scholarly journals Growth in weight and of some tissues in the bullfrog: fitting nonlinear models during the fattening phase

2014 ◽  
Vol 38 (6) ◽  
pp. 598-606 ◽  
Author(s):  
Marcelo Maia Pereira ◽  
Cleber Fernando Menegasso Mansano ◽  
Edney Pereira da Silva ◽  
Marta Verardino De Stéfani
Keyword(s):  
Food Intake ◽  
Logistic Model ◽  
Fat Body ◽  
Nonlinear Models ◽  
Logistic Models ◽  
Live Weight ◽  
Initial Weight ◽  
Expected Values ◽  
Growth Of Animals ◽  
Cumulative Food Intake

Knowledge of the growth of animals is important so that zootechnical activity can be more accurate and sustainable. The objective of this study was to describe the live weight, development of liver tissue and fat body, leg growth, and cumulative food intake of bullfrogs during the fattening phase using nonlinear models. A total of 2,375 bullfrog froglets with an initial weight of 7.03 ± 0.16 g were housed in five fattening pens (12 m²). Ten samplings were performed at intervals of 14 days to obtain the variables studied. These data were used to estimate the parameters of Gompertz and logistic models as a function of time. The estimated values of weight (Wm) and food intake (FIm) at maturity and time when the growth rate is maximum (t*) were closer to expected values when the logistic model was used. The Wm values for live weight and liver, adipose and leg weights and the FIm value for food intake were 343.7, 15.7, 19.6, 96.03 and 369.3 g, respectively, with t* at 109, 98, 105, 109 and 107 days. Therefore, the logistic model was the best model to estimate the growth and food intake of bullfrogs during the fattening phase.

scholarly journals The use of the nonlinear models in the growth of pears of ‘Shinseiki’ cultivar

2017 ◽  
Vol 48 (1) ◽  
Author(s):  
Thais Destefani Ribeiro ◽  
Taciana Villela Savian ◽  
Tales Jesus Fernandes ◽  
Joel Augusto Muniz
Keyword(s):  
Logistic Model ◽  
Least Squares Method ◽  
Nonlinear Models ◽  
Logistic Models ◽  
Information Criterion ◽  
Fruit Weight ◽  
Coefficient Of Determination ◽  
Pear Fruit ◽  
Asian Pear ◽  
Residual Correlations

ABSTRACT: The goal of this study was to elucidate the growth and development of the Asian pear fruit, on the grounds of length, diameter and fresh weight determined over time, using the non-linear Gompertz and Logistic models. The specifications of the models were assessed utilizing the R statistical software, via the least squares method and iterative Gauss-Newton process (DRAPER & SMITH, 2014). The residual standard deviation, adjusted coefficient of determination and the Akaike information criterion were used to compare the models. The residual correlations, observed in the data for length and diameter, were modeled using the second-order regression process to render the residuals independent. The logistic model was highly suitable in demonstrating the data, revealing the Asian pear fruit growth to be sigmoid in shape, showing remarkable development for three variables. It showed an average of up to 125 days for length and diameter and 140 days for fresh fruit weight, with values of 72mm length, 80mm diameter and 224g heavy fat.

Effects of ardacin supplementation on food intake and growth rate of growing and finishing steers

1995 ◽  
Vol 60 (3) ◽  
pp. 409-417 ◽  
Author(s):  
M. G. Keane ◽  
M. P. Read ◽  
A. P. Moloney
Keyword(s):  
Growth Rate ◽  
Food Intake ◽  
Live Weight ◽  
Basal Diet ◽  
Initial Weight ◽  
Grazing Season ◽  
Treatment Groups ◽  
Grass Silage ◽  
Finishing Steers ◽  
Ad Libitum

