Influence of abomasal infusion of high levels of lysine or methionine, or both, on ruminal fermentation, eating behavior, and performance of lactating dairy cows.

Abstract

Four multiparous late-lactation Holstein cows were fed a basal ration designed to be co-limiting in intestinally absorbable supplies of methionine and lysine. Cows were supplemented with no amino acids, lysine by abomasal infusion to 140% of the calculated intestinally absorbable requirement, methionine by abomasal infusion to 140% of requirement, or both amino acids in a 4 x 4 Latin square design with 28-d periods. Unsupplemented cows consumed 23.8 kg/d of dry matter and produced 36.9 kg/d of milk containing 3.70% fat, 3.22% protein, and 4.82% lactose. Cows ate less dry matter and produced less milk and milk lactose, and tended (P = .06 or .08) to produce less milk protein when abomasally infused with methionine alone or together with lysine. Infusion of lysine alone resulted in production values numerically between those of unsupplemented cows and those cows supplemented with methionine alone or together with lysine. Evaluation of the results with two metabolic models of dairy cows indicated that performance of unsupplemented cows may have been limited by delivery of metabolizable or digestible protein, or intestinally absorbable lysine, isoleucine, or histidine, depending on the metabolic model used to evaluate animal performance. Regardless, results are consistent with those using nonruminant species, which have shown that imbalanced profiles of intestinally absorbable amino acids are associated with reduced dry matter intake and animal performance. Results also show that negative effects on performance of lactating dairy cows can occur if methionine is supplied at levels substantially in excess of calculated intestinally absorbable requirements, either alone or together with lysine.

Effects of ruminally protected methionine and/or phenylalanine on performance of high producing Holstein cows fed rations with very high levels of canola meal

“…Indeed this hypothesis agrees with results of a study where the control ration had the lowest production, even with a calculated ratio close to 3.0, while positive production responses were seen for both Met and Lys supplementation, even when the supplementation changed the ratios to 1.3 and 4.6 respectively (Wang et al, 2010). Robinson et al (2000) reported that oversupplying both Met and Lys simultaneously changed partitioning of energy, with their combined infusion improving energetic efficiency of the cows without affecting general animal performance, thereby increasing the NE density of the ration to prevent a negative energy balance in the cows. This corresponds to our study where combined supplementation of Phe and Met changed the way energy was utilized vs. when Met was supplemented alone.…”

“…As the predicted Lys:Met ratios may not reflect the actual ratios, interpretation of the Lys:Met ratio concept in studies outside the NRC (2001) is difficult. In the study of Robinson et al (2000), creating an imbalance in the suggested optimum Lys:Met ratio by supplementing Lys (i.e., changing the ratio from 3.0 to 3.9) had no effect on production, but creating a theoretical imbalance by supplementing Met (i.e., changing the ratio from 3.0 to 2.3), reduced DM intake, milk production and lactose yields. While restoring the ratio to 3:1 by supplementing Lys and Met together did not impact production, the negative effects of high Met supplementation remained, even at the 3.0 Lys:Met ratio.…”

“…Patton (2010) suggests that a slight increase in milk yield can also be expected, and, even though this is consistent with the increases in milk yield reported earlier (Wang et al, 2010;Čermáková et al, 2012;Osorio et al, 2013), it does not agree with the reduction in milk lactose yield, or the tendency for milk yield to decrease with MET, in our study. A study by Robinson et al (2000), to determine effects of a Met oversupply, showed that abomasal Met infusion to increase its intestinal delivery by 34 to 39% markedly reduced animal performance. Indeed Robinson et al (2000) reported a sharp decline in milk and lactose yields, which is similar to our results in relative terms, although not quantitatively as all changes in our study were modest even though supplementation with RP Met increased estimated intestinally available Met by ~ 38% in our study, suggesting that an oversupply of Met was possible.…”

“…A study by Robinson et al (2000), to determine effects of a Met oversupply, showed that abomasal Met infusion to increase its intestinal delivery by 34 to 39% markedly reduced animal performance. Indeed Robinson et al (2000) reported a sharp decline in milk and lactose yields, which is similar to our results in relative terms, although not quantitatively as all changes in our study were modest even though supplementation with RP Met increased estimated intestinally available Met by ~ 38% in our study, suggesting that an oversupply of Met was possible.…”

Post-ruminal or intravenous infusions of carbohydrates or amino acids to dairy cows 1. Early lactation

“…The AA reaching the duodenum in a common grass silage-based diet can be limiting in specific AA. Infusion of individual AA, as His (Vanhatalo et al, 1999), Met (Pisulewski et al, 1996;Robinson et al, 2000) and Lys (Robinson et al, 2000) has increased the milk protein production, which indicates that these AA have been limiting milk protein synthesis. Compared with in His limiting diets (Thivierge et al, 2002), the present plasma His concentrations were high, and combined with low extraction rates, this suggests that His was not limiting on the AP or AB treatments.…”