Effect of postweaning implantation of zeranol and dietary energy level on growth and reproductive performance of replacement beef heifers

1991 ◽  
Vol 71 (2) ◽  
pp. 265-270 ◽  
Author(s):  
M. Makarechian ◽  
P. F. Arthur ◽  
M. A. Price

Eighty-one heifer calves weaned at an average age of 6 mo were used to study the effect of postweaning zeranol implantation, on the growth and reproductive performance of heifers fed to grow slowly on three dietary energy levels. Forty heifers were implanted with 36 mg of zeranol at 30 d and again at 120 d postweaning. The remaining heifers were used as ummplanted controls. Within the implanted and control groups, heifers were subdivided into three groups and fed either a low, medium or high energy diet, which provided approximately 105, 130 and 160%, respectively, of NRC maintenance energy requirement, until 1 yr of age. The heifers were then turned out to pasture with hay supplementation. Heifers were exposed to bulls for 35 d at approximately 14 mo of age. Zeranol had no significant effect on growth. The effect of zeranol on the reproductive traits studied was not significant, although the trend was that the zeranol implanted heifers had lower calf crop born (52.3 vs. 63.6%) and lower incidence of calving difficulty (18.5 vs. 32.1%) than control heifers. The level of energy in the diet had a significant (P < 0.01) effect on growth of the heifers, with those on the high energy diet having the highest mean growth rate, but no significant effect on reproductive performance. Key words: Zeranol, dietary energy, growth, reproduction, heifers

2009 ◽  
Vol 103 (5) ◽  
pp. 629-642 ◽  
Author(s):  
Catherine-Ines Kolditz ◽  
Elisabeth Plagnes-Juan ◽  
Edwige Quillet ◽  
Florence Lefèvre ◽  
Françoise Médale

Energy intake and genetic background are major determinants of muscle fat content in most animals, including man. We combined genetic selection and dietary energy supply to study the metabolic pathways involved in genetic and nutritional control of fat deposition in the muscle of rainbow trout (Oncorhynchus mykiss). Two experimental lines of rainbow trout, selected for lean (L) or fat (F) muscle, were fed with diets containing either 10 or 23 % lipids from the first feeding, up to 6 months. At the end of the trial, trout exhibited very different values of muscle fat content (from 4·2 to 10·1 % wet weight). Using microarrays made from a rainbow trout multi-tissue cDNA library, we analysed the molecular changes occurring in the muscle of the two lines when fed the low-energy or high-energy diet. The results from microarray analysis revealed that eleven metabolism-related genes were differentially expressed according to the diet while selection resulted in expression change for twenty-six genes. The most striking observation was the increased level of transcripts encoding the VLDL receptor and fatty acid translocase/CD36 following both the high-fat diet and upward selection for muscle fat content, suggesting that these two genes are relevant molecular markers of fat deposition in the white muscle of rainbow trout.


2016 ◽  
Vol 29 (7) ◽  
pp. 1004-1012 ◽  
Author(s):  
S. S. Jin ◽  
S. W. Jung ◽  
J. C. Jang ◽  
W. L. Chung ◽  
J. H. Jeong ◽  
...  

Animals ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 109 ◽  
Author(s):  
Xiaokang Lv ◽  
Kai Cui ◽  
Minli Qi ◽  
Shiqin Wang ◽  
Qiyu Diao ◽  
...  

Supplying sufficient nutrients, such as dietary energy and protein, has a great effect on the growth and rumen development of ruminants. This study was conducted to evaluate the effects of dietary energy and protein levels on growth performance, microbial diversity, and structural and physiological properties of the rumen in weaned lambs. A total of 64 two-month-old Hu lambs were randomly allotted to 2 × 2 factorial arrangements with four replicates and with four lambs (half male and half female) in each replicate. The first factor was two levels of dietary metabolizable energy (ME) density (ME = 10.9 MJ/Kg or 8.6 MJ/Kg), and the second factor was two levels of dietary crude protein (CP) content (CP = 15.7% or 11.8%). The trial lasted for 60 days. A low dietary energy level restrained the growth performance of lambs (p < 0.05). The ruminal concentration of acetate and the ratio of acetate to propionate increased but the propionate concentration decreased significantly with the low energy diet. However, the rumen morphology was not affected by the diet energy and protein levels. Moreover, a low energy diet increased ruminal bacterial diversity but reduced the abundance of the phylum Proteobacteria (p < 0.05) and genus Succinivibrionaceae_uncultured (p < 0.05), which was associated with the change in ruminal fermentation phenotypes. By indicator species analysis, we found three indicator OTUs in the high energy group (Succinivibrionaceae_uncultured, Veillonellaceae_unclassified and Veillonellaceae_uncultured (p < 0.01)) and two indicator OTUs in the low energy group (Bacteroidales_norank and Lachnospiraceae_uncultured (p < 0.01)). In conclusion, these findings added new dimensions to our understanding of the diet effect on rumen microbial community and fermentation response, and are of great significance for establishing the optimal nutrient supply strategy for lambs.


