Productive and Economic Performance of Broiler Chickens Subjected to Different Nutritional Plans

The objective of the study was to evaluate the effect of nutritional plans on the productive and economic performance of Hubbard Flex broiler chickens. A completely randomized experimental design was applied, consisting of five treatments. Treatments consisted of five different nutritional plans: a basal diet containing the nutrient and energy levels recommended by literature and designated reference diet; two diets containing 1.5% and 3% lower levels than the reference diet; and two diets containing 1.5% and 3% higher levels than the reference diet (-3%, -1.5%, reference plan, +1.5% and +3%). Feed intake (FI), body weight (BW), feed conversion rate (FCR), livability (L) and productive efficient index (PEI) were determined when broilers were 42 days old. Broilers were processed, and carcass and parts (breast fillet, leg, and wings) yields were determined. The economic viablility of the nutitional plans was evaluated as a function of feed cost/kg live and carcass weights, economic efficiency index (EEI), and cost index (CI). Feed intake and the feed conversion rate decreased as dietary nutrient and energy levels increased. Feed cost/kg live weight, economic efficiency index, and cost index cost increased as dietary nutrient and energy levels increased. Feed intake, feed conversion ratio, production efficiency index, and breast yield improved with increasing nutritional and energy levels. However, worse economic results were obtained with higher nutritional and energy levels.

Productive and Economic Performance of Broiler Chickens Subjected to Different Nutritional Plans

The objective of the study was to evaluate the effect of nutritional plans on the productive and economic performance of Hubbard Flex broiler chickens. A completely randomized experimental design was applied, consisting of five treatments. Treatments consisted of five different nutritional plans: a basal diet containing the nutrient and energy levels recommended by literature and designated reference diet; two diets containing 1.5% and 3% lower levels than the reference diet; and two diets containing 1.5% and 3% higher levels than the reference diet (-3%, -1.5%, reference plan, +1.5% and +3%). Feed intake (FI), body weight (BW), feed conversion rate (FCR), livability (L) and productive efficient index (PEI) were determined when broilers were 42 days old. Broilers were processed, and carcass and parts (breast fillet, leg, and wings) yields were determined. The economic viablility of the nutitional plans was evaluated as a function of feed cost/kg live and carcass weights, economic efficiency index (EEI), and cost index (CI). Feed intake and the feed conversion rate decreased as dietary nutrient and energy levels increased. Feed cost/kg live weight, economic efficiency index, and cost index cost increased as dietary nutrient and energy levels increased. Feed intake, feed conversion ratio, production efficiency index, and breast yield improved with increasing nutritional and energy levels. However, worse economic results were obtained with higher nutritional and energy levels.(AU)

Estimativa de custos de três sistemas alimentares para a recria de novilhas acasaladas aos 18 meses de idade / Feeding systems costs for rearing beef heifers bred at 18 months of age

A idade ao acasalamento da novilha está relacionada com a eficiência econômica da produção de bovinos. A determinação de sistemas alimentares para a recria é fundamental para que as novilhas apresentem elevada taxa de prenhez. O objetivo deste trabalho foi estimar e avaliar os custos de alternativas alimentares na recria de novilhas de corte destinadas aoacasalamento aos 18 meses de idade. Foram avaliados sistemas alimentares que atendessem o ganho de peso em cada fase da recria utilizando o campo natural e suplementos alimentares para determinar o custo final do sistema. Para tanto foram definidos os seguintes pressupostos: peso ao desmame – 160 kg; ganho do desmame ao início do acasalamento – 140 kg; peso ao início do acasalamento – 300 kg (raça britânica, 65% do peso adulto). Os tratamentos foram denominados conforme o ganho de peso diário médio (GDM) no primeiro (INV), segundo (PRI) e terceiro (VER) período, respectivamente: BAM – Baixo (0,000 kg/d), Alto (1,111 kg/d) e Moderado (0,500 kg/d); MMA – Moderado (0,120 kg/d), Moderado (0,800 kg/d) e Alto (0,500 kg/d); ABB – Alto (0,373 kg/d), Baixo (0,600 kg/d) e Baixo (0,300 kg/d). O sistema de recria ABB apresentou o menor custo (R$ 96,19/cab), seguido pelo MMA (R$ 114,60/cab) e pelo BAM (R$ 134,40/cab). A utilização de diferentes sistemas alimentares apresenta implicações econômicas na recria de fêmeas. Novilhas destinadas ao acasalamento aos 18 meses no outono necessitam de suplementação alimentar durante pelo menos um dos três períodos de recria. A suplementação visando obter altas taxas de ganho de peso durante o primeiro período de recria (inverno) apresentou menor custo em relação a ganhos elevados no segundo e terceiro períodos (primavera e verão, respectivamente).

