scholarly journals Evaluation of "Pampa-Corte" simulation model in different beef cattle fattening systems in Spain

2011 ◽  
Vol 41 (3) ◽  
pp. 497-500 ◽  
Author(s):  
Vicente Celestino Pires Silveira ◽  
Isabel Casasús ◽  
Mireia Blanco ◽  
Margalida Joy ◽  
Alberto Bernués
Keyword(s):  
Beef Cattle ◽  
Simulation Model ◽  
Adult Animal ◽  
Growth Parameters ◽  
Animal Management ◽  
Early Maturing ◽  
Grazing Systems ◽  
Animal Growth ◽  
Animal Size ◽  
Best Fit

The Pampa-Corte model was developed to simulate the growth of beef cattle in grazing systems in a dynamic and mechanistic way. It was validated under Brazilian conditions. This paper aims to verify the performance of the model in conventional and alternative beef cattle finishing systems in Spain. An experimental dataset of 21 Parda de Montaña calves of similar age and weight at weaning was used to evaluate the model. They were slaughtered individually on reaching 450kg liveweight. The model considered genetic group maturity rather than breed, in order to adjust growth parameters, once Parda de Montaña breed is not contemplated by AFRC (1993). Parameters from late maturing group were initially used considering adult animal size of Parda de Montaña animals; however, the best fit was with values from the early maturing group. The model predicted accurately animal growth in grazing and conventional finishing systems in Spain, although estimates were less precise when changes in animal management involved physiologic modifications.

scholarly journals A Physiological-Monitoring Electronic Platform for Cattle Grazing Systems

2020 ◽  
Vol 11 (3) ◽  
pp. 1-12
Author(s):  
Ricardo R. Santos ◽  
Fabiana V. Alves ◽  
Patrik O. Bressan ◽  
Ricardo E. Aguiar ◽  
Wellington O. Santos ◽  
...  
Keyword(s):  
Beef Cattle ◽  
Skin Temperature ◽  
Mobile Device ◽  
Electronic Device ◽  
Cattle Grazing ◽  
Physiological Data ◽  
Physiological Monitoring ◽  
Physiological Variables ◽  
Non Invasive ◽  
Grazing Systems

In this work, we present a non-invasive electronic platform for physiological data acquisition on cattle grazing systems. The platform can be used for dairy and beef cattle to continuously monitor physiological variables such as skin temperature, heartbeats, and respiratory frequency. The set of sensors are coupled into a halter so that they are in touch with the animal's forehead. Users can monitor the data acquired by the electronic device using a mobile device (smartphone or tablet) and it visualizes important physiological parameters in the platform cloud system.

Growth Models with Corrections for the Retardative Effects of Tagging

1994 ◽  
Vol 51 (2) ◽  
pp. 263-267 ◽  
Author(s):  
Yongshun Xiao
Keyword(s):  
Growth Parameters ◽  
Growth Models ◽  
Simulated Data ◽  
Fish Growth ◽  
Lates Calcarifer ◽  
General Utility ◽  
Potential Applications ◽  
Length Increment ◽  
Animal Growth ◽  
Special Case

Length increment data from mark–recapture experiments are commonly used to obtain information on animal growth, assuming that tagging does not affect the growth of marked animals. The assumption is violated in many studies, but the effects of tagging on growth and estimates of growth parameters have not been and cannot be examined without appropriate models. This paper describes a model allowing quantification and estimation of the retarding effects of tagging on animal growth simultaneously with growth parameters in all existing growth models, reduction or elimination of biases in growth parameters induced by tagging, and relaxation of a key assumption in growth analysis using length increment data. A special case of this model was applied to simulated data and to tagging data from a centropomid perch (Lates calcarifer) to demonstrate its general utility. Tagging was inferred to have stopped the fish growth for 36.44 d (ASE = 12.70 d) if von Bertalanffy growth is assumed, but the period of recovery from tagging seemed size or age independent within the size range studied. If tagging retards animal growth, L∞ is slightly overestimated and K underestimated for unbiased data. Potential applications and limitations of the model are also discussed.

scholarly journals Genetic aspects of growth and maturing rate in trypanotolerant beef cattle: N'Dama

2021 ◽  
Vol 30 (2) ◽  
pp. 149-156
Author(s):  
O. O Mgbere ◽  
O. Olutogun
Keyword(s):  
Growth Rate ◽  
Beef Cattle ◽  
Growth Traits ◽  
Physiological Stress ◽  
Genetic Parameter ◽  
High Standard ◽  
Parameter Estimates ◽  
Production Environment ◽  
Genetic Progress ◽  
Animal Management