2008 ◽  
Vol 48 (9) ◽  
pp. 1217 ◽  
Author(s):  
A. Y. Abdullah ◽  
F. T. Awawdeh ◽  
H. S. Musallam ◽  
H. H. Titi ◽  
B. S. Obeidat ◽  
...  

Thirty Black goat male kids were used in a 3 × 2 factorial arrangement to evaluate the effects of three dietary energy levels (EL) and early castration (TRT) on growth performance, body and carcass characteristics. Upon weaning at 90 days of age, kids were randomly divided into three equal groups (n = 10: five intact and five castrated) and assigned to one of the three dietary treatments containing 15% CP and different energy levels: low (LEL; 10.44 MJ ME/kg DM), medium (MEL; 11.60 MJ ME/kg DM) and high energy (HEL; 12.90 MJ ME/kg DM). Kids were individually fed on an ad libitum basis and were slaughtered at the end of the fattening period. Results showed no differences between castrated and intact kids in feed and nutrient intake. The level of dietary energy affected dry matter intake (P < 0.05), metabolisable energy intake (P < 0.01), crude protein intake (P < 0.05), neutral detergent fibre (P < 0.001) and acid detergent fibre intakes (P < 0.001). Dry matter intake was 280, 305 and 264 g/kg W0.75.day for kids receiving LEL, MEL and HEL diets, respectively. Metabolisable energy intake was the highest for kids receiving the MEL diet (0.90 Mcal/kg W0.75.day) compared with LEL (0.73 Mcal/ kg W0.75.day) and HEL (0.88 Mcal/kg W0.75.day) diets. Final liveweight and average daily gain (ADG) were greater (P < 0.01) in MEL diets. Kids fed MEL gained 133 g/day, while ADG values were 92 and 100 g/day for kids fed LEL and HEL diets, respectively. Total muscle percentage was greater (P < 0.05) for kids fed MEL diets (55.9%) compared with LEL (53.8%) and HEL (51.1%) diets. Castrated kids had lower (P < 0.01) carcass muscle percentage, but higher carcass (P < 0.01) and subcutaneous (P < 0.001) fat percentages than intact kids. It can be concluded that the best growth performance was observed in kids receiving the MEL with no differences between castrated and intact kids. Castration influenced accretion of fat in castrated kids.


2019 ◽  
Vol 97 (Supplement_3) ◽  
pp. 79-80
Author(s):  
Chandima Jayanath Gajaweera ◽  
Ki Yong Chung ◽  
Seung Hwan Lee

Abstract Focusing high marble deposition, Hanwoo feedlot system uses high-energy diet over the prolonged fattening period. However, due to the individual genetic variation, around 40% of them are graded into inferior quality grades (QG), despite they utilized the same resources. Therefore, focusing to develop a genomic-based precision management model, this study was to evaluate the response to the divergent selection on genetic merit for marbling score (MS), under different dietary TDN (total digestible nutrient) levels. Total of 112 calves were genotyped and initially grouped for estimated breeding value (high and low) for marbling score (MS-EBV). Subsequently, managed under two levels of feed TDN%, over the growing period, early, middle, and final fattening periods following 2X2 factorial arrangement (figure 1). Carcasses were evaluated for MS, Backfat thickness (BFT) and Korean beef quality grading standard. As the direct response to the selection was significant, the results confirmed the importance of initial genetic grouping of Hanwoo steers for MS-EBV. However, dietary TDN level did not show an effect (P &gt; 0.05) on the MS. Further, no genetic-by-nutrition interaction for MS (P &gt; 0.05) was also observed. The present results showed no correlation response on BFT (P &gt; 0.05), indicating that the selection based on MS-EBV can be used to enhance the MS without undesirable effect on BFT. Ultimate turnover of the Hanwoo feedlot operation is primarily determined by the QGs. The present model shows that the initial grouping for MS-EBV increased the proportion of carcasses graded for higher QGs (QG1++ and QG1+) by approximately 20%. Moreover, there appears to be a potential to increase the proportion of QG 1++ animals among the high-genetic group by further increasing the dietary energy content. Overall, this precision management strategy suggests the importance of adopting an MS based initial genetic grouping system for Hanwoo steers with a subsequent divergent management based on dietary energy level.


