Navegando por Autor "Canesin, Roberta Carrilho"
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Item Development and evaluation of prediction equations for methane emission from Nellore cattle(2019) Pires Sobrinho, Tatiana Lucila; Branco, Renata Helena; Magnani, Elaine; Berndt, Alexandre; Canesin, Roberta Carrilho; Mercadante, Maria Eugênia ZerlottiABSTRACT. Dry matter intake (DMI), nutrient intake and enteric CH4 emission were evaluated in 48 Nellore cattle (392 ± 27 days of age). Equations were generated from intake data and evaluated using root mean square prediction error (RMSPE), and validated by cross-validation. Equations that included DMI and hemicellulose intake (HEMI) [ C H 4 M J d - 1 = 4.08 ± 1.65 + 11.6 ± 2.34 D M I k g d - 1 - 33.4 ± 7.21 H E M I ( k g d - 1 ) ]; DMI and total carbohydrate intake (TCHI) [ C H 4 M J d - 1 = 5.26 ± 1.69 - 6.3 ± 1.47 D M I k g d - 1 + 8.8 ± 1.81 T C I k g d - 1 ]; metabolizable energy intake (MEI) and cellulose intake (CELI) [ C H 4 M J d - 1 = 5.16 ± 1.72 - 0.13 ± 0.048 M E I M J d - 1 + 7.37 ± 1.53 C E L I k g d - 1 ], and non-fiber carbohydrate intake (NFCI) [ C H 4 M J d - 1 = 3.14 ± 1.48 + 3.65 ± 1.05 N F C I k g d - 1 ] resulted in the lowest RMSPE (14.3, 14.1, 14.3 and 14.7%, respectively). When literature equations were evaluated using our database, the most accurate predictions were obtained with equations that included DMI and lignin intake (RMSPE = 15.27%) and MEI, acid detergent fiber intake and lignin intake (RMSPE = 15.7%). The mean error of predicting enteric CH4 emission with the equations developed in this study based on DMI and nutrient intake is 17% and the most accurate predictions are obtained with equations including DMI, carbohydrate intake and MEI.Item Growth performance, reproductive parameters and fertility measures in young Nellore bulls with divergent feed efficiency(2022) Rossi, Guilherme Fazan; Bastos, Natália Marins; Vrisman, Dayane Priscila; Rodrigues, Naiara Nantes; Vantini, Roberta; Garcia, Joaquim Mansano; Dias, Erika Aline Ribeiro; Simili, Flávia Fernanda; Guimarães, André Lasmar; Canesin, Roberta Carrilho; Mercadante, Maria Eugênia Zerlotti; Freitas-Dell’Aqua, Camila de Paula; Athayde, Flávia Regina Florencio de; Monteiro, Fabio Morato; Mingoti, Gisele ZoccalAbstract The growth, sexual maturity and fertility-related parameters related of young Nellore bulls with divergent residual feed intake (RFI) raised on pasture were evaluated. After classification of 48 young males as low and high RFI (more and less efficient, respectively), the animals were evaluated for growth and reproductive parameters at 28-day intervals from 14.3 to 24.6 months of age. The semen was cryopreserved in the last sampling and fresh and post-thaw semen samples were evaluated. Low RFI bulls exhibited higher initial and final body weight (P < 0.05), but feed intake, body condition score and growth measures evaluated by carcass ultrasound were unaffected by RFI (P > 0.05). The scrotal circumference, sperm concentration, defects, and quality of fresh semen, and ultrasonographic testicular characteristics were unaffected by RFI (P > 0.05). However, velocity parameters such as average path and curvilinear velocities determined by computer-assisted sperm analysis of thawed semen submitted to the rapid thermoresistance test were improved (P < 0.05) in low RFI bulls, but this improvement in quality did not enhance in vitro sperm fertilizing ability. Our results demonstrated significant differences in metabolism and growth performance between bulls of divergent RFI. In addition, there was slight improvement in the semen quality of bulls with low RFI bulls, but this did not enhance in vitro fertilizing ability. Selection of beef bulls for RFI can be performed, which will result in economic benefits by improving