Daily Digestible Energy Intake Research Articles

Relationship between energy intake and growth performance and body composition in pigs selected for low backfat thickness.

Genetic selection of pigs over recent decades has sought to reduce carcass fat content to meet consumer demands for lean meat in many countries (e.g., Australia). Due to the impacts of genetic changes, it is unknown whether the carcass fat measures are still responsive to energy intake. Thus, the present experiment aimed to quantify the relationship between tissue composition and dietary energy intake in finisher pigs selected for low carcass backfat. Intact male and female pigs (n = 56 for each sex; Primegro Genetics, Corowa, NSW, Australia) were fed seven different amounts of an amino acid adequate wheat-based diet containing 14.3 MJ digestible energy (DE)/kg to provide the following daily DE intakes- 25.8, 29.0, 32.6, 35.3, 38.5, 41.5, and 44.2 (ad libitum) MJ DE/d for males, and 25.8, 28.9, 32.0, 35.6, 38.3, 40.9, and 44.5 (ad libitum) MJ DE/d for females between 60 and 108 kg live weight. Body composition of anesthetized pigs was measured using the dual energy X-ray absorptiometry (DXA) method when individual pigs reached 108 kg, and protein, fat, and ash deposition rates were calculated. Pigs were slaughtered on the second day post-DXA scan for carcass backfat measurement. The results showed that the carcass backfat thickness (standardized at 83.7 kg carcass) increased by 0.125 mm for every MJ increase in daily DE intake in male pigs (P = 0.004; R2 = 0.130), but carcass backfat of female pigs (standardized at 85.1 kg carcass) was not responsive to daily DE intake. Whole-body fat composition and fat deposition rate increased linearly (both P < 0.01) in male pigs but quadratically (both P < 0.01) in female pigs in response to DE intake. Every MJ increase of daily DE intake increased the rate of daily protein deposition by 3.8 g in intact male pigs (P < 0.001; R2 = 0.781) and by 2.5 g in female pigs (P < 0.001; R2 = 0.643). In conclusion, the selection for low backfat thickness over the last two decades has altered the response of fat deposition and backfat thickness to energy intake, particularly in female pigs. Despite this change, the linear relationship between DE intake and protein deposition rate was maintained in these modern genetics.

Meta-analysis of energy intake of growing-finishing pigs in China.

Data from 655 treatments of 116 studies were used in a meta-analysis to determine the daily digestible energy (DE), metabolizable energy (ME) and net energy (NE) intake of Chinese growing-finishing pigs, and to predict feed efficiency responses to change in dietary DE, ME and NE. Three alternative functions (i.e., polynomial, Bridges and asymptotic function) were employed for fitting daily DE, ME or NE intakes to mean body weight. The results showed that the three models from the current study provided reasonable fit (all R2 >0.83) for the energy intake data. However, under the same energy system, the polynomial function had the smallest Akaike's information criteria (AIC) and residual standard deviation (RSD), followed by Bridges and asymptotic functions. The three model-generated energy intakes of growing pigs were significantly less than that of the Chinese Feeding Standard of Swine, but similar to that of the National Research Council (2012), while the values of finishing pigs were greater than both standards. Compared with those that predict feed efficiency based on DE or ME, the equation with NE as a predictor had the minimized AIC and RSD. It was also found that feed efficiency increased with increasing dietary energy density (DED), but this response varied with pig body weight, and the lighter pigs were more sensitive to DED than heavier pigs.

Silvicultural herbicides and forest succession influence understory vegetation and nutritional ecology of black-tailed deer in managed forests

The increasing intensity of forestry practices, especially using herbicides to promote early survival and growth of planted conifers, has the potential to influence the abundance of nutritious, shade-intolerant forbs and shrubs on which black-tailed deer (Odocoileus hemionus columbianus) and other forest ungulates depend. Therefore, we compared summer forage resources and nutrition of female black-tailed deer in stands that received herbicide treatments paired with stands that did not in Douglas-fir/western hemlock forests of western Washington. We investigated how these responses changed as forests aged from early seral to canopy closure (2–20 years post-harvest) in both treatments, and also in unmanaged mid-seral stands (30–90 years old). We measured the biomass and nutritional quality of understory vegetation and the diet composition, diet quality and nutrient intake of tractable black-tailed deer within each paired stand. We found that herbicides did not affect the rate of closure of the overstory canopy, but influenced plant species composition of the understory vegetation and reduced total and non-conifer understory biomass, primarily in the first 9 years before canopy closure. Herbicides also reduced the biomass of two of the six plant functional groups, evergreen shrubs and deciduous shrubs and trees, but did not reduce forb, graminoid, or fern biomass. Herbicides reduced bite size, harvest rate, daily dry matter intake and daily digestible energy (DE) intake of deer, but increased dietary digestible protein (DP) content, and these effects occurred primarily in the first 3 years post-treatment. Biomass of plants suitable for black-tailed deer, and the deers’ bite rate, daily feeding time, dietary DE, and daily digestible DP intake did not respond to herbicides. Our yearling and sub-adult, non-lactating deer met requirements for yearling growth and adult maintenance for dietary DE in 78%, and DE intake in 27% of plots, but only met the higher requirements for lactating females in 5% of plots. All plots where daily DE requirements of lactation or growth were met were <10 years old. Deer were equally likely to obtain diets that satisfied requirements in treated and untreated plots, indicating that although herbicide application reduced understory biomass and DE intake, it did not explain whether deer were able to meet requirements. We also found that the biomass of deciduous shrubs and trees, forbs, and suitable forage was ~25 times greater in 4–9 year old stands than closed canopy stands (14–90 years old), indicating the importance of maintaining early seral habitat for sustaining populations of black-tailed deer.

