Assessment of dietary ratios of red clover and corn silages on milk production and milk quality in dairy cows

Abstract

Twenty-four multiparous Holstein-Friesian dairy cows were used in a replicated 3×3 Latin square changeover design experiment to test the effects of changing from corn (Zea mays) silage to red clover (Trifolium pratense) silage in graded proportions on feed intakes, milk production, and whole-body N and P partitioning. Three dietary treatments with ad libitum access to 1 of 3 forage mixtures plus a standard allowance of 4kg/d dairy concentrates were offered. The 3 treatment forage mixtures were, on a dry matter (DM) basis: (1) R10: 90% corn silage and 10% red clover silage, (2) R50: 50% corn silage and 50% red clover silage, and (3) R90: 10% corn silage and 90% red clover silage. In each of 3 experimental periods, there were 21d for adaptation to diets, and 7d for measurements. Diet crude protein intakes increased, and starch intakes decreased, as the silage mixture changed from 90% corn to 90% red clover, although the highest forage DM intakes and milk yields were achieved on diet R50. Although milk fat yields were unaffected by diet, milk protein yields were highest with the R 0250 diet. Whole-body partitioning of N was measured in a subset of cows (n=9), and both the daily amount and proportion of N consumed that was excreted in feces and urine increased as the proportion of red clover silage in the diet increased. However, the apparent efficiency of utilization of feed N for milk protein production decreased from 0.33g/g for diet R10 to 0.25g/g for diet R90. The urinary excretion of purine derivatives (sum of allantoin and uric acid) tended to increase, suggesting greater flow of microbial protein from the rumen, as the proportion of red clover silage in the diet increased, and urinary creatinine excretion was affected by diet. Fecal shedding of E. coli was not affected by dietary treatment. In conclusion, even though microbial protein flow may have been greatest from the R 0450 diet, optimum feed intakes and milk yields were achieved on a diet that contained a 1:1 DM mixture of corn and red clover silages.

Post‐ruminal non‐protein nitrogen supplementation as a strategy to improve fibre digestion and N efficiency in the ruminant

“…To manage these unexpected differences, in the second experiment, we performed total urine collection as to improve the estimation of urinary N loss and N metabolism. Similar to our first study, creatinine analysis revealed a significant effect of treatment, in agreement with several experiments where creatinine concentration responded to dietary formulation (Moorby, Ellis, & Davies, 2016;Valadares, Broderick, Valadares Filho, & Clayton, 1999) and to increasing osmolality of drinking water of ruminants (Alves et al, 2017).…”

“…Similar to our first study, creatinine analysis revealed a significant effect of treatment, in agreement with several experiments where creatinine concentration responded to dietary formulation (Moorby, Ellis, & Davies, 2016;Valadares, Broderick, Valadares Filho, & Clayton, 1999) and to increasing osmolality of drinking water of ruminants (Alves et al, 2017). To manage these unexpected differences, in the second experiment, we performed total urine collection as to improve the estimation of urinary N loss and N metabolism.…”

The effects of high-sugar ryegrass/red clover silage diets on intake, production, digestibility, and N utilization in dairy cows, as measured in vivo and predicted by the NorFor model

“…The average daily creatinine excretion of 23.4 mg/kg of BW in urine was similar to the 24.1 mg/kg of BW found by Chizzotti et al (2008), and is in agreement with the bulk of previous results from our laboratory. However, we have no obvious explanation for the different levels in the 2 study years, but treatment or period effects of larger magnitude are known from other studies (Gonda et al, 1996;Moorby et al, 2016).…”

Relationship of Milk Odd- and Branched-Chain Fatty Acids with Urine Parameters and Ruminal Microbial Protein Synthesis in Dairy Cows Fed Different Proportions of Maize Silage and Red Clover Silage

“…Therefore, mixtures of RCS and MS are argued to have the potential to maximize the MCP in the rumen via better synchronization between the rapidly fermentable fractions of CPs and carbohydrates. To date, only few studies have evaluated mixtures of RCS and MS in terms of the performance of dairy cows [13][14][15][16], and no published study so far exits about the effect of RCS on OBCFA. Therefore, the main objectives of this study are to study the relationship of OBCFA with urinary PD and the estimated MCP synthesis in the rumen of dairy cows.…”