2018 ◽  
Vol 5 (1) ◽  
pp. 33-42
Author(s):  
Sa’adu Aliyu ◽  
Yahaya A Bashar ◽  
Aminu Abubakar ◽  
Aminu U Abdullahi ◽  
Mohammed Ibrahim Ribah ◽  
...  

Three commercial broiler strains (Arbor-acre, Marshall and Hubbard) were placed under three dietary energy and crude protein levels of 2900 Kcal/kg (ME) - 22% CP, 3100 Kcal/kg (ME) - 23% CP, and 3300 Kcal/kg (ME) - 24% CP as low, medium and high energy levels at starter phase, respectively. At the finisher phase, the birds were fed 2800 Kcal/kg (ME) - 19% CP, 3000 Kcal/kg(ME) - 20% CP and 3200 Kcal/kg (ME) - 21% CP, in order to determine their productive performance in wet season of semi-arid. A total of 675 birds were used in a completely randomized design (CRD) comprising 225 birds each of each strain serving as treatments. Each group was replicated five times so that each replicate had 15 birds. Each strain group was fed three dietary energy levels at both starter and finisher phases for 56 days. Feed and water intakes, mortality, weight gain, feed conversion ratio, Cost/kg gain was determined at the end of the trial. Data recorded for each phase were subjected to Analysis of variance (ANOVA) and least significant difference (LSD) was used to compare the means. Results indicated that Hubbard strain had significantly (P<0.05) lowest cost/kg gain, mortality, feed conversion ratio, feed intake and higher weight gain than other strains. Low energy diet had significant higher (P<0.05) weight gain and lower cost/kg gain than both medium and high energy diets. The study concluded that; Hubbard strain fed low energy diet should be raised in wet season of semi-arid Sokoto due to its lower cost/kg gain, mortality, better feed conversion ratio and higher average daily gain compared to other strains.Res. Agric., Livest. Fish.5(1): 33-42, April 2018


Animals ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 39 ◽  
Author(s):  
Chao Yang ◽  
Jianbo Zhang ◽  
Anum Ahmad ◽  
Pengjia Bao ◽  
Xian Guo ◽  
...  

The objective of this study was to investigate the effects of different dietary energy levels on serum concentrations of growth hormone (GH) and insulin-like growth factor 1 (IGF-1), as well as gene expression of their associated binding proteins and receptors in yak. Fifteen adult male yaks with BW of 276.1 ± 3.5 kg were allotted in three dietary groups and were fed with low (LE), medium (ME), and high energy (HE) level diet having different NEg of 5.5 MJ/kg, 6.2 MJ/kg, 6.9 MJ/kg, respectively. The effects of these treatments on ADG, BW, ADFI, and feed conversion ratio were significant (p < 0.05) throughout the experimental period. Serum GH concentration decreased (p < 0.05) with an increase in dietary energy level on d 30 and d 60. While IGF-1 concentration was higher (p < 0.05) in ME group, as compared to LE and HE groups on d 60. The expression level of growth hormone receptor (GHR) was decreased (p < 0.001) and IGF-1 was increased with the increase in the dietary energy level. The relative expression of insulin-like growth factor binding protein 3 (IGFBP-3) was higher (p < 0.001) in ME and HE groups, except the LE group. In conclusion, our findings provide a first insight into the combined effect of GH and IGF-1 in controlling the metabolism and productivity of yak. It also showed that medium energy level diet contributed to promote growth performance of yak during the cold season.


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