Exploration of Available Feed Resources, Feeding Practices, Morphometric and Nutritional Status of Horses in Kashmir Valley of India

Nutrition is a critical component of equine health. Horse owners’ knowledge of nutrition is likely to affect their feeding practices. The study was conducted with the aim to survey available feed resources for equines, existing feeding practices and morphometric and nutritional status of horses in four major horse rearing tehsils (Sopore, Pattan, Tangmarg and Gulmarg) of district Baramulla in Kashmir valley. Twelve equine keeping families from each study area were selected at random. The daily dry matter (DM), crude protein (CP), digestible energy (DE) and macro minerals (Ca and P) intakes by different classes of horses were calculated from the feed intakes and compared with the nutrient requirement given in the feeding standard. Among body morphometry, body weight (BW) was calculated using body measurements, age was predicted by dentition and body condition scoring (BCS) was done using the Henneke BCS system. Adult horses were being fed rice straw and wheat bran; however, in addition to these, maize grains was fed in Tangmarg and Gulmarg areas, while jaggery was fed as energy supplement in Sopore only. The horses were fed blend of spicy ingredients locally called as “masala”. None of the farmers offered any oil seeds/cakes, compound pelleted feed or mineral supplement to their horses, though, salt licks were allowed to the adult animals on daily basis in all the study areas. The chemical composition of all the feeds and fodders fed to horses in the study areas of district Baramulla were within the ranges as prescribed for Indian feeds and fodders. During the survey, no lactating mare was observed in the entire study areas, while no foal was observed in Sopore and Gulmarg areas. Average age of the adult animal was 7.08±0.29 years, BW was in the range of 224.40 to 271.13 kg, and BCS ranged from 4.28 to 5.21 with an average of 4.93. While adult horses received optimum DM, the daily CP and DE intakes were found to be deficient along with imbalanced Ca and P intake when compared to the standard requirements. Foals were found to get diets deficient in DM, DE, CP and Ca but surplus in P. It was concluded that horse owners of district Baramulla lack basic knowledge on equine nutrition, feeding un-balanced diets to adult horses that were optimum only in terms of quantity; however, foals were fed diets deficient both in quantity as well as quality. The veterinarian-client dialog needs to be enhanced to address the misconceptions of horse owners about nutrition and feeding practices.

Available feed resources, feeding practices and nutritional status of horses in Budgam district of Kashmir valley

A study was conducted in four major horse rearing tehsils (Beerwah, Khag, Chadoora and Budgam) of district Budgam in Kashmir valley regarding available feed resources, feeding practices being followed and nutritional status of horses. Twelve equine keeping families from each study area were selected at random. The daily dry matter (DM), crude protein (CP), digestible energy (DE) and macro minerals (Ca and P) intakes by different classes of horses were calculated from the feed intakes and compared with the nutrient requirement given in the feeding standard. Adult horses were being fed rice straw, rice bran and wheat bran; however, in addition to these, bengal gram was fed in areas of Chadoora and Khag only, while maize grains was fed to the horses in Chadoora only. The horses were fed blend of spicy ingredients locally called as ‘masala’. None of the farmers offered any oil seeds/cakes, compound pelleted feed or mineral supplement to the horses, though, salt licks were allowed to the adult animals on daily basis in all the study areas. The chemical composition of all the feeds and fodders fed to horses in the study areas of district Budgam were within the ranges as prescribed for Indian feeds and fodders. While adult horses received optimum DM, the daily CP and DE intake was found to be deficient along with imbalanced Ca and P intake when compared to the standard requirements. Foals were found to get diets deficient in DM, DE, CP and Ca but surplus in P. Lactating mares received daily rations with optimum DM content, excess DE, slightly less CP and excessive Ca and P. It was concluded that the adult horses and lactating mares were being fed rations optimum in terms of quantity, but was not balanced in terms of nutrients; however, foals were fed diets deficient in both in quantity as well as quality.

