Feed efficiency, as defined by the fraction of feed energy captured in products, has more than doubled for the US dairy industry in the past 100 years. This increased feed efficiency resulted from increased milk production per cow achieved through genetics, nutrition, and management with the desired goal being greater profitability. With increased milk production per cow, more feed is consumed ...

This study examined the relationship of residual feed intake (RFI) and performance with methane emissions, rumen fermentation, and digestion in beef heifers. Individual DMI and growth performance were measured for 22 Simmental heifers (mean initial BW 449 kg, SD = 46.2 kg) offered grass silage ad libitum for 120 d. Ultrasonically scanned muscle and fat depth, BCS, muscularity score, skeletal me...

In beef cattle, production feedstuffs are the largest variable input cost. Beef cattle also have a large carbon footprint, raising concern about their environmental impact. Unfortunately, only a small proportion of dietary energy is directed toward protein deposition and muscle growth whereas the majority supports body maintenance. Improving feed efficiency would, therefore, have important cons...

The use and partition of feed energy are key elements in productive efficiency of pigs. This study aimed to determine whether dietary energy sources affect the partition of body lipids and tissue biochemical pathways of energy use between pigs differing in feed efficiency. Forty-eight barrows (pure Large White) from two divergent lines selected for residual feed intake (RFI), a measure of feed ...

The identification of functional genetic variants and associated candidate genes linked to feed efficiency may help improve selection for in dairy cattle, providing economic environmental benefits the industry. This study used RNA-sequencing data obtained from liver tissue 9 Holstein cows [n = 5 low residual intake (RFI), n 4 high RFI] 10 Jersey (n RFI, RFI), which were selected a single popula...

The amine/phenol-metabolome of rumen fluid was analyzed to identify amino acid metabolism-related biomarkers associated with phenotypic selection for low or high residual feed intake (RFI) in beef cattle. Fourteen steers (most feed-efficient (HFE; RFI = −1.89 kg/d, n 7) and least (LFE; +2.05 7)) were selected from a total 56 crossbred growing (average BW 261 ± 18.5 kg) after 49-d feeding period...

Context Feed is the largest expense on a dairy farm, therefore improving feed efficiency important. Recording dry-matter intake (DMI) prerequisite for calculating efficiency. Genetic variation of and varies across lactation stages parities. DMI an expensive difficult-to-measure trait. This raises question which time periods during would be most appropriate to measure DMI. Aims The aim was evalu...

Objectives were to evaluate the associations between residual dry matter (DM) intake (RFI) and N (RNI) in early lactation, from 1 5 wk postpartum, mid 9 15 assess production performance risk of diseases cows according RFI lactation. Data 4 experiments including 399 Holsteins used this study. Intakes DM N, yields milk components, body weight, condition evaluated daily or weekly for first 105 d p...

Selection for the wide range of traits for which most beef breed associations calculate expected progeny differences focus on increasing the outputs of the production system, thereby increasing the genetic potential of cattle for reproductive rates, weights, growth rates, and end-product yield. Feed costs, however, represent a large proportion of the variable cost of beef production and genetic...