Este trabalho foi conduzido com o objetivo de avaliar o desempenho produtivo de vacas de corte. Foram utilizadas 30 vacas da raça Aberdeen Angus e 32 da raça Charolês primíparas, prenhes no início do experimento, com bezerros puros ou mestiços Nelore. As vacas foram submetidas a diferentes tratamentos alimentares durante o inverno e a primavera: T1 - pastagem natural, T2 - pastagem cultivada por 60 dias (24 horas/dia), do início de setembro ao início de novembro, T3 - acesso à pastagem cultivada por duas horas diárias, por um período de 60 dias (de início de julho ao início de setembro), T4 - acesso à pastagem cultivada por duas horas diárias, por um período de 60 dias (de início de julho ao início de setembro), e mais 60 dias (24 horas/dia) de pastagem cultivada do início de setembro ao início de novembro. As medidas de eficiência produtiva foram: EPPARTO = (P205/PVP)*100; EPDESMAME = (P205/PVD)*100; EPMBPARTO = (P205/PVP0,75); EPMBDESMAME = (P205/PVD0,75); e EPNDT = NDTTOTAL/P205, em que P205 é o peso ao desmame dos bezerros; PVP e PVD, os pesos das vacas ao parto e ao desmame, respectivamente; e NDTTOTAL, a exigência em energia para manutenção e produção de leite das vacas. As vacas Aberdeen Angus, com bezerros machos e aquelas com bezerros mestiços, foram mais eficientes. Vacas que utilizaram a pastagem cultivada por um período de tempo maior (T4) tiveram melhor desempenho do que aquelas que permaneceram apenas em pastagem natural(T1); as vacas dos outros tratamentos tiveram desempenhos intermediários.

-The objectives of this study were to evaluate the environmental effects (age of dam at lambing, type of birth and sex of lamb) and genetic groups (Santa Inês and ½ Santa Inês) on weight and morphometric measurements (heart girth, body length and height) of lambs; to test linear and allometric regressions to predict the weight through the measurements; and to describe the type of growth of the measurements from weight. Weight and morphometric measurements were sampled from birth to 154 days of age, at every 14 days. For the evaluation of the environmental factors and to predict the regressions the data of birth, weaning and 154 days of age were used; and to determine the type of growth all the data collected were used. The lambs derived from younger (two-tooth) ewes recorded lower averages than the ones from eighttooth ewes for weight, heart girth and body length at birth and length at weaning. The animals born from single births presented higher average weight from birth to weaning, as well as of all the measurements from birth to 154 days of age than those from twin births. There was no difference between the genetic groups Santa Inês and ½ Santa Inês. The correlations between the weight and measurements were significant, and it was possible to predict the weight from the morphometric measurements through regressions. The type of weight gain with heart girth was isometric, while with length it was positive allometric, and with height it was negative allometric. Thereby, in the absence of a scale it is possible to predict the weight from the morphometric measurements, and the type of birth is the most important factor that affects the development of lambs from birth to weaning.

The main objective of this study was to evaluate the influence of the energy levels in the diet of ewes in the last third of gestation and lactation on body measurements and weights of lambs from birth to weaning. As secondary objectives were also evaluated the effects of year of birth, sex of the lamb, type of birth and age of the ewe at lambing on the same characteristics. Forty-five Santa Inês lambs were evaluated. They were born from 40 ewes distributed randomly to three treatments: 2.0, 2.2 and 2.4 Mcal of metabolizable energy/kg of dry matter). Ewes were subjected to the experimental diets during the last third of gestation and lactation. Lambs were kept with their mothers until weaning, which occurred at 70 days. Feeding energy level did not affect traits measured on the lambs at birth. Regression analysis showed a linear increasing in all traits at weaning and in average daily gain until weaning as the energy level increased. Male lambs were heavier at birth and at weaning. All morphometric measurements performed were similar between males and females, except for thoracic perimeter at 70 days, which was higher in male lambs. Single lambs were larger and heavier than twin lambs. Lambs born from ewes of intermediate age (4 and 6 teeth) showed higher means for average daily weight gain. Among morphometric measurements, thoracic perimeter showed the best correlation to body weight at birth and at weaning. Besides the nutrition of the ewe, it is important to consider other environmental factors that affect animal's growth characteristics by acting on the expression of genetic potential.

