scholarly journals Feed Intake of Growing Dairy Heifers Raised under Tropical Conditions: A Model Evaluation Using Meta-Analysis

Animals ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 3181
Author(s):  
Marcos Busanello ◽  
Debora Gomes de Sousa ◽  
Filipe Araújo Canedo Mendonça ◽  
Veridiana Lourenço Daley ◽  
Rodrigo de Almeida ◽  
...  

Several models for predicting dry matter intake (DMI) of replacement dairy heifers have been developed; however, only a few have been evaluated using data from heifers of different breeds raised under tropical conditions. Thus, the objective of this study was to evaluate the DMI equations for dairy heifers managed under tropical conditions. A total of 230 treatment means from 61 studies using dairy heifers (n = 1513 heifers, average body weight = 246 kg) were used. The animals were grouped into two groups based on their genetics: (1) Bos taurus (Holstein, Jersey, Brown Swiss, and Holstein × Jersey) and (2) crossbred (Bos taurus × Bos indicus). Seven previously published DMI equations (HH, HHJ, QUI, STA, 2001 NRC, OFLin, and OFNLin) for heifers were evaluated using mean bias, slope bias, mean squared prediction errors (MSPE) and its decomposition, and other model evaluation statistics. For Bos taurus heifers, our results indicated that OFNLin and HHJ had lower mean bias (0.13 and 0.16 kg/d, respectively) than other models. There was no significant slope or mean bias for HHJ and OFNLin (p > 0.05), indicating agreement between the observed and predicted DMI values. All other models had a significant mean bias (p < 0.05), whereas the QUI model also presented a significant slope bias (p < 0.02). For crossbred heifers, the STA equation was the only one that did not present mean and slope bias significance (p > 0.05). All other DMI models had significant mean bias when evaluated using crossbred data (p < 0.04), and QUI, OFLin, and OFNLin also presented significant slope bias (p < 0.01). Based on our results, predictions from OFNLin and HHJ best represented the observed DMI of Bos taurus heifers (MSPE ≤ 1.25 kg2/d2, mean bias ≤ 0.16 kg/d), whereas STA was the best model for crossbred heifers (MSPE = 1.25 kg2/d2, mean bias = 0.09 kg/d). These findings indicate that not all available models are adequate for estimating the DMI of dairy heifers managed under a tropical climate, with HHJ and OFNLin for Bos taurus and STA for crossbreds being the most suitable models for DMI prediction. There is evidence that models from Bos taurus heifers could be used to estimate the DMI of heifers under tropical conditions. For heifer ration formulation is necessary to consider that DMI is influenced by breed, diet, management, and climate. Future work should also include animal genetic and environmental variables for the prediction of DMI in dairy heifers.

1998 ◽  
Vol 1998 ◽  
pp. 23-23
Author(s):  
F. Herrera Gomez ◽  
F.D.DeB Hovell ◽  
C.A. Sandoval Castro

The purine derivatives (PD) have been proposed as a non-invasive method to estimate microbial-N supply to the small intestine (Chen et al., 1990a; Verbic et al., 1990). The use of PD urinary excretion has the advantage that it can be used with intact animals thus reducing the concern of animal welfare issues. Although, there are known differences in purine metabolism between cattle (B. taurus), sheep and buffaloes (Bubalis bubalis) (Chen et al., 1990b; Chen et al., 1996), no direct comparison of PD urinary excretion has been made so far between cattle especies, therefore, the objective of the present experiment was to compare PD urinary excretion of B. taurus and B. indicus cattle fed similar diets under tropical conditions.


2009 ◽  
Vol 49 (6) ◽  
pp. 367 ◽  
Author(s):  
S. A. Barwick ◽  
D. J. Johnston ◽  
H. M. Burrow ◽  
R. G. Holroyd ◽  
G. Fordyce ◽  
...  

