کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
8985703 1110415 2005 6 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Development of Replacement Heifers Using Programmed Feeding1
موضوعات مرتبط
علوم زیستی و بیوفناوری علوم کشاورزی و بیولوژیک علوم دامی و جانورشناسی
پیش نمایش صفحه اول مقاله
Development of Replacement Heifers Using Programmed Feeding1
چکیده انگلیسی
This experiment was conducted to determine the effects of diet and pattern of gain on reproductive performance. On November 24, 80 spring-born Angus- and Brangus-sired heifers (BW = 230 ± 23 kg) were allotted by breed and BW to one of four treatments (two replicates per treatment). Heifers were program-fed to gain 0.68 kg/d until April 14 (134 d, MODERATE), grazed wheat (cv. Hickory, Triticum aestivum L.) and ryegrass (cv. Marshall, Lolium multiflorum Lam.) interseeded into bermudagrass pasture (GRAZED), or were program-fed to gain 0.23 kg/d until February 4 (71 d) and then program-fed to gain 0.91 kg/ d (63 d, SLOW-FAST) or grazed wheat and ryegrass pastures (SLOW-GRAZED). On February 4, MODERATE heifers were heavier (P<0.05) than heifers on other treatments, but BW did not differ on April 8 (P=0.46). At the end of breeding, GRAZED heifers were heavier (P<0.05) than MODERATE and SLOW-FAST heifers; SLOW-GRAZED heifers were intermediate. Over the dry-lot feeding period, the MODERATE heifers consumed more (P=0.04) feed than SLOW-FAST heifers, but feed efficiency did not differ (P=0.57). Age and BW at puberty did not differ (P>0.70) among treatments. Pregnancy rate tended to be less (P=0.16), conception date was later (P<0.05), and serum urea N (SUN) tended to be greater (P=0.14) for GRAZED and SLOW-GRAZED heifers than for MODERATE and SLOW-FAST heifers. Program feeding can be a valuable tool for developing replacement heifers as long as BW goals pre-breeding are reached. Grazing heifers on cool-season annuals during breeding may impair reproduction as a result of the high forage N concentrations, causing reduced fertility.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: The Professional Animal Scientist - Volume 21, Issue 5, October 2005, Pages 365-370
نویسندگان
, , , ,