Effects of source of forage and level of concentrate on chewing activity and milk production response in late lactation cows

Abstract

. 1997. Effects of source of forage and level of concentrate on chewing activity and milk production response in late lactation cows. Can. J. Anim. Sci. 77: 253-258. Four cannulated Holstein cows in late lactation were used in a 4 × 4 Latin square design experiment to determine the effects of forage source with different NDF concentrations and level of concentrate on chewing activity and milk production. Diets were 65% first-cut alfalfa silage with 54% NDF and 35% concentrate, 50% alfalfa and 50% concentrate, 65% bromegrass silage with 65.5% NDF and 35% concentrate and 50% bromegrass silage and 50% concentrate. Diets were fed in 2 × 2 factorial design (silage sources, alfalfa vs. bromegrass and two levels of concentrate, 35 vs. 50%). Dry matter intake averaged 15.2 kg d -1 and was not affected by either forage source or level of concentrate. Intake of NDF was lower for the cows fed the alfalfa-based diet vs. bromegrass silage but the level of concentrate did not affect NDF intake. Time spent eating was not affected by either forage source or concentrate level of the diet. Time spent eating and ruminating kg -1 NDF intake was higher for cows fed alfalfa-based diets than for cows fed the bromegrass-based diets. Total chews g -1 NDF intake tended (P = 0.06) to decrease when cows were fed bromegrass-based diets but eating and ruminating chews g -1 NDF intake were not affected by source of forage or level of concentrate in the diet. Diets with either alfalfa or bromegrass had no effect on daily yields of milk, FCM, fat, protein and lactose. Diets with 50% concentrate increased milk and FCM yields by 11 and 14%, respectively. Fat and lactose yields were also increased by 17 and 11% in cows fed diets with the higher concentrate level. Results suggest that chewing activities during eating and ruminating phases of the eating cycle adjusted for DMI may decrease with increased concentrate level and are not affected by source of forage in the diet. However, chewing activities adjusted for NDF intake are influenced by source of forage but not by level of concentrate in the diet. The results also suggest that yields of both milk and milk components in late lactation cows are influenced by level of concentrate in the diet, while only milk components are affected by source of forage.Key words: Dairy cattle, chewing activity, forage, milk production Okine, E. K., Khorasani, G. R. et Kennelly, J. J. 1997. Effets de la nature du fourrage et de la proportion d'aliments concentrés dans le régime sur l'activité masticatoire et sur la production laitière de vaches en fin de lactation. Can. J. Anim. Sci. 77: 253-258. Quatre vaches Holstein fistulisées, en fin de lactation, ont été utilisées dans une expérience conduite en carré latin 4 × 4 pour déterminer les effets de fourrages de teneurs diverses en NDF et du niveau de concentrés de la ration sur l'activité masticatoire et sur la production de lait. Les régimes consistaient en : 65 % ensilage de luzerne de première pousse à 54 % de NDF et 35 % de concentrés, 50 % ensilage de luzerne ...

Effects of maturity and harvest season of grass-clover silage and of forage-to-concentrate ratio on milk production of dairy cows

“…The ECM yield followed to some extent the concentration of CP in the ration. Previous results of Okine et al (1997) suggested that a higher milk yield could be induced by a higher CP intake and a slightly higher DMI, and NRC (2001) also concluded that an increased CP concentration in the ration increased the milk yield. Their results were based on several protein feeding trials and was true until 19% CP.…”

Glucose transporter gene expression in bovine mammary gland.

“…The diet of these cows was formulated to satisfy the nutrient requirements of a Holstein cow weighing 600 to 650 kg and producing 30 kg of milk daily. The diet was a 50:50 forage:concentrate ratio (DM basis) composed of a first-cut alfalfa with 54% NDF and a mixture of barley, canola and soybean meal, ground corn, molasses, and mineral-vitamin premix (Okine et al, 1997). Mammary glands were collected from two of the cows directly off the processing line at a local abattoir and from the other two slaughtered by exsanguination at the University of Alberta Research Station.…”

Effects of rations and seasons on milk yield and composition in small and medium dairy farms from a Tunisian northern area (Bizerte Region)

“…However, a variation of about 4.7 % was recorded between TR1 (containing 54 % of concentrate) and the other rations. Okine et al (1997) found that lactose yield was increased by 11 % in cows fed 50 % concentrate diets compared with cows fed 35 % concentrate diets. Malossini et al (1996) found also a small but significant increase following the increase in feeding level (1.6 % with diet high feeding level (7 % of UFL above the allowances) and 1.4% with diet very high feeding level (14 % of UFL above the allowances) comparatively to normal feeding level.…”