AbstractArdacin is an antibacterial glycopeptide with ruminal activity. The objective of this study was to measure its effects on food intake and growth rate of growing and finishing steers. Two experiments were carried out simultaneously using the same foods and the same ardacin supplementation levels. In experiment 1, 72 growing steers (8 months old and 240 kg initial weight) in four treatment groups were individually offered a basal diet of grass silage ad libitum. In experiment 2, 44 finishing steers (19 months old and 463 kg initial weight), also in four treatment groups were individually offered a basal diet of grass silage ad libitum plus 3 kg (5 kg for the final 28 days) concentrates per head daily. The four treatments were 0, 50, 125 and 210 mg ardacin per head daily incorporated into 1 kg ground barley. This was offered in addition to the basal diet. The duration of the experimental period was 154 days after which 48 of the growing steers were put to pasture for a 196-day grazing season. The finishing steers were slaughtered following a withdrawal period of 7 days. Mean daily silage dry-matter intakes, and mean daily total metabolizable energy intakes for the treatments as listed above were 4·91, 5·15, 5·10 and 5·03 (s.e. 0·083) kg and 63, 66, 65 and 65 (s.e. 0·7) MJ (experiment 1), and 5·63, 5·62, 5·51 and 5·54 (s.e. 0·059) kg and 108, 108, 107 and 107 (s.e. 0·4) MJ (experiment 2), respectively. In the same order, mean daily live-weight gains during the treatment period were 612, 758, 784 and 798 (s.e. 25·2) g (experiment 1) and 911, 942, 851 and 860 (s.e. 40·0) g (experiment 2). In the growing steers proportionately 0·64 of the weight response to ardacin was retained to the end of the following grazing season. It is concluded that ardacin supplementation increased live-weight gain and improved the efficiency of conversion of food to live weight in growing steers but had no significant effect on finishing steers in this study.

scholarly journals Nonlinear models for describing lettuce growth in autumn-winter

2020 ◽  
Vol 50 (7) ◽  
Author(s):  
Fernanda Carini ◽  
Alberto Cargnelutti Filho ◽  
Rafael Vieira Pezzini ◽  
Jéssica Maronez de Souza ◽  
Gabriela Görgen Chaves ◽  
...  
Keyword(s):  
Critical Points ◽  
Logistic Model ◽  
Dry Matter ◽  
Nonlinear Models ◽  
Logistic Models ◽  
Intrinsic Curvature ◽  
Dependent Variables ◽  
Thermal Sum ◽  
Lettuce Growth ◽  
Curvature Measures

ABSTRACT: The objectives of this study were to fit the Gompertz and Logistic models for the fresh and dry matter of leaves and the fresh and dry matter of shoots of three lettuce cultivars and indicate the best model to describe their growth in autumn-winter. The lettuce cultivars Gloriosa, Pira Verde, and Stella were evaluated in the autumn-winter of 2016 and 2017, in soilless in a protected environment. After transplantation, the fresh and dry matter of leaves and shoots were weighed every seven days. These dependent variables were fit using the accumulated thermal sum. The parameters of the Gompertz and Logistic models were estimated, the assumptions of the models were verified, the indicators of fit quality and critical points were calculated and the parametric and intrinsic curvature measures quantified. The Logistic and Gompertz models presented a satisfactory adjustment for the fresh and dry matter of leaves and the fresh and dry matter of shoots, for the lettuce cultivars Gloriosa, Pira Verde and Stella, in autumn-winter. The Logistic model best describes the growth of the lettuce cultivars.

scholarly journals Classical nonlinear models to describe the growth curve for Murrah buffalo breed

2012 ◽  
Vol 42 (3) ◽  
pp. 520-525 ◽  
Author(s):  
Ronyere Olegário de Araújo ◽  
Cintia Righetti Marcondes ◽  
Maria Cecília Florisbal Damé ◽  
Analía del Valle Garnero ◽  
Ricardo José Gunski ◽  
...  
Keyword(s):  
Logistic Model ◽  
Nonlinear Models ◽  
Logistic Models ◽  
Growth Curves ◽  
Coefficient Of Determination ◽  
Von Bertalanffy ◽  
Average Deviation ◽  
Absolute Deviation ◽  
Murrah Buffalo ◽  
Deviation Coefficient

With the objective of to adjust nonlinear models for the growth curves for a buffaloes herd raised in floodable lands in Rio Grande do Sul state, monthly records measured from birth to two years-old of 64 males and 63 females born between 1982 and 1989 were used. The models used were: Von Bertalanffy, Brody, Gompertz and Logistic. The parameters were estimated by NLIN procedure and the criteria used to evaluate the adjustment given by the models were: asymptotic standard deviation; coefficient of determination; average absolute deviation of residues and asymptotic index. Von Bertalanffy and Brody models overestimated the male asymptotic weight (A) in 15.9 and 171.3kg, respectively, and the Gompertz and Logistic models underestimated it in 4.5 and 13.4kg, respectively. For females, the Logistic model underestimated the asymptotic weight (-2.09kg), and Gompertz, Von Bertalanffy and Brody overestimated this parameter in 8.04, 17.7, and 280.33kg, respectively. The biggest average deviation was estimated by Brody model for both sexes, characterizing the biggest index. Considering the criteria, it is recommended the Gompertz and Logistic models for adjust females and males Murrah buffaloes breed growth curves.

