Selection of the best dairy animals for breeding could be made on the basis of juvenile predictors through the use of genotyping coupled with phenotypic profiling of type traits and metabolic parameters.
Take Home Message: Selection for increased milk yield and lower somatic cell counts based on 305-d lactation data is resulting in a shift in peak yield, a flatter lactation curve and lower cell counts in mid-late lactation.
The rate of change of milk predicted transmitting abilities (PTAs) at various days in milk (DIM) is greatest around [...]
Take Home Message: Selecting for milk yield decreases fertility and body condition score.
Selecting for increased milk production leads to a deterioration in genetic merit for fertility and condition score. That was the unequivocal conclusion of a study carried out by geneticists at SAC on the college’s Langhill herd, which was under maximum selection for milk [...]
Take Home Message: Selecting for carcass conformation in dairy cows will reduce milk yield but improve fertility, with little effect on somatic cell count or lifespan.
Selection on an index that improves carcass conformation of Holstein Friesian beef by 0.1 of a unit will lead to a reduced rate of improvement in production traits and an [...]
Take Home Message: Earlier turnout for 2-3h per day in the Spring will decrease total mixed ration intake and have no effect on milk yield or composition, improving margin over feed by 50p/cow/day
Allowing access to grazing for two hours per day in the spring had no effect on milk yield or milk composition in autumn [...]
Take Home Message: If you wish to have extended lactations above 305 days then select bulls with a high genetic merit for milk and milk protein yield that produce a high proportion of milk in the first few months of lactation
Protein yield early in lactation – the first two months – has a genetic correlation [...]
Take Home Message: Feeding maize silage will increase intake and milk output, but has little effect on milk fatty acid composition
Despite some beneficial changes associated with the replacement of grass silage with maize silage, the overall effects on milk fatty acid composition would not be expected to substantially improve long-term human health.
That was just one [...]
Take Home Message: Methane output from dairy cows can be decreased by up to 40% by including 150 g/kg DM extruded linseeds in the diet without affecting intake or milk yield.
It is possible to feed cattle using extruded linseeds to reduce methane production without altering milk yield. That was the finding of two studies, carried [...]
Take Home Message: Agricultural green house gas emissions can be reduced by 5% by altering management, particularly by the wider use of genetic improvement in the beef and dairy industries.
There are a range of cost-effective options – either nil or low cost – for the UK livestock sector that will abate greenhouse gas (GHG) emissions. [...]
Take Home Message: Breeding dairy cows for increased yield will reduce the CO2 output from dairy farming by 0.6% for every 1% increase in yield.
A non-market or ‘shadow’ environmental value can be incorporated into selection indices, using increased milk yield to reduce the herd size required to maintain herd output as the goal trait.
“And a [...]
