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1.
Ghavi Hossein-Zadeh N 《Tropical animal health and production》2012,44(3):531-536
The objective of the present study was to estimate genetic changes of body weight at different ages in Moghani sheep. Traits
included were birth weight (BW, n = 4,208), 3-month weight (3MW, n = 4,175), 6-month weight (6MW, n = 3,138), 9-month weight (9MW, n = 2,244), and yearling weight (YW, n = 1,342). Data and pedigree information used in this study were collected at the Breeding Station of Moghani sheep during
1989–2005. The analysis was carried out for five traits, using the MTGSAM program. Breeding values of individual animals were
obtained from a multivariate animal model analysis and genetic trends were obtained by regressing the means of predicted breeding
values on year of birth for each trait. Direct genetic trends were positive and significant (P < 0.05) for BW, 3MW, 6MW, 9MW, and YW and were 1.63, 69.20, 79.38, 66.83, and 110.22 g/year, respectively. Also, maternal
genetic trends for BW, 3MW, 6MW, 9MW, and YW were positive and significant (P < 0.05) and were 2.36, 49.18, 37.33, 17.73, and 9.67 g/year, respectively. The results showed that improvement of body weights
of Moghani sheep seems feasible in selection programs. 相似文献
2.
The reproductive performance of 48 Damara, 42 Dorper and 46 Merino ewes was evaluated under an optimum nutritional regime
for Merino ewes that included one annual joining in a mixed (cropping and sheep) farming system in the eastern wheatbelt of
Western Australia (W.A.) over a 3-year period. In 2005, when the Damara, Dorper and Merino ewes were aged between 8 and 9 months
at joining and weighed 41.2, 42.4 and 33.3 kg with average body condition scores of 2.3, 2.4 and 1.8, respectively, their
weaning rates were 71% (Damara), 81% (Dorper) and 13% (Merino). The Merino ewes had significantly lighter body weights and
were lower conditioned (p < 0.001) resulting in significantly lower weaning rates (p < 0.001). In 2006, the Damara, Dorper and Merino ewes weighed 61.9, 69.5 and 61.6 kg at joining, with body condition scores
of 2.8, 3.3 and 2.8, respectively, resulting in weaning rates of 52% (Damara), 122% (Dorper) and 117% (Merino). While the
Damara and Merino weights and body condition scores were not different (p > 0.05), the Damara weaning rates were significantly lower compared with the Dorper and Merino groups (p < 0.001). The Dorpers were heavier and greater conditioned (p < 0.001); however, the weaning rates between the Dorper and Merino were not different (p > 0.05). In 2007, the Damara, Dorper and Merino ewes weighed 71.6, 77.1 and 70.2 kg at joining with body condition scores
of 2.8, 2.8 and 2.5, respectively. Again, the Dorper ewes were heavier (p < 0.001) than the Damaras and Merinos, which were not different (p > 0.05). The Damara and Dorper had the same body condition while the Merino ewes were less and different (p < 0.05). However, there were differences in weaning rates between the three breeds (p < 0.001), of 64% (Damara), 105% (Dorper) and 134% (Merino). Over the 3-year period, under a nutritional management system
optimal for Merino sheep and with one annual joining, with increasing age the Merino ewes weaned more lambs. However, while
the Damara and Dorper ewes conceived and weaned relatively high lamb numbers when they were joined as lambs, their reproductive
performance decreased over time. This nutritional regime resulted in increased levels of fatness of the Damara and Dorper
ewes with no increase in reproduction rates under an annual joining system. A significant factor for the lower conception
and weaning rates in the Damara ewes was the enlarged fat tail due to the increased fat levels, which made it difficult for
the rams to impregnate the ewes. 相似文献
3.
Effect of feed flushing on ovulation rate was investigated during the autumn seasons on 24 adult Malpura ewes (BW 34.8 ± 0.58 kg
and age 4–7 years) equally divided into two groups. Ewes in G1 (group 1) were grazed 8–10 h daily on Cenchrus ciliaris pasture interspersed with seasonal shrub. In addition to grazing, concentrate was provided at 1.5% of BW to the animals in
G2 (group 2) for a period of 35 days. Estrus was synchronized by a double injection schedule of PGF2α at 0 and 10 days of the experiment and detected by parading aproned rams at 6 h intervals. Blood samples were collected at
weekly interval during the estrous cycle. A rumen fermentation study was conducted on day 23 of the experiment at 0 and 4 h
post-concentrate feeding. Ovarian responses in terms of number of corpora lutea and large follicles was examined on all the
ewes by laparoscopy after 3 to 6 days of each estrus and were found to be similar in both the groups. Hemoglobin and packed
cell volume, total protein, albumin, and globulin were similar among the groups. Concentration of plasma glucose (12 and 22 days)
was higher (P < 0.05) in G2 vis-à-vis control. Plasma urea was higher (P < 0.01) in the control than G2. Rumen liquor pH, concentration of total N, TCA–ppt N, NH3–N, and TVFA were significantly higher (P < 0.01) in G2 than the control. Thus, it can be concluded that concentrate supplementation in ewes prior to mating (flushing)
did not enhance ovulation response during the autumn season. 相似文献
4.
