[Replacing of residue from production of palm Palm Royal Australian (Archontophoenix alexan- drae) in silage of sugar cane in diets of sheep]. / Substituição do resíduo da produção de palmito da Palmeira Real Australiana (Archontophoenix alexandrae) na silagem de cana-de-açúcar em dietas de ovinos.

The aim of this study was to evaluate the chemical composition, voluntary intake and apparent digestibility of the diets containing residue from palm heart of Australian Royal Palm (Archontophoenix alexandrae) to replace sugar cane on sheep. Twelve sheep were used with average live weight of 23.3 ± 2.8 Kg and they placed in metabolism cages and distributed in six latin square 2 x 2 in a factorial design 3 x 2 (three types of residue--sheet, bark and composed--and two levels of residue's replacement, 5% and 15%). It was observed higher intake of dry matter (DM), organic matter (OM), nonfiber carbohydrates (NFC) by substitution of composed residue. The average values of apparent digestibility of DM, OM, crude protein (CP), neutral detergent fibre correct for ash and protein (NDFap) and total digestible nutrients (TDN) were higher for sheet residue. There was interaction between type of residue and level of residue's replacement on the urinary excretion of total nitrogen (NUE), apparent nitrogen balance (BNA) and microbial nitrogen compost (NMIC). Residues from palm heart of Australian Royal Palm can be used as roughage in the ruminants'diet, and of these residues, the sheet and composed residue showed better response in the evaluated characteristics.

Effect of timing of paddock allocation in tropical grass on performance, nitrogen excretion, and enteric methane emissions from dairy cows.

The objective of this study was to investigate the influence of timing of paddock allocation (AM or PM) in tropical grass on nutritive value of the herbage, dry matter intake (DMI), milk yield and composition, ruminal fermentation, nitrogen excretion, and enteric CH4 emissions of dairy cows. Twenty cows were grouped in pairs and randomly distributed within pair to one of two treatments. PM herbage had greater contents of dry matter (DM), soluble carbohydrates, starch, and nonfibrous carbohydrate to protein ratio and lower contents of neutral detergent fiber and acid detergent fiber. There was no treatment effect on DMI, N excretion, milk yield, and CH4 emissions. However, milk protein and casein yields tended to be greater for PM than AM, while milk urea nitrogen concentration was lower for PM than AM. The increase in nutritive value of the afternoon relative to the morning herbage within the framework of this study was not large enough to increase DMI and milk yield or to decrease CH4 emission intensity by the dairy cows as hypothesized. The findings indicate that PM treatment can be a simple and useful grazing strategy that results in an herbage harvest with greater nutritional value and in lower excretion of urea N into milk.

Performance and muscle lipogenesis of calves born to Nellore cows with different residual feed intake classification.

This study aimed to evaluate relationships among maternal residual feed intake (RFI) with growth performance and expression of genes involved in lipid metabolism in offspring of Nellore cattle. Fifty-three cows classified as negative or positive RFI by genomic prediction were exposed to fixed-time artificial insemination (FTAI) protocols at 2 and 3 years of age using semen from the same bull. In the first year, cows gestated under grazing conditions and nursed their calves in the feedlot. In the second year, the opposite occurred. Cows were weighed every 28 days during pregnancy and calves were weighed at birth and every 28 days until weaning. Ultrasound images were collected from the carcass of cows and calves. Muscle gene expression was evaluated in calves at birth and weaning. Data were analyzed by year considering the fixed effects of RFI class and FTAI protocol for variables measured in cows, and RFI class, FTAI protocol and sex for variables measured in calves. There was no effect of maternal RFI on calves performance in the first year. Lower expression of FABP4 gene and trend towards lower expression of SREBF1 and LPL genes were detected in samples collected after birth from calves born to negative RFI cows, indicating that adipogenesis was reduced during the fetal and neonatal period. In the second year, negative RFI cows had greater subcutaneous fat thickness than positive RFI cows, and their calves tended to be heavier at birth and to have less rump fat thickness at weaning. No significant differences in expression of genes studied were detected between cow RFI classes. Nellore cows classified as negative RFI consume less feed and produce calves whose growth potential is similar to that of calves produced by positive RFI cows.

Animals selected for postweaning weight gain rate have similar maintenance energy requirements regardless of their residual feed intake classification.

