Energy requirements for maintenance and growth of Caninde goat kids

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Energy requirements for growth of pubertal female Saanen goats

Previous research on energy requirements of female Saanen goats, using the factorial approach, has not considered the specific requirements for maintenance and growth during the pubertal phase. Thus, the purpose of this study was to estimate energy requirements for maintenance (Trial 1) and growth (Trial 2) of non-pregnant and non-lactating female Saanen goats at the pubertal phase from 30 to 45 kg. In Trial 1, the net energy requirements for maintenance (NEm ) were estimated using 18 female Saanen goats randomly assigned to three levels of intake: ad libitum, and 70% and 40% of ad libitum intake. These animals were pair-fed in six slaughter groups, each consisting of one animal for each level of intake. In Trial 2, the net energy requirements for growth (NEg ) were estimated using 18 female Saanen goats, which were fed ad libitum and slaughtered at targeted BW of 30, 38 and 45 kg. The NEm was 52 kcal/kg(0.75) of BW. The NEg increased from 3.5 to 4.7 Mcal/kg of BW gain as BW increased from 30 to 45 kg. Our results suggest that the guidelines of the major feeding systems for the entire growth phase may not be adequate for females at pubertal phase.

Metabolizable energy and oil intake in brown commercial layers

With the objective to establish the best metabolizable energy (ME) intake for layers, and the best dietary vegetable oil addition level to optimize egg production, an experiment was carried out with 432 30-week-old Hisex Brown layers. Birds were distributed into nine treatments with six replicates of eight birds each according to a 3 x 3 factorial arrangement, consisting of three daily metabolizable energy intake (280, 300 or 320 kcal/bird/day) and three oil levels (0.00; 0.75 and 1.50 g/bird/day). Daily feed intake was limited to 115, 110 and 105 g/bird in order to obtain the desired energy and oil intake in each treatment. The following parameters were evaluated: initial weight, final weight, body weight change, egg production, egg mass, feed conversion ratio per dozen eggs and per egg mass and energy conversion. There was no influence of the treatments on egg production (%) or egg mass (g/bird/day). Final weight and body weight change were significantly affected by increasing energy intake. Feed conversion ratio per egg mass, feed conversion ratio per dozen eggs and energy conversion significantly worsened as a function of the increase in daily energy intake. An energy intake of 280 kcal/bird/day with no addition of dietary oil does not affect layer performance.

Apparent digestibility and metabolizable energy content of lipid sources in poultry

A trial was conducted to determine the apparent digestibility (ATTD) and AME content of different lipid sources in 21d-old broilers. There were a control diet based on corn and soybean meal without any supplemental fat and 6 additional diets forming a 3x2 factorial with 3 sources of fat (soy oil, SBO; reconstituted monoglyceride oil, RMG; and reconstituted triglyceride oil, RTG) included in the diet (3 or 6%) at expenses (wt:wt) of the basal diet.

Energy requirements in pressure irrigation systems

Modernization of irrigation schemes, generally understood as transformation of surface irrigation systems into pressure –sprinkler and trickle- irrigation systems, aims at, among others, improving irrigation efficiency and reduction of operation and maintenance efforts made by the irrigators. However, pressure irrigation systems, in contrast, carry a serious energy cost. Energy requirements depend on decisions taken on management strategies during the operation phase, which are conditioned by previous decisions taken on the design project of the different elements which compose the irrigation system. Most of the countries where irrigation activity is significant bear in mind that modernization irrigation must play a key role in the agricultural infrastructure policies. The objective of this study is to characterize and estimate the mean and variation of the energy consumed by common types of irrigation systems and their management possibilities. The work includes all processes involved from the diversion of water into irrigation specific infrastructure to water discharge by the emitters installed on the crop fields. Simulation taking into account all elements comprising the irrigation system has been used to estimate the energy requirements of typical irrigation systems of several crop production systems. It has been applied to extensive and intensive crop systems, such us extensive winter crops, summer crops and olive trees, fruit trees and vineyards and intensive horticulture in greenhouses. The simulation of various types of irrigation systems and management strategies, in the framework imposed by particular cropping systems, would help to develop criteria for improving the energy balance in relation to the irrigation water supply productivity.