Almutairi Sallal E. Boujenane Ismaïl Musaad Abdelgader Awad-Acharari Falah 《Tropical animal health and production》2010,42(8):1845-1853
The study was based on a set of 256 records for milk yield at 305 days, 1,899 records of test day yield, and 466 growth records
collected at Al Jouf center from 1987 to 2009. Except season of calving, milk yield at 305 days was affected by parity and
calving year, whereas test day yield was influenced by parity, calving year, stage of lactation, and test milk day. Only birth
year had a significant effect on all growth traits, whereas dam’s parity influenced weights at birth and 3 months, and birth
season affected birth weight, weight at 6 months and average daily gain (ADG) 3–6 months. Variance components estimated using
an animal model showed that heritability and repeatability estimates for milk yield at 305 days were 0.24 and 0.28, respectively.
The corresponding estimates for test day yield were 0.22 and 0.66, respectively. Direct heritabilities were 0.37, 0.50, 0.60,
and 0.85 for body weights at birth, 3, 6, and 12 months of age, respectively, and 0.25, 0.37, 0.49, and 0.29 for ADG 0–3,
3–6, 6–12, and 0–12 months, respectively. The annual genetic progress was 0.05 kg for milk yield at 305 days and 0.0003 kg
for test day yield. Annual genetic gains during 23 years were 0.050, −0.185, 0.079, and 0.331 kg for body weights, respectively,
and −9, −5, −4, and −13 g, for ADG, respectively. It was concluded that it is necessary to set up a field milk and growth
recording system in order to collect a large number of records to check these estimates. 相似文献
5.
Yueting Pan Yongjia Wang Shanning Lou Metha Wanapat Zhaofeng Wang Wanhe Zhu Fujiang Hou 《Journal of animal physiology and animal nutrition》2021,105(4):611-620
Low selenium (Se) in soil and forage can adversely affect on the quality of animal-derived foods, and hence on human health. Lambs grazed on mixed pastures of alfalfa (Medicago sativa) and tall fescue (Festuca arundinacea) were supplemented with five levels of Se [0, 3, 6, 9 and 12 µg/kg body weight (BW)]. The intake of dry matter (DM) and organic matter (OM) varied with the level of Se supplementation, with a peak at 6 µg Se per kg BW (p ≤ 0.05). Gross energy (GE) intake, digestive energy (DE) intake and metabolic energy (ME) intake were higher at 6 µg Se per kg BW than at other Se levels (p < 0.01); in addition, methane energy (CH4-E) output was lower at 6 µg Se per kg BW. Supplementation with Se significantly increased nitrogen (N) intake, faecal N and urine N, for which the peak values were 20.2 g N/, 5.62 g N/day and 7.92 g N/day, respectively, at 6 µg Se per kg BW. Se intake, blood Se, faecal Se, urine Se and retained Se were negatively correlated with forage crude protein (CP) content (p < 0.001) but were positively correlated with the content of neutral detergent fibre (NDF) (p < 0.001) and acid detergent fibre (ADF) (p < 0.001). Thus, we recommend the addition of 6 µg Se per kg BW to sheep grazed on pastures in regions with low soil Se. 相似文献
6.
Thirty yearling male intact Arsi-Bale sheep with initial body weight (BW) of 15.5 ± 0.21 kg (mean ± SD) were used in 90 days
feeding trial, 10 days digestibility trial followed by evaluation of carcass parameters at Bokoji, Ethiopia. The objectives
were to evaluate effects of supplementation with linseed (Linum usitatissimum) cake (LSC), wheat bran (WB), and their mixtures at 2:1 and 1:2, respectively on feed intake, digestibility, daily BW gain,
and carcass parameters. The five treatments included ad libitum feeding of natural pasture hay (control) and with daily supplementation
of 300 g dry matter (DM) sole LSC, 2LSC:1WB mix, 1LSC:2WB mix, and sole WB. Six sheep were randomly assigned to each treatment
using randomized complete-block design. Four sheep in each treatment were randomly selected and used for determination of
digestibility and carcass characteristics using a completely randomized design. The intake of hay DM was higher (P < 0.001) for the non-supplemented sheep compared with the supplemented ones, but the contrary was true for total DM intake.
