isotopes in Animals

Genetics and analysis of quantitative traits

Clinical Biochemistry of Domestic Animals

/pdf/nutrient-requirements-of-goats-6uelo7m3a7.pdf

Nutrient requirements of goats

Applied categorical data analysis

Derivation of a regression equation to estimate the ratios of energy expenditure of walking on the level and on gradients to that of standing and application of the equation for the estimation of energy expenditures of grazing cows in abandoned paddy fields

Factors affecting the lactation curve parameters of Japanese saanen goats

Livestock farming in Nepal, especially buffalo farming alone contributes a major share in livelihoods of farmers. Stall feeding of buffalo is common in Chitwan with occasional grazing. This raises questions about status of nutrients supplied to maintain productivity as feed resources varied in forest and crop land according to the season. A study was carried out in Chitwan from April 2015 to March 2016 to find out the status of nutrient supply in relation to the feeding system of buffalo. Total fifteen farms were selected from three villages, the amount of feedstuff fed to the animals was measured every month and the nutrient contents of the feed were analyzed. The mean concentrations of DM, CP, TDN, Ca and P were 641g/kg, 75.0 g/kg, 462 g/kg, 4.9 g/kg and 4.2 g/kg. A significant difference of CP contents among the villages was observed (72.0 g/kg, 70.7 g/kg and 81.2 g/kg (P<0.01), and the highest content of CP, TDN, Ca and P were found in July (P<0.05)). The study showed variation in nutrient supplied, irrespective of the status and condition of buffalo in the farms which need to be considered to maintain productivity of the animals.

/pdf/study-on-nutrient-supply-in-relation-to-feeding-system-of-26wgyvqerv.pdf

Study on nutrient supply in relation to feeding system of buffalo in Chitwan, Nepal.

Liquefied sake lees, a by-product of Japanese sake, is rich in Saccharomyces cerevisiae, proteins, and prebiotics derived from rice and yeast. Previous studies have reported that Saccharomyces cerevisiae fermentation products improved the health, growth, and faecal characteristics of preweaning calves. This study investigated the effects of adding liquefied sake lees to milk replacer on the growth performance, faecal characteristics, and blood metabolites of preweaning Japanese Black calves from 6 to 90 days of age. Twenty-four Japanese Black calves at 6 days of age were randomly assigned to one of three treatments: No liquefied sake lees (C, n = 8), 100 g/d (on a fresh matter basis) liquefied sake lees mixed with milk replacer (LS, n = 8), and 200 g/d (on a fresh matter basis) liquefied sake lees mixed with milk replacer (HS, n = 8). The intake of milk replacer and calf starter, as well as, the average daily gain did not differ between the treatments. The number of days counted with faecal score 1 in LS was higher than in HS (P < 0.05), while the number of days with diarrhoea medication in LS and C was lower than HS (P < 0.05). The faecal n-butyric acid concentration tended to be higher in LS compared to C (P = 0.060). The alpha diversity index (Chao1) was higher in HS than in C and LS at 90 days of age (P < 0.05). The principal coordinate analysis (PCoA) using weighted UniFrac distance showed that the bacterial community structures in faeces among the treatments at 90 days of age were significantly different (P < 0.05). The plasma β-hydroxybutyric acid concentration, an indicator of rumen development, was higher for LS than in C throughout the experiment (P < 0.05). These results suggested that adding liquefied sake lees up to 100 g/d (on a fresh matter basis) might promote rumen development in preweaning Japanese Black calves. 

Hajime Kumagai

Papers

Derivation of a regression equation to estimate the ratios of energy expenditure of walking on the level and on gradients to that of standing and application of the equation for the estimation of energy expenditures of grazing cows in abandoned paddy fields

Factors affecting the lactation curve parameters of Japanese saanen goats

Study on nutrient supply in relation to feeding system of buffalo in Chitwan, Nepal.

Effects of liquefied sake lees on growth performance and faecal and blood characteristics in Japanese Black calves.

Environmental and economic evaluation for integration systems between crop and animal production using linear programming