Relationships Among Digestible Energy Intake, Body Weight, and Body Condition in Mature Idle Horses

The objective of this study was to evaluate the relationships among digestible energy (DE) intake, body weight (BW), and body condition score (BCS) in lean/moderate condition horses. The feed intake of 35 Quarter Horses (age 5.3 ± 1.2 years; BW 462 ± 39 kg; BCS 4.5 ± 0.5) was recorded daily over three, 42-day feeding trials. Horses were offered 1.75–2.00 kg DM/100 kg BW in Orchard grass hay and 0.2 kg/100 kg BW in whole oats. Body weight and BCS were recorded biweekly. Daily DE intake was calculated according to Pagan and recorded as the amount fed minus any refusal. The daily kilogram intake was multiplied by the DE (Mcal/kg) content of the feed to equal the total calories per day. The mean within-horse ΔBW and ΔBCS from 0 to 42 days of each trial were evaluated using paired t tests. Trial 1 horses consumed 24.5 Mcal/d and BW increased (P < .001) by 24 ± 3 kg; however, there was no significant change in BCS (0.0 ± 0.5). Trial 2 horses consumed 22.8 Mcal/d and BW increased (P = .009) by 8 ± 3 kg and BCS tended to increase (P = .06) by 0.5 ± 0.5. Trial 3 horses consumed 25.7 Mcal/d and BW and BCS increased (P < .001) by 22 ± 2 kg and 1.0 ± 0.5, respectively. According to trial, horses required approximately 19, 34, and 18 Mcal/kg of weight gain, respectively. Additional factors affecting weight gain are related to the individual.

Digestibility of a new diet for captive short-beaked echidnas (Tachyglossus aculeatus).

Short-beaked echidnas (Tachyglossus aculeatus) are myrmecophages, or ant and termite insectivore specialists, and replicating their exact diet in captivity is problematic. Diets for captive animals often incorporate raw meat, eggs and cat food mixed together with water, and vitamin and mineral supplements. These diets have promoted a number of health problems in captive echidnas, such as gastritis, cystitis, gut impaction, obesity, and diarrhea. A manufactured diet was designed and three echidnas from two zoos were transitioned onto this diet to assess the acceptability and digestibility of this diet for echidnas. The new "test" diet was readily accepted by the echidnas with a 1 week transition period. Daily digestible energy intake was 280 kJ kg-0.75 d-1 , similar to another myrmecophagous species. Digestibility values were above 74% for all macronutrients. It was determined that this diet was an acceptable replacement for the previous diets and it was decided that the remaining echidnas at both institutions would be transitioned to the new diet. The diet will also be used for wild echidnas being rehabilitated in the zoo hospitals prior to release and commercially available within Australia. Further data are being collected to assess the use of this diet for seasonal weight management, transitioning hand-reared puggles and effects on gastrointestinal tract health. Zoo Biol. 36:56-61, 2017. © 2017 Wiley Periodicals, Inc.

Effects of alginate and resistant starch on feeding patterns, behaviour and performance in ad libitum-fed growing pigs

This study assessed the long-term effects of feeding diets containing either a gelling fibre (alginate (ALG)), or a fermentable fibre (resistant starch (RS)), or both, on feeding patterns, behaviour and growth performance of growing pigs fed ad libitum for 12 weeks. The experiment was set up as a 2×2 factorial arrangement: inclusion of ALG (yes or no) and inclusion of RS (yes or no) in the control diet, resulting in four dietary treatments, that is, ALG−RS− (control), ALG+RS−, ALG−RS+, and ALG+RS+. Both ALG and RS were exchanged for pregelatinized potato starch. A total of 240 pigs in 40 pens were used. From all visits to an electronic feeding station, feed intake and detailed feeding patterns were calculated. Apparent total tract digestibility of energy, dry matter (DM), and CP was determined in week 6. Pigs’ postures and behaviours were scored from live observations in weeks 7 and 12. Dietary treatments did not affect final BW and average daily gain (ADG). ALG reduced energy and DM digestibility (P<0.01). Moreover, ALG increased average daily DM intake, and reduced backfat thickness and carcass gain : digestible energy (DE) intake (P<0.05). RS increased feed intake per meal, meal duration (P<0.05) and inter-meal intervals (P=0.05), and reduced the number of meals per day (P<0.01), but did not affect daily DM intake. Moreover, RS reduced energy, DM and CP digestibility (P<0.01). Average daily DE intake was reduced (P<0.05), and gain : DE intake tended to be increased (P=0.07), whereas carcass gain : DE intake was not affected by RS. In week 12, ALG+RS− increased standing and walking, aggressive, feeder-directed, and drinking behaviours compared with ALG+RS+ (ALG×RS interaction, P<0.05), with ALG−RS− and ALG−RS+ in between. No other ALG×RS interactions were found. In conclusion, pigs fed ALG compensated for the reduced dietary DE content by increasing their feed intake, achieving similar DE intake and ADG as control pigs. Backfat thickness and carcass efficiency were reduced in pigs fed ALG, which also showed increased physical activity. Pigs fed RS changed feeding patterns, but did not increase their feed intake. Despite a lower DE intake, pigs fed RS achieved similar ADG as control pigs by increasing efficiency in DE use. This indicates that the energy utilization of RS in pigs with ad libitum access to feed is close to that of enzymatically digestible starch.

