Effects of maceration at mowing on digestibility and ruminal fermentation of timothy hay in steers

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Effect of maceration on nitrogen fractions in hay and silage. Can. J. Anim. Sci. 78: 399-405. An intensive mechanical conditioning treatment, referred to as maceration, was applied at mowing to alfalfa or timothy in order to enhance drying rate, reduce wilting time and possibly reduce respiration losses and proteolysis. In 1995, a laboratory trial was conducted using two levels of force (1750 and 3500 Newton) and five levels of conditioning: a control (no conditioning), one passage, three passages, five passages and seven passages through two steel knurled rolls. All forages were dried in a controlled environment at 30°C and conserved as hay. The level of force did not affect the chemical composition of the forages obtained. However the nitrogen (N) fractions were affected by the level of maceration. As the level of conditioning increased, the soluble N fractions (A and B1) of both forages decreased (P < 0.001). Meanwhile, the slowly degradable N fraction (B3) increased linearly (P < 0.001) in timothy and quadratically (P < 0.003) in alfalfa. The fraction of unavailable N (fraction C) also increased linearly (P < 0.01) with intensity of maceration. In 1996, alfalfa was conditioned in the field at four intensity levels: a control (rubber roll-conditioning), one passage, two passages, and three passages through a full-size mower-macerator with three knurled rolls. The alfalfa dried under poor climatic conditions with alternating rain and sunshine and was conserved as silage at 30% dry matter (DM) after a 40-h wilt or as hay after a 90-h wilt. Neutral detergent fibre (NDF), acid detergent fibre (ADF), and ash contents increased linearly (P < 0.001) with the level of maceration; the increase was greater in hay than in silage. The non protein nitrogen (fraction A) decreased (P < 0.001) while fraction B3 and unavailable N (fraction C) increased (P < 0.001) with level of maceration. The results suggest that maceration decreases the extent of proteolysis during conservation and preserves a higher proportion of the slowly degradable N (escape nitrogen). Key words: Forage, maceration, chemical composition, nitrogen fractionsAgbossamey, Y. R., Savoie, P. et Seoane, J. R. 1998. Effet du surconditionnement sur les fractions azotées du foin et de l'ensilage. Can. J. Anim. Sci. 78: 399-405. Un surconditionnement mécanique intense a été appliqué lors de la fauche de la luzerne et de la fléole des prés dans le but d'accélérer la vitesse de séchage, de réduire le temps de fanage et de réduire possiblement les pertes dues à la respiration et à la protéolyse. En 1995, une expérience a été menée au laboratoire en utilisant deux niveaux de force (1750 et 3500 Newton) et cinq niveaux de conditionnement: un témoin (aucun conditionnement), un passage, trois passages, cinq passages et sept passages du fourrage à travers deux rouleaux broyeurs. Les fourrages ont été séchés à 30°C dans un environnement contrôlé et ont été conservés sous forme de foin. La force appliquée au surconditionnement n'a pas affecté la composition chimique des four...

Section: Changes In Chemical Compositionmentioning

confidence: 92%

Effect of maceration on nitrogen fractions in hay and silage

Agbossamey¹,

Savoie²,

Seoane³

1998

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“…In the companion study of Savoie et al (1996) we did not observe a rapid increase in fermentation rate in RB silage, unlike Muck et al (1989) who followed fermentation patterns in PC silage. A major influence on fermentation rate had been expected because of the massive disruption of cellular integrity resulting from maceration (Chiquette et al 1994). As with PC silages, maceration had little influence on protein solubility in RB silage, even though in this case DM concentration was increased.…”

Section: Silage Qualitymentioning

confidence: 99%

“…Maceration also aids the digestion of forage in the rumen by exposing greater surface area for microbial attack (Chiquette et al 1994;Petit et al 1994). While Charmley et al (1997) did not find this increased digestibility with PC silage, we expect the digestibility of RB silage would be improved with maceration, as is the case with hay (Petit et al 1994).…”

mentioning

confidence: 99%

Effect of maceration at mowing on silage conservation,voluntary intake, digestibility and growth rate of steers fed precision chopped or round bale silages

