Amino Acids Supplementation for the Milk and Milk Protein Production of Dairy Cows

Abstract

As the preference of consumers for casein products has increased, the protein content of milk from dairy cows is drawing more attention. Protein synthesis in the milk of dairy cows requires a proper supply of dietary protein. High protein supplementation may help to produce more milk protein, but residues in feces and urine cause environmental pollution and increase production costs. As such, previous studies have focused on protein supplements and amino acid (AA) supply. This review concerns AA nutrition for enhancing milk protein in dairy cows, and mainly focuses on three AAs: methionine, lysine, and histidine. AA supplementation for promoting protein synthesis is related to the mammalian target of rapamycin (mTOR) complex and its downstream pathways. Each AA has different stimulating effects on the mTOR translation initiation pathway, and thus manifests different milk protein yields. This review will expand our understanding of AA nutrition and the involved pathways in relation to the synthesis of milk protein in dairy cows.

Actualidades en el uso de aminoácidos en la industria lechera

“…La naturaleza ha hecho de la nutrición proteica de las vacas lecheras en lactación algo complicado debido que cuando las vacas son alimentadas, dos sistemas están siendo alimentados: un sistema microbiano que puede usar AAs, pero que su requerimiento básico es amoniaco y nitrógeno no proteico (NNP) y el sistema del mamífero que requiere AAs y debe desintoxicar su sistema de exceso de amoniaco como otras especies de mamíferos (Patton et al, 2014). Los rumiantes obtienen nitrógeno (N) para su metabolismo de las fuentes que están disponibles en la dieta, de la proteína microbiana y la descamación endógena (Kim & Lee, 2021). La proteína dietética se refiere a la PC definida para los alimentos como el contenido de nitrógeno multiplicado por el factor 6.25.…”

“…En su respectivo metaanálisis Patton (2010) y Zanton et al ( 2014) resumieron la respuesta productiva esperada del uso de fuentes de metionina protegida de la degradación ruminal (MetPR) en la nutrición de vacas lecheras. Los AAs protegidos de la degradación ruminal, Met, Lys, o ambos, han sido ampliamente estudiados y utilizados, con resultados variables (Kim & Lee, 2021). Se realizaron dos ensayos con MetPR con vacas lecheras Holstein alimentadas con dietas basadas en alfalfa y ensilado de maíz (Broderick et al, 2008).…”

Effect of Undegraded Dietary Protein, Probiotic, and Premixes in Complete Rations on Fat-Tailed Sheep Productivity

“…The microbial protein passing from the rumen to the intestines is insufficient to attain the requirement for intestinally absorbable amino acids in the high-producing dairy cow [17], [18]. Thus, providing the dairy cow amino acids from undegraded protein is necessary.…”

“…The level of dry matter consumption can be affected by the consumption of treated rations and the chemical composition of the rations. Kim and Lee [17] stated that the factors that affected digestibility included the physical form of the feed, the composition of the ration, temperature, the rate of travel through the digestive tract, and the influence on the ratio of other nutrients [24], [25]. The role of probiotics in increasing microbes in the rumen is thought to cause the increase in dry matter consumption in R4.…”

Effect of Methionine Analogues on Growth Performance, Serum Biochemical Parameters, Serum Free Amino Acids and Rumen Fermentation of Yaks

“…Rumen is a unique protein metabolism site in ruminants. Ruminants obtain nitrogen (N) sources that are available for metabolism from dietary intake, microbial proteins, and endogenous N [ 6 ]. Rumen-degradable protein (RDP) and rumen-undegradable protein (RUP) are the two main classifications of dietary protein.…”