A Comparison of Actual and Suggested Digestible Energy Intakes of Miniature Horses Derived from Different Feeding Recommendations

Despite being largely studied as models of equine nutrition, few published data exist on actual nutritional requirements of Miniature horses. Small equines are particularly prone to obesity, insulin resistance, and the metabolic disorders for which these are risk factors. Improper feed rationing, overfeeding in particular, puts horses at risk for these metabolic problems. Feed manufacturers, however, generally supply feeding recommendations for horses weighing ≥360 kg, whereas the average Miniature horse weighs around 100 kg. Lack of nutritional guidelines for small equines makes it difficult for owners to properly estimate the amount of hay and grain to feed their Miniature horse. The purpose of this study was to determine whether feeding recommendations provided by feed manufacturers for average-sized horses could be linearly extrapolated to Miniature horses. This study surveyed nutritional management of 12 mature Miniature horses that represented the ideal body condition of the breed. Each horse’s hay, grain, and pasture intake was recorded and the average daily digestible energy (DE) intake was calculated from those data. The daily DE intake of the surveyed horses was compared with the extrapolated recommendations published by several different sources. When linearly extrapolated to fit the body weight of a Miniature horse, recommendations significantly (P < .002) misestimated the amount of daily DE that the surveyed horses were consuming. The majority of recommendations overestimated the DE consumed by the Miniature horses per day. However, one source that was designed specifically for Miniature horses, severely (P < .001) underestimated their required DE.

Nutrition-induced differences in body composition, compensatory growth and endocrine status in growing pigs ,

In this experiment, we assessed the effect of amino acid (AA) intake restriction in entire male Yorkshire pigs between 15 and 38 kg BW (restriction phase) on BW gain, body composition and plasma levels of blood urea nitrogen (BUN), cortisol, insulin-like growth factor I (IGF-I), growth hormone (GH) and leptin during the subsequent re-alimentation phase. During the restriction phase, 36 pigs were allotted to one of two dietary treatments: adequate AA intake (control) or AA-limiting diets (AA-30%). Thereafter, pigs were fed common non-limiting diets up to 110 kg BW. Throughout the experiment, pigs were scale-fed at 90% of the estimated voluntary daily digestible energy intake. At the end of the restriction phase, pigs on AA-30% had lesser BW gain (650 v. 784 g/day; P < 0.001), loin area (LA; 12.2 v. 14.2 cm2; P < 0.001), BUN (4.6 v. 6.3 mg/dl; P < 0.02), lesser plasma levels of IGF-I (440 v. 640 ng/m; P < 0.001) and cortisol (8.2 v. 19.2 μg/dl; P < 0.001), greater backfat thickness (BF; 7.56 v. 6.56 mm; P < 0.02), and greater plasma levels of leptin (2.7 v. 1.8 ng/ml; P = 0.027) and GH (3.3 v. 2.0 ng/ml; P = 0.05) than pigs on control. During the re-alimentation phase, previously restricted pigs showed full compensatory growth (CG) in terms of BW gain (1170 v. 1077 g/day; P < 0.002), whole-body protein deposition (Pd) (179 v. 163 g/day; P < 0.001) as well as physical and chemical body composition (whole-body lipid to body protein mass ratio, LB/PB; 1.14 v. 1.15; P > 0.10). Besides GH at 45 kg BW (4.2 v. 2.4 ng/ml; P = 0.066), there were no effects of previous AA intake restriction on leptin, IGF-I and BUN during the re-alimentation phase (P > 0.10). Plasma cortisol and IGF-I levels may act as an indicator of AA-induced restriction in Pd in growing pigs. Plasma BUN level does not appear as a sensitive indicator for compensatory Pd. Plasma leptin and GH levels allow for the involvement of the brain in controlling chemical body composition. Full CG was observed during the energy-dependent phase of Pd in growing pigs and might be driven by a target LB/PB, possibly mediated via plasma leptin, IGF-I and GH levels.

