Background：The experiment evaluated the effect of nutrition levels and sex on the growth performance,carcass characteristics and meat quality of F1 Angus × Chinese Xiangxi yellow cattle.Methods：During the backg...Background：The experiment evaluated the effect of nutrition levels and sex on the growth performance,carcass characteristics and meat quality of F1 Angus × Chinese Xiangxi yellow cattle.Methods：During the background period of 184 d,23 steers and 24 heifers were fed the same ration,then put into a2×2×2 factorial arrangement under two levels of- dietary energy（TON：70/80%DM）,protein（CP：11.9/14.3%DM）and sex（S：male/female） during the finishing phase of 146 d.The treatments were-（1） high energy/low protein（HELP）,（2） high energy/high protein（HEHP）,（3） low energy/low protein（LELP） and（4） low energy/high protein（LEHP）.Each treatment used 6 steers and 6 heifers,except for HELP- 5 steers and 6 heifers.Results：Growth rate and final carcass weight were unaffected by dietary energy and protein levels or by sex.Compared with the LE diet group,the HE group had significantly lower dry matter intake（DMI,6.76 vs.7.48 kg DM/d）,greater chest girth increments（46.1 vs.36.8 cm）,higher carcass fat（19.9 vs.16.3%） and intramuscular fat content（29.9 vs.22.8%DM）.The HE group also had improved yields of top and medium top grade commercial meat cuts（39.9 vs.36.5%）.The dressing percentage was higher for the HP group than the LP group（53.4 vs.54.9%）.Steers had a greater length increment（9.0 vs.8.3 cm）,but lower carcass fat content（16.8 vs.19.4%） than heifers.The meat quality traits（shear force value,drip loss,cooking loss and water holding capacity） were not affected by treatments or sex,averaging 3.14 kg,2.5,31.5 and 52.9%,respectively.The nutritive profiles（both fatty and amino acid composition） were not influenced by the energy or protein levels or by sex.Conclusions：The dietary energy and protein levels and sex significantly influenced the carcass characteristics and chemical composition of meat but not thegrowth performance,meat quality traits and nutritive profiles.展开更多
Genomic imprinting is an epigenetic process that regulates gene expression in the mammalian genome. Although there are specific imprinting differences between the mammalian species, cattle present unique opportunity f...Genomic imprinting is an epigenetic process that regulates gene expression in the mammalian genome. Although there are specific imprinting differences between the mammalian species, cattle present unique opportunity for characterizing imprinted genes because of its sub-species classification. Five putative imprinted genes (TSSC4, CDKN1C, KCNQ1, PHLDA2 and NAP1L4) on bovine chromosome 29 (Bta 29) which had been characterized to have promoter CGI were quantitatively assayed for their relative expression across eight tissues (muscle, brain, liver, kidney, spinal cord, heart, lymph and skin) sampled in Angus cattle. The differential abundance of these genes in muscle and skin tissues of Angus, White Fulani and N’Dama cattle breeds was comparatively analyzed. These three breeds are representative of the Bos taurus and Bos indicus cattle sub-species while the two tissues are selected based on their strategic economic importance in cattle production. All the genes, except TSSC4, were relatively expressed across all the tissues. It was observed that Angus had the highest differential abundance in muscle tissues for TSSC4, PHLDA2 and NAP1L4 while N’Dama and White Fulani were the most abundant for KCNQ1 and NAP1L4 in skin tissues. The study identified marked differences in the expression profiles of the genes in both muscle and skin tissues of the three breeds that were characteristics of their genetics, environment and nutrition.展开更多
基金the National Beef Cattle Industry and Technology System for their financial support
文摘Background：The experiment evaluated the effect of nutrition levels and sex on the growth performance,carcass characteristics and meat quality of F1 Angus × Chinese Xiangxi yellow cattle.Methods：During the background period of 184 d,23 steers and 24 heifers were fed the same ration,then put into a2×2×2 factorial arrangement under two levels of- dietary energy（TON：70/80%DM）,protein（CP：11.9/14.3%DM）and sex（S：male/female） during the finishing phase of 146 d.The treatments were-（1） high energy/low protein（HELP）,（2） high energy/high protein（HEHP）,（3） low energy/low protein（LELP） and（4） low energy/high protein（LEHP）.Each treatment used 6 steers and 6 heifers,except for HELP- 5 steers and 6 heifers.Results：Growth rate and final carcass weight were unaffected by dietary energy and protein levels or by sex.Compared with the LE diet group,the HE group had significantly lower dry matter intake（DMI,6.76 vs.7.48 kg DM/d）,greater chest girth increments（46.1 vs.36.8 cm）,higher carcass fat（19.9 vs.16.3%） and intramuscular fat content（29.9 vs.22.8%DM）.The HE group also had improved yields of top and medium top grade commercial meat cuts（39.9 vs.36.5%）.The dressing percentage was higher for the HP group than the LP group（53.4 vs.54.9%）.Steers had a greater length increment（9.0 vs.8.3 cm）,but lower carcass fat content（16.8 vs.19.4%） than heifers.The meat quality traits（shear force value,drip loss,cooking loss and water holding capacity） were not affected by treatments or sex,averaging 3.14 kg,2.5,31.5 and 52.9%,respectively.The nutritive profiles（both fatty and amino acid composition） were not influenced by the energy or protein levels or by sex.Conclusions：The dietary energy and protein levels and sex significantly influenced the carcass characteristics and chemical composition of meat but not thegrowth performance,meat quality traits and nutritive profiles.
文摘Genomic imprinting is an epigenetic process that regulates gene expression in the mammalian genome. Although there are specific imprinting differences between the mammalian species, cattle present unique opportunity for characterizing imprinted genes because of its sub-species classification. Five putative imprinted genes (TSSC4, CDKN1C, KCNQ1, PHLDA2 and NAP1L4) on bovine chromosome 29 (Bta 29) which had been characterized to have promoter CGI were quantitatively assayed for their relative expression across eight tissues (muscle, brain, liver, kidney, spinal cord, heart, lymph and skin) sampled in Angus cattle. The differential abundance of these genes in muscle and skin tissues of Angus, White Fulani and N’Dama cattle breeds was comparatively analyzed. These three breeds are representative of the Bos taurus and Bos indicus cattle sub-species while the two tissues are selected based on their strategic economic importance in cattle production. All the genes, except TSSC4, were relatively expressed across all the tissues. It was observed that Angus had the highest differential abundance in muscle tissues for TSSC4, PHLDA2 and NAP1L4 while N’Dama and White Fulani were the most abundant for KCNQ1 and NAP1L4 in skin tissues. The study identified marked differences in the expression profiles of the genes in both muscle and skin tissues of the three breeds that were characteristics of their genetics, environment and nutrition.
