Annual Ryegrass Pasture for Dairy Cows Receiving Total Mixed Ration

The inclusion of herbage in the diet of medium yielding dairy cows offered a total mixed ration (TMR) may be beneficial. This study, which involved mid lactation dairy cows, examined the effect of partial replacement of a TMR with annual temperate pasture. Treatments were ad libitum TMR (TMR100), 75% ad libitum TMR + ryegrass (Lolium multiflorum ‘Maximus’) (TMR75), and 50% ad libitum TMR + ryegrass (TMR50). Twelve multiparous Holstein and F1 Jersey × Holstein cows were divided into six homogeneous groups, taking account of milk production (26.6 ± 4.5 kg/day), days in milk (128 ± 50) and body weight (546 ± 31 kg). Treatments were compared in a replicated 3×3 Latin square design, comprising three 21-day periods (measurements during final 5 days). Cows on TMR75 and TMR50 strip grazed between morning and afternoon milking (7 h/day), with a target pre- and post-grazing sward height of 24 and 12 cm, respectively. Herbage DM intake was estimated as the difference between pre- and post-grazing herbage mass. The TMR and herbage had a crude protein content of 150 and 303 g/kg DM, and a NDF content of 366 and 495 g/kg DM, respectively. Herbage DM intake increased from 4.8 kg/day in TMR75 to 6.7 kg/day on TMR50. Total DM intake decreased from 19.4 kg/day (TMR100), to 18.1 and 15.9 kg/day (TMR75 and TMR50, respectively). Milk production, milk fat and milk protein content were similar between treatments, averaging 25.6 kg/day, 44.6 g/kg and 33.7 g/kg, respectively. The net energy for lactation (NEL) supply was 113, 104 and 92% of NEL requirements, for cows receiving TMR100, TMR75 and TMR50, respectively. Ryegrass pastures were able to replace up to 50% of TMR offered to mid lactation dairy cows without any adverse effects on milk production and milk composition

Variation Between Individuals in Voluntary Intake and Herbage Intake of Grazing Dairy Cows

Herbage intake and milk yield of unsupplemented grazing dairy cows are highly variable between animals within a herd (Delaby et al., 2001). The objective of this experiment was to describe the relationship between the individual voluntary intake (VI) of dairy cows measured before turnout and their herbage intake at grazing, at two herbage allowances

Milk fatty acid composition of cows and ewes supplemented with black wattle tannin extract.

This study evaluated the effects of Acacia mearnsii tannin extract on milk fatty acid profile of dairy ewes and cows. In experiment 1, twenty-four Lacaune ewes received one of the following dietary treatments: control (no tannin extract added to the diet), T30 (30 g tannin extract/kg concentrate), and T40 (40 g extract/kg concentrate). In experiment 2, thirty Jersey cows received either a control diet (no tannin extract added to the diet) or the same diet containing 40 g tannin extract/kg concentrate (T40). Dry matter intake, milk production and milk solids content of ewes and cows were unaffected by tannin supplementation. The cis-9, trans-11 conjugated linoleic acid (CLA) content increased linearly by 21% in milk fat from ewes fed tannin extract, while the C18:2 n-6 (linoleic acid) content tended (P = 0.051) to increase by 13% in cows fed TE. The supplementation with black wattle tannin extract improves the nutritional quality of milk fat of ewes and cows to a small extent, with no adverse effects on performance or gross milk composition

Predicting Forage Intake by Sheep through the Pampa Corte Model or NRC

The aim of the present study was to evaluate the precision and accuracy of the Pampa Corte and National Research Council (2007; NRC) models for predicting forage intake (FI) by sheep. Individual data (n = 213) of observed FI, body weight and chemical composition of consumed diet were taken from fifteen indoor digestibility trials conducted with male sheep housed in metabolic cages and fed only forage ad libitum. The diets were composed of tropical grasses, temperate grasses and legumes. Individual observations of FI were averaged by treatment (n = 32) into each experiment which were then compared to FI values predicted by Pampa Corte model or NRC using concordance correlation coefficient (CCC) and regression analysis. The average value of observed FI was 847 (± 241) whereas those predicted by Pampa Corte model and NRC were, respectively, 826 (± 230) and 987 (± 208) g DM/day. Observed values of FI were linearly related (P \u3c 0.01) to those predicted through either Pampa Corte or NRC. However, the Pampa Corte resulted in higher CCC than NRC. Also, through the Pampa Corte model, the linear regression presented a slope not different from 1 and an intercept not different from 0. The NRC model, however, resulted in a slope of the linear regression lower than 1 despite the intercept was not different from 0. The Pampa Corte model was more precise and accurate in predicting FI by sheep fed only forage than NRC

An Algebraic q-Deformed Form for Shape-Invariant Systems

A quantum deformed theory applicable to all shape-invariant bound-state systems is introduced by defining q-deformed ladder operators. We show these new ladder operators satisfy new q-deformed commutation relations. In this context we construct an alternative q-deformed model that preserve the shape-invariance property presented by primary system. q-deformed generalizations of Morse, Scarf, and Coulomb potentials are given as examples

Avaliação de cultivares de gergelim no outono - inverno na região Norte-Fluminense.

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Pastagem de missioneira-gigante submetida a alturas de corte e severidades de desfolha em pleno sol e com restrição de luminosidade.

A ampliação das áreas em sistemas integrados de produção agropecuária, aliado a necessidade do aumento de produtividade, gera uma demanda de conhecimento que norteie a implantação e o manejo dos sistemas como um todo. Neste contexto, objetivou-se com este trabalho a avaliação das características morfológicas e estruturais da pastagem de Missioneira-gigante submetida a diferentes alturas de corte, severidades de desfolha em pleno sol e com restrição de luminosidade. A missioneira-gigante foi cultivada em vasos de 0,30 m2 (1,0 x 0,3 m), com profundidade de 0,5 m. A sombra foi reproduzida por ripados de madeira, com 50% de redução da luminosidade. Os tratamentos consistiram na combinação de quatro alturas de corte (15, 25, 35 e 45 cm), quatro severidades de desfolha (20, 40, 60 e 80%), em dois ambientes luminosos (sol e sombra), avaliados em esquema fatorial 4 x 4 x 3, em delineamento inteiramente casualizado, com 3 repetições, totalizando 96 unidades experimentais. Em ambiente com restrição de luminosidade as plantas apresentaram 7,0 cm a mais na altura do dossel para atingir o mesmo nível de interceptação luminosa, quando comparado ao pleno sol. A missioneira-gigante submetida a maior severidade de desfolha apresenta menor densidade populacional de perfilhos vegetativos e totais, independente da condição luminosa

Impacto do manejo e luminosidade na produção de massa aérea e raízes em missioneira-gigante.

Em um sistema de pastejo, a planta deve ser estudada como um todo (parte aérea e raízes), pois as diferentes estruturas interagem para o crescimento e produção. Objetivou-se avaliar a produção de massa da parte aérea e de raízes da pastagem de Missioneira-gigante submetida a diferentes alturas de corte (15, 25, 35 e 45 cm), severidades de desfolha (20, 40, 60 e 80%) em pleno sol e sombra (redução de 50% da luminosidade), avaliados em esquema fatorial 4x4x2, em delineamento inteiramente casualizado, com 3 repetições. A missioneira-gigante foi cultivada em caixas de 0,15 m3. A altura de pastejo ou corte para Missioneira-gigante deve situar-se entre 25 e 35 cm. Severidade de 40% pode ser aplicada para manejo em pleno sol e de 20% para manejo na sombra