Effect of protein supplementation in the final third of pregnancy on fetal programming, and performance of offspring submitted to different supplementation strategies

Author(s)

Filipe Marinho da Rocha

• Document type: Master's Dissertation
• Press: Pirassununga.
• Institution: Universidade de São Paulo (USP). Faculdade de Medicina Veterinária e Zootecnia (FMVZ/SBD)
• Defense date: 2012-12-11

Examining board members

Alexandre Vaz Pires; Juliano José de Resende Fernandes; Paulo Henrique Mazza Rodrigues

• Advisor: Alexandre Vaz Pires

Abstract

The primary objective of the study was to evaluate the effect of protein supplementation of cows in the final third of pregnancy on fetal programming, as measured by the performance of their offspring submitted to growth rates up to 318 days old. The secondary objective, was to economically evaluate the different strategies of supplementation. In phase I we used 411 Nellore pregnant cows at the beginning of last trimester of gestation, with a mean age of 7.6 ± 2.1 years, mean body weight of 429 ± 49 kg and body condition score (BCS) of 2.84 ± 0.44 (range from1 to 5). Cows were assigned to two treatments according to BCS, body weight, age and father of calves . The treatments consisted of Supplemented-Cow group (SCO) (n = 212) and Control-Cow group (CCO) (n = 199). The cows SCO received daily 0.56 kg of protein supplement composed of 0.50 kg of soybean meal and 0.06 kg of minerals. The cows CCO received only mineral supplement. In phase II, which correspond to the period in which supplementation was offered to calves. Half of cows of each group from the first phase, with their offspring (2 months old), were redistributed in two treatments. 1- creep-feeding, offered ad libitum, Supplemented-Calf (SCA) (n = 201). 2 - Only mineral supplementation, Control-Calf (CCA) (n = 188). During phase II the animals were weighed four times, at 108, 149, 182 208 (weaning time) days old. After weaning they were sent to a pasture and remained for 25 days until the start of phase III. In phase III, which corresponds to winter season, lasted 85 days, the calves were regrouped into two groups. In group I, the calves were kept in feed lot, Supplemented-Growth group (SGG) (n = 209). In group II, the calves were kept in pasture composed predominantly of Panicum maximum or Brachiaria brizantha, Control-Growth group (CGG) group (n = 180). In this phase males and females were kept separated and finished when claves reached 318 days old. The economic analysis was based on the calculation of gross margin, obtained by subtracting the cost differential of total revenue. Effect was observed (P <0.05) of maternal supplementation during the first three weighings of phase II, the control group had higher weights. However, the weight at 208 days, was not (P> 0.05) influenced by maternal supplementation. Effect was observed (P<0.05) supplementing in the creep feeding at weaning time affected the body weight , (P <0.05), calves supplemented were heavier. The effect of sex of calves, bull calves were heavier, had higher (P <0.05) average daily gain (ADG) and total weight gain (TWG) than females in all weighings of phase II. The maternal supplementation on the offspring did not affect (P> 0.05) ADG in phase II between treatments. The effect of supplementation of calves in creep-feeding on daily gain (DG) and total weight gain (TWG) was higher for supplemented calves (P <0.05). The effect of maternal supplementation on weight of calves during phase III, did not showed differences (P> 0.05) between treatments. Supplementation of calves on creepfeeding was effective in keeping the weight difference obtained at weaning time for all phase III. The ADG and TWG of offspring at 318 days old were not affected (P> 0.05) by pre-partum maternal supplementation. Calves that were supplemented on creep-feeding in the phase III lost less weight (P <0.05) than control group. Interaction effect was observed (P <0.05) between feeding management in phase III and sex, both the animals fed in fed lot as well as for animals kept at pasture, males had better weight gains than females. Gross margin was higher for treatments CCO-CCA-SGG (R$ 40,014.48) and CCO-CCA-CGG (R$ 38,266.03), followed by treatments SC-CCA-CGG (R$ 35,574.47) and CCO-SCA-SGG (R$ 35,501.23). The lower gross margin was obtained by treatment SCO-SCA-CGG (32,452.03). The costs of acquiring supplements, machine works and other differential costs of treatments impacted significantly on the gross margin. The animals fed SCO-SCA-SGG, SCO-SCA-CGG, SCO-CCA-SGG, SCO-CCA-CGG, SCO-SCA-SGG, CCO-SCA-CGG CCO-CCA-CGG should have an additional gain of 29.08, 32.62, 20.61, 19.15, 19.47, 20.01, and 7.54 kg respectively, so that the gross margin of these treatments was equal to CCO-CCA-SGG treatment. The protein supplementation of cows in the last trimester of gestation had no effect on weight and weight gain of offspring. Thus, creep-feeding provided greater weaning weight, but the calve were not programmed for greater performance in subsequent phases. Calves in feedlot was effective in providing greater weight to 318 days and higher ADG. Investments in pre-partum supplementation and supplementation pre-weaning were not effective in providing higher gross margins, suggesting that better performance does not necessarily imply better economic performance. (AU)

• FAPESP's process: 10/14712-4 - Effect of nutritional management of cows in the last third of gestation on fetal programming and subsequent performance of their offspring until twelve months of age
• Grantee: Filipe Marinho da Rocha
• Support Opportunities: Scholarships in Brazil - Master