Production responses of weaned pigs after chronic exposure to airborne dust and ammonia

2004 ◽  
Vol 78 (1) ◽  
pp. 87-97 ◽  
Author(s):  
C. M. Wathes ◽  
T. G. M. Demmers ◽  
N. Teer ◽  
R. P. White ◽  
L. L. Taylor ◽  
...  
Keyword(s):  
Food Intake ◽  
Chronic Exposure ◽  
Type I Error ◽  
Live Weight ◽  
Ammonia Concentration ◽  
Dust Concentration ◽  
Barley Straw ◽  
Type I ◽  
Weaned Pigs ◽  
Airborne Dust

AbstractNine hundred and sixty weaned pigs were exposed for 5·5 weeks to controlled concentrations of airborne dust and ammonia in a single, multi-factorial experiment. Production and health responses were measured but only the former are reported here. The treatments were a dust concentration of either 1·2, 2·7, 5·1 or 9·9 mg/m3(inhalable fraction) and an ammonia concentration of either 0·6, 10·0, 18·8 or 37·0 p. p. m., which are representative of commercial conditions. The experiment was carried out over 2·5 years and pigs were used in eight batches, each comprising five lots of 24 pigs. Each treatment combination was replicated once and an additional control lot (nominally ≈ 0 mg/m3dust and ≈ 0 p. p. m. ammonia) was included in each batch to provide a baseline. The dust concentration was common across the other four lots in each batch in which all four ammonia concentrations were used; thus the split-plot design was more sensitive to the effects of ammonia than dust.The pigs were kept separately in five rooms in a purpose-built facility. The pollutants were injected continuously into the air supply. Ammonia was supplied from a pressurized cylinder and its concentration was measured with an NOxchemiluminescent gas analyser after catalytic conversion. The endogenous dust in each room was supplemented by an artificial dust, which was manufactured from food, barley straw and faeces, mixed by weight in the proportions 0·5: 0·1: 0·4. The ingredients were oven-dried, milled and mixed and this artificial dust was then resuspended in the supply air. Dust concentration was monitored continuously with a tribo-electric sensor and measured continually with an aerodynamic particle sizer and gravimetric samplers.Live weight per pig and cumulative food intake per pen of 12 pigs were measured after 5·5 weeks of exposure. Exposure to both aerial pollutants depressed live weight relative to the control (control v. pollutant, 25·7 v. 25·0 (s.e.d. = 0·33) kg, P = 0·043) and there was a trend for food intake to be lower for pollutant-exposed pigs (control v. pollutant 292 v. 280 (s.e.d. = 7·1) kg per pen, P = 0·124). The reduction in live weight and food intake was dependent upon the concentration of dust (mean across all ammonia concentrations for increasing dust concentration; live weight 25·3, 26·4, 24·0 and 24·5 (s.e.d. = 0·65) kg, P = 0·081; food intake 295, 316, 248 and 263 (s.e.d. = 14·3) kg per pen, P = 0·016) but not ammonia (mean across all dust concentrations for increasing ammonia concentration; live weight 24·4, 25·1, 25·3 and 25·3 (s.e.d. = 0·41) kg, P = 0·158; food intake 279, 275, 288 and 279 kg (s.e.d. = 9·0) kg per pen, P = 0·520). There was an interaction between dust and ammonia for live weight (P = 0·030) but the effects were complicated and may have been the result of a type I error. There was no interaction for food intake (P = 0·210). In general, both food intake and live-weight gain, but not food conversion efficiency, were lower for weaned pigs exposed to 5·1 and 9·9 mg/m3dust concentrations compared with 1·2 and 2·7 mg/m3treatments. Other measures of production were also analysed and supported the overall interpretation that dust concentrations of 5·1 mg/m3and higher depress performance.This study is the first to quantify the effects of chronic exposure to common aerial pollutants on the performance of weaned pigs. The results suggest that dust concentrations of 5·1 or 9·9 mg/m3(inhalable fraction) across ammonia concentrations up to 37 p.p.m. adversely affect performance. The commercial significance of these findings depends on the financial benefits of the superior production at low dust concentrations relative to the cost of providing air of this quality.