Data of comparative slaughter were used to determine Nellore bulls' net energy requirements classified as efficient or inefficient according to residual feed intake (RFI) and selection lines (SL). Sixty-seven Nellore bulls from the selected (SE) and control (CO) lines of the selection program for postweaning weight gain were used. The animals underwent digestibility trials before being submitted to the finishing trial. Sixteen bulls were slaughtered at the beginning of the finishing trial, and their body composition was used as the baseline for the remaining animals. For body composition determinations, whole empty body components were weighed, ground, and subsampled for chemical analyses. Initial body composition was determined with equations developed from the baseline group using shrunk body weight, fat, and protein. The low RFI (LRFI) and CO animals had a lower dry matter (DMI) and nutrient intake (P < 0.05) than high RFI (HRFI) and SE animals, without alterations in digestibility coefficients (P > 0.05). During the finishing trial, DMI remained lower for LRFI and CO animals. Growth performance was similar between RFI classes, except for empty body weight gain that tended to be higher for LRFI than HRFI (P = 0.091). The SE animals had less fat content on the empty body (P = 0.005) than CO. Carcasses tended to be leaner for LRFI than HRFI (P = 0.080) and for SE than CO (P = 0.066) animals. LRFI animals retained more energy (P = 0.049) and had lower heat production (HP; P = 0.033) than the HRFI ones. Retained energy was not influenced by SL (P = 0.165), but HP tended to be higher for SE when compared to CO (P = 0.075) animals. Net energy requirement for maintenance (NEm) was lower for LRFI than HRFI (P = 0.009), and higher for SE than CO (P = 0.046) animals. There was an interaction tendency between RFI and SL (P = 0.063), suggesting that NEm was lower for LRFI+CO than HRFI+CO (P = 0.006), with no differences for SE (P = 0.527) animals. The efficiency of ME utilization for maintenance (km) of LRFI and HRFI animals were 62.6% and 58.4%, respectively, and for SE and CO were 59.0% and 62.1%, respectively. The breeding program for postweaning weight has not improved feed efficiency over the years, with RFI classification not being a promising selection tool for SE animals. Classification based on RFI seems to be useful in animals that have not undergone the breeding program, with LRFI animals having lower energy requirements than the HRFI ones.

Residual feed intake of Nellore calves is not repeatable across pre and post weaning periods / Consumo alimentar residual de bezerros Nelore na pré e pós-desmama tem baixa repetibilidade

ABSTRACT: This study measured milk and solid feed intake in pre- weaning period and feed intake in postweaning period of Nellore calves, and to correlated them with performance traits and ingestive behavior of animals classified as most and least efficient. During pre weaning phase, feed efficiency was evaluated in 51 cow-calf pairs from 21±5 days after calving until weaning. During post-weaning phase, only male calves (n=23) were evaluated. Pre-weaning milk intake of calves was estimated based on cow's milk production. Pre-weaning daily metabolizable energy intake (MEI) of calves was estimated as the sum of MEI from milk and solid diet. There was no difference in ADG between calves with negative and positive pre RFI, with a consequent better feed conversion to more efficient calves. The most efficient calves spent less time at the feed bunk, with a shorter feeding duration and higher rate of intake, compared to the least efficient animals. Correlations between feed intake and metabolic body weight of the animals during pre- and postweaning phases were positive, of medium to high magnitude, and significant, while correlation between ADG values was close to zero. Results suggested that part of the animals ranked based on pre weaning feed intake won't maintain their rank during postweaning phase. In conclusion, calves classified as most efficient during pre-weaning phase have similar weight gain but lower milk intake and MEI than least efficient animals. The estimated pre RFI is weakly correlated with post RFI, showing that RFI is not consistent or repeatable across two periods.

