scholarly journals Implanting Melatonin at Lambing Enhances Lamb Growth and Maintains High Fat Content in Milk

Author(s):  
José Alfonso Abecia ◽  
Silvia Luis ◽  
Francisco Canto

Abstract Background: Recent studies have shown that melatonin implants administered during pregnancy reduced neonatal lamb mortality and produced high survival rates at weaning. This study was designed to quantify the effects of melatonin implantation of ewes and lambs immediately after lambing on the growth of lambs and the quality of milk throughout lactation.Results: In experiment 1, treatment with melatonin the lambs did not have a significant effect on liveweight (LW) (±S.E.M.) at weaning or average daily gain (ADG) until weaning. These results were similar in experiment 2, although lambs reared by melatonin-implanted ewes presented significantly (P<0.05) higher LW at weaning and ADG than did lambs from control ewes. The effect of melatonin implantation of the mothers was particularly evident in male lambs, so that male lambs reared by treated ewes presented significantly higher LW at week 2, 3, and 4 than did male lambs reared by control ewes. The fat content of milk was significantly (P<0.05) higher in implanted ewes than it was in control ewes at day 45 of lactation. Protein and lactose content of milk did not differ significantly between groups. In experiment 3, using artificially-reared lambs, melatonin treatment of the lambs at birth did not have a significant effect on LW at weaning, or ADG. Conclusions: Melatonin treatment of ewes at lambing induced a high growth rate of their lambs and increased the fat content of the milk; however, the direct treatment with melatonin of the lambs at birth did not have an effect in their growth rate.

2021 ◽  
Author(s):  
José Alfonso Abecia ◽  
Silvia Luis ◽  
Francisco Canto

Abstract Three experiments were designed to study the effects of melatonin implantation of ewes and lambs after lambing on the growth of lambs and milk quality throughout lactation. In experiment 1, 53 lambs either did (n = 28) or did not (n = 25) receive a subcutaneous 18-mg melatonin implant. In experiment 2, 55 lambs and their mothers either did (lambs: n = 28; ewes: n = 15) or did not (lambs: n = 27; ewes: n = 16) receive a melatonin implant. Milk samples were collected at 15, 30, and 45 d after lambing. In experiment 3, 16 lambs were separated from their mothers 24 h after birth, moved to an artificial rearing unit, and either did (n = 9) or did not (n = 7) receive a melatonin implant. In the three experiments, implants were inserted 24 h after lambing, and lambs were weighed (LW) weekly until weaning. Average daily gains (ADG) from birth to weaning were calculated. Melatonin treatment of lambs did not have a significant effect on LW at weaning or ADG, but lambs reared by implanted ewes in experiment 2 presented higher (P < 0.05) LW (± S.E.M.) at weaning and ADG than did lambs reared by control ewes. At day 45 of lactation, milk fat and total solid content were higher (P < 0.05) in implanted ewes than in control ewes. In conclusion, melatonin treatment of ewes at lambing induced a high growth rate of their lambs and increased the fat content of the milk; however, the direct treatment with melatonin of the lambs at birth did not have an effect in their growth rate.


2020 ◽  
Vol 60 (6) ◽  
pp. 852
Author(s):  
Luiz H. P. Silva ◽  
Pedro V. R. Paulino ◽  
Pedro D. B. Benedeti ◽  
Mauricio M. Estrada ◽  
Lyvian C. Alves ◽  
...  