The genetics of heifer performance in tropical ‘wet’ and ‘dry’ seasons, and relationships with steer performance, were studied in Brahman (BRAH) and Tropical Composite (TCOMP) (50% Bos indicus, African Sanga or other tropically adapted Bos taurus; 50% non-tropically adapted Bos taurus) cattle of northern Australia. Data were from 2159 heifers (1027 BRAH, 1132 TCOMP), representing 54 BRAH and 51 TCOMP sires. Heifers were assessed after post-weaning ‘wet’ (ENDWET) and ‘dry’ (ENDDRY) seasons. Steers were assessed post-weaning, at feedlot entry, over a 70-day feed test, and after ∼120-day finishing. Measures studied in both heifers and steers were liveweight (LWT), scanned rump fat, rib fat and M. longissimus area (SEMA), body condition score (CS), hip height (HH), serum insulin-like growth factor-I concentration (IGF-I), and average daily gains (ADG). Additional steer measures were scanned intra-muscular fat %, flight time, and daily (DFI) and residual feed intake (RFI). Uni- and bivariate analyses were conducted for combined genotypes and for individual genotypes. Genotype means were predicted for a subset of data involving 34 BRAH and 26 TCOMP sires. A meta-analysis of genetic correlation estimates examined how these were related to the difference between measurement environments for specific traits. There were genotype differences at the level of means, variances and genetic correlations. BRAH heifers were significantly (P < 0.05) faster-growing in the ‘wet’ season, slower-growing in the ‘dry’ season, lighter at ENDDRY, and taller and fatter with greater CS and IGF-I at both ENDWET and ENDDRY. Heritabilities were generally in the 20 to 60% range for both genotypes. Phenotypic and genetic variances, and genetic correlations, were commonly lower for BRAH. Differences were often explained by the long period of tropical adaptation of B. indicus. Genetic correlations were high between corresponding measures at ENDWET and ENDDRY, positive between fat and muscle measures in TCOMP but negative in BRAH (mean of 13 estimates 0.50 and –0.19, respectively), and approximately zero between steer feedlot ADG and heifer ADG in BRAH. Numerous genetic correlations between heifers and steers differed substantially from unity, especially in BRAH, suggesting there may be scope to select differently in the sexes where that would aid the differing roles of heifers and steers in production. Genetic correlations declined as measurement environments became more different, the rates of decline (environment sensitivity) sometimes differing with genotype. Similar measures (LWT, HH and ADG; IGF-I at ENDWET in TCOMP) were genetically correlated with steer DFI in heifers as in steers. Heifer SEMA was genetically correlated with steer feedlot RFI in BRAH (0.75 ± 0.27 at ENDWET, 0.66 ± 0.24 at ENDDRY). Selection to reduce steer RFI would reduce SEMA in BRAH heifers but otherwise have only small effects on heifers before their first joining.


2009 ◽  
Vol 38 (8) ◽  
pp. 1581-1586
Author(s):  
Douglas Sampaio Henrique ◽  
César de Queiroz ◽  
Ricardo Augusto Mendonça Vieira ◽  
Mosar Faria Botelho

The efficiency of fat and protein retention by Bos indicus and its cross-breds was estimated from data obtained in the literature to verify possible differences between these animals and Bos taurus. After estimating the efficiencies, a correction factor was used to discount the metabolizable energy fraction that was spent in the maintenance and support metabolism processes. The efficiencies were then estimated again, assuming that all the remaining energy would correspond to the metabolizable energy available for body mass retention. The correction value used was considered satisfactory to discount energetic losses for maintenance and support. The efficiency values of partial body fat and protein retention in Bos indicus and its cross-bred were very similar to values reported by other authors who researched Bos taurus exclusively.


2013 ◽  
Vol 25 (1) ◽  
pp. 234
Author(s):  
E. K. N. Arashiro ◽  
S. Wohlres-Viana ◽  
M. P. Palhao ◽  
L. S. A. Camargo ◽  
M. Henry ◽  
...  