Sheep in the control treatment lost BW (−1.5 g/day), while the supplemented ones gained 69.0–104.1 g BW/head/day. Digestibility
of CP was higher (P < 0.001) for supplemented sheep as a result of higher (P < 0.001) CP intake. Slaughter weight, empty BW, and hot carcass weight were lower (P < 0.001) for sheep in the control treatment compared with the rest. Sheep supplemented with LSC and its mixtures with WB
had better (P < 0.001) performance in daily BW gain than sole WB supplemented ones indicating the advantages of using supplements as mixed
rations. Moreover, supplementation proved to be profitable, whereas feeding hay alone led to economic loss. 相似文献
7.
Satish Kumar I Vijaya Kumar C Gangaraju G Sapna Nath Thiruvenkadan A.K. 《Tropical animal health and production》2017,49(7):1431-1438
In the present study, (co)variance components and genetic parameters in Nellore sheep were obtained by restricted maximum likelihood (REML) method using six different animal models with various combinations of direct and maternal genetic effects for birth weight (BW), weaning weight (WW), 6-month weight (6MW), 9-month weight (9MW) and 12-month weight (YW). Evaluated records of 2075 lambs descended from 69 sires and 478 dams over a period of 8 years (2007–2014) were collected from the Livestock Research Station, Palamaner, India. Lambing year, sex of lamb, season of lambing and parity of dam were the fixed effects in the model, and ewe weight was used as a covariate. Best model for each trait was determined by log-likelihood ratio test. Direct heritability for BW, WW, 6MW, 9MW and YW were 0.08, 0.03, 0.12, 0.16 and 0.10, respectively, and their corresponding maternal heritabilities were 0.07, 0.10, 0.09, 0.08 and 0.11. The proportions of maternal permanent environment variance to phenotypic variance (Pe2) were 0.07, 0.10, 0.07, 0.06 and 0.10 for BW, WW, 6MW, 9MW and YW, respectively. The estimates of direct genetic correlations among the growth traits were positive and ranged from 0.44(BW-WW) to 0.96(YW-9MW), and the estimates of phenotypic and environmental correlations were found to be lower than those of genetic correlations. Exclusion of maternal effects in the model resulted in biased estimates of genetic parameters in Nellore sheep. Hence, to implement optimum breeding strategies for improvement of traits in Nellore sheep, maternal effects should be considered. 相似文献
8.
T. Ma G.‐S. Xu K.‐D. Deng S.‐K. Ji Y. Tu N.‐F. Zhang Q.‐Y. Diao 《Journal of animal physiology and animal nutrition》2016,100(6):1081-1089
The net and metabolizable energy (NE and ME) requirements of Dorper cross‐bred female lambs with BWs of 20–35 kg were assessed in a comparative slaughter trial. Thirty‐five Dorper × thin‐tailed Han cross‐bred female lambs weaned at ~50 days of age (20.3 ± 2.15 kg BW) were used. Seven randomly selected lambs were slaughtered at the start of the trial (baseline group). An intermediate group consisting of seven randomly selected lambs fed ad libitum was slaughtered when the lambs reached an average BW of 28.5 kg. The remaining 21 lambs were allotted randomly to three levels of dry matter intake: ad libitum or restricted to 70% or 40% of the ad libitum intake. All the lambs were slaughtered when the sheep fed ad libitum reached a BW of 35 kg. Total body energy, nitrogen, fat, ash and moisture content were determined. In a digestibility trial, an additional 15 Dorper × thin‐tailed Han cross‐bred female lambs (28.7 ± 1.75 kg BW) were housed in metabolism cages and used in a completely randomized design experiment to evaluate the ME value of the diet at the three feed intake levels. The maintenance requirements for NE and ME were 245.5 and 380.3 kJ/kg metabolic shrunk body weight (SBW0.75) respectively. The partial efficiency of energy use for maintenance was 0.645. The NE requirements for growth ranged from 1.18 to 5.18 MJ/d for the lambs gaining 100–350 g/d from 20 to 35 kg BW. Partial efficiency of ME for growth was 0.44. In conclusion, the current study suggests that the NE requirement for maintenance and growth of Dorper early‐weaned cross‐bred female lambs is lower than the current AFRC and NRC recommendations. 相似文献
9.
