A comparison of alternative sources of inocula in an in vitro digestibility technique

Copyright © Elsevier / INRA, 1996.In this paper we make the comparison between sources of inocula for an in vitro digestibility method based on that of Tilley and Terry (1963) as modified by Alexander and McGowan (1966). The best results for the prediction of the in vivo digestibility were obtained using the traditional method of rumen liquor from fistulated sheep. However, with the two alternative methods, one using rumen liquor from slaughtered cattle, and another, a sheep faeces suspension as inocula sources, we obtained results significantly correlated with in vivo digestibility at the 5% level, although with lower correlation coefficients. The method that uses rumen liquor from slaughtered cattle is, in our opinion, a valid alternative to the traditional method

Effects of Condensed Tannins from Quebracho Extract on the Kinetic of in vitro Gas Production on Trifolium repens, Lotus corniculatus and Lolium perenne

The aim of this work was to study the effect of condensed tannins (CT) on the kinetic of gas production in vitro, on the three main species of Azorean pasture: Trifolium repens, Lotus corniculatus and Lolium perenne, using Quebracho extract as the source of CT, and also to calculate total tannins and condensed tannins on the species studied. Lotus corniculatus, Lolium perenne and Trifolium repens were tested in vitro with the inclusion of Quebracho extract in doses of 0%, 2.5% and 5% DM. The total content in tannins was determined in the 3 species. We have found, in comparison with standard tannic acid, that tannins exist in the flower of T. repens (0.81 equivalents of tannic acid) and in L .corniculatus (1.07 equivalents of tannic acid) but not in L .perenne (0 equivalents of tannic acid). The concentration of condensed tannins in the 3 species was: 0.34 mg/mL for T. repens; 0.83 mg/mL for L. corniculatus and 0 mg/ml for L. perenne. We verified that a significant reduction (P < 0.05) of gas production happened for doses of 5% of CT in comparison with the other two concentrations: 0% and 2.5% of CT. The results of this study express a reduction of the fermentation rate, which implies a reduction of gas production, so, a reduction of methane emission to the atmosphere and an increase of exploitation of the protein by ruminants

Variação do valor nutritivo e da degradabilidade in situ da matéria seca e da proteína bruta da erva castelhana com a época de corte e com o método de conservação

Neste trabalho determinámos o valor nutritivo da erva castelhana (Lolium multiflorum) em três épocas de corte, em verde e ensilada. O valor mais elevado de energia metabolizável foi determinada na fase de crescimento 5% espigado, nas forragens verdes e na fase de aparecimento da 4ª folha, para as silagens. Verificou-se um aumento da digestibilidade in vivo e da ingestão voluntária, da fase de 4ª folha para a fase 5% espigada, seguindo-se um decréscimo para a fase 100% espigada: A degradabilidade in situ da matéria seca, e da proteína bruta decresce (p≤0.05) com o avançar da fase de crescimento. A degradabilidade da proteína bruta é superior nas forragens verdes (p≤0.05) em relação às forragens ensiladas. Podemos concluir que a melhor época de corte, para a erva castelhana, verifica-se na fase de crescimento com 5% espigado.ABSTRACT: The nutritive value of Italian ryegrass (Lolium multiflorum) cut at three stages of growth and in fresh and ensiled, was determined in this study. The highest metabolisable energy content was found at 5% ear in fresh forages, and at the fourth leaf stage in silages. In vivo digestibility and voluntary intake increased from fourth leaf to the 5% ear stage of growth which was followed by a reduction at the 100% ear stage of growth. In situ dry matter and protein degradability decreased (p≤0.05) with advancing stage of growth. In fresh forages protein degradability was higher (p≤0.05) than in ensiled forages. It was concluded that the best harvest time for Italian ryegrass was at the 5% ear stage of growth for both fresh forage, as well as silage

Characterization of in situ dry matter and protein degradation of green and ensiled oats forages at three stages of growth

Special Issue: IVth International Symposium on the Nutrition of Herbivores, Clermont-Ferrand (France), September 11-15, 1995

The feeding value of green and ensiled São Jorge natural pasture

Special Issue: IVth International Symposium on the Nutrition of Herbivores, Clermont-Ferrand (France), September 11-15, 1995.This paper presents the results of a study of the feeding value of São Jorge pastures in green and in big bale silage

Comparison of three sources of inocula for predicting apparent digestibility of ruminant feedstuffs

Copyright © INRA, EDP Sciences 2001.In the present study, gas production of three sources of inocula rumen liquor from fistulated sheep, rumen liquor from slaughtered cattle, and a suspension of sheep faeces, were evaluated to predict the apparent digestibility of ruminant feedstuffs. The highest gas production was obtained with rumen liquor from slaughtered cattle, and the lowest (P 0.05)

Association between Plasma and Milk Urea on the Insemination Day and Pregnancy Rate in Early Lactation Dairy Cows

Lactatingdairy cows (n=177) feed with grass and corn silage ad libitum kept in pasture, were randomly assigned to evaluate how urea nitrogen in plasma and milk can be related to their pregnancy rate. Blood and milk samples were collected on the artificial insemination (AI) day to evaluate plasma urea nitrogen (PUN) and milk urea nitrogen (MUN) as well as progesterone levels, excluding cows with progesterone higher than 0.5 ng/ml. Cows were considered pregnant if six weeks after artificial insemination, they did not return to estrus.Concentrations of PUN or MUN greater than the average (16 mg/dl) were associated with decreased pregnancy rates (13% and 14%, respectively) (p< 0.05) as compared to the cows with urea levels less than this value on the insemination day. As PUN and MUN increased to greater than 16 mg/dl, the likelihood ratio for pregnancy decreased. There was a high correlation between PUN and MUN concentrations (r²= 0.97, p≤ 0.001). The results of this study indicate that an increase in PUN or MUN can exert director indirect effects in reproduction, impairing the conception of grazing dairy cows

