Energia líquida e ractopamina para leitoas em terminação sob altas temperaturas ambientais

Abstract

Energia líquida e ractopamina para leitoas em terminação sob altas temperaturas ambientaisNet energy and ractopamine to finishing gilts under high temperature environment

Net energy and ractopamine levels for barrows weighing 70 to 100kg

“…This response is possibly associated with the linear reduction in feed intake with increasing dietary energy levels. Similar results were reported by APPLE et al (2004) for barrows and gilts and by MOURA et al (2011a) for finishing gilts.…”

“…No effect of interaction (P>0.05) between net energy and ractopamine levels ( Table 2) was observed on performance variables, corroborating the results obtained by MOURA et al (2011a), who reported no effect of interaction between net energy (2,300; 2,424; 2,548; and 2,668Kcal kg -1 ) and ractopamine levels (0 and 20ppm) on the performance of finishing gilts subjected to high ambient temperatures.…”

“…The literature reports a positive effect of ractopamine on carcass characteristics, particularly in decreasing back-fat thickness; this effect is explained by the ability of this compound to reduce fatty acid synthesis in adipose tissue and to increase protein synthesis in muscle tissue (SANCHES et al, 2010). In the present study, however, ractopamine levels had no effect on back-fat thickness, corroborating results obtained by HINSON et al (2011). MOURA et al (2011a reported that the effectiveness of ractopamine in reducing lipogenesis in porcine adipose tissue is more pronounced when diets have higher energy content, particularly in the form of lipids.…”

Ractopamine for Pigs: A Review about Nutritional Requirements

“…The protein deposit rate is directly related to increased demand for lysine, therefore ractopamine may alter the needs of this amino acid and other essential amino acids in pigs since there is a direct relationship between lysine and other amino acids for maximum protein deposit in the body of the animal [5,6]. Supplementing the diet with higher levels of lysine may alter production responses of pigs subjected to diets with ractopamine, especially early in the administration of -adrenergic (up to 14 days) when the responses are more evident [6][7][8]. Additionally, the responses of animals fed diets with ractopamine can be modified according to the period and dose used [6].…”

“…Pigs are warm-blooded animals and sensitive to environmental temperatures, especially when adults. Temperatures greater than 25°C have been considered critical for finishing pigs and there has also been reports correlating temperature with metabolic alterations and body weight of the animals, as well as feed intake [8]. Thus, if the presence of ractopamine in the diet of animals in high temperature environments also contributes to reduced fee intake, its use may be impractical, given that increased body temperature already contributes to reduced feed intake.…”