It is well documented that the size of the dominant follicle at deviation is smaller in Bos indicus compared with in Bos taurus breeds. The physiological mechanisms underlying this difference, however, are unknown. The aim of the present study was to evaluate the dynamic of oestradiol production during follicle development close to the expected moment of deviation in Bos taurus and Bos indicus dairy heifers. Intrafollicular concentration of oestradiol (E2) and P450 aromatase gene expression in granulosa cells (GC) were evaluated in Gir (n = 10) and Holstein (n = 10) heifers. Follicular waves were synchronized with an intravaginal progesterone device (1 g, Sincrogest, Ourofino Agropecuária, São Paulo, Brazil) and benzoate oestradiol (2 mg im, Sincrodiol, Ourofino Agropecuária). Ultrasonography evaluations (MyLab30 Vet Gold, Esaote, Genova, Italy, with a 7.5-MHz transducer) were performed every 24 h to detect the emergence of the new follicular waves. The largest follicle of each wave was individually aspirated by ovum pickup before, at the expected diameter, or after deviation in both Gir (4.6 ± 0.2, 6.3 ± 0.2, and 8.5 ± 0.6 mm, respectively) and Holstein heifers (6.0 ± 0.5, 8.6 ± 0.4, and 10.2 ± 0.2 mm, respectively), as previously described (Arashiro et al. 2012 Reprod. Fertil. Dev. 24, 175). Follicular fluid (FF) samples were centrifuged and the supernatant stored at –20°C until E2 and progesterone (P4) determination by RIA. The pellet of GCs was washed twice with PBS, kept in RNAlater, and frozen at –20°C until RNA extraction and reverse transcription. Relative transcript quantification was performed by real-time PCR. The β-actin gene was used as control. Samples of FF with E2:P4 ratio <1 or presenting contamination by theca cells (detected by the expression of 17α-hydroxylase) were not used for statistical analyses. Concentration of E2 in FF was evaluated between breeds and among follicle size classes by ANOVA and differences among means compared by Student t-test or Tukey’s test, respectively. Within breeds, relative gene expression was accessed by pair-wise fixed reallocation randomization test (software REST®). Results are shown as mean ± SEM. In both breeds, concentration of E2 in FF progressively increased with follicular diameter (P < 0.05). Intrafollicular concentration of E2 (ng mL–1) was greater (P < 0.05) in Holstein than in Gir before (58.5 ± 11.7 v. 8.8 ± 2.0), at expected (226.0 ± 49.9 v. 78.9 ± 21.0), and after follicle deviation (579.1 ± 45.0 v. 185.0 ± 34.9). Interestingly, however, follicles with similar diameters (~6 or 8 mm) showed similar (P > 0.05) E2 concentrations between Holstein and Gir. Moreover, in both breeds, the relative expression of P450 aromatase gene in GC first increased (3.9 ± 2.4 and 67.5 ± 52.8 for Holstein and Gir, respectively; P < 0.05) at the same stage of follicular development (8 mm). The present results suggest that the smaller size of follicles at deviation in Bos indicus is not related to an earlier increase in intrafollicular E2 production. CNPq, CAPES, and Fapemig (CVZ APQ 02863/09).


2011 ◽  
Vol 89 (12) ◽  
pp. 3973-3982 ◽  
Author(s):  
V. A. Thompson ◽  
J. G. Fadel ◽  
R. D. Sainz

2004 ◽  
Vol 52 (4) ◽  
pp. 501-508 ◽  
Author(s):  
C. Ahuja ◽  
F. Montiel

Induction of ovulation for timed artificial insemination (TAI) with the Ovsynch protocol was evaluated in 49 anoestrous and lactating Bos taurus × Bos indicus cows. Palpation per rectum and transrectal ultrasonography were used on Days -30, -20, -10 and 0 (start of treatment) to confirm anoestrus but with the presence of follicles = 10 mm, and every other day during treatment to determine ovarian activity. Cows were randomly assigned to: (1) Ovsynch (n = 24; Day 0, 200 µg GnRH; Day 7, 150 µg PGF2a; Day 9, 200 µg GnRH + TAI 16 to 20 h later) and (2) control (n = 25; no treatment). Rates of ovulation for the first GnRH injection, detection of a corpus luteum (CL) at PGF2a injection, pregnancy and induction of cyclicity were greater (P < 0.05) with Ovsynch. There was no effect of body condition score (P ? 0.05). In conclusion, the Ovsynch protocol was not effective in obtaining acceptable pregnancy rate for TAI, but it was effective for induction of cyclicity in anoestrous and lactating Bos taurus × Bos indicus cows under tropical conditions.


2021 ◽  
Vol 225 ◽  
pp. 106668
Author(s):  
Roberta Ferreira Leite ◽  
João Diego de Agostini Losano ◽  
Daniel de Souza Ramos Angrimani ◽  
Raphaela Gabrielle Brito Sousa ◽  
Álvaro de Miranda Alves ◽  
...  

2021 ◽  
pp. 186-192
Author(s):  
Ariadne Pegoraro Mastelaro ◽  
Eliane Sayuri Miyagi ◽  
Nivaldo Karvatte Junior ◽  
Gilberto Romeiro de Oliveira Menezes ◽  
Paulo Gustavo Macedo de Almeida Martins ◽  
...  