RESUMO: Este estudo teve como objetivo mensurar o consumo de leite e sólidos no período pré-desmama e o consumo alimentar no período pós-desmama, e relacioná-los com características de desempenho e comportamento ingestivo de animais classificados como mais eficientes e menos eficientes. Na fase pré-desmama foram avaliados 51 pares vaca-bezerro da raça Nelore quanto à eficiência alimentar dos 21±5 dias após o parto até a desmama. Na fase pós-desmama, apenas os bezerros machos (n=23) foram avaliados. O consumo de leite dos bezerros na pré-desmama foi estimado pela produção de leite das vacas. O consumo diário de energia metabolizável do bezerro na pré-desmama (CEM), foi estimado pela soma do consumo de energia metabolizável do leite e do consumo diário de energia metabolizável da dieta. Bezerros CARpre negativo não diferiram dos bezerros CARpre positivo quanto ao GMD, resultando em melhor CA dos bezerros mais eficientes. Bezerros mais eficientes ficaram menos tempo no cocho, com menor duração da refeição e com maior taxa de alimentação comparativamente aos animais menos eficientes. As correlações entre o consumo alimentar e peso corporal metabólico dos animais na pré e pós-desmama foram positivas, de média a alta magnitudes e significativas, enquanto que a correlação entre ganho médio diário foi próxima de zero. Os resultados sugerem que parte dos animais classificados pelo consumo alimentar na pré-desmama manterão a classificação na pós-desmama. Na fase pré-desmama bezerros classificados como mais eficientes tem ganho de peso similar, porém com menor consumo de leite e consumo de energia metabolizável do que bezerros menos eficientes. A estimativa do consumo alimentar residual na fase pré-desmama é fracamente relacionada à estimativa do consumo alimentar residual na fase pós-desmama, mostrando que o consumo alimentar residual não é consistente e repetível nos dois períodos.

Substituição do resíduo da produção de palmito da Palmeira Real Australiana (Archontophoenix alexandrae) na silagem de cana-de-açúcar em dietas de ovinos / Replacing of residue from production of palm Palm Royal Australian (Archontophoenix alexandrae) in silage of sugar cane in diets of sheep

Objetivou-se avaliar a composição química, consumo voluntário e digestibilidade aparente de dietas contendo resíduo oriundo da produção de palmito da palmeira Real Australiana (Archontophoenix alexandrae) em substituição à cana-de-açúcarem ovinos. Foram utilizados 12 ovinos com peso vivo médio de 23,3 ± 2,8 kg, mantidos em gaiolas metabólicas distribuídos em seis quadrados latinos 2x2 implementado em esquema fatorial 3 x 2 (três tipos de resíduo - folha, bainha e composta - e dois níveis de substituição do resíduo, 5% e 15%). Verificou-se maior consumo de matéria seca (MS), matéria orgânica (MO), carboidratos não fibrosos (CNF) na substituição pelo resíduo composta. Os valores médios de digestibilidade aparente da MS, MO, Proteína bruta (PB), fibra insolúvel em detergente neutro corrigido para cinzas e proteína(FDNcp) e nível dietético de NDT foram maiores para o resíduo folha. Constatou- se efeito de interação entre resíduo e o nível de substituição sobre as excreções urinárias de nitrogênio total (EUN), balanço nitrogenado aparente (BNA) e compostos nitrogenados microbianos (NMIC). Resíduos da produção de palmito oriundos da palmeira Real Australiana podem ser utilizados como alimentos volumosos na dieta de animais ruminantes, sendo destes, o resíduo folha e composta os que apresentaram melhores respostas nas características avaliadas.

The aim of this study was to evaluate the chemical composition, voluntary intake and apparent digestibility of the diets containing residue from palm heart of Australian Royal Palm (Archontophoenix alexandrae) to replace sugar cane on sheep. Twelve sheep were used with average live weight of 23,3 ± 2,8 Kg and they placed in metabolism cages and distributed in six latin square 2 x 2 in a factorial design 3 x 2 (three types of residue -sheet, bark and composed - and two levels of residue’s replacement, 5% and 15%). It was observed higher intake of dry matter (DM), organic matter (OM), nonfiber carbohydrates (NFC) by substitution of composed residue. The average values of apparent digestibility of DM, OM, crude protein (CP), neutral detergent fibre correct for ash and protein (NDFap) and total digestible nutrients (TDN) were higher for sheet residue. There was interaction between type of residue and level of residue’s replacement on the urinary excretion of total nitrogen (NUE), apparent nitrogen balance (BNA) and microbial nitrogen compost (NMIC). Residues from palm heart of Australian Royal Palm can be used as roughage in the ruminants’diet, and of these residues, the sheet and composed residue showed better response in the evaluated characteristics.