Charmley¹,

Savoie²,

McRae³

et al. 1999

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X. 1999. Effect of maceration at mowing on silage conservation, voluntary intake, digestibility and growth rate of steers fed precision chopped or round bale silages. Can. J. Anim. . Four silages were made from the primary growth of an orchardgrass (Dactylis glomerata)/white clover (Trifolium repens) sward in mid-June. Precision chopped (PC) and round bale (RB) silages were made from wilted forage that had been cut either with a regular mower conditioner (CON) or a mower macerator (MAC). Silages were fed to growing steers in a 10-wk feeding trial using a 2 × 2 factorial design. To determine apparent digestibility, silages were fed to wether sheep and ruminally incubated in nylon bags using two canulated cows. The DM concentration of silages ranged between 273 and 362 g kg -1 and was higher in RB than PC silage. Maceration increased fibre concentration in RB silage but had little influence on PC silage. Nitrogen and its fractions were not influenced by treatment. Maceration increased total acid concentration in PC silages but lowered it in RB silage. Lactic acid accounted for a higher proportion of total acids in macerated silages than in control silages. Steers fed RB silage consumed 35% more DM than those fed PC silage (P < 0.001). Maceration reduced intake of PC silage by 18% but did not affect intake of RB silage (interaction; P < 0.05). Maceration had no effect on BW gain in steers fed PC silage, but in RB silage gains were increased from 0.87 kg d -1 to 1.09 kg d -1 (interaction; P < 0.05). Feed utilization efficiency was poorer for RB than PC silage (P < 0.001) and maceration improved feed utilization (P < 0.001). The DM, OM and NDF digestibility coefficients were reduced by maceration in RB but not in PC silage (interaction; P < 0.05); a similar trend was observed for ADF (interaction; P < 0.10). Apparent N digestibility was less in MAC than CON silage (P < 0.01). Dry matter disappearance from nylon bags was not influenced by maceration in PC silage but was higher in RB-MAC than RB-CON silage. It is concluded that influences of maceration on intake and gain is dependent upon the physical form of the silage. . Les ensilages étaient servis à des bouvillons en croissance dans le cadre d'un essai d'alimentation de 10 semaines, selon un dispositif expérimental factoriel 2 × 2. Pour la mesure de la digestibilité apparente, ils étaient servis à des moutons mâles castrés et mis à incuber en sachets de nylon dans le rumen de 2 vaches fistulisées. La teneur en m.s. de l'ensilage, qui allait de 273 à 362 g kg -1 , était plus élevée dans l'ensilage BC que dans l'ensilage CF. Le surconditionnement mécanique provoquait l'accroissement de la teneur en fibre de l'ensilage BC, mais avait peu d'effet à cet égard dans l'ensilage CF. L'azote et ses diverses fractions étaient les mêmes quel que soit le traitement. La surconditionnement accroissait la concentration des acides totaux l'ensilage CF, mais avait l'effet inverse dans l'ensilage BC. L'acide lactique comptait pour une plus grande proportion des acides totaux dans l'...

“…Chiquette et al (1994) reported no increase in total digestibility of macerated timothy hay fed to steers. Frost et al (1995) also observed no improvement in the feed value of macerated ryegrass stored as chopped silage and fed to sheep.…”

mentioning

confidence: 99%

Effect of intensity of maceration on digestibility and intake of alfalfa hay and silage fed to sheep

Agbossamey¹,

Savoie²,

Seoane³

et al. 2000

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. 2000. Effect of intensity of maceration on digestibility and intake of alfalfa hay and silage fed to sheep. Can. J. Anim. Sci. 80: 113-121. A study was conducted to determine the influence of intensity of mechanical conditioning on the nutritive value of alfalfa conserved as hay or silage. Fresh alfalfa was mowed and conditioned at three levels of maceration prior to field wilting during 45 h for silage (29-39% DM) or 94 h for hay (87% DM, after barn-curing), under light rain conditions during the first 2 d. The conditioning treatments were: control (conventional mowing-conditioning), light maceration (one passage through three knurled steel rolls), medium maceration (two passages), and intense maceration (three passages). Concentrations of NDF, ADF, hemicellulose, CP-NDF, and CP-ADF increased linearly (P < 0.001) with the level of maceration. Silage pH, acetic acid, propionic acid, and butyric acid increased, while lactic acid decreased (P < 0.001), with the level of maceration. The effective rumen degradabilities of DM, CP, and NDF, measured with fistulated cows, were not affected (P > 0.10) by the level of mechanical conditioning. Forty-eight male sheep (46.8 ± 6.7 kg BW) were fed a 100% forage diet according to a completely randomized design with a 2 × 4 factorial arrangement of treatments (two storage methods and four levels of conditioning). Under restricted feeding, DM, NDF, ADF, and hemicellulose digestibilities decreased linearly (P < 0.001) with the level of maceration. However, the digestibility of CP-NDF increased with the level of maceration; the effect was more important in hay than in silage (P < 0.001 for the interaction). When silages were fed ad libitum to 24 sheep, daily DMI was 2.31, 2.88, 2.76, and 2.41% of BW and DM digestibility was 60.8, 60.1, 56.2, and 46.7%, for control, light, medium, and intense maceration, respectively (P < 0.01). The results suggest that light maceration increases DM intake while maintaining digestibility of forages fed to sheep. Because of humid conditions and potential soil contamination due to multiple windrow pickup, intense maceration caused severe nutrient loss, which might be avoided under dry field wilting and good storage conditions. Key words: Alfalfa, hay, silage, digestion, degradability, intake Agbossamey, Y. R., Savoie, P., Seoane, J. R. et Petit H. V. 2000. Effet de l'intensité du conditionnement mécanique sur la digestibilité et la prise alimentaire du foin et de l'ensilage de luzerne chez le mouton. Can. J. Anim. Sci. 80: 113-121. Une étude a été menée afin de déterminer l'influence de l'intensité du conditionnement mécanique sur la valeur alimentaire de la luzerne conservée sous forme de foin ou d'ensilage. La luzerne fraîchement coupée a été traitée à trois niveaux de surconditionnement et fanée au champ durant 45 h pour l'ensilage (29 à 39% MS) ou 94 h pour le foin (87% MS après ventilation en grange), sous des conditions de pluie légère durant les deux premiers jours. Les niveaux de conditionnement étaient: un témoin (conditionnement conventio...