Synchronous feeding of liquid protein source with different grains on performance, digestibility, ruminal fermentation, blood metabolites, and carcass characters in growing lambs

Effects of low-quality forage and starter protein content in starter diet of young calves on growth performance, rumen fermentation, and urinary purine derivatives

Feeding low-quality forage (LQF) has been evaluated in mature ruminants and results show that it has been improved nitrogen utilization efficiency. The present study evaluated the interaction effect of feeding wheat straw as LQF (0 and 7.5%, DM basis) and starter protein level (20 vs. 24%, DM basis) on growth performance, ruminal fermentation, and microbial protein synthesis in Holstein dairy calves raised under moderate heat stress condition. Forty-eight 3-day old dairy calves (averaging 40.6 kg) were assigned in four experimental treatments as follow; 1) no LQF with 20% CP (NLQF-20CP), 2) no LQF with 24% CP (NLQF-24CP), 3) 7.5% LQF with 20% CP (LQF-20CP) and 4) 7.5% LQF and 24% CP (LQF-24CP). The calves were weaned on d 53 of age but the experiment extended until d 73 of age. Feeding LQF increased starter intake, average daily gain (tendency), ruminal acetate concentration, and improved fecal score of calves. The average daily gains before and after weaning were positively influenced with greater starter protein content. Hence, weaning and final BWs were improved when calves received greater CP content. In addition, greater starter CP content increased total ruminal volatile fatty acid concentration. With respect to the interaction effect between LQF feeding and starter protein content, the lower nitrogen excretion through urine was obtained for LQF-20CP diet among experimental treatments. The results of the current study showed that feeding LQF improved ruminal fermentation pattern and improved growth performance through increased starter intake. In addition, greater starter protein content is advisable during pre-weaning period for calves raised under mild heat stress condition. In conclusion, based on the results found in the current study, it can be suggested that feeding LQF for calves under heat stress condition can improve nitrogen utilization when dietary protein content is low. This can be opportunity to formulate starter diets with greater nitrogen utilization efficiency which is critical for accelerated growth programs at early stages of growth for young calves while calves raised under hot season condition.

Supplementation of n-3 fatty acid and ruminal undegradable to degradable protein ratio in young lambs raised under heat condition: effects on growth performance and urinary purine derivatives

The present study evaluated the effect of supplementation alpha-linolenic fatty acid source (ALA) with different rumen undegradable to degradable protein ratios [low ratio (LR) = 26:74; high ratio (HR) = 36:64 based on CP%] on growth performance, nutrient digestibility, fecal score, animal feeding behavior, and urinary purine derivatives (PD) in young lambs during hot season. Forty 10-day-old lambs (averaging body weight of 7.9 ± 0.8 kg) were used in a completely randomized block design with a 2 × 2 factorial arrangement as following treatments (10 lambs/treatment): (1) no n-3 FA supplementation with LR diet (NALA-LR), (2) no ALA supplementation with HR diet (NALA-HR), (3) supplementation of ALA with LR diet (ALA-LR), and (4) supplementation of ALA with HR diet (ALA-HR). Results showed that ALA supplementation slightly increased feed efficiency (FE; tendency, P = 0.076), improved fecal score (P = 0.045), and reduced rectal temperature (tendency, P = 0.064) during pre-weaning period. The HR diets improved average daily gain (ADG; P < 0.01), wither height (post-weaning; P = 0.015), and final BW (P = 0.048) compared with LR diets. The greatest ADG (pre-weaning; P = 0.012), structural growth, and the lowest urinary nitrogen exertion (P = 0.043) were found in the ALA-HR treatment. No change was found for ruminal fermentation, nutrient digestibility, and animal behavior in lambs fed different experimental treatments. In summary, results indicated that concurrent feeding of ALA and high dietary RUP:RDP ratio can be recommendable that is likely due to more efficient nitrogen utilization when young lambs are raised during hot season. HIGHLIGHTS: • The interaction of n-3 FA and nitrogen was evaluated in pre-weaning lambs raised under heat condition. • Supplementation of n-3 FA increased FE and improved fecal score in heat-exposed lambs during pre-weaning period. • The high RUP:RDP ratio improved skeletal growth during post-weaning period. • Concurrent feeding of n-3 FA and high dietary RUP:RDP ratio is recommendable in young lambs raised during hot season.

Innovative high digestibility protein feed materials reducing environmental impact through improved nitrogen-use efficiency in sustainable agriculture

Sustainable development in agriculture brings both environmental and economic benefits. Contemporary agriculture is also about increasing nutrient use efficiency, especially nitrogen, as the critical nutrient causing the most significant environmental pressure. This creates the need to produce highly digestible protein feed with high bioavailability, reducing losses of biogenic elements to feces. In this review, the latest trends and the potential for their implementation in sustainable agriculture have been compared, as well as the need to reduce the negative environmental impact of agriculture has been demonstrated. Applying local protein sources to feed animals reduces greenhouse gas emissions associated with transportation. The production of highly digestible fodder leads to a reduction in environmental pollution caused by excessive nitrogen outflows. Another approach indecreasing ammonia emissions from livestock farming is feed protein reduction and amino acid supplementation. All of the aforementioned approaches may result in beneficial long-term changes, contributing to environmental safety, animal welfare and human health.