ABSTRACT.- Success in conserving biodiversity in rangelands depends on effectively managing the systems to achieve positive economic outcomes while preserving biodiversity. In the native grasslands of the Río de la Plata region, livestock production often falls below its potential due to low forage availability. Cattle management strategies that promote taller grass height can increase forage mass without replacing native vegetation, enhancing cattle dry matter intake and potentially boosting production. Nonetheless, the impact of such changes on grassland bird populations remains unclear.

Farmers use various pesticides to control pests, weeds, and diseases in order to meet the demands in terms of yields and quality of agricultural products. The use of pesticides in Uruguay has increased steadily since 2000(1). The total number and amount of active substances imported increased from 3.9 to 10.6 thousand tons between years 2000 and 2020. Within plant protection products, herbicides had the highest increase, from 2.1 thousand tons in 2000 to 9.5 thousand tons in 2020(1). Similar trends are observed worldwide(2).

As our understanding of ovarian function in cattle has improved, our ability to control it has also increased. The development of Fixed-Time Artificial Insemination (FTAI) protocols at the end of the 20th century has increased exponentially the number of animals inseminated over the last 20 years. The main reasons for this growth were the possibility of obtaining acceptable pregnancy rates without heat detection and, above all, the induction of cyclicity in suckled cows in postpartum anestrus and prepubertal heifers at the beginning of the breeding season.

As our understanding of ovarian function in cattle has improved, our ability to control it has also increased. The development of Fixed-Time Artificial Insemination (FTAI) protocols at the end of the 20th century has increased exponentially the number of animals inseminated over the last 20 years. The main reasons for this growth were the possibility of obtaining acceptable pregnancy rates without heat detection and, above all, the induction of cyclicity in suckled cows in postpartum anestrus and prepubertal heifers at the beginning of the breeding season.

This article provides an overview of assisted reproductive technologies (ART) and genome engineering to improve livestock production systems for the contribution of global sustainability. Most ruminant production systems are conducted on grassland conditions, as is the case of South American countries that are leaders in meat and milk production worldwide with a well-established grass-feed livestock. These systems have many strengths from an environmental perspective and consumer preferences but requires certain improvements to enhance resource efficiency.

Most plant pathogens exhibit host specificity but when former barriers to infection break down, new diseases can rapidly emerge. For a number of fungal diseases, there is increasing evidence that hybridization plays a major role in driving host jumps. However, the relative contributions of existing variation versus new mutations in adapting to new host(s) is unclear. Here we reconstruct the evolutionary history of two recently emerged populations of the fungus Pyricularia oryzae that are responsible for two new plant diseases:wheat blast and grey leaf spot of ryegrasses.

ABSTRACT.- This systematic review-meta-analysis (MA) estimates the impact of including tannins in beef and dairy cattle diets on short-chain fatty acids (SCFA), ammonia nitrogen (N-NH3), dry matter digestibility (DMD), and methane (CH4) production. The effects are described according to the sources (natural or extract), type of tannin (condensed, CT, or hydrolyzed HT or blend), total tannin concentration in the source, and doses. The bibliographic search was performed in five electronic databases:CAB-Abstracts, PubMed, Scopus, Science Direct, and Web of Science.

ABSTRACT.- This systematic review-meta-analysis (MA) estimates the impact of including tannins in beef and dairy cattle diets on short-chain fatty acids (SCFA), ammonia nitrogen (N-NH3), dry matter digestibility (DMD), and methane (CH4) production. The effects are described according to the sources (natural or extract), type of tannin (condensed, CT, or hydrolyzed HT or blend), total tannin concentration in the source, and doses. The bibliographic search was performed in five electronic databases: CAB-Abstracts, PubMed, Scopus, Science Direct, and Web of Science.

ABSTRACT.- The objective of the study was to characterize adaptations of hepatic metabolism of dairy cows of two Holstein strains with varying proportions of grazing in the feeding strategy.

ABSTRACT.- The most adequate fixative solution for equine ovarian tissue is still to be determined as a tool to evaluate the improvement of methodological studies in assisted reproductive techniques and fertility preservation. This study aimed to evaluate a short-time ethanol 70% (ST-EtOH, 45 min) exposure as an alternative fixative compared with two classically fixatives [Carnoy's (CAR) solution and paraformaldehyde 4% (PFA)] at different fixation times (6 h, 12 h).