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Biomedical subjects

D Sauvant

Publications and source records attributed to D Sauvant.

At least 37 records · Page 2Linked to original sources
PubMed1990

[Additivity of in sacco degradation of dry matter from simple mixtures of feed concentrates].

Barley and maize were combined with either lupine seeds or corn gluten meal so that the 4 blends present different rumen degradation rates for their carbohydrate and/or nitrogen constituents. The measured values (dm) of dry matter in sacco degradability of these concentrates were higher before and lower after 8 h of incubation compared to the calculated values of degradability (dc) obtained by the additive method according to their composition. Moreover, the differences (dm-dc) were the highest for the less degradable feeds.

Animal Feed↗
PubMed1990

[Comparison of different adjustment models of curves of fecal excretion of transit markers].

Seventy nine fecal excretion curves of rare earth were adjusted with 3 published models (Grovum and Williams, 1973; Dhanoa et al, 1985; Siddons et al, 1983). The models provided statistically similar estimations of particulate turnover in the first compartment and mean retention time. However, some important individual differences between parameter values could be observed from one model to another.

Animals↗
PubMed1990

[Influence of the quantity of ingested dry matter and food retention time on feed digestibility in dairy goats].

Simultaneous measurements of organic matter digestibility (OMD) and particulate mean retention time (MRT) of diets containing various proportions of hay and concentrate (bran or beet pulp) were performed in lactating or dry goats. Beyond the hay and concentrate influences, the OMD decreased by 0.5 and 1.3 points as the dry matter intake level increased by 10 g/kg LW0.75 and MRT decreased by 5 h, respectively.

Animal Feed↗
PubMed1990

[Combined effects of injected 1-29 GRF and diet energy level in lactating goats].

Subcutaneous injections of 1-29 GRF and diet energy level were studied in 48 dairy goats using a 2 x 2 factorial design. Energy and GRF effects were additive on milk production and some interactions were observed on the milk fat and protein contents. Subcutaneous injections seemed to be less efficient in promoting milk secretion than the intravenous route used in a previous trial.

Animals↗
PubMed1989

Associative effects between two fibre sources on ileal and overall digestibilities of amino acids, energy and cell-wall components in growing pigs.

1. The associative effects of two fibre sources on ileal and overall digestibility of amino acids, energy and cell-wall components were studied by comparing wheat bran and soya-bean hulls in semi-purified diets given to growing pigs. 2. Castrated male pigs were prepared with ileo-rectal anastomosis to measure ileal digestibility, and overall digestibility was measured in pigs without anastomosis. 3. The three diets contained 190 g total fibre/kg dry matter (DM), derived from each fibre source or from a mixture of both fibre sources, so that each source provided half the amount of total fibre, and 170 g crude protein (nitrogen x 6.25)/kg DM by additions of casein. 4. The effects of fibre sources on the ileal digestibility of amino acids were additive for most amino acids; the only significant interactions were found for threonine, methionine and aspartic acid. In contrast with ileal digestibility, systematic negative interactions between fibre sources on overall digestibility of amino acids were noted. 5. There was no interaction between fibre sources in their effects on the digestibility of energy or of cell-wall components, irrespective of the site of digestion. The digestibility values were higher with soya-bean hulls than with wheat bran, especially at the faecal level. 6. It is concluded that ileal digestibility of amino acids provides a better estimate of amino acid availability, as ileal measurements allow a better discrimination between diets than faecal measurements when distinct fibre sources are used alone or in combination at the same total fibre content. In contrast, for energy, the measurement of digestibility at both faecal and ileal levels permits the estimation of the partition of available nutrients between the small and large intestines.

Amino Acids↗
PubMed1988

[Modelling of digestion in the rumen].

The ruminal ecosystem illustrates the main concepts of system analysis. Due to its structure and functional complexity and to its determinant role in ruminant nutrition and feeding, the reticulo-rumen has been the target of modelling works. The proposed models have been static or dynamic. The later have known a recent development but the former have until now largely contributed to the knowledge progress. The complexity of dynamic models is proportional to the number of biological mechanisms taken into account. The simplest models describe, for instance, a degradation or a transit elementary process. The aggregated models take simultaneously into account 2 to 4 processes while the general models aim at describing the digestive behaviour of the ruminal ecosystem by integrating its main functions. These mechanistic models have been studied for about 20 years. They are on the whole satisfactory but they are not sufficiently able to describe some diet differences and some variations in the dynamic properties of feed particles.

Animals↗
PubMed1988

[Secretion of fatty acids into milk as a function of the characteristics of the diet and the nutritional status of the goat at the onset of lactation].

The amounts of 11 milk fatty acids secreted by 210 individual goats during the 2nd week of lactation were explained by 4 variables: the intake of digestible organic matter and ether extracts, the organic matter digestibility and a lipid mobilization index. Significant effects varied according to the acids. About a quarter of the absorbed acetate equivalent appeared to be secreted as milk fat.

Animal Feed↗
PubMed1988

[Estimation of body water in the lactating goat by injection of urea].

Urea dilution technique (130 mg/kg live weight) was used to estimate total body water (BW) in 12 goats. Empty body water (EBW) determined by lyophilization was more closely related to urea space (US) than total BW. EBW was estimated with a better precision (CV = 4.7%) from the prediction equation including US measured 20 min after urea infusion and body weight. This urea technique was considered convenient.

Animals↗
PubMed1986

Mammary metabolism in the goat during normal or hormonally-induced lactation.