Age at first breeding of heifers is related with economic efficiency of cattle production. The determination of feeding systems for rearing heifers is essential to reach high pregnancy rates. The aim of this study was to estimate and evaluate the costs of feeding systems for rearing beef heifers bred at 18 months of age. Feeding systems witch enable a suitable weight gain during each rearing phase were analyzed. Native pasture and supplements were used to compose the feeding systems and to calculate the final cost of each system. Therefore, the following assumptions were defined: weaning weight – 160 kg; weight gain from weaning to breeding – 140 kg; weight at breeding – 300 kg (British breed, 65% of mature body weight). Treatments were determined according to the average daily gain (ADG) in the winter (WIN), spring (SPR) and summer (SUM) period, respectively: LHM – Low (0.000 kg/d), High (1.111 kg/d) e Moderate (0.500 kg/d); MMH – Moderate (0.120 kg/d), Moderate (0.800 kg/d) and High (0.500 kg/d); HLL – High (0.373 kg/d), Low (0.600 kg/d) and Low (0.300 kg/d). HLL reached the lowest cost (R$ 96,19/head), followed by MMH (R$ 114,60/head) and LHM (R$ 134,40/head). The utilization of different feeding systems has economic involvements for rearing females. Heifers bred at 18 months in the autumn need be supplemented at least during one of the three rearing periods. Supplementing heifers to get higher weight gain during the first rearing period (winter) was cheaper than reach higher gains during the second and third periods (spring and summer, respectively).

Estimativa de custos de três sistemas alimentares para a recria de novilhas acasaladas aos 18 meses de idade / Feeding systems costs for rearing beef heifers bred at 18 months of age

A idade ao acasalamento da novilha está relacionada com a eficiência econômica da produção de bovinos. A determinação de sistemas alimentares para a recria é fundamental para que as novilhas apresentem elevada taxa de prenhez. O objetivo deste trabalho foi estimar e avaliar os custos de alternativas alimentares na recria de novilhas de corte destinadas aoacasalamento aos 18 meses de idade. Foram avaliados sistemas alimentares que atendessem o ganho de peso em cada fase da recria utilizando o campo natural e suplementos alimentares para determinar o custo final do sistema. Para tanto foram definidos os seguintes pressupostos: peso ao desmame 160 kg; ganho do desmame ao início do acasalamento 140 kg; peso ao início do acasalamento 300 kg (raça britânica, 65% do peso adulto). Os tratamentos foram denominados conforme o ganho de peso diário médio (GDM) no primeiro (INV), segundo (PRI) e terceiro (VER) período, respectivamente: BAM Baixo (0,000 kg/d), Alto (1,111 kg/d) e Moderado (0,500 kg/d); MMA Moderado (0,120 kg/d), Moderado (0,800 kg/d) e Alto (0,500 kg/d); ABB Alto (0,373 kg/d), Baixo (0,600 kg/d) e Baixo (0,300 kg/d). O sistema de recria ABB apresentou o menor custo (R$ 96,19/cab), seguido pelo MMA (R$ 114,60/cab) e pelo BAM (R$ 134,40/cab). A utilização de diferentes sistemas alimentares apresenta implicações econômicas na recria de fêmeas. Novilhas destinadas ao acasalamento aos 18 meses no outono necessitam de suplementação alimentar durante pelo menos um dos três períodos de recria. A suplementação visando obter altas taxas de ganho de peso durante o primeiro período de recria (inverno) apresentou menor custo em relação a ganhos elevados no segundo e terceiro períodos (primavera e verão, respectivamente).(AU)

Age at first breeding of heifers is related with economic efficiency of cattle production. The determination of feeding systems for rearing heifers is essential to reach high pregnancy rates. The aim of this study was to estimate and evaluate the costs of feeding systems for rearing beef heifers bred at 18 months of age. Feeding systems witch enable a suitable weight gain during each rearing phase were analyzed. Native pasture and supplements were used to compose the feeding systems and to calculate the final cost of each system. Therefore, the following assumptions were defined: weaning weight 160 kg; weight gain from weaning to breeding 140 kg; weight at breeding 300 kg (British breed, 65% of mature body weight). Treatments were determined according to the average daily gain (ADG) in the winter (WIN), spring (SPR) and summer (SUM) period, respectively: LHM Low (0.000 kg/d), High (1.111 kg/d) e Moderate (0.500 kg/d); MMH Moderate (0.120 kg/d), Moderate (0.800 kg/d) and High (0.500 kg/d); HLL High (0.373 kg/d), Low (0.600 kg/d) and Low (0.300 kg/d). HLL reached the lowest cost (R$ 96,19/head), followed by MMH (R$ 114,60/head) and LHM (R$ 134,40/head). The utilization of different feeding systems has economic involvements for rearing females. Heifers bred at 18 months in the autumn need be supplemented at least during one of the three rearing periods. Supplementing heifers to get higher weight gain during the first rearing period (winter) was cheaper than reach higher gains during the second and third periods (spring and summer, respectively).(AU)