RESUMO -Objetivou-se com este estudo analisar o desempenho reprodutivo de ovelhas submetidas a diferentes formas de suplementação alimentar antes e durante o período de acasalamento. Utilizaram-se 112 ovelhas (63 no primeiro ano e 49 no segundo) dos grupos raciais Hampshire Down, Ile de France, Suffolk e Corriedale. Os animais foram separados em três grupos: T1 (sem suplementação), T2 (suplementação com 600 g/dia de milho triturado) e T3 (suplementação com 600 g/dia de concentrado constituído de 75% de milho triturado e 25% de farelo de soja). As ovelhas sob suplementação (T2 e T3) apresentaram maiores pesos e ganhos de peso até o final da estação de monta. Os escores da condição corporal também foram maiores ao final da estação de acasalamento nas ovelhas sob suplementação, implicando maior deposição de tecidos (músculo e gordura) no corpo do animal. O flushing não resultou em maior taxa de parição nem em aumento de partos gemelares, porém, Reproductive performance of ewes submitted to different feeding managements before and during the breeding period ABSTRACT -The objective of this study was to investigate the reproductive performance of ewes submitted to different feeding management before and during the breeding period. A total of 112 ewes, 63 in year one and 49 in year two of the study, from the genetic groups Hampshire Down, Ile de France, Suffolk and Corriedale, were used. The ewes were separated in three groups: T1 (without supplementation), T2 (supplemented with 600 g/day of ground corn) and T3 (supplemented with 600 g/day of a concentrate containing 75% of ground corn and 25% of soybean meal). Supplemented ewes (T2 and T3) had higher body weight and more weight gain until the end of the breeding period than those not supplemented. Body condition scores were also greater at the end of the breeding period for supplemented ewes, indicating a greater fat and muscle deposition.Supplementation did not improve fertility rate and twins birth rate, but increased birth rate in ewes supplemented with corn. Age and genetic group both affected birth rate. It was concluded that feeding corn to ewes improved the number of lambs per ewe.

No abstract

-The objective of this study was to evaluate the influence of feeding energy levels during the last third of gestation and lactation on performance of ewes and lambs up to weaning. The experiment was carried out in the sheep raising sector of Universidade Estadual de Londrina (UEL), from August to December of 2007. Thirty-two adult lambs with 105 days of gestation, average live weight of 57.55 kg and average body condition scores of 3.42 were used in the beginning of the experiment. The animals were confined in collective pens, distributed randomly in three treatments: 2.4; 2.2 and 2.0 Mcal of metabolizable energy (ME)/kg of dry matter (DM). Feed supply was ad libitum during the last third of gestation and lactation.Weaning occurred at 70 days. Body weight, body condition score and milk production of ewes and body weight of the lambs were analyzed. There were no significant differences for body weight and body condition of ewes at lambing; however, the level of 2.4 Mcal enabled better results for those characteristics at weaning and higher gain in weight and body condition scoring during the experiment. Severe energetic restriction (2.0 Mcal ME/kg DM) determined lower average daily milk production.Lambs from levels 2.4 and 2.2 presented similar weights in all measurements and were superior to those in level 2.0. Lambs from level 2.4 presented higher average weight gain from birth to weaning. The energetic restriction upon lambs at the end of gestation and during lactation limits the performance of ewes and lambs up to weaning.

Este experimento foi realizado para avaliar o efeito de dois níveis de casca de soja (CS) e de três fontes de nitrogênio sobre a digestão total e parcial aparentes no rúmen e nos intestinos. Seis novilhos Holandês x Zebu com idade média de 12 meses e 229 kg de PV foram fistulados no rúmen e no abomaso e distribuídos em quadrado latino 6x6 e alimentados individualmente ad libitum. O consumo e as digestibilidades totais e parciais dos nutrientes foram avaliados. Não houve efeito da fonte de proteína sobre o consumo, quantidades de matéria seca (MS), matéria orgânica (MO), proteína bruta (PB), fibra em detergente neutro (FDN) e da fibra em detergente ácido (FDA) no rúmen, no abomaso e nas fezes e sobre os coeficientes de digestibilidades destes componentes. O aumento, porém, do nível de casca de soja elevou os coeficientes de digestibilidade de todos os componentes estudados nos locais do trato digestivo, com exceção nos intestinos, onde o nível de casca de soja não afetou a digestão da PB, FDN e da FDA. Os resultados indicam que a casca de soja pode substituir tanto o milho como, parcialmente, a fração volumosa nas rações de ruminantes. A farinha de subproduto avícola e a amiréia podem substituir o farelo de soja nas rações de bovinos sem reflexos negativos sobre a digestão de seus componentes nutritivos.

O objetivo deste experimento foi avaliar o desempenho de bovinos em confinamento alimentados com rações suplementadas com concentrados protéicos à base de farelo de algodão (AL), uréia (UR) ou amiréia (AM), tendo como volumoso silagem de milho. O confinamento teve duração de 80 dias. As rações foram compostas mantendo a proporção volumoso:concentrado no nível de 63:37, com aproximadamente 13% PB. Não se constataram diferenças quanto ao ganho de peso diário (GDP) durante o período experimental total entre os tratamentos AL, UR ou AM (1,14; 1,17; e 1,23 kg/anim.•dia), ou na ingestão de MS em % PV (2,63; 2,60; e 2,60% PV), em g/kg0,75•dia (136,19; 134,74; e 134,81) ou kg/anim.•dia (9,42; 9,35; e 9,40), respectivamente. Os valores de ingestão de PB foram de 1,28; 1,24; e 1,34 kg de PB/anim.•dia e de 18,54; 17,86; e 19,24 g/kg0,75•dia para os tratamentos AL, UR ou AM, não diferindo entre si. Valores obtidos para conversão alimentar da matéria seca foram de 8,41; 8,01; e 7,67 kg MSI/kg GPD e para conversão protéica, 1,15; 1,06; e 1,09 kg PBI/kg GPD, respectivamente, para os tratamentos AL, UR e AM, que foram semelhantes.