The influence of the body weight and the characteristics of the carcass about the creatinine excretion and the use of spot sample of urine to estimate the excretion of purine derivatives and the nitrogenous compounds in nelore heifers

Objetivou-se avaliar a relação entre o peso corporal, a quantidade de músculo na carcaça, a área de olho de lombo e a espessura de gordura subcutânea com a excreção diária de creatinina em novilhas Nelore de diferentes pesos. Avaliaram-se também as excreções totais de creatinina a intervalos de 4 e 24 horas e as relações de derivados de purina (DP), uréia (U) e compostos nitrogenados totais (NT) com a creatinina (C), obtidas de coletas spot de urina a intervalos de 2 horas. Utilizaram-se quinze novilhas, sendo agrupadas em função do peso corporal em três grupos, sendo um grupo com quatro novilhas com peso médio de 127 kg ± 24,2 (baixo), três de 221 kg ± 22,3 (médio) e oito de 434 kg ± 29,2 (alto). Os animais do grupo de maior peso corporal (alto) foram distribuídos aleatoriamente em dois subgrupos, cada um com quatro animais, sendo que a um deles (alto restrito) a dieta foi fornecida ao nível próximo da mantença (1,3% do peso corporal) e ao outro grupo (alto voluntário) a dieta foi fornecida ad libitum. Para o grupo baixo e médio, a mesma dieta, constituída de 60% de volumoso (silagem de milho), 30% de concentrado (mistura à base de casca de soja, milho moído, farelo de soja, uréia/sulfato de amônia, cloreto de sódio e minerais) e 10% de caroço de algodão, foi fornecida ad libitum. O período experimental teve duração de nove dias, após 30 dias de adaptação. As coletas de urina foram realizadas utilizando-se sondas de Folley nº 22 ou 26, conforme o peso da novilha. Considerando o período de coleta de 24 horas, a excreção diária de creatinina (C), expressa em g, mg/kg de peso corporal (PC), mg/kg de peso de corpo vazio (PCVZ) e mmol/kg de peso metabólico (PC0,75) foi influenciada pelo peso corporal e pela quantidade de músculo (MUS) na carcaça (P0,05). Não houve efeito (P>0,05) de períodos de coleta (00h00- 04h00, 04h00-08h00, 08h00-12h00, 12h00-16h00, 16h00-20h00, 20h00-00h00) sobre a excreção de creatinina expressa em qualquer unidade. A partir da coleta spot de urina a intervalos de 2 horas foi observado que a relação DP:C não variou durante o dia (P>0,05), permitindo o cálculo da excreção de DP (mmol/dia) ser efetivado com coletas obtidas em qualquer horário do dia. Houve efeito (P 0.05). There was no effect (P> 0.05) of the collection periods (00h00-04h00, 04h00-08h00, 08h00-12h00, 12h00-16h00, 16h00-20h00, 20h00-00h00 hours) in the creatinine excretion expressed in any unit. From the collection of spot urine at intervals of 2 hours was observed the relationship PD:C has not varied during the day (P> 0.05), allowing the calculation of the excretion of PD (mmol/day) to be done with obtained sample at any time of the day. There was effect (P<0,05) of the periods of the urine spot sample over the relations U:C and NC:C, which were analyzed by Fourier serie, obtaining two points daily close to the average of 7,77 to the relation of U:C and 6,42 to the relation NC:C. The two points got very close to food time (08h00 and 16h00). To estimate the nitrogenous compounds excretions, recommends two spot collections, right after the food is given. It is concluded that the lack of time effect of collection over the relationship of PD:C indicates that one can use the sample spot obtained at any time to determine, the excretion of PD, there is no need in the total collection urine.Conselho Nacional de Desenvolvimento Científico e Tecnológic

Overnutrition of Ewe in Late Gestation and the Impact on Placental Efficiency and Lamb’s Performance

The objective of the study was to evaluate energy or energy/protein supplementation in the ewe diet, in the last third of gestation, on maternal placental and endocrine characteristics, as well as its effects on the behavior of neonatal lambs and productive performance until weaning. A total of 128 ewes were used, and the experimental diet was fed from 100 days gestation until lambing, with the birth of 172 lambs. The ewes were distributed into three treatments: CTL (control, n = 43) with metabolizable energy (ME) and crude protein (CP) intake according to NRC (1985); ME (energy supplementation, n = 44) plus 21% ME; and MECP (energy/protein supplementation, n = 41) plus 26% ME and CP. Body weight, body condition score, serum hormone concentrations, placental characteristics, lamb performance and behavior, and production efficiency of the ewe from lambing to weaning were measured. ME and MECP ewes were heavier before (p = 0.006) and just after lambing (p = 0.002) and had higher serum triiodothyronine (p = 0.001) and cortisol (p = 0.004) concentrations on the day of lambing. ME ewes had higher placental efficiency (p = 0.036) and lower total cotyledon weight (p = 0.011). ME and MECP diets increased both lamb birth weight (p = 0.015) and weaning weight (p = 0.009). Production efficiency at birth and at weaning was not influenced (p > 0.05) by treatments. Lamb behavior was influenced by the ME and MECP diets, reducing the time to kneel (p ≤ 0.05), to try to stand (p ≤ 0.05), and the latency to stand (p ≤ 0.005). It is concluded that overnutrition in the last third of gestation was positive for the ovine production system, with improved production rates, hormonal profile, placental characteristics, and neonatal behavior