Genetic parameters for Absolute Growth Rate (AGR), Relative Growth Rate (RGR) and Absolute Maturing Rate (AMR) at various age interval from birth to maturity in N 'Dama beef cattle raised in the humid Tropics of Nigeria were estimated. Performance data used were accumulated between 1948 and 1964 at Fasola cattle ranch in Oyo, Nigeria and the number of records analysed ranged from 44 to 678. prewering (B - W) growth and maturing rates in N’Dama calves were 0.377 ± 0.009 kg/day (AGR), 0.643 ± 0.006 %/day (RGR) and 0.120 ± 0.003% A/day (AMR) and fluctuated subsequently, following the animals' state of development and certain physiological stress conditions.  At post weaning (W-12), these rates decreased to 0.249 ± 0.049 kg/day, 0.204 ± 0.029 %/day and 0.075 ± 0.014 % A/day for AGR, RGR and AMR respectively. Estimates of heritability at the various age intervals were considered low in these growth traits with values obtained ranging from 0.03 to 0.24 for AGR, 0.03 to 0.21 for RGR and 0.02 to 0.42 for AMR, with high standard errors. The low estimates though, consistent with literature reports were attributed to the poor standard of animal management and production environment at Fasola. It was evident from this study that selection of N'Dama calves based on post weaning (W-12) growth or maturing rates would yield substantial genetic progress. However, improved animal management and production environment on the ranch would not only improve precision of the genetic parameter estimates but would also enhance N 'Dama growth performance generally.

Growth of carcass joints and tissues in steers of three breed types fed two dietary energy levels

1990 ◽  
Vol 1990 ◽  
pp. 13-13
Author(s):  
M. G. Keane ◽  
G. J. More O’ Ferrall ◽  
J. Connolly
Keyword(s):  
Beef Cattle ◽  
Energy Levels ◽  
Carcass Composition ◽  
Dietary Energy ◽  
Beef Production ◽  
Beef Breed ◽  
Slaughter Weight ◽  
Breed Type ◽  
Early Maturing ◽  
Metabolisable Energy

Factors which affect the carcass composition of beef cattle include breed type, plane of nutrition and slaughter weight. With increasing weight, the relative proportions of the carcass joints and tissues change and if these changes were known or could be predicted then cattle could be slaughtered at the desired carcass composition. Dairy bred calves for beef production can be classified into three breed categories -straightbred Friesians, early maturing beef breed x Friesians and late maturing beef breed x Friesians. The objectives of the present study were to compare the changes in carcass composition associated with changes in slaughter weight in Friesian (FF), Hereford x Friesian (HF) and Charolais x Friesian (CF) steers and to determine the effects of dietary metabolisable energy (ME) content.

Development of the lateral eye of American horseshoe crabs: Visual field and dioptric array

1995 ◽  
Vol 12 (3) ◽  
pp. 485-492 ◽  
Author(s):  
Michael J. Shih ◽  
William W. Weiner ◽  
Kathleen Kier Wheatley ◽  
Jennifer L. DePonceau ◽  
Mary Anne Sydlik ◽  
...  
Keyword(s):  
Visual Field ◽  
Sexual Maturity ◽  
Adult Animal ◽  
Significant Trend ◽  
Aperture Diameter ◽  
Entrance Aperture ◽  
Lateral Eye ◽  
Horseshoe Crabs ◽  
Optical Alignment ◽  
Animal Size

AbstractWe used a precision two-circle goniometer mounted to the stage of a compound microscope to determine the optical alignment and to measure the entrance aperture diameter of individual cuticular cones in the dioptric array of the lateral eye of juvenile horseshoe crabs in order to learn about the development of the visual field. Our results show that the extent of the visual field of juvenile horseshoe crabs with prosomal lengths about 20% ofadult size (14–21 mm) is about 70% that of the visual field of adult horseshoe crabs (prosomal lengths: 100+ mm). The visual field of such juvenile animals covers between 77 and 85 deg vertically and 140 and 145 deg horizontally. Assuming that the dioptric array is uniform and square packed, the average interommatidial angle of the juvenile animals is between 5.6 and 6.0 deg as compared to 4.6 deg for an adult animal. The diameter of the entrance aperture of individual cuticular cones increases markedly with increasing animal size. In addition, we noted a statistically significant trend for entrance aperture diameters to increase from anterior to posterior within the eye for animals of all sizes. There may be a slight trend for entrance aperture diameters to increase from dorsal to ventral within the eye. Our results indicate that the extent of the visual field and the resolution of the lateral eye approach adult values in advance of animals' reaching sexual maturity.

