scholarly journals Observational study on the breeding performance of emus (Dromaius novaehollandiae) in Brazil

2020 ◽  
Vol 72 (6) ◽  
pp. 2157-2164
Author(s):  
J.C.P. Quintero ◽  
L.F.L. Calixto ◽  
A.J. Almeida ◽  
Y.R. Moreira ◽  
S.S. Rocha ◽  
...  

ABSTRACT The objective of this study was to describe emus’ breeding performance in Brazil at different ages, grouped in couples or colonies. The duration of the breeding season and the production of eggs per female housed were recorded, and the productivity and breeding variables were associated with the variation of the photoperiod. The total production of the flock was 180 eggs, and the breeding season lasted 167 days (April-September), a period with an average of 11 h and 11min of daylight. The breeding season lasted 113, 133 and 82 days, the numbers of eggs produced per female were 7.29, 25.67 and 17.3, and productivity values were 31.6, 38.6, and 45.4% in the groups of birds with ages of two, four and seven years, respectively. The breeding season in 2016 occurred between April and August in Brazil. Older birds tended to start breeding later. The production rate observations indicated that earlier peak production was associated with lower egg production potential. Finally, there was a tendency for better breeding performance of birds housed in couples than in groups with more birds.

Author(s):  
H. Lambrechts ◽  
S.W.P. Cloete ◽  
D. Swart ◽  
J.P.C. Greyling

An ostrich breeding flock, joined as individual breeding pairs (n = 136 pairs), was used to investigate the possibility of diagnostic ultrasonography as a method to predict the reproductive performance of ostrich females during a breeding season. Follicular activity was easily detected and quantified by using diagnostic ultrasonography. One to 8 follicles were recorded in 25 % of females scanned at the beginning of the 9-month breeding season. At the end of the breeding season, 1-3 follicles were observed in 28.7 % females. Females in which follicular activity was observed came into production earlier than those in which no follicles were observed, with the mean (±SE) number of days to the production of the 1st egg being 22.3 ± 12.5 and 87.4 ± 7.2 days, respectively. Females in which follicular activity was observed at the beginning of the breeding season, produced on average 181 % more eggs during the 1st month of the breeding season (P < 0.01) than females in which no follicular activity was observed (6.67 ± 0.70 vs 2.37 ± 0.41 eggs). Egg production over the first 2 months of breeding and over the entire breeding season were similarly affected (P <0.01), with the mean number of eggs produced over the first 2 months of the breeding season being 14.7 ± 1.5 for females with observed follicular activity and 7.4 ± 0.9 eggs for females with no observed follicular activity. Females in which follicular activity was observed at the end of the breeding season produced on average 108 % more eggs (P<0.01) during the last month of the breeding season than females in which no follicular activity was observed (2.77 ± 0.43 vs. 1.33 ± 0.27 eggs). There was a tendency (P = 0.06) for egg production over the last 2 months to be similarly affected (6.10 ± 0.85 vs 4.19 ± 0.54 eggs). No relationship with egg production over the entire breeding season was found for the end-of-the-breeding-season observations. Diagnostic ultrasonography can thus be used as a management tool to identify reproductively healthy ostrich females and also females with a higher egg production potential over a period of 2 months after or prior to assessment. Future studies should focus on the development of the technique to predict reproductive performance over entire breeding seasons for selection purposes.


2017 ◽  
Vol 16 (25) ◽  
pp. 1428-1433 ◽  
Author(s):  
Kesia Faria Vidal Ana ◽  
da Costa Barbe Tatiane ◽  
Figueiredo Daher Rogerio ◽  
Eustáquio Almeida Filho Janeo ◽  
Samara Nunes de Lima Roberta ◽  
...  