Minimising total energy requirements in amplified links by optimising amplifier spacing

We investigate the energy optimization (minimization) for amplified links. We show that using the using a well-established analytic nonlinear signal-to-noise ratio noise model that for a simple amplifier model there are very clear, fiber independent, amplifier gains which minimize the total energy requirement. With a generalized amplifier model we establish the spacing for the optimum power per bit as well as the nonlinear limited optimum power. An amplifier spacing corresponding to 13 dB gain is shown to be a suitable compromise for practical amplifiers operating at the optimum nonlinear power. © 2014 Optical Society of America.

A new method for resolving uncertainty of energy requirements in large water breathers: the ‘mega-flume’ seagoing swim-tunnel respirometer

Body size is a key determinant of metabolic rate, but logistical constraints have led to a paucity of energetics measurements from large water-breathing animals. As a result, estimating energy requirements of large fish generally relies on extrapolation of metabolic rate from individuals of lower body mass using allometric relationships that are notoriously variable. Swim-tunnel respirometry is the ‘gold standard’ for measuring active metabolic rates in water-breathing animals, yet previous data are entirely derived from body masses <10 kg – at least one order of magnitude lower than the body masses of many top-order marine predators. Here, we describe the design and testing of a new method for measuring metabolic rates of large water-breathing animals: a c. 26 000 L seagoing ‘mega-flume’ swim-tunnel respirometer. We measured the swimming metabolic rate of a 2·1-m, 36-kg zebra shark Stegostoma fasciatum within this new mega-flume and compared the results to data we collected from other S. fasciatum (3·8–47·7 kg body mass) swimming in static respirometers and previously published measurements of active metabolic rate measurements from other shark species. The mega-flume performed well during initial tests, with intra- and interspecific comparisons suggesting accurate metabolic rate measurements can be obtained with this new tool. Inclusion of our data showed that the scaling exponent of active metabolic rate with mass for sharks ranging from 0·13 to 47·7 kg was 0·79; a similar value to previous estimates for resting metabolic rates in smaller fishes. We describe the operation and usefulness of this new method in the context of our current uncertainties surrounding energy requirements of large water-breathing animals. We also highlight the sensitivity of mass-extrapolated energetic estimates in large aquatic animals and discuss the consequences for predicting ecosystem impacts such as trophic cascades.

A new method for resolving uncertainty of energy requirements in large water breathers: the ‘mega-flume’ seagoing swim-tunnel respirometer

Body size is a key determinant of metabolic rate, but logistical constraints have led to a paucity of energetics measurements from large water-breathing animals. As a result, estimating energy requirements of large fish generally relies on extrapolation of metabolic rate from individuals of lower body mass using allometric relationships that are notoriously variable. Swim-tunnel respirometry is the ‘gold standard’ for measuring active metabolic rates in water-breathing animals, yet previous data are entirely derived from body masses <10 kg – at least one order of magnitude lower than the body masses of many top-order marine predators. Here, we describe the design and testing of a new method for measuring metabolic rates of large water-breathing animals: a c. 26 000 L seagoing ‘mega-flume’ swim-tunnel respirometer. We measured the swimming metabolic rate of a 2·1-m, 36-kg zebra shark Stegostoma fasciatum within this new mega-flume and compared the results to data we collected from other S. fasciatum (3·8–47·7 kg body mass) swimming in static respirometers and previously published measurements of active metabolic rate measurements from other shark species. The mega-flume performed well during initial tests, with intra- and interspecific comparisons suggesting accurate metabolic rate measurements can be obtained with this new tool. Inclusion of our data showed that the scaling exponent of active metabolic rate with mass for sharks ranging from 0·13 to 47·7 kg was 0·79; a similar value to previous estimates for resting metabolic rates in smaller fishes. We describe the operation and usefulness of this new method in the context of our current uncertainties surrounding energy requirements of large water-breathing animals. We also highlight the sensitivity of mass-extrapolated energetic estimates in large aquatic animals and discuss the consequences for predicting ecosystem impacts such as trophic cascades.