the growth performance of the animals without affecting reproductive parameters.Item Phenotypic association between feed efficiency and feeding behavior, growth and carcass traits in Senepol cattle(2017) Guimarães, André Lasmar; Mercadante, Maria Eugênia Zerlotti; Canesin, Roberta Carrilho; Branco, Renata Helena; Lima, Maria Lucia Pereira; Cyrillo, Joslaine Noely dos Santos GonçalvesABSTRACT The objective of this study was to evaluate the associations between feed efficiency and feeding behavior, growth and carcass traits in Senepol cattle. A total of 137 animals were evaluated. Of these animals, 36 males were evaluated in a second test, totaling 173 records (initial age of 466±96 days and initial weight of 426±104 kg). Residual feed intake (RFI) was calculated as the difference between observed and expected dry matter intake, estimated by regression of dry matter intake on average daily gain and metabolic body weight (BW0.75), and the animals were classified as negative (high efficiency) and positive RFI (low efficiency). The mean RFI was -0.838±0.078 and 0.797±0.075 kg DM day-1 for negative and positive RFI animals, respectively, with a difference of 1.63 kg dry matter day-1. The dry matter intake of negative RFI animals, expressed as kg day-1 and percentage of mean body weight, was 11.3% and 13.1% lower than that of positive RFI animals. Negative RFI animals spent less time at the feed bunk and ingested less dry matter per visit than positive RFI animals, but did not differ in terms of chest girth, scrotal circumference, or hip height. However, negative RFI animals had lower rump fat deposition (7.13±0.477 mm) than positive RFI animals (7.83±0.473 mm). The Spearman correlation between RFI estimated in the first and second tests was 0.69, indicating that RFI is consistent when evaluated during two different periods of the life of the animal. Senepol animals with low residual feed intake (high efficiency) deposit less subcutaneous rump fat, but this reduction is not accompanied by a reduction in backfat thickness and longissimus muscle area.Item Relationship between residual feed intake and enteric methane emission in Nellore cattle(2015) Mercadante, Maria Eugênia Zerlotti; Caliman, Ana Paula de Melo; Canesin, Roberta Carrilho; Bonilha, Sarah Figueiredo Martins; Berndt, Alexandre; Frighetto, Rosa Toyoko Shiraishi; Magnani, Elaine; Branco, Renata HelenaFeed intake and average daily gain (ADG) in Nellore cattle were determined to calculate residual feed intake in two performance tests: first during the growth phase (RFIgrowth) and then during a measurement of the methane emission phase (RFImet). During the RFIgrowth test, 62 males and 56 females were classified as low-, medium-, and high-RFI. Enteric methane emission was measured in 46 animals; 23 males used for RFImet measurement plus 23 females (22 low-RFIgrowth and 24 high-RFIgrowth). Diet consisted of Brachiaria brizantha cv. Marandu hay (445 g/kg DM) and concentrate (555 g/kg DM). During the RFIgrowth and RFImet phases, DMI was lower in the animals with low RFI, with no difference in ADG. Residual feed intake was -0.359 and 0.367 kg DM/d for low- and high-RFI animals. Enteric methane emission (g/d, g/kg BW0.75 and g/kg ADG) did not differ between RFIgrowth classes. Enteric methane emission (g/d) was higher in high RFImet and lower in low RFImet males. Spearman correlations among traits obtained during both tests, which were high between metabolic BW (r = 0.959) and between DMI (r = 0.718), and zero between ADG (r = -0.062), resulted in moderate correlation between RFIgrowth and RFImet (r = 0.412). However, it is not possible to confirm that high-efficiency animals release less enteric methane, since different results were obtained when enteric methane was compared between the RFIgrowth and RFImet classes.