2021 ◽  
Vol 39 (3) ◽  
pp. 250-257
Author(s):  
Alessandro Dal’Col Lúcio ◽  
Maria Inês Diel ◽  
Bruno G Sari

ABSTRACT Biologically based growth models can be an alternative in identifying the productive response of multiple harvest vegetables. By interpreting the estimates of the parameters of the models, it is possible to estimate the total production, the rate of fruit production, and the moment when the crop reaches its maximum production potential. Besides, by estimating confidence intervals, these responses can be compared between genotypes or between different treatments. Therefore, the purpose of this manuscript is to present a literature review, and a detailed step-by-step, to interpreting the evolution of the production cycle of vegetables with multiple harvests crops based on non-linear regression. All the requirements that must be met in this type of analysis were presented in detail based on non-linear regression, providing the necessary steps for this type of analysis in details. Demonstration is given using data from strawberry cultivation along with the associated R scripts and interpretation of analysis output in material supplemental. This approach can allow for more relevant inferences than standard means analyses through better examination and modeling of the underlying biological processes.


2021 ◽  
Author(s):  
I.M. Pershin ◽  
A.V. Malkov ◽  
S.N. Rusak ◽  
V.A. Nosova

1969 ◽  
Vol 20 (3) ◽  
pp. 491 ◽  
Author(s):  
GJ Faichney

Acetic, propionic, and butyric acids labelled with 14C were infused into the caecum of continuously fed sheep. The specific activity of the volatile fatty acids (VFA) in the caecum was determined at intervals during the infusion. The production rate was calculated by isotope dilution from the results of those experiments in which steady state conditions were obtained. Substantial interconversions occurred between the fatty acid fractions. The total production of VFA was about 440 mmoles/day, equivalent to 125 kcal/day or 5.3% of the animal's digestible energy intake.


2019 ◽  
Vol 41 (5) ◽  
pp. 741-758 ◽  
Author(s):  
Josephine GrØnning ◽  
Nam X Doan ◽  
Nguyet T Dinh ◽  
Khuong V Dinh ◽  
Torkel Gissel Nielsen

ABSTRACT The calanoid copepod Pseudodiaptomus annandalei is used as live feed in aquaculture because of its nutritional value and the ability to cope with environmental fluctuations in outdoor ponds. However, little knowledge exists on its ecology. Here we investigated the ecology of P. annandalei in an aquaculture pond in Vietnam. Temperature, salinity, chlorophyll a and biomass of protozoans and copepods were monitored every other day for 1 month. Experiments on protozoan growth and grazing by P. annandalei were also conducted. Copepod fecal pellet production and temperature-dependent egg hatching rates were likewise quantified. Despite very high phytoplankton biomass, biomass of P. annandalei was surprisingly low. Copepod production was estimated from three independent methods: clearance, weight-specific egg production rate (SEP) and specific fecal pellet production rate. SEP proved to be accurate to predict the in situ population growth in the pond. A simple model for production of P. annandalei based on SEP was developed. Our study extends our knowledge of how environmental conditions in the pond may affect the population dynamics and production of copepods. The results have important implications for pond managements ensuring stable copepod production and harvest.


Slavic Review ◽  
1969 ◽  
Vol 28 (1) ◽  
pp. 63-71 ◽  
Author(s):  
John W. De Pauw

Western specialists have long recognized the importance of the private sector1 of Soviet agriculture to the economy in general and to family subsistence and income in particular. It provides a large proportion of the country's crop and vegetable output (primarily potatoes, vegetables, and fruits) and an even larger share of the products obtained from animal husbandry. In 1966, for example, the private sector produced 55,800,000 tons of potatoes or 64 percent of the USSR's total gross production of potatoes; 7,400,000 tons of vegetables or 43 percent of total production; 40 percent of its meat; 39 percent of its milk; and 66 percent of its egg production (see table). Of paramount significance is the fact that the private sector produces these quantities on only slightly more than 3 percent of the USSR's total sown land.


1948 ◽  
Vol 27 (6) ◽  
pp. 719-726 ◽  
Author(s):  
Wilbor O. Wilson

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