Energy requirements for the continuous biohydrogen production from Spirogyra biomass in a sequential batch reactor

The current energy market requires urgent revision for the introduction of renewable, less-polluting and inexpensive energy sources. Biohydrogen (bioH2) is considered to be one of the most appropriate options for this model shift, being easily produced through the anaerobic fermentation of carbohydrate-containing biomass. Ideally, the feedstock should be low-cost, widely available and convertible into a product of interest. Microalgae are considered to possess the referred properties, being also highly valued for their capability to assimilate CO2 [1]. The microalga Spirogyra sp. is able to accumulate high concentrations of intracellular starch, a preferential carbon source for some bioH2 producing bacteria such as Clostridium butyricum [2]. In the present work, Spirogyra biomass was submitted to acid hydrolysis to degrade polymeric components and increase the biomass fermentability. Initial tests of bioH2 production in 120 mL reactors with C. butyricum yielded a maximum volumetric productivity of 141 mL H2/L.h and a H2 production yield of 3.78 mol H2/mol consumed sugars. Subsequently, a sequential batch reactor (SBR) was used for the continuous H2 production from Spirogyra hydrolysate. After 3 consecutive batches, the fermentation achieved a maximum volumetric productivity of 324 mL H2/L.h, higher than most results obtained in similar production systems [3] and a potential H2 production yield of 10.4 L H2/L hydrolysate per day. The H2 yield achieved in the SBR was 2.59 mol H2/mol, a value that is comparable to those attained with several thermophilic microorganisms [3], [4]. In the present work, a detailed energy consumption of the microalgae value-chain is presented and compared with previous results from the literature. The specific energy requirements were determined and the functional unit considered was gH2 and MJH2. It was possible to identify the process stages responsible for the highest energy consumption during bioH2 production from Spirogyra biomass for further optimisation.

Apparent metabolizable energy of microalgae (Spirulina sp.) for broilers under different methodologies.

2016

Cow/calf preweaning efficiency of Nellore and Bos taurus x Bos indicus crosses

The objectives of this study were to determine if percentage Bos taurus (0 or 50%) of the cow had an effect on ME requirements and milk production, and to compare cow/calf efficiency among 3 mating systems. Metabolizable energy requirements were estimated during a feeding trial that encompassed a gestation and lactation feeding trial for each of 2 groups of cows. Cows were 0 or 50% Bos taurus ( 100 or 50% Nellore) breed type: Nellore cows (NL; n = 10) mated to Nellore bulls, NL cows ( n = 9) mated to Angus bulls, Angus x Nellore (ANL; n = 10) and Simmental x Nellore (SNL; n = 10) cows mated to Canchim (5/ 8 Charolais 3/ 8 Zebu) bulls. Cows were individually fed a total mixed diet that contained 11.3% CP and 2.23 Mcal of ME/kg of DM. At 14-d intervals, cows and calves were weighed and the amount of DM was adjusted to keep shrunk BW and BCS of cows constant. Beginning at 38 d of age, corn silage was available to calves ad libitum. Milk production at 42, 98, 126, and 180 d postpartum was measured using the weigh-suckle-weigh technique. At 190 d of age, calves were slaughtered and body composition estimated using 9-10-11th-rib section to obtain energy deposition. Regression of BW change on daily ME intake (MEI) was used to estimate MEI at zero BW change. Increase in percentage Bos taurus had a significant effect on daily ME requirements (Mcal/d) during pregnancy (P < 0.01) and lactation (P < 0.01). Percentage Bos taurus had a positive linear effect on maintenance requirements of pregnant (P = 0.07) and lactating (P < 0.01) cows; during pregnancy, the ME requirements were 91 and 86% of those in lactation (131 +/- 3.5 vs. 145 +/- 3.4 Mcal.kg(-0.75).d(-1)) for the 0 and 50% B. taurus groups, respectively. The 50% B. taurus cows, ANL and SNL, suckling crossbred calves had greater total MEI (4,319 +/- 61 Mcal; P < 0.01) than 0% B. taurus cows suckling NL (3,484 +/- 86 Mcal) or ANL calves (3,600 +/- 91 Mcal). The 0% B. taurus cows suckling ANL calves were more efficient (45.3 +/- 1.6 g/Mcal; P = 0.03) than straightbred NL (35.1 +/- 1.5 g/Mcal) and ANL or SNL pairs (41.0 +/- 1.0 g/Mcal). Under the conditions of this study, crossbreeding improved cow/ calf efficiency and showed an advantage for cows that have lower energy requirements.