Slow life-history traits of a neritic predator, the bronze whaler (Carcharhinus brachyurus)

2017 ◽  
Vol 68 (3) ◽  
pp. 461 ◽  
Author(s):  
Michael Drew ◽  
Paul Rogers ◽  
Charlie Huveneers
Keyword(s):  
Life History ◽  
Growth Parameters ◽  
Isolated Populations ◽  
Life History Characteristics ◽  
Regional Estimates ◽  
Males And Females ◽  
Size At Age ◽  
Slow Growing ◽  
Best Fit ◽  
Age Estimates

Intra-species plasticity in the life-history characteristics of sharks leads to the need for regional estimates to accurately determine resilience to anthropogenic effects. The present study provides the first length-at-age, growth and maturity estimates for the bronze whaler (Carcharhinus brachyurus) from southern Australia. Age estimates were obtained from vertebral sections of 466 individuals spanning 50–308-cm total length. Maximum estimates of age for males and females were 25 and 31 years respectively. The three-parameter logistic model for females (L∞=308cm LT, k=0.15, α=742) and for males (L∞=317cm LT, k=0.13, α=782) provided the best fit to the size at age data. Males matured at a similar age (16 years), but smaller size than females (224v. 270cm LT). Growth parameters and age-at-maturity estimates were similar to those for genetically isolated C. brachyurus populations, and the sympatric dusky shark (C. obscurus). The southern Australian C. brachyurus population is long-lived, slow growing and late maturing. These growth parameters are needed to undertake demographic analyses to assess the resilience of C. brachyurus to fishing, and provide an example of a wide-ranging elasmobranch with similar life-history characteristics across isolated populations.

Profitability of calving heifers at 2 compared with 3 years of age and the effect of incidence of assistance at parturition on profitability

2010 ◽  
Vol 50 (6) ◽  
pp. 354 ◽  
Author(s):  
R. E. Hickson ◽  
N. Lopez-Villalobos ◽  
P. R. Kenyon ◽  
B. J. Ridler ◽  
S. T. Morris
Keyword(s):  
New Zealand ◽  
Beef Cattle ◽  
Cattle Herd ◽  
Replacement Rate ◽  
Systems Model ◽  
Grazing Systems ◽  
Farm System ◽  
First Time ◽  
Made In

There is potential to increase the profitability of beef-breeding cows in New Zealand by calving heifers for the first time at 2 instead of 3 years of age; however, calving at this earlier age is often associated with an increase in assistance at calving. This study used a simulated farm system within the Grazing Systems Model to estimate the profitability of calving heifers at 2 years of age with various incidences of assistance at calving. Annual profit from the beef cattle herd was greater for primiparous 2-year-old heifers than for 3-year-old primiparous heifers when the incidence of assisted calving in 2-year-old heifers was less than 89%. Replacement rate increased with increased assistance at parturition. These results indicated that a considerable gain in profitability could be made by calving heifers for the first time at 2 instead of 3 years of age, and further gains could be made in herds already calving heifers at 2 years of age by reducing the incidence of assistance at calving.

Using length data in the Schnute Model to describe growth in a metapenaeid from waters off Australia

2010 ◽  
Vol 61 (12) ◽  
pp. 1435 ◽  
Author(s):  
Steven S. Montgomery ◽  
Chris T. Walsh ◽  
Malcolm Haddon ◽  
Caitlin L. Kesby ◽  
Daniel D. Johnson
Keyword(s):  
Growth Parameters ◽  
Maximum Size ◽  
Growth Function ◽  
Novel Approach ◽  
Von Bertalanffy Growth Function ◽  
Female Data ◽  
Fitting Length ◽  
Schnute Model ◽  
Length Data ◽  
Best Fit

This paper presents a novel approach for fitting length data to the Schnute growth model. Cohorts were fitted manually to a time series of length distributions from two stocks (Clarence and Hunter Rivers) of Metapenaeus macleayi and considered analogous to individuals from tag–recapture data, in order to estimate growth parameters. Data for Clarence males best fitted the three-parameter Schnute Model (L∞ = 21.3 mm CL, κ = 0.025 day–1 and γ = –1.35), whereas those for Hunter males were best fitted to a two-parameter version of the model (L∞ = 33.5 mm CL, κ = 0.009 day–1 and γ = 0 fixed). The equivalent to the von Bertalanffy growth function was the best fit to female data from both stocks (L∞ = 36.6 and 40.2 mm CL, κ = 0.004 and 0.005 day–1 and γ = 1 fixed for Clarence and Hunter respectively). Females grew larger than males and took longer to achieve their maximum size. No significant differences in female growth were found between stocks; however, males from the Hunter grew to a longer mean maximum length but at a slower rate than those from the Clarence. This study shows how the Schnute Model can be fitted to length based data and thus include the flexibility of comparing fits between asymptotic and non-asymptotic growth functions.

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