Animals kept in extensive production systems are constantly exposed to the effects of climatic aspects, which could favour thermal discomfort, decreasing productive and reproductive performances. Utilisation of Bos taurus crosses with Bos indicus animals is increasing in the tropics aimed at improving production and it is now well known how these animals respond in such environment. The objective was to characterize the morpho-physiological thermoregulation responses of weaned heifers from four different genetic groups to infer regarding the different degrees of adaptation to heat under tropical conditions Forty-eight, pasture-kept, 6-month-old, weaned heifers from four distinct genetic groups: (1) Nellore; (2) Senepol; (3) Angus x Nellore; and, (4) ¼ Brahman x ¼ Nellore x ½ Senepol (Tri-cross) were evaluated. Skin, hair coat and rectal temperatures; sweating rate; respiratory and heart rates; visual analysis of hair and hair coat colour; hair coat temperature and thickness; and length, diameter, density and number of hairs were evaluated. In addition, the temperature-humidity index, black-globe temperature and humidity index, and radiant thermal load were determined. Angus x Nellore animals presented the lowest (P=0.008) respiratory rate. Rectal temperature did differ (P=0.001) between seasons. Angus x Nellore heifers showed the greatest (P=0.001) values for the morphological measures in the evaluated months, coinciding with thermal comfort indexes above those considered comfortable for cattle.  Nellore (Bos indicus), Brahman x Nellore x Senepol, and Senepol (B. taurus) present the best adaptive traits in savanna. The utilisation of B. indicus animals or adapted breed confers desirable morphological characteristics for the tropical environment. 


2006 ◽  
Vol 18 (2) ◽  
pp. 184 ◽  
Author(s):  
H. Nava-Trujillo ◽  
A. Hernández ◽  
H. Hernández-Fonseca ◽  
E. Soto-Belloso ◽  
F. Perea-Ganchou

First service fertility is an important factor affecting the calving-conception interval and the number of services per conception. In the present study, first service fertility of 618 multiparous dual purpose cows was analyzed according to breed predominance (Bos indicus and Bos taurus) and service season: dry (December-March); sub-humid (April-August); and humid season (September-November). All cows were located in a sub-humid tropical forest area, characterized by 1950 mm/year of rainfall and a mean daily temperature of 28.3�C. Cows were milked and suckled twice a day. Estrus was detected twice a day with a minimum observation period of 30 min. All cows were serviced according to the international rule AM-PM with semen of one of two Brahman bulls (A and B). All cows received water and mineral salt ad libitum during the entire year. Additionally, during the dry season cows received an energy supplementation. Data were analyzed using the chi-square procedure of SAS (SAS/STAT User's Guide, 8.2 ed. Cary, NC: SAS Institute, Inc., 2001). No bull effects were observed on first service fertility (bull A: 37.70%, 105/305; and bull B: 40.26%, 126/313; P > 0.05). Breed predominance significantly affected the first service fertility, being higher in Bos indicus cows (47.48%) than in Bos taurus cows (32.78%; P < 0.05). The higher first service fertility of Bos indicus cows seen during the year was probably because Bos indicus cattle are more thermotolerant than Bos taurus cattle (Hansen 2004 Anim. Reprod. Sci. 82-83, 349-360). Moreover, season of service did not affect the first service fertility of Bos indicus cows (dry: 48.95%, 70/143; sub-humid: 50%, 33/66; and humid: 41.30%, 19/46; P > 0.05). While in Bos taurus cows, first service fertility was higher in cows serviced during the dry season (43.24%) in comparison with those serviced during the sub-humid (28.26%; P < 0.05) or humid season (23.58%; P < 0.05). No differences were observed between Bos taurus cows serviced in the sub-humid and the humid season (P > 0.05). First service fertility did not differ between Bos indicus and Bos taurus cows serviced during the dry season (P > 0.05), which is likely due to the lower relative humidity and extra energy supplementation. This may improve oocyte quality. In conclusion, fertility of Bos taurus cattle is more sensitive than that of Bos indicus cattle under tropical conditions; therefore, the implementation of a reproductive seasonality scheme is recommended to increase the reproductive efficiency of Bos taurus cattle.


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