Exigências energéticas para mantença e para o crescimento de frangos de corte

O trabalho foi realizado com o objetivo de determinar, pelo método fatorial, as exigências de energia metabolizável (EM) de frangos de corte. Foi conduzido um ensaio em câmaras climáticas mantidas às temperaturas de 13, 23 e 32ºC (±2ºC) para se verificar o efeito da temperatura sobre as exigências de energia metabolizável para mantença utilizando-se a técnica do abate comparativo. As exigências de energia metabolizável para ganho de peso foram determinadas com base no teor de energia corporal e na eficiência energética de utilização da EM. As exigências de mantença foram de 159,36; 116,17 e 128,66 kcal/kg0,75/dia para 13, 23 e 32ºC, respectivamente, verificando-se efeito quadrático da temperatura sobre as exigências de mantença (EMm=300,14 - 14,61.T + 0,2876.T², r²=0,90). As exigências de em para ganho de peso corporal foram de 3,72 kcal/g para machos e 3,98 kcal/g para fêmeas de 1 a 21 dias; 4,21 para machos e 3,93 para fêmeas de 22 a 42 dias; e 4,51 para machos e 7,04 para fêmeas de 43 a 56 dias. Considerando-se as exigências determinadas, foram elaborados modelos de predição das exigências diárias de energia para frangos de corte, nos quais foram considerados o peso corporal, a temperatura ambiente (para estimativa das exigências de mantença) e o ganho de peso (para cálculo das exigências de ganho). Com base nas comparações das exigências determinadas pelos modelos e nas recomendações do manual da linhagem, conclui-se que os modelos elaborados predizem as exigências energéticas dos frangos de corte.

Programas de alimentação para matrizes pesadas após o pico de postura, com base em modelos para predizer a exigência energética

Este trabalho foi conduzido com o objetivo de avaliar o desempenho de matrizes pesadas, submetidas a diferentes programas de alimentação estabelecidos pela aplicação de modelos para predizer as exigências energéticas, após o pico de postura. O experimento foi conduzido no setor de avicultura da UNESP Campus Jaboticabal, com duração de 84 dias (três períodos de 28 dias). Foram utilizadas 740 matrizes de corte Hubbard Hy-Yield e 80 machos Petterson, com 55 semanas de idade. O delineamento foi inteiramente casualizado, com quatro tratamentos e cinco repetições de 37 aves por repetição (box) e um modelo fatorial 4´3 (quatro tratamentos ´ três períodos). Os programas de alimentação avaliados foram: T1 - Fornecimento de ração de acordo com o padrão da linhagem (428 kcal/ave/dia de 55 a 66 semanas de idade); T2 - Redução semanal de energia (2 kcal de EM/ave em cada semana); T3 - Fornecimento de ração de acordo com o modelo de exigência de EM, UNESP (2000); e T4 - Fornecimento de ração de acordo com o modelo, NRC (1994). O programa de alimentação com redução semanal de energia foi adequado para manter os desempenhos produtivo e reprodutivo das aves, indicando a possibilidade de redução de 2 kcal/ave/dia, em cada semana, na alimentação de matrizes pesadas após 55 semanas de idade. Os modelos UNESP e NRC proporcionaram estimativas mais elevadas das exigências energéticas que o modelo padrão, provavelmente em decorrência do ganho de peso das matrizes, que esteve acima do recomendado para a linhagem, promovendo maiores exigências de energia para mantença.