Effect of increased dietary salinity on the reproductive status and energy intake of xeric and mesic populations of the spiny mouse, Acomys

The possible role of increased dietary salinity as a proximate regulator of reproduction in xeric population of golden spiny mice ( Acomys russatus) and mesic population of common spiny mice ( A. cahirinus) was tested. In the wild, as the dry season progresses, evaporative water loss in the vegetation increases. This leads to increase in particle concentration of plant tissues. Thus, species consuming a plant diet are exposed to increased dietary salinity. Both male and female individuals of A. russatus were subjected to gradually increasing dietary salinity (0.9%, 2.5%, 3.5%, and 5%) while those of A. cahirinus only up to 3.5% for a total period of 8 and 6 weeks, respectively. Urine osmolarity showed a significant increase under 3.5% and 5% salinity in A. russatus and 2.5% and 3.5% in A. cahirinus. Testis mass and spermatogenesis were significantly reduced while uterine mass and vaginal estrus cycles were not affected in A. russatus. None of the parameters was significantly affected in A. cahirinus. Increase in salinity also significantly reduced body mass in A. russatus but not in A. cahirinus. Mass-specific daily digestible energy intake was not significantly affected by increased salinity in both species. Recovery individuals regained body mass quickly and surpassed initial values after four weeks. However, testis mass and spermatogenesis did not show recovery. The results suggest that increase in dietary salinity could be used as a proximate signal to regulate reproduction in A. russatus by halting it in males, as the dry season progresses while such role in the mesic population of A. cahirinus is unlikely.

Fontes energéticas para bezerros de corte desmamados aos 80 dias de idade

Foram avaliadas diferentes fontes energéticas na fração concentrada da dieta de bezerros de corte em confinamento, previamente desmamados aos 80 dias de idade, com peso médio de 90 kg. As fontes energéticas testadas foram: grão de milho moído (GM), farelo de arroz integral (FA), casca do grão de soja (CS), grão de milho + farelo de arroz integral (GM + FA), farelo de arroz integral + casca do grão de soja (FA + CS) e grão de milho + casca do grão de soja (GM + CS). As dietas foram isonitrogenadas (13% PB) e apresentavam relação volumoso:concentrado 50:50. A fração volumosa foi representada por silagem de sorgo AG-2005E. Não foram verificadas diferenças significativas para os consumos diários de MS (CMS) expressos em kg (4,43 kg), por 100 kg de peso vivo (3,17%) e por unidade de peso metabólico (109,10 g). Bezerros alimentados com CS apresentaram consumos diários de FDN maiores que os alimentados com GM, quando expressos em kg por dia, por 100 kg de peso vivo e por unidade de peso metabólico (2,41 kg, 1,73% e 59,46 g versus 1,44 kg, 1,02% e 35,01 g, respectivamente). Os consumos diários de energia digestível (CED), nas três formas de expressão, o ganho médio diário (0,986 kg), a conversão alimentar (4,52 kg CMS/kg de ganho de peso) e a eficiência energética (12,23 Mcal CED/kg de ganho de peso) foram similares entre as fontes energéticas. No entanto, ao comparar, por intermédio da análise de contraste, as duas dietas contendo CS (CS e CS + FA) versus as duas dietas com GM (GM e GM + FA), observou-se que animais alimentados com as dietas contendo CS consumiram mais MS que aqueles alimentados com as dietas contendo GM, quando expresso por 100 kg de PV (3,28 vs 3,06%) e por unidade de peso metabólico (UTM) (112,67 vs 105,59 g). Houve diferença também nas formas de expressão do CED, com superioridade das dietas contendo GM (12,47 Mcal/dia e 0,304 Mcal/UTM) em relação àquelas contendo CS (11,67 Mcal/dia e 0,288 Mcal/UTM). A conversão alimentar nos tratamentos com GM (4,21) foi melhor que naqueles com CS (4,80).

