Applying assisted reproductive technology and reproductive management to reduce CO2-equivalent emission in dairy and beef cattle: a review

Abstract

Methane emission from beef and dairy cattle combined contributes around 4.5-5.0% of total anthropogenic global methane. In addition to enteric methane (CH 4 ) produced by the rumen, cattle production also contributes carbon dioxide (CO 2 ) (feed), nitrous oxide (N 2 O) (feed production, manure) and other CH 4 (manure) to the total greenhouse gas (GHG) budget of beef and dairy production systems. The relative contribution in standard dairy systems is typically enteric CH 4 58%, feed 29% and manure 10%. Herds with low production efficiency can have an enteric CH 4 contribution up to 90%. Digestibility of feed can impact CH 4 emission intensity. Low fertility herds also have a greater enteric CH 4 contribution. Animals with good feed conversion efficiency have a lower emission intensity of CH 4 /kg of meat or milk. Feed efficient heifers tend to be lean and have delayed puberty. Fertility is a major driver of profit in both beef and dairy cattle, and it is highly important to apply multi-trait selection when shifting herds towards improved efficiency and reduced CH 4 . Single nucleotide polymorphisms (SNPs) have been identified for feed efficiency in cattle and are used in genomic selection. SNPs can be utilized in artificial insemination and embryo transfer to increase the proportion of cattle that have the attributes of efficiency, fertility and reduced enteric CH 4 . Prepubertal heifers genomically selected for favourable traits can have oocytes recovered to produce IVF embryos. Reproductive technology is predicted to be increasingly adopted to reduce generation interval and accelerate the rate of genetic gain for efficiency, fertility and low CH 4 in cattle. The relatively high contribution of cattle to anthropogenic global methane has focussed attention on strategies to reduce enteric CH 4 without compromising efficiency and fertility. Assisted reproductive technology has an important role in achieving the goal of multiplying and distributing cattle that have good efficiency, fertility and low CH 4 .

The impacts of precision livestock farming tools on the greenhouse gas emissions of an average Scottish dairy farm

“…Differences in management and the overall mix of enterprises mean that effects of technology introduction on emissions intensity will vary greatly between farms. For example, a farm with poorer fertility that would benefit greatly from PLF introduction would be expected to show a greater corresponding reduction in emissions (Baruselli et al, 2023). This is exemplified with group 3, the higher yielding farm with poorer baseline fertility, showing greater reductions in emissions from milk production in comparison to group 2, a lower yielding herd with better fertility.…”

Metabolic imprinting in beef calves supplemented with creep feeding on performance, reproductive efficiency and metabolome profile

“…Particularly in Bos indicus cattle, achieving puberty at older ages (around 22–36 months) represents a significant challenge for improving beef production efficiency 3 . Consequently, the late first calving of heifers not only impairs the implementation of intensive beef production practices but also contributes to adverse environmental impacts, such as greenhouse gas emissions (GHG) 4 , 5 . Studies have demonstrated that reducing the age at first calving and implementing strategies to increase fertility can substantially reduce GHG emissions (25–37%), promoting greater economic returns over the entire beef production cycle 6 , 7 .…”

Evaluation of a Commercial Pregnancy Test Using Blood or Plasma Samples in High-Producing Dairy Cows

“…The general public is also calling for reductions in the environmental footprint. Adequate herd-level reproductive programs not only bring increased milk output on the herds but also make the use of land resources more efficient, thus reducing greenhouse gas emissions [ 14 , 15 , 16 ]. In fact, good reproductive performance reduces the generation interval and, thus, hastens genetic gain for efficient feed use, fertility, and low CO2-equivalent emissions [ 16 ].…”

“…Adequate herd-level reproductive programs not only bring increased milk output on the herds but also make the use of land resources more efficient, thus reducing greenhouse gas emissions [ 14 , 15 , 16 ]. In fact, good reproductive performance reduces the generation interval and, thus, hastens genetic gain for efficient feed use, fertility, and low CO2-equivalent emissions [ 16 ]. In this context, intensive reproductive control meets the needs of today’s management practices in dairy herds.…”