Dairy cows lameness represents a significant welfare issue for the dairy industry. The aim of this study was to investigate metabolic and hormonal parameters associated with lameness in cows. The study included two treatment groups of 10 multiparous Holstein–Friesian dairy cows each. The control group consisted of cows with locomotion score 1 and in the experimental group cows with locomotion scores 3 and 4 were included. Milk, urine and blood samples were collected to determine the fat, protein, urea, creatinine, electrolytes and copeptin vasopressin (AVP) content. The milk fat, protein and energy-corrected milk (ECM) levels were higher in lame animals compared with non-lame cows. The blood urea nitrogen (BUN) and BUN/serum creatinine ratio were lower at the start of the trial in lame animals suggesting a metabolic acidosis state. There were significantly lower serum Na levels in the lame cows, from the start until the end of the trial (p < 0.011), as well as between lame and non-lame groups at the end of the trial (p = 0.041). A lower copeptin AVP was detected in lame compared with non-lame cows at the end of the trial (p = 0.004). The decrease of serum Na levels as the comfort improves indicates that the animals started to recover from the effect of cortisol on mineralocorticoid receptors. Our data also indicates that the BUN and BUN/serum creatinine ratios are associated with lameness. Further investigations involving a larger number of cows would be recommended to confirm these results and to evaluate these parameters in the early stages of lameness.

This experimental trial explored the impact of incorporating specific nutritional feed into the diet of dairy cows and assessed their influence on the quality of products derived from the processing of raw milk. Results showed that nutritional feed changed several parameters of dairy products, such as dry matter, crude protein, crude fat, ash, and fatty acid profiles between the two groups for produced dairy products. The resulting two types of cheeses, namely Caș and Telemea, made from the milk of Experimental Group (EG) cows had a decreased content of saturated fatty acids (SFA) and an elevated content of unsaturated fatty acids (UFA) compared to the Control Group (CG), whereas the situation was the opposite. The associations of the n6:n3 ratio were lower in the Caș cheese from the EG compared to CG, while in the Telemea cheese, the observations also revealed inverted results.

This paper aimed to review the literature concerning nitrogen metabolism and excretion in dairy cows in the light of actual global climate change picture. Nutritional factors like dietary crude protein or dietary carbohydrate concentration have a significant effect on nitrogen balance, through the decreasing capacity of the total N excretion and improving the milk nitrogen efficiency. At the same time, the protein and carbohydrate degradability rates as well as dietary minerals will impact the excretion routes, urinary and faecal. Shifting between urinary to faecal pathway could benefit to the mitigation of air pollution as the faecal nitrogen content is less prone to volatilisation compared to the urine nitrogen. Feed additives such as direct feed microbial, plant secondary metabolites and rumenprotected amino acids can mitigate and shift the N excretion from the urinary to the faecal pathway. Finally, breeding animals for lower MUN traits could also be considered as an efficient approach for a longer-term strategy to reduce N emissions.

This paper aimed to review the nitrogen emissions from the agriculture and livestock sector and their impact on the environment in the light of the actual global climate change picture. Emissions of ammonia, nitrogen oxide and nitrous oxide contribute to air pollution and global warming, while nitrates contribute to soil and water pollution. The agriculture and livestock sector is responsible for ammonia emissions representing approximately 80-90% of total anthropogenic emissions. Approximately 52% of total nitrous oxide emissions are coming from agriculture, and there is a strong correlation with the application rates of synthetic fertilizers. The nitrogen lost in the soil and water through leaching represents an important nitrate emission with negative effects on the environment due to acidification and eutrophication. As a result of human activity in recent decades, significant amounts of reactive nitrogen were released into the environment, disrupting the natural nitrogen cycle. The main causes of nitrogen emissions in the agriculture and livestock sector are represented by the excessive and inefficient use of synthetic fertilizers, manure management, including the low efficiency of nitrogen conversion into milk, meat and eggs by animals.

The aim of the study was to investigate the impact of lameness on nitrogen (N) metabolism and excretion. Two treatment groups of 20 multiparous Holstein–Friesian dairy cows were included in study; the control group consisted of cows with locomotion score ≤2, while the experimental group consisted of cows with locomotion scores 3 and 4. Fodder, milk, feces, and urine were collected to determine nitrogen emissions. The milk yield, the energy-corrected milk, the fat and protein yield were higher for lame animals compare with non-lame cows. Differences were also detected in the milk urea nitrogen (MUN) between groups where lame cows had a 15% lower MUN than non-lame animals. Urine volume was lower (p < 0.008), while urinary creatinine concentration was higher (p < 0.05) in lame animals compare with those in the non-lame group. Consequently, the creatinine/urea ratio was significantly higher (p < 0.001) in the lame vs. no-lame animals. Nitrogen excretion in milk was higher (p = 0.008) and N in urine was lower (p < 0.001) in the lame compared to non-lame cows with lower urinary N emissions in lame animals. Taken together, our results show that urinary creatinine concentration and urinary creatinine/urea ratio have the potential to be used as a tool for lameness detection.