Modelling of Herbage Intake and Milk Production by Grazing Dairy Cows

Key-points Models predicting intake and performance of grazing ruminants from animal, sward, grazing and supplements characteristics are rare, but they are now included in several decision support systems (DSS). An evaluation of the performance and accuracy of published models are rarely undertaken by their authors, but this is proposed in this paper. There is still a need for experimental research but also for the development of generic and dynamic models to predict intake and performance over a wide range of grazing conditions

Corn silage supplementation for dairy cows grazing annual ryegrass at two pasture allowances

Corn silage supplementation for dairy cows grazing in temperate annual pastures has rarely been investigated. The aim of this study is to compare two supplementation levels (0 and 4kg dry matter [DM]/day of a 7:1 mixture of corn silage and soybean meal) in dairy cows strip-grazing annual ryegrass (Lolium multiflorum Lam.) at two pasture allowances (PA, low= 25 and high = 40kg DM/d at ground level). The study was carried out according to an incomplete 4 × 3 Latin square design, using 12 cows and three experimental periods of 12 days. The green leaves allowances were only 4.9 and 8.5kg DM/d at the low and high PA, respectively. The total DM intake and milk production increased in supplemented cows compared to un-supplemented cows at the low PA, but were similar between supplementation levels at the high PA. The PI was unaffected by the PA, whereas the substitution rate was 0.68 in cows at the low PA and 1.35 in cows at the high PA. Corn silage supplementation may improve the total DM intake and milk production of dairy cows grazing in temperate annual pastures, but only at a low PA

Consumo de materia seca de vacas lecheras en sistemas que combinan pastoreo, concentrados y forrajes conservados: tasa de sustitución y respuesta en producción

Consumo de materia seca de vacas lecheras en sistemas que combinan pastoreo, concentrados y forrajes conservados: tasa de sustitución y respuesta en producción. XLVII jornadas urugayas buiatri

Le chargement, c’est quoi ?

Le chargement, c’est quoi

Estimación del consumo de pasto por vaca y por hectárea a nivel de predios lecheros: indicadores prácticos para toma de decisiones de manejo

Estimación del consumo de pasto por vaca y por hectárea a nivel de predios lecheros: indicadores prácticos para toma de decisiones de manejo. XLVII jornadas urugayas buiatri

Foraging behavior and ruminal fermentation of dairy cows grazing ryegrass pasture alone or with white clover

The objective of this work was to evaluate the influence of pasture composition and regrowth age on the relationship between feeding behavior and ruminal fermentation in dairy cows grazing perennial ryegrass with or without white clover. The experiment was carried out in a 2x2 factorial arrangement, with two sward types and two ages of regrowth. Swards of perennial ryegrass sown alone (PRG) and of perennial ryegrass mixed with white clover (GC) were evaluated. Twelve late‑lactation Holstein cows, fistulated at the rumen, were distributed in a 4x4 latin square experimental design with four 12‑day periods. Daily distribution of grazing was similar in the PRG and the GC swards, but the concentration of rumen volatile fatty acids (VFA) was higher and the proportion of propionate was lower on mixed swards during the day. Daily distributionof grazing was similar in pastures of different ages. However, in the oldest swards, rumen fluid pH increasedand VFA concentration decreased after evening milking. Time spent grazing does not influence ruminalfermentation, which depends on the changes that occur as different sward layers are grazed.The objective of this work was to evaluate the influence of pasture composition and regrowth age on the relationship between feeding behavior and ruminal fermentation in dairy cows grazing perennial ryegrass with or without white clover. The experiment was carried out in a 2x2 factorial arrangement, with two sward types and two ages of regrowth. Swards of perennial ryegrass sown alone (PRG) and of perennial ryegrass mixed with white clover (GC) were evaluated. Twelve late‑lactation Holstein cows, fistulated at the rumen, were distributed in a 4x4 latin square experimental design with four 12‑day periods. Daily distribution of grazing was similar in the PRG and the GC swards, but the concentration of rumen volatile fatty acids (VFA) was higher and the proportion of propionate was lower on mixed swards during the day. Daily distribution of grazing was similar in pastures of different ages. However, in the oldest swards, rumen fluid pH increased and VFA concentration decreased after evening milking. Time spent grazing does not influence ruminal fermentation, which depends on the changes that occur as different sward layers are grazed. azevém perene consorciado com trevo branco (TB) – e duas  idades de rebrota. A distribuição diária do pastejo foi semelhante nos pastos AZ e TB, mas a concentração ruminal de ácidos graxos voláteis (AGV) foi maior e a proporção de propionato foi menor nos pastos em associação, ao longo do dia. A distribuição das atividades de pastejo foi semelhante nos pastos com idades diferentes. Entretanto, nos pastos mais velhos, o pH ruminal aumentou e a concentração de AGV diminuiu após a ordenha da tarde. O tempo de pastejo tem pouca influência sobre a fermentação ruminal, a qual depende de alterações que ocorrem à medida que os diferentes estratos são pastejados

Valeur de l’herbe pâturée

Valeur de l’herbe pâturé

Ruminal degradability of leaves of Morus alba and Fraxinus excelsior managed as pollards or high stem trees

Ruminal degradability of leaves of [i]Morus alba[/i] and [i]Fraxinus excelsior[/i] managed as pollards or high stem trees. 4. World Congress on Agroforestr

Does the Feeding Behaviour of Dairy Cows Differ When Fed Ryegrass Indoors vs. Grazing?

Dairy cows eating ryegrass ingest smaller boli when grazing than when fed indoors (93 vs. 142 g; Boudon et al., 2004). To investigate whether this difference in bolus affects feeding behaviour of the cows, an automated system (chewing halters) was used to monitor feeding behaviour of cows given ad libitum access to perennial ryegrass in individual feed troughs (indoor feeding, IF) or at pasture (grazing, GR)