کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
10977566 | 1108050 | 2013 | 14 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Characterization of a changing relationship between milk production and liveweight for dairy goats undergoing extended lactation
ترجمه فارسی عنوان
مشخص کردن رابطه تغییری بین تولید شیر و وزن زنده برای بز های شیری که تحت شیر مادر رشد می کنند
دانلود مقاله + سفارش ترجمه
دانلود مقاله ISI انگلیسی
رایگان برای ایرانیان
کلمات کلیدی
بز گاو شیری، طولانی شدن شیردهی مدل سازی،
موضوعات مرتبط
علوم زیستی و بیوفناوری
علوم کشاورزی و بیولوژیک
علوم دامی و جانورشناسی
چکیده انگلیسی
This study aimed to characterize the time-profile of extended lactation (EL) for dairy goats, and the relationships between milk production, liveweight, and intake that are associated with this profile. For this, 20 nonpregnant multiparous dairy goats were monitored daily for about 90Â d from the onset of EL [i.e., when an increase in milk yield (MY) was observed]. These 20 individual profiles were pooled to create a group average profile at the onset of EL for the purpose of parameterizing a simple compartmental model. Moreover, 9 of the 20Â EL goats were kept to compare their 24-mo profiles of body weight and milk production with those observed during 2 successive normal lactations (NL). Despite being kept in the same environment and on the same feed, a clear change from decreasing to increasing MY was identified (time of change, Tchange) for all of the 20Â EL goats around 330Â d in milk. During the whole 24-mo period, EL goats produced as much milk as NL goats but this total milk production was unequally split before (56%) and after (44%) Tchange. In terms of body weight, the most striking difference between EL and NL goats was the rapid and very high increase (+9.3Â kg with an average daily gain of 60.4Â g/d) that was observed concurrently with the increase in MY. Model parameterization with the group average profile does not support that the rise in MY drives the increase in resource acquisition as is generally assumed at the onset of an NL. Rather, it demonstrates that the transfer of energy from feed to milk is delayed at the onset of EL. Moreover, assessing the model ability to fit the range of individual profiles showed that the performances over the first 90Â d of EL are largely predetermined by the animal state at Tchange. The analysis of individual variability in EL efficiency showed that it depends both on an increase in resource acquisition and on the potential of goats to partition energy from the diet toward milk production instead of to body tissue gain. Finally, predicting the suitability for EL requires the consideration of more than just milk production for 300Â d in milk.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Dairy Science - Volume 96, Issue 9, September 2013, Pages 5698-5711
Journal: Journal of Dairy Science - Volume 96, Issue 9, September 2013, Pages 5698-5711
نویسندگان
F. Douhard, N.C. Friggens, J. Tessier, O. Martin, M. Tichit, D. Sauvant,