Pittosporum Undulatum and Hedychium Gardnerianum: nutritive value and secondary metabolites on cattle reproductive performances

Hedychium gardnerianum (HG) and Pittospporum undulatum (PU) are invasive plants all over the world, being in the Azores supplied to cattle on periods of shortage food. As these plants produce secondary metabolites, including a diverse range of phytochemicals compounds, the aim of the presente study is to identify how these metabolites can be related to animal’s reproductive performances. For such purpose, plants were harvested on winter, compounds extracted by method of decoction and analysed by combination of liquid chromatography and mass spectrometry as well as highperformance liquid chromatography. For nutritive evaluations, Van Soest and Weende methodologies were used. In HG quercetin-3, 4'-di-O-betaglucopyranoside, myricetin rhamnoside, quercetin rhamnoside, and gibberellin A1 and A8 were identified, while for PU were found cafeic acid derivatives, including dicaffeoylquinic acid and caffeoylquinic acid. In nutritional terms, these plants can be considered as poor, presenting percentages of dry matter (DM%) of 16.34% and 40.39%, respectively for HG and PU. Values for ash 10.4%, crude protein (CP) 7.75%, neutral detergent fiber (NDF) 64.5, acid detergent fiber (ADF) 34.69%, acid detergent lignin (ADL) 3.47% and ether extract (EE) 2.03% were found for HG. For PU values were ash 6.64%, CP 6.11%, NDF 43.84%, acid ADF 35.57%, ADL 3.56% and EE 2.71%. This study clearly indicated that, besides their low nutritive values, these plants can be used to feed ruminants, especially when pasture lacks. Nevertheless, as some compounds, namely the caffeoylquinic and dicaffeoylquinic acids, are known to be associated to physiological reproductive mechanisms, one could speculate that these compounds can be directly or indirectly associated to reproductive performances in bovine fed with these plants

The effects of supplementation with sunflower and soybean oils on the fatty acid profile of milk fat from grazing dairy cows

Copyright © INRA, EDP Sciences, 2005.The objective of this study was to observe the effect of supplementation with vegetable oils (VO) on the fatty acid profiles and conjugated linoleic acid (CLA) content of milk fat. Twelve dairy cows in mid lactation fed on pasture were blocked by body weight, milk production and days in lactation and randomly allocated from blocks to 3 treatments repeated in a Latin square design with periods of 28 day duration. The treatments were as follows: cows on pasture supplemented with 5 kg concentrate per head per day (C), supplemented with 4.5 kg concentrate + 0.5 kg sunflower oil per head per day (SFO) and supplemented with 4.5 kg concentrate + 0.5 kg soybean oil per head per day (SBO). The animals were grazed as a group and were stocked at 2.5 heads per hectare. The treatments had no effect on milk yield or protein yield and content, but decreased milk fat yield and content (P < 0.05). Milk fat from the cows supplemented with VO had a lower concentration of short and medium chain fatty acids (P < 0.05) and a higher concentration of long chain fatty acids (P < 0.05). The addition of VO to the diet also resulted in a reduction in saturated and an increase in unsaturated fatty acids of milk fat (P < 0.05). The hypercholesterolemic fatty acids in milk fat (i.e. C12:0, C14:0 and C16:0) decreased while the concentration of oleic and linoleic acids increased with VO (P < 0.05). There was no effect on linolenic acid. Finally, the inclusion of VO in the diet increased (P < 0.05) the contents in milk fat of the various cis/trans isomers of oleic acid (including trans-vacenic, TVA) and of CLA which increased by 61%

Effect of diet on the fatty acid pattern of milk from dairy cows

Copyright © INRA, EDP Sciences, 2004.Twelve dairy cows 130 days in milk were sorted by milk production and body weight and assigned to three feeding regimens in a 3 × 3 Latin-square design, in order to study the effects of diet on milk fatty acid (FA) composition. The cows were fed a total mixed ration (TMR) consisting of corn silage (60%) and concentrate (40%) on dry matter basis, or grazed pasture, without (P) or with 5 kg•d-1 concentrate as a supplement (SP). Supplemented grazing dairy cows produced significantly more milk than the cows on the TMR and P diets (P < 0.05). The supplementation of grazing dairy cows with a low fat concentrate did not significantly affect the milk fat FA profile. The pasture diet, with a supplement or not, decreased the concentration of saturated FA (P < 0.05) and increased the concentration of unsaturated FA (P < 0.05), of milk fat as compared to the TMR diet. The reduction in medium-chain FA was offset in large part by increases in long-chain FA (mainly oleic acid). The concentrations of conjugated linoleic acid (CLA) (P < 0.05) and trans-vaccenic acid were higher (P < 0.05) in the milk fat from the grazing cows. The results showed substantial variation among individual cows within treatments on milk fat content of CLA. Significant correlations were found for individual cow's milk fat CLA content across diets. Overall, this study indicates that the concentration of CLA in milk fat is enhanced by the dietary intake of pasture and that moderate low fat concentrate supplementation of grazing dairy cows increases performance without compromising the FA profile of milk fat