Context Previously feed-restricted cattle may exhibit compensatory growth during the finishing phase. However, the efficiency in converting feed into carcass should be evaluated since cattle undergoing compensatory growth usually have high non-carcass weight gain. Aims The objective of this study was to evaluate the effect of growth rate throughout the post-weaning growing phase on subsequent feed efficiency, carcass gain, and gain composition. Methods Thirty-nine weaned young Nellore bulls averaging 230.4 ± 5.62 kg of bodyweight and 8.5 ± 0.25 months of age were used. Initially, five bulls were slaughtered as a reference initial group. The remaining bulls were randomly assigned to one of three nutritional plans to achieve Low (0 kg/day), Medium (0.6 kg/day) or High (1.2 kg/day) average daily gain (ADG) throughout the post-weaning growing phase, followed by high growth rate during the finishing phase. One-half of the bulls from each treatment were slaughtered at the end of the post-weaning growing phase, and the other one-half after the finishing phase. During both phases the feed intake, apparent digestibility, performance, and body composition were evaluated. Key results Throughout the post-weaning growing phase, High bulls had greater ADG and more efficiently converted feed into carcass, compared with other nutritional plans (P &lt; 0.01). Throughout the finishing phase, Low bulls had greater ADG, carcass gain, and feed efficiency than High and Medium bulls (P &lt; 0.01). Previous feed restriction did not affect (P &gt; 0.05) apparent digestibility. During the finishing phase, previously restricted bulls fully compensated for the lost visceral organ weight, whereas the losses of bodyweight and carcass weight were only partially compensated. Throughout finishing, Low bulls had the greatest feed efficiency and profitability among nutritional plans. However, considering the overall experiment, Hight bulls converted feed into carcass more efficiently than Low bulls (P = 0.02), but did not differ from Medium (P &gt; 0.05). Conclusions Although previously restricted bulls had greater performance and efficiency throughout finishing, the improvement was not enough to reach the same carcass weight at the same age of the unrestricted bulls. Implications Despite the greater profitability of previously restricted bulls throughout finishing, unrestricted bulls were more profitable considering both growing and finishing phases.


2015 ◽  
Vol 821-823 ◽  
pp. 133-136 ◽  
Author(s):  
Takanori Tanaka ◽  
Naoyuki Kawabata ◽  
Yoichiro Mitani ◽  
Masashi Sakai ◽  
Nobuyuki Tomita ◽  
...  

The reduction of the growth pressure was demonstrated to have the same effect as the addition of chloride-containing gas on preventing the Si nucleation and the epitaxy with high growth rate (>50 μm/h) was achieved by using the decreasing pressure condition in a horizontal CVD reactor without chloride-containing gas. The quality of a 30-μm-thick epilayer grown with 40 μm/h was also investigated. Downfall and triangle defect density in the layer was as low as 0.16 /cm2, indicating that a high quality epitaxial wafer can be easily obtained under the condition with high throughput in the sinple CVD system.


2010 ◽  
Vol 645-648 ◽  
pp. 103-106 ◽  
Author(s):  
Siva Prasad Kotamraju ◽  
Bharat Krishnan ◽  
Yaroslav Koshka

Thick 4H-SiC epitaxial layers have been grown using a combination of two chlorinated precursors silicon tetrachloride (SiCl4) and chloromethane (CH3Cl) at 16000C. Growth rates up to 100 m/hr have been demonstrated. The use of chloro-silane precursor eliminated the problem of homogenous nucleation of Si in the gas phase, which was significant in CH3Cl/SiH4 growth. Much higher values of Si/H2 and C/H2 ratios without morphology degradation were made possible by increasing the growth temperature from 1300 to 1600°C. Results of photoluminescence and high-resolution X-ray diffraction and time-resolved PL were used to evaluate the quality of the epitaxial layers. The crystalline quality and the growth rate achieved so far offer a promise of exceeding the state of the arts results achieved with more traditional hydro-carbon precursors.


2013 ◽  
Vol 740-742 ◽  
pp. 323-326
Author(s):  
Kassem Alassaad ◽  
François Cauwet ◽  
Davy Carole ◽  
Véronique Soulière ◽  
Gabriel Ferro

Abstract. In this paper, conditions for obtaining high growth rate during epitaxial growth of SiC by vapor-liquid-solid mechanism are investigated. The alloys studied were Ge-Si, Al-Si and Al-Ge-Si with various compositions. Temperature was varied between 1100 and 1300°C and the carbon precursor was either propane or methane. The variation of layers thickness was studied at low and high precursor partial pressure. It was found that growth rates obtained with both methane and propane are rather similar at low precursor partial pressures. However, when using Ge based melts, the use of high propane flux leads to the formation of a SiC crust on top of the liquid, which limits the growth by VLS. But when methane is used, even at extremely high flux (up to 100 sccm), no crust could be detected on top of the liquid while the deposit thickness was still rather small (between 1.12 μm and 1.30 μm). When using Al-Si alloys, no crust was also observed under 100 sccm methane but the thickness was as high as 11.5 µm after 30 min growth. It is proposed that the upper limitation of VLS growth rate depends mainly on C solubility of the liquid phase.


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