The response of sows to increased nutrient intake during mid to late gestation

Five hundred and ten multiparous sows were allocated at 66 days after mating to one of 6 dietary treatments that were imposed for the subsequent 35 days. The dietary treatments were 5 feeding levels of 2.2, 2.6, 3.0, 3.4, and 3.8 kg/day of a gestation diet containing 12.9 MJ DE/kg, 127 g crude protein/kg, and 5.6 g lysine/kg, plus a protein intake treatment where sows received 2.8 kg/day of a lactation diet containing 13.8 MJ DE/kg, 168 g crude protein/kg, and 8.3 g lysine/kg. After the treatment period, all sows were offered the lactation diet at the common feeding level of 3.0 kg/day and after farrowing, all sows were offered this diet ad libitum throughout lactation. Increasing feeding levels between Day 66 and Day 101 of pregnancy increased (P &lt; 0.001) liveweight gain prior to farrowing but increased (P &lt; 0.001) liveweight loss during lactation. The majority of the extra maternal energy intake during mid to late gestation was deposited as maternal gain. These linear weight responses during lactation were explained by the significant inverse relationship between voluntary daily feed intake in lactation (FI) and average daily digestible energy intake in the previous gestation (DE): Neither increasing the feeding level during mid to late gestation nor increasing the protein content of the diet had any significant effect on litter birth weight, average piglet birth weight, or the standard deviation of individual piglet birth weight within the litter. In addition, there were no significant effects of gestation feeding treatments on litter size weaned or weaning weight. Furthermore, neither increasing the feeding level during mid to late gestation nor increasing the protein content of the gestation diet had any significant effect on subsequent fertility or litter size. In conclusion, when average individual piglet birth weight is already well in excess of 1.5 kg, there is no significant response to feed intake levels between 2.2 and 3.8 kg/day when offered between Day 66 and Day 101 of gestation.

Desempenho de novilhos de gerações avançadas do cruzamento alternado entre as raças Charolês e Nelore, terminados em confinamento

Foram avaliadas as características de estado corporal, peso, ganho de peso, consumo e eficiência alimentar de novilhos puros (Charolês - C e Nelore - N) e mestiços da segunda (G2) (¾C ¼N e ¾N ¼C), terceira (G3) (5/8C 3/8N e 5/8N 3/8C) e quarta (G4) (11/16C 5/16N e 11/16N 5/16C) geração de cruzamento, terminados em confinamento. Os novilhos foram alimentados com a mesma dieta, contendo 12,32% de proteína bruta e 2,96 Mcal de energia digestível/kg de matéria seca, com relação volumoso:concentrado de 52:48. Os consumos médios diários de matéria seca, energia digestível e de fibra em detergentes neutro e ácido, expressos em kg/animal, foram maiores nos animais mestiços em todas as gerações de cruzamento. No entanto, quando estes consumos foram expressos por 100 kg de peso vivo, as diferenças deixaram de ser significativas. A heterose retida (5,46%) foi significativa para ganho de peso médio diário. As heteroses para eficiências alimentar (ganho de peso/kg de matéria seca) e energética (ganho de peso/Mcal de energia digestível) foram negativas em todas gerações, indicando que novilhos mestiços foram menos eficientes que a média dos puros. As porcentagens de heterose para estado corporal e pesos corporais inicial e final foram expressivas e significativas em todas as gerações. O comportamento do grau de heterose nestas características acompanhou a oscilação da heterozigose individual. O cruzamento rotativo gerou mestiços superiores quanto ao consumo de matéria seca e ao peso e estado corporal, em relação aos animais puros. Os animais mestiços apresentaram mesma eficiência alimentar que os Nelore, mas foram inferiores aos Charolês quanto à eficiência alimentar e ao ganho de peso médio diário.

Protein and Energy Requirements of Pre-weaned West African Dwarf Goats Fed Soyabean Diet as a Replacement for Milk in a Tropical Environment

Twenty-one early-weaned West African dwarf goats weighing between 1.0 and 1.5 kg at birth were used to assess the protein and energy requirement of pre-weaned West African Dwarf (WAD) goats fed soyabean diet. Three isonitrogenous diets (24%) were prepared such that dried whole-milk protein was replaced by corn starch and soyabean concentrate protein at 0.0%, 25.0% and 50.0% levels such that a 14.5% total solid solution was obtained for each diet. Results indicated that a daily digestible energy (expressed as kcal/day/W0.75 kg) intake of 58.2, 63.7, 98.5 and 114.6 kcal was required for maintenance, while a corresponding value of 7.37, 4.50, 2.18 and 1.91 kcal was required per day per gram live weight gain by the kids at 4, 6, 9 and 13weeks old, respectively. Similarly, a digestible crude protein (DCP) intake of 3.59 g/day/W0.75 kg) appeared to be adequate for maintenance of the kids between 0 and 13 weeks, while 0.34 g/day/W0.75 kg of DCP intake was required per day per gram live weight.

