Banca de QUALIFICAÇÃO: LUCCA GABRIEL BATISTA PEREIRA

Uma banca de QUALIFICAÇÃO de MESTRADO foi cadastrada pelo programa.
DISCENTE: LUCCA GABRIEL BATISTA PEREIRA
DATA: 27/12/2023
HORA: 09:00
LOCAL: online
TÍTULO:

Intensification Systems Evaluating Quantitative Parameters of Metabolism and Physiology in Beef Cows

PALAVRAS-CHAVES:

beef cows, intensification, pasture-based, physiology, skeletal muscle

PÁGINAS: 23
GRANDE ÁREA: Ciências Agrárias
ÁREA: Zootecnia
SUBÁREA: Produção Animal
ESPECIALIDADE: Criação de Animais
RESUMO:

Beef cattle production in Brazil predominantly relies on pasture-based systems, mainly concentrated in the Central region, characterized by fluctuating climatic conditions that affect forage production and quality. These fluctuations present a critical challenge in beef cattle farming.

According to DU et al. (2010), the seasonal variation in protein levels poses a major limitation to animal performance. The scarcity of crude protein in tropical dry season pastures disrupts the balance of energy and protein in the rumen, consequently reducing fiber digestion and overall energy intake (Sampaio et al., 2009).

The reproductive season in this region is aligned with the rainy season, resulting in calving during the transition from the dry to the rainy season, when pasture quality improves (GIONBELLI et al., 2015). This timing meets nutritional requirements during lactation, improving cow body condition scores (BCS) and reducing the need for artificial insemination (AI) protocols (MARQUEZ et al., 2017).

However, cows face nutritional constraints in the middle and final third of gestation due to dry season forage seasonality. This leads to qualitative and quantitative changes in forage, resulting in limited protein levels, impacting both cow and fetal nutrition (RODRIGUES et al., 2020).

To mitigate these effects, various nutritional strategies, including silage, protein-energy supplements, and deferred grazing, are employed to enhance nutrient intake during gestation. Intensification in beef cattle production, particularly during the cow-calf phase, becomes vital.

This study hypothesizes that intensified production systems will enhance cow physiology and metabolism and increase calf production. Furthermore, it aims to maintain cows in better nutritional conditions year-round, preventing abrupt body condition changes and maternal tissue losses.

General Objectives

The study aims to evaluate productive, metabolic, and physiological parameters of beef cows based on their production cycle phase and the level of intensification.

Specific Objectives

• Assess weight variations among cows in different treatments within the same block.
• Measure body tissue deposition and/or mobilization.
• Correlate body weight variations and carcass ultrasound results with BCS measurements.
• Investigate body changes through biochemical blood variables.

Theoretical Background The research discusses the impact of maternal nutrition during gestation, especially during different stages, on fetal programming and postnatal development. Maternal undernutrition during the dry season can negatively affect muscle development, adipogenesis, and meat quality. The timing of nutritional restriction during gestation also plays a crucial role, with the middle and final stages being the most critical.

The study explores intensification strategies, including deferred grazing, protein supplementation, silage production, and Total Mixed Ration (TMR), to optimize pasture utilization and cow nutrition. These strategies aim to counteract the negative effects of seasonal forage limitations.

Materials and Methods The experiment will be conducted at the Federal University of Lavras (UFLA) Beef Cattle Sector over 24 months. Thirty-six pregnant Tabapuã breed cows will be utilized each year, with a randomized block design. Cows will undergo fixed-time artificial insemination, and treatments will include control, intensive, and super-intensive management.

Control treatment mimics extensive beef cattle farms, intensive treatment represents moderate intensification, and super-intensive is designed for maximum feed resource utilization. The treatments involve nitrogen fertilization, deferred grazing, silage production, and protein supplementation, with variations in stocking rates.

Supplementation includes mineral supplementation for all cows, protein supplementation for intensive treatment cows during the dry season, and TMR silage for super-intensive treatment cows.

Evaluations will include body weight, BCS, carcass ultrasound scans, and uterine blood flow assessments to analyze the impact of different intensification levels on cow physiology and productivity.

In summary, this research explores strategies to mitigate the effects of seasonal forage limitations on beef cattle production, focusing on improving maternal nutrition, fetal development, and overall herd performance through intensification methods.

MEMBROS DA BANCA:
Externo à Instituição - PEDRO DEL BIANCO BENEDETI - UDESC (Membro)
Externo à Instituição - KAROLINA BATISTA NASCIMENTO - UFLA (Membro)
Externo à Instituição - HERLON MENEGUELLI ALHADAS - UFLA (Membro)
Presidente - ERICK DARLISSON BATISTA (Membro)
Interno - DANIEL RUME CASAGRANDE (Suplente)