Mammary metabolism was studied in 4 normal lactating goats (group N) and in 4 non-pregnant goats induced to lactate by hormonal treatment (group 1). Tissue was sampled by biopsy after 3, 9 and 18 weeks of lactation. Although milk potential was the same in both groups, group 1 produced 45% less milk than group N. The RNA-DNA ratio, activities of lipoprotein lipase (LPL), glucose-6-phosphate dehydrogenase and acetyl-CoA carboxylase, and the beta-casein % of in vitro protein synthesis were not significantly lower in the 1 than in the N goat mammary tissue. This suggests that differences in mammary cell hyperplasia during hormonal treatment, and not potential metabolic activities, partially accounted for the difference in milk yield levels. Milk composition was comparable in the two groups. However, milk fat in group N had a higher long-chain fatty acid content (stearic and oleic acids) during the first month of lactation due to the higher mobilization of body lipids in high-yielding animals. Another qualitative difference was the delayed increase in milk LPL secretion during the first 3 months of lactation in induced goats.

Animals↗
PubMed1986

Digestion of milk, fish and soya-bean protein in the preruminant calf: flow of digesta, apparent digestibility at the end of the ileum and amino acid composition of ileal digesta.

1. Digesta were collected from eleven preruminant calves fitted with re-entrant (four calves in Expt 1 and three in Expt 2) or single cannulas (four calves in Expt 1) in the terminal ileum. Collection periods lasted 24 h (Expt 1) or 96 h (Expt 2). 2. Two milk-substitutes (fish and soya bean) and a control diet were given to the calves. In the control diet, protein was entirely provided by skim-milk powder. In the other two diets, protein was provided mainly by a partially hydrolysed white-fish protein concentrate or a soya-bean protein concentrate prepared by extracting soya-bean meal with hot aqueous ethanol. 3. In Expt 1, flow rates of fresh matter, dry matter, nitrogen and ash exhibited two maxima between 6 and 8 h after the morning meal and between 4 and 6 h (control and soya-bean diets) or 6 and 8 h (fish diet) after the evening meal. Minimum pH values were observed at times of maximum flow rate. Variations observed in the flow rates and pH values were larger with fish and especially soya-bean diets than with the control diet. 4. The apparent digestibility of the three diets in the terminal ileum was significantly higher in Expt 2 than in Expt 1: for N, the values were 0.92, 0.83 and 0.75 (Expt 1), and 0.94, 0.87 and 0.88 (Expt 2) with the control, fish and soya-bean diets respectively. 5. The amount of N apparently absorbed in the terminal ileum represented 90-96% of the amount that disappeared from the whole digestive tract in Expt 1 and 95-99% in Expt 2. 6. In Expt 1 the amino acid (AA) composition of digesta changed little with the flow rate when the calves were given the control diet (from 158 to 179 g glutamic acid/kg AA). With the fish and soya-bean diets the AA composition was similar to that observed with the control diet when the flow rate was minimum, but differences became apparent as the flow rate increased (281 and 161 g glutamic acid/kg AA for the soya-bean and control diets respectively with maximum flow rate). In Expt 2, the mean compositions of the digesta were very similar to the means obtained in Expt 1. 7. Different comparisons with dietary, endogenous and bacterial proteins indicated that for the three diets a common mixture containing approximately 65% endogenous and 35% bacterial proteins reached the terminal ileum.(ABSTRACT TRUNCATED AT 400 WORDS)

Amino Acids↗
PubMed1986

[The relationship between udder secretion and the content of blood energy nutriments and nitrogen in the goat at the onset of lactation].

An experiment was performed on 29 dairy goats at the onset of lactation; energy and protein deficits were maximal during the first week of lactation. This was confirmed for energy by the plasma contents on non-esterified fatty acids (NEFA), beta-OH-butyrate and glucose. However, protein deficit was more critical during the second week, as shown by plasma urea, glycine and 3-CH3-histidine contents. At that time, nutritional status depended more on udder production than on intake level. Moreover, the nutritional parameters of body lipid and protein mobilization were positively correlated. Milk protein content was positively correlated with the nutritive balance and status of the goats.

3-Hydroxybutyric Acid↗
PubMed1983

Methods of comparing amino acid composition of proteins: application to undigested proteins in the preruminant calf.

The digestive utilization of dietary proteins at different sites along the digestive tract and the effects of their ingestion on the function of the digestive tract (secretion of endogenous proteins, development of microflora) can be inferred from the proportions of dietary, endogenous or microbial proteins. A first approach was to examine the proportions of some characteristic amino acids. A more accurate interpretation could be made by studying the additional undigested protein provided by the ingestion of an 'experimental' diet whose composition was calculated, for example, with regard to the undigested protein obtained with a very digestible diet (milk in the calf). These interpretations were often insufficient and did not extract all of the possible information. Thus, more global methods with statistical criterions had to be used. Some allowed two proteins (correlation and linear regression, average relative difference, chi 2) to be compared. Others made it possible to take many proteins into consideration (factorial correspondence analysis). Finally, examples were given to seek the respective proportions of many proteins in a complex mixture or to estimate the most probable amino acid composition of the 'microbial + endogenous' proteins which escaped digestion in the small intestine. These various approaches have been discussed, with examples taken from our experimental results obtained in the preruminant calf, to show their advantages and limitations. In any case, the quality of the interpretation depends on the quality of the available results on the amino acid composition of endogenous, microbial and undigested dietary proteins.

Amino Acids↗
PubMed1980

[Description of feed intake in goats].

Four adult goats were given lucerne hay ad libitum and had access to water, salt stone and the litter straw. They were housed in a box and were completely free to move. Their meals consisted of the main behavioural activity of hay intake and other activities such as salt-stone licking, water drinking and straw intake. Ingestion was relatively slow because the goats took a long time to choose what they ingested. They chose the hay with more leaves and less stems which had a higher nutritive value.

Animal Feed↗