Níveis de proteína bruta em rações para suínos machos castrados em fase inicial de crescimento, mantidos em ambiente de baixa temperatura

Objetivando-se avaliar níveis de proteína bruta da ração para suínos machos castrados em fase inicial de crescimento, mantidos em ambiente de baixa temperatura (15ºC), foram utilizados 60 suínos mestiços (Landrace x Large White), com peso inicial médio de 15,1 ± 0,50 kg e idade média de 56 ± 3,6 dias. Os animais foram distribuídos em delineamento experimental de blocos ao acaso, com cinco tratamentos, seis repetições e dois animais por unidade experimental. Os tratamentos foram constituídos de rações com 17,0; 18,0; 19,0; 20,0 e 21% de proteína bruta (PB). Os níveis de PB da ração influenciaram o ganho de peso diário, que aumentou de forma quadrática até o nível de 19,6%. A conversão alimentar também variou de forma quadrática, melhorando até o nível de 20%. Os consumos de ração e de energia digestível diários não foram influenciados pelos tratamentos. O ajuste dos dados pelo modelo LRP indicou como nível adequado 20% de PB, a partir do qual os dados permaneceram em um platô. Os tratamentos influenciaram a taxa de deposição de proteína, que aumentou de forma linear, enquanto a de gordura não variou. Concluiu-se que o nível de 20% de PB da ração, associado a um consumo de 10,7 g de lisina diário, promove os melhores resultados de desempenho para suínos machos castrados de 15 a 30 kg, mantidos em ambiente de baixa temperatura.

Avaliação da silagem de capim papuã (Brachiaria plantaginea) por meio do desempenho de bezerros de corte confinados

O experimento teve como objetivo estudar os parâmetros relativos ao desempenho de bezerros de corte em confinamento, alimentados com três dietas, contendo diferentes fontes de volumoso: SPSI - silagem de capim papuã (Brachiaria plantaginea) sem inoculante bacteriano, SPCI - silagem de capim papuã com inoculante bacteriano e SMMS - mistura de silagem de milho (Zea mays) e silagem de sorgo (Sorghum bicolor). Foram utilizados 36 bezerros com média de peso vivo inicial de 159kg e média de idade de sete meses. O confinamento compreendeu 105 dias de avaliação, sendo divididos em cinco períodos de 21 dias. A relação volumoso:concentrado foi de 65:35 para todas as dietas testadas. O uso de inoculante bacteriano, na silagem de papuã, não afetou (P&gt;0,05) as variáveis estudadas. Não houve interação (P&gt;0,05) entre fonte de volumoso e período de avaliação para os consumos médios de matéria seca (CMS) e de energia digestível (CED), expressos em kg dia-1 e Mcal dia-1 (CMSD e CEDD), por 100kg de peso vivo (PV) (CMSP e CEDP) e por unidade de tamanho metabólico (CMSM e CEDM), ganho de peso médio diário (GMD), conversão alimentar (CA) e eficiência energética (EE). A análise de contraste entre as dietas que incluíam silagem de capim papuã (SPSI + SPCI) contra a que incluía a mistura de silagem de milho e sorgo (SMMS) revelou que os animais alimentados com silagem de capim papuã apresentaram menor CMSD (4,99 contra 5,56kg dia-1) sem diferença para o CMSP e CMSM, menor GMD (0,800 contra 1,061kg dia-1) e pior CA (6,26 contra 5,30) em relação à mistura de silagens de milho e sorgo.

Produção do Superprecoce a Partir de Bezerros Desmamados aos 72 ou 210 Dias de Idade

O experimento foi conduzido com o objetivo de avaliar o desempenho em confinamento, dos 210 aos 408 dias de idade, de bezerros previamente desmamados aos 72 (T72) ou 210 (T210) dias. Foram utilizados 36 machos não castrados da raça Braford (5/8 Hereford 3/8 Nelore). O peso médio no início do experimento foi de 209 kg (T72) e 192 kg (T210). O confinamento compreendeu 30 dias de adaptação dos animais e 168 dias de avaliação, sendo dividido em quatro períodos de 42 dias. A relação volumoso:concentrado foi de 60:40 para o 1º e 2º períodos, 50:50 para o 3º período e 45:55 para o 4º período. Não houve interação entre idade de desmame e período de avaliação em confinamento para os parâmetros relativos aos consumos médios por animal de matéria seca (CMS) e de energia digestível (CED), expressos em kg/dia e Mcal/dia (CMSD e CEDD), por 100 kg de peso vivo (CMSP e CEDP) e por unidade de tamanho metabólico (CMSM e CEDM), ao ganho de peso médio diário (GMD), à conversão alimentar (CA) e eficiência energética (EE). Animais desmamados aos 210 dias apresentaram maiores CMSP (2,25 contra 2,07% PV) e CEDP (7,05 contra 6,48% PV) em relação aos animais desmamados ao 72 dias de idade. Não houve diferença no CMSD (6,75 contra 6,98 kg/dia), no GMD (1,066 contra 1,074 kg/dia), na eficiência de conversão da matéria seca (6,42 contra 6,72 kg de MS/kg ganho de PV) e da energia digestível consumida (20,18 contra 21,13 Mcal/kg ganho de PV) em ganho de peso vivo para os animais desmamados aos 72 ou 210 dias de idade, respectivamente. Os pesos de abate e de carcaça quente foram similares entre as duas idades, sendo, respectivamente, de 424 e 232 kg para os animais do T72 e de 406 e 221 kg para dos T210. Os resultados mostram que animais desmamados aos 72 dias de idade apresentaram desempenho durante a terminação, pesos de abate e de carcaça similares aos desmamados aos 210 dias.

