Desempenho de ovelhas da raça Bergamácia alimentadas com dieta contendo gordura protegida

Abstract

RESUMO -Objetivou-se com este trabalho avaliar o efeito do uso de gordura protegida na dieta de ovelhas da raça Bergamácia sobre a produção e composição do leite e a dinâmica de peso das ovelhas. Utilizaram-se 77 ovelhas distribuídas em 2 grupos de forma homogênea por ordem de parição e idade, mantidas com uma dieta controle, com silagem de milho e concentrado, ou com a dieta controle contendo gordura protegida (35 g/ovelha.dia) adicionada ao concentrado. As dietas foram isoenergéticas e isoproteicas e continham 16% PB e 70% NDT na matéria seca. Durante o dia, os cordeiros eram mantidos com suas mães em pasto, à noite eram separados e retornavam à suas mães após a ordenha matinal; foram desmamados aos 45 dias de idade. As ovelhas, após 48 horas do parto, foram ordenhadas mecanicamente uma vez ao dia, às 7 h, e sua produção de leite foi mensurada diariamente durante 60 dias. Amostras de leite foram coletadas semanalmente para determinação dos teores de proteína e gordura. A dieta com gordura protegida proporcionou maior produção média diária de leite após a desmama dos cordeiros (0,531 vs 0,489 kg/animal.dia). Entretanto, a produção de todo o período não diferiu entre as dietas (0,468 vs 0,453 kg/animal.dia, com gordura protegida e controle, respectivamente). As produções de leite corrigidas para 6,5% de gordura e para 6,5% de gordura e 5,8% de proteína foram semelhantes entre as dietas.Palavras-chave: gordura bypass, leite, ovino, produção de leite, suplementação Performance of Bergamasca ewes fed diet with bypass fatABSTRACT -The objective of this study was to observe the effect of using bypass fat in the diet of Bergamasca ewes on milk yield, milk composition and ewe weight dynamics. Seventy seven ewes were distributed in two homogeneous groups, according to lambing order and age fed a control diet with corn silage and concentrate; or with a control diet with bypass fat (35 g/ewe/day) added to the concentrate. The diets were isoenergetic and isonitrogenous, presenting 16% CP and 70% TDN on dry matter basis. The lambs stayed with their mothers in pastures during the day and were separated at night. They returned to their mothers after the morning milking and were weaned at 45 days of age. Forty-eight hours after lambing, ewes were machine milked once daily at 7 am and the milk yield was recorded for a period of 60 days. Milk samples were collected weekly to determine the content of milk protein and fat. The bypass fat diet showed a higher daily average milk yield after weaning the lambs (0.531 vs 0.489 kg/animal.day). However, milk yield throughout the period was not different between the two diets (0.468 vs 0.453 kg/animal.day, for bypass fat and control, respectively). Milk yield corrected to 6.5% fat and 6.5% fat and 5.8% protein were similar in both diets.

Production, composition and processing of milk from ewes fed soybean seeds

“…On the other hand, Susin (1996) reports the peak between the 3rd and 5th week, while in this research there was no effect of days of lactation on milk production (439.85 mL day −1 ). The peak was observed at 14 days of lactation (496.52 mL day −1 ), close to the values reported by Emediato et al (2009), for Bergamacia sheep, of DI -desaturase index; AI -atherogenicity index; UNSAT/SAT -unsaturated:polyunsaturated fatty acid ratio; CV -coefficient of variation. Cheese yield calculated after 120 ripening days expressed as L of milk/kg of cheese, using the following formula: %Y = (CM/MM) × 100, in which %Y = percentage yield; CM = cheese mass; and MM = milk mass.…”

“…Likewise, Emediato et al (2009) evaluated the performance of Bergamácia sheep fed a diet with 16 g crude protein/100 g of diet. These authors reported no weight loss during a 60 day lactation period, with weights of 54.27 and 62.78 kg, immediately after parturition and after 60 days, respectively.…”

Productive and reproductive performances of Santa Inês ewes fed diets supplemented with protected fat in the postpartum

“…This shows that DMI was possibly not affected by the supply of PF in the concentrate 60 days after lambing, due to the great need for nutrient uptake by lactating ewes. Similar results were observed by Emediato et al (2009b) and Stradiotto et al (2010), who used a supplementation of 35 g PF (Megalac-E) per day in the diet of Bergamácia ewes up to 60 days after parturition. Silva et al (2007) found a decrease in crude protein and lactose and an increase in milk fat levels as PF levels were increased to 6% DM in the concentrate.…”

“…In all diets, the body weight of ewes showed a quadratic behavior, with a reduction during the lambing period up to 40 days postpartum, followed by a recovery at the end of the experimental period (Figure 1). Emediato et al (2009a) also observed weight gains for Bergamácia ewes 60 days after postpartum, regardless of the inclusion of PF in the concentrate. For lactating ewes, weight loss is attributed to the difficulty in providing nutrients for feeding in amounts suitable for the matrices during this phase, since the energy demand increases more rapidly than the dry matter intake; therefore, the ewes use energy reservations to produce milk and stop accumulating body mass (Araújo et al, 2008).…”

“…According to Emediato et al (2009a), Bergamácia ewes fed a diet supplemented with 35 g per day of PF in the concentrate also presented, at 60 days after …”