Prolactin stimulates food intake in a dose-dependent manner

1989 ◽  
Vol 256 (1) ◽  
pp. R276-R280 ◽  
Author(s):  
T. Gerardo-Gettens ◽  
B. J. Moore ◽  
J. S. Stern ◽  
B. A. Horwitz
Keyword(s):  
Food Intake ◽  
Female Rats ◽  
High Dose ◽  
Dependent Manner ◽  
Additional Control ◽  
The Mean ◽  
Ovine Prolactin ◽  
Dose Dependent ◽  
Medium Dose ◽  
Cumulative Food Intake

Lactation in the rat is marked by pronounced hyperphagia and suppression of brown fat (BAT) thermogenic capacity. We previously examined the possibility that elevated prolactin levels mediate these changes. The present study evaluated the effect of varying prolactin levels on food intake, BAT mitochondrial GDP binding, and carcass adiposity. Female rats were injected daily for 10 days with ovine prolactin at one of three doses: high = 3.0, medium = 1.0, or low = 0.3 micrograms/g body wt. Controls were injected with 0.9% NaCl. A group of uninjected rats served as an additional control. Cumulative food intake was significantly elevated in a dose-dependent manner in the prolactin-treated animals relative to the saline-injected and uninjected controls. Compared with the saline controls, the mean cumulative food intake was greatest at the high dose (20% increase), intermediate at the medium dose (17%), and smallest at the low dose (12%). Prolactin-treated rats gained significantly more weight during the experiment than did controls. Despite the hyperphagia in the prolactin-treated rats, no significant differences in BAT mitochondrial GDP binding were observed among the five groups. These data indicate that elevated prolactin levels stimulate food intake in a dose-dependent manner and that this hyperphagia is not accompanied by an increase in BAT mitochondrial GDP binding.

Effect of Dehydration and Rehydration on the Water Content and Na+ and K+ Balance in Adult Male Periplaneta Americana

1977 ◽  
Vol 71 (1) ◽  
pp. 49-66
Author(s):  
LOIS E. TUCKER
Keyword(s):  
Water Content ◽  
Adult Male ◽  
Periplaneta Americana ◽  
Fat Body ◽  
Live Weight ◽  
Ion Content ◽  
Food Reserves

Changes in live weight and in the water, Na+ and K+ content of the tissues and faeces have been examined in adult male Periplaneta americana in various states of hydration. During dehydration the haemolymph volume decreases markedly, but the Na+ and K+ concentrations rise only slightly. Less than 25% of the Na+ removed from the haemolymph during dehydration was found to be excreted, but the K+ excreted during dehydration was in excess of that removed from the haemolymph alone. It seems likely that the major tissue for regulating the haemolymph Na+ during dehydration and rehydration is the fat body, in which dehydration causes an increase, and rehydration a decrease, in the Na:K ratio. The Na+ and K+ content of the fat body was found to be variable in both hydrated and dehydrated animals and absolute changes in the ion content of the tissue could not be estimated because of unknown changes in the amount of food reserves and excretory products.

The rôles of photoperiod and nutrition in the seasonal increases in growth and insulin-like growth factor-1 secretion in male red deer

2001 ◽  
Vol 73 (2) ◽  
pp. 305-311 ◽  
Author(s):  
J. R. Webster ◽  
I. D. Corson ◽  
R. P. Littlejohn ◽  
S. K. Martin ◽  
J. M. Suttie
Keyword(s):  
Growth Factor ◽  
Food Intake ◽  
Growth Rates ◽  
Energy Demand ◽  
Red Deer ◽  
Young Male ◽  
Live Weight ◽  
Metabolizable Energy ◽  
Plasma Prolactin ◽  
Insulin Like Growth Factor

