Effect of rumen protected methionine supplementation on early lactational responses of dairy cows fed a grass silage and cereals diet

To investigate the milk production limiting potential of a diet based on grass silage (40%), hay (15%), dried sugar beet pulp (13%) and grain compound mixture (32%), 28 multiparous cows in early lactation were randomly assigned to two treatment groups: a control group and a group receiving supplementary rumen protected methionine (RPMet) treatment (12 g intestinally available methionine/ cow/day, given 1–120 days postpartum; Smartamine™; RPAN’s technology). The diet was formulated to meet the requirements for protein and net energy. RPMet supplementation had no significant effect on DMI (kg/cow/day), milk dry mass, milk lactose and milk urea contents. Responses for mean daily milk yield, mean milk fat and milk protein yields were significantly higher (P < 0.05) in cows supplied with RPMet than in controls. Mean daily milk yield, milk protein and milk fat yields increased by 2.4 kg, 108 g and 124 g, respectively. The mean daily milk protein and casein contents were increased by 1.8 g and 0.9 g and milk fat content by 1.2 g in 1 kg of milk, respectively. The results suggest that in cows fed grass silage and a grain compound mixture milk production is limited by methionine insufficiency, but milk production performance can be increased significantly by the addition of RPMet to the diet

Fermentacja i proteoliza procesu kiszenia świeżej i podsuszonej zielonki z di- oraz tetraploidalnych form koniczyny czerwonej

form of red clover (2n – 4n), cultivars within the genetic form: 2n (Krynia, Parada), 4n (Jubilatka, Bona) and DM x form, DM x 2n, DM x 4n. Fermentation and proteolysis during the ensilage of red clover were affected primarily by wilting, whereas genetic factors (genetic form, cultivar) exerted a lesser effect. However, the genetic form of red clover affected the true protein content of silage and the extent of proteolysis during the ensiling process. The effect of the genetic form of red clover on the extent of proteolysis in silage (at similar levels of water-soluble carbohydrates and buffering capacity) suggests that diploid and tetraploid red clover cultivars differ with respect to chemical properties (poliphenol oxidase activity, polyphenol content) affecting proteolysis.Analizowano wpływ podsuszenia surowca, formy genetycznej koniczyny czerwonej (2n – 4n), odmiany w obrębie danej formy genetycznej: 2n (Krynia – Parada), 4n (Jubilatka – Bona) oraz SM x forma, SM x 2n, SM x 4n. Uzyskane wyniki wykazały dominujący wpływ czynnika podsuszenia nad czynnikami genetycznymi (forma genetyczna, odmiana) na przebieg fermentacji i zakres proteolizy podczas zakiszania koniczyny czerwonej. Stwierdzono jednak wpływ formy genetycznej koniczyny na zawartość białka właściwego w kiszonkach oraz stopień proteolizy w trakcie zakiszania. Stwierdzony wpływ formy genetycznej koniczyny na zakres proteolizy w kiszonkach (przy zbliżonym udziale cukrów rozpuszczalnych i pojemności buforowej zakiszanych zielonek) pozwala przypuszczać, że występuje zróżnicowanie innych chemicznych cech zielonek wpływających na proteolizę (aktywność PPO, zawartość polifenoli) między formami genetycznymi i odmianami

Fermentation and Proteolysis During the Ensilage of Wilted and Unwilted Diploid and Tetraploid Red Clover

The effects of the following factors were analyzed in the study: wilting degree, genetic form of red clover (2n – 4n), cultivars within the genetic form: 2n (Krynia, Parada), 4n (Jubilatka, Bona) and DM x form, DM x 2n, DM x 4n. Fermentation and proteolysis during the ensilage of red clover were affected primarily by wilting, whereas genetic factors (genetic form, cultivar) exerted a lesser effect. However, the genetic form of red clover affected the true protein content of silage and the extent of proteolysis during the ensiling process. The effect of the genetic form of red clover on the extent of proteolysis in silage (at similar levels of water-soluble carbohydrates and buffering capacity) suggests that diploid and tetraploid red clover cultivars differ with respect to chemical properties (poliphenol oxidase activity, polyphenol content) affecting proteolysis