Minor milk constituents are affected by protein concentration and forage digestibility in the feed ration

Abstract

The present study was conducted in order to investigate if selected minor milk components would be indicative for the nutritional situation of the cow. Forty-eight dairy cows were offered a high digestible ration vs. a lower digestible ration combined with 2 protein levels in a 4 × 4 Latin square design. Milk glucose, glucose-6-phosphate, cholesterol, triacylglycerides (TAG), uric acid and β-hydroxybutyrate (BHBA) were measured and correlated mutually and towards other milking parameters (yield, h since last milking, days in milk (DIM), urea, etc). The variation range of the suggested variables were broad, a fact that may support their utilisation as predictive parameters. The content of milk metabolites was significantly affected by the change in rations as milk glucose, glucose-6-phosphate, uric acid, and the ratio cholesterol: triacylglycerides increased with higher energy intake while BHBA and TAG decreased. The content of some of the milk metabolites changed during 24 h day/night periods: BHBA, cholesterol, uric acid and TAG increased whereas free glucose decreased in the night period. Certain associations between milk metabolites and calculated energy parameters like ECM, body condition score (BCS), and body weight gain were found, however, these associations were to some extent explained by an interaction with DIM, just as changes in milk metabolites during a 24 h period seems to interfere. It is concluded that the practical use of the suggested milk variables should be based on more than one metabolite and that stage of lactation and possibly time of the day where the milk is collected should be incorporated in predictive models.

Effect of postpartum propylene glycol allocation to over-conditioned Holstein cows on concentrations of milk metabolites

“…The energy boost from PG might have stimulated the microbial turnover in the rumen, thereby more uric acid is formed by degradation of microbial purines in DNA and RNA (Chibisa et al 2009; Stentoft et al 2015). A comparable situation was seen when high density energy rations were tested against low energy density rations (Larsen et al 2016). In contrast, it has been hypothesised that PG allocation would reduce ruminal microbial protein production (Chibisa et al 2009).…”

Replacement of alfalfa hay ( Medicago sativa ) with maralfalfa hay ( Pennisetum sp.) in diets of lactating dairy goats

“…The glucose 6 P content of the milk in the M group was higher compared to milk from the A group. The same tendency was observed by Larsen et al (2016) who reported significantly higher levels (P < 0.001) of both monosaccharides in cows on a highly digestible ration compared to a lower digestible ration. The present goats were in positive energy balance and no significant differences were observed for the plasma metabolites related to fat mobilization, i.e.…”

Lack of evidence of mastitis as a causal factor for postpartum dysgalactia syndrome in sows123

“…In cows, reduced UA concentrations in urine were related with reduced nitrogen flow to the duodenum and hence a reduced production of microbial protein in the rumen ( Tas and Susenbeth, 2007 ). Recently, however, Larsen et al (2016) found increased UA concentration in milk when cows were fed highly digestible feed versus a low-digestibility feed. The present finding of a reduced UA concentration in milk from PDS+ sows remains unclear, but against this background, it might be speculated that the intestinal function or health of PDS+ sows could be compromised.…”