The effect of maize starch or soya-bean oil as energy sources in lactation on sow and piglet performance in association with sow metabolic state around peak lactation

AbstractThe effects of different energy sources in the lactation diet on sow and piglet performance were assessed in association with effects on the metabolic state of the sow around peak lactation. Either maize starch (S) or soya-bean oil (F) was added to a basal diet to provide 0·34 of total digestible energy (DE) intake, such that the experimental diets provided the same daily intakes of DE and crude protein. Twenty-four multiparous sows were allocated between two groups at farrowing, each given one of the two dietary treatments for a lactation period of 28 days. Sow weight and backfat (P2) as well as individual piglet weights were measured on a weekly basis. Litter sizes were standardized to 10 piglets. Milk samples were collected from sows on days 8, 12, 17, 21 and 25 of lactation to measure milk composition and prolactin concentrations. Blood samples were taken via an ear vein catheter from a subsample (7 S, 6 F) of sows on day 14 of lactation; two pre- and seven post-feeding samples were taken at 60-min intervals to measure plasma prolactin, insulin, glycerol, triglyceride, non-esterified fatty acid, urea, b-hydroxybutyrate and glucose concentrations. There was no effect of energy source on sow weight or P2 loss or on subsequent weaning-to-oestrus interval. Sows offered starch weaned more piglets than sows offered soya-bean oil (9·4 v. 8·4, P &lt; 0·05). Litter weight gains were higher for S than F sows in week 3 of lactation (2·2 v. 1·7 kg/day, P &lt; 0·05), irrespective of litter size. Significantly increased plasma urea and b-hydroxybutyrate concentrations and lower post-prandial increases in plasma glucose and insulin concentrations were observed in F sows around peak lactation. Neither milk nor plasma prolactin concentrations were significantly affected by dietary treatments. The metabolic indices indicated that the F diet was more limiting in dietary glucose availability, which was associated with impaired milk yield as indicated by poorer litter performance. In conclusion, this study suggests that starch is superior to fat as an energy source in sow lactation diets, particularly in the later stages of lactation.

Níveis de Proteína Bruta para Leitoas dos 30 aos 60 kg Mantidas em Ambiente de Conforto Térmico (21ºC)

O experimento foi conduzido para avaliar níveis de proteína bruta (PB) para leitoas em crescimento, mantidas em conforto térmico. A temperatura interna da sala manteve-se durante o período experimental em 21,3 ± 0,53°C, a umidade relativa em 70,5 ± 5,11% e o Índice de Temperatura de Globo e Umidade (ITGU) calculado no período em 68,7 ± 0,93. Foram utilizadas 40 leitoas mestiças, com peso inicial médio de 29,4 ± 1,42 kg, em delineamento de blocos ao acaso com cinco tratamentos (16, 17, 18, 19 e 20% de PB), quatro repetições e dois animais por unidade experimental. As rações experimentais foram isoenergéticas, com 3400 kcal de ED/kg de ração, e formuladas para satisfazerem às exigências dos animais, exceto em PB. A ração e a água foram fornecidas à vontade até o final do experimento, quando os animais atingiram peso médio de 60,6 ± 1,76 kg. O nível de PB da ração influenciou o ganho de peso diário (GPD), que aumentou, e a conversão alimentar (CA), que melhorou linearmente. Apesar do efeito linear dos níveis de PB sobre o GPD e CA, o modelo "Linear Response Platô" (LRP) foi o que melhor se ajustou aos dados, estimando em 18,78 e 19,15%, os níveis de PB a partir do qual o GPD e a CA, permaneceram em um platô. Os consumos diários de proteína e lisina aumentaram linearmente em razão do nível de PB da ração, porém não se observou efeito dos tratamentos sobre os consumos de ração e de energia digestível diários. Concluiu-se que leitoas em crescimento, mantidas em ambiente de conforto térmico, exigem 19,15% de PB na ração, correspondendo a um consumo de 343 e 19,08 g/dia de proteína e lisina total, respectivamente.