AbstractYoung male red deer follow a seasonal growth pattern that can be shifted by altering the photoperiod they experience. An increase in photoperiod to 16 h of light per day (16L : 8D) during winter advances the onset of rapid growth and high food intake that normally commences in spring. These changes are associated with increased growth hormone (GH) and insulin-like growth factor-1 (IGF-1) secretion. The GH/IGF-1 axis is acutely sensitive to the level of nutrition and the relative rôles of photoperiod and nutrition in determining the spring IGF-1 rise is unknown. The present experiment set out to examine this by exposing two groups of deer (no. = 8 per group) to a photoperiod shift during their 1st year of life (16L : 8D from 2 June), designed to cause accelerated growth and increased food intake after approximately 7 weeks. However, after 6 weeks the food intake (pellets containing 11 MJ metabolizable energy and 160 g crude protein per kg dry matter (DM)) of one group (LDRES) was clamped, thereby preventing the intake component of the response. The intake of the other group (LDAL) remained ad libitum for a further 12 weeks until 6 October, when the experiment concluded.During the first 6 weeks of 16L : 8D, growth rate (118 (s.e. 15·4) g/day) and food intake (1·37 (s.e. 0·031) kg DM per head per day) did not differ between the groups. Food intake following the clamp in LDRES averaged 1·40 (s.e. 0·015) kg per head per day. The intake of LDAL increased 2 weeks after the clamp and thereafter was higher than LDRES (P < 0·001). Food intake of LDAL averaged 2·13 (s.e. 0·051) kg during the nutritional clamp period. Growth rates increased in both groups during the first 3 weeks of the clamp, averaging 237 (s.e. 25·0) g/day, then growth slowed in LDRES and live weights diverged. Growth rates until the end of the experiment (147 (s.e.23·0) g/ day v. 299 (s.e. 12·5) g/day, P < 0·001) and mean live weight over the last 5 weeks of the experiment were lower (P < 0·05) in LDRES than LDAL, weights reaching 88·3 (s.e. 1·86) kg and 97·9 (s.e. 2·74) kg respectively on the final sampling date. Metatarsal bone length grew more in LDAL than in LDRES (3·1 v. 2·2 cm, s.e.d. = 0·23, P < 0·01). Prior to the nutritional clamp, mean plasma prolactin and IGF-1 concentrations increased at 3 and 6 weeks after 16L : 8D respectively, in both groups. Prolactin concentrations were lower in LDRES than LDAL on two occasions, at weeks 3 and 7 after the onset of the nutritional clamp, and IGF-1 concentrations were lower in LDRES than LDAL (676 v. 872 ng/ml, s.e.d. = 73·8, P < 0·05) over the last 7 weeks of sampling.In summary, a photoperiodically driven increase in IGF-1 occurred even when the usual associated increase in food intake was prevented. This indicates that the seasonal IGF-1 rise in red deer is not a consequence of the increased food intake, although the latter appears necessary to maintain elevated IGF-1 concentrations. The rise in IGF-1 may therefore be considered as a component of the photoperiodically entrained seasonal drive to grow, and the increase in food intake a response to satisfy the increased energy demand.

The effect of body reserves at farrowing on the reproductive performance of first-litter sows

1989 ◽  
Vol 48 (2) ◽  
pp. 449-457 ◽  
Author(s):  
B. P. Mullan ◽  
I. H. Williams
Keyword(s):  
Food Intake ◽  
Milk Production ◽  
Reproductive Performance ◽  
Live Weight ◽  
Low Level ◽  
Body Reserves ◽  
H 30 ◽  
Voluntary Food Intake

ABSTRACTThe level of body reserves in first-litter sows was manipulated by giving gilts one of three levels (high (H), medium (M) or low (L)) of food from selection (44 kg live weight) to parturition. The aim of this experiment was either to maintain or to mobilize these reserves during lactation (31·4 days) by feeding sows to appetite (high (H)) or 2·0 kg/day (low (L)).When the level of body reserves was increased prior to farrowing (171 kg live weight, 32 mm backfat) sows had a lower voluntary food intake during lactation than those animals that farrowed with a low level of body reserves (126 kg live weight, 20 mm backfat) (H-H v. L-H, 3·4 v. 4·9 kg/day; P < 0·001). Both groups had a normal return to oestrous activity after weaning (mean interval between weaning and mating of 14 days) but the heavier animals mobilized more of their body reserves (H-H −30·7 kg live weight, -4·3 mm backfat; L-H -3·6 kg live weight +0·9 mm backfat; P < 0·001). When food intake during lactation was restricted to 2·0 kg/day the interval between weaning and mating was increased by 50% regardless of the level of body reserves present at farrowing. For the same animals, there were insufficient body reserves to support milk production at the same level as for those animals given food t o appetite.

A note on the response of pigs weaned at 28 days to dietary protein

1986 ◽  
Vol 42 (3) ◽  
pp. 427-429 ◽  
Author(s):  
R. G. Campbell ◽  
M. R. Taverner
Keyword(s):  
Growth Rate ◽  
Food Intake ◽  
Dietary Protein ◽  
Live Weight ◽  
Gain Ratio ◽  
Digestible Energy ◽  
Voluntary Food Intake

ABSTRACTThirty-six piglets were used to investigate the effect of six concentrations of dietary protein ranging from 155 to 235 g/kg, and corresponding dietary lysine concentrations from 10·1 to 15·4 g/kg, on the performance of pigs weaned at 28 days of age and growing between 7·5 and 20 kg live weight. Voluntary food intake was not significantly affected by dietary protein, and growth rate increased with increase in dietary protein and lysine up to 167 and 10·9 g/kg respectively (0·75 g lysine per MJ digestible energy (DE)). Food: gain ratio improved significantly with each increase in dietary protein and lysine up to 177 and 11·6 g/kg (0·79 g lysine per MJ DE) respectively.

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