Hossein Mohammadi Mohammad Moradi Shahrebabak Mahmood Vatankhah Hossein Moradi Shahrebabak 《Tropical animal health and production》2012,45(1):185-191
Genetic parameters and genetic trends for birth weight (BW), weaning weight (WW), 6-month weight (6MW), and yearling weight (YW) traits were estimated by using records of 5,634 Makooei lambs, descendants of 289 sires and 1,726 dams, born between 1996 and 2009 at the Makooei sheep breeding station, West Azerbaijan, Iran. The (co)variance components were estimated with different animal models using a restricted maximum likelihood procedure and the most appropriate model for each trait was determined by Akaike’s Information Criterion. Breeding values of animals were predicted with best linear unbiased prediction methodology under multi-trait animal models and genetic trends were estimated by regression mean breeding values on birth year. The most appropriate model for BW was a model including direct and maternal genetic effects, regardless of their covariance. The model for WW and 6MW included direct additive genetic effects. The model for YW included direct genetic effects only. Direct heritabilities based on the best model were estimated 0.15?±?0.04, 0.16?±?0.03, 0.21?±?0.04, and 0.22?±?0.06 for BW, WW, 6MW, and YW, respectively, and maternal heritability obtained 0.08?±?0.02 for BW. Genetic correlations among the traits were positive and varied from 0.28 for BW–YW to 0.66 for BW–WW and phenotypic correlations were generally lower than the genetic correlations. Genetic trends were 8.1?±?2, 67.4?±?5, 38.7?±?4, and 47.6?±?6 g per year for BW, WW, 6MW, and YW, respectively. 相似文献
10.
Estimates of (co)variance components and genetic parameters for growth traits of Avikalin sheep 总被引:2,自引:2,他引:0
Leslie Leo L. Prince Gopal R. Gowane Ashish Chopra Amrit L. Arora 《Tropical animal health and production》2010,42(6):1093-1101
(Co)variance components and genetic parameters for various growth traits of Avikalin sheep maintained at Central Sheep and
Wool Research Institute, Avikanagar, Rajasthan, India, were estimated by Restricted Maximum Likelihood, fitting six animal
models with various combinations of direct and maternal effects. Records of 3,840 animals descended from 257 sires and 1,194
dams were taken for this study over a period of 32 years (1977–2008). Direct heritability estimates (from best model as per
likelihood ratio test) for weight at birth, weaning, 6 and 12 months of age, and average daily gain from birth to weaning,
weaning to 6 months, and 6 to 12 months were 0.28 ± 0.03, 0.20 ± 0.03, 0.28 ± 0.07, 0.15 ± 0.04, 0.21 ± 0.03, 0.16 and 0.03 ± 0.03,
respectively. Maternal heritability for traits declined as animal grows older and it was not at all evident at adult age and
for post-weaning daily gain. Maternal permanent environmental effect (c
2) declined significantly with advancement of age of animal. A small effect of c
2 on post-weaning weights was probably a carryover effect of pre-weaning maternal influence. A significant large negative genetic
correlation was observed between direct and maternal genetic effects for all the traits, indicating antagonistic pleiotropy,
which needs special care while formulating breeding plans. A fair rate of genetic progress seems possible in the flock by
selection for all traits, but direct and maternal genetic correlation needs to be taken in to consideration. 相似文献
11.
The study was conducted to determine the effect of supplementation with rice bran (RB) and /or noug seed (Guizotia abyssinica) meal (NSM) on feed intake, digestibility, and body weight (BW) change in hay based feeding of Farta sheep. Twenty five yearling
Farta rams with a mean initial BW of 19.23 ± 0.28 kg were used in randomized complete block design arranged into five blocks
of five animals. The five dietary treatments that consisted of hay alone (T1), hay + RB (T2), hay + mixture of RB and NSM at a ratio of 1:2 (T3), hay + mixture of RB and NSM at a ratio of 2:1 (T4) and hay + NSM (T5) were randomly assigned to each sheep within a block. The supplements were daily offered at 300 g dry matter (DM) head−1 in two equal parts at 800 and 1600 h. Supplementation improved the total DM and acid detergent fiber (ADF) intake (P < 0.05),
organic matter (OM) intake (P < 0.01), crude protein (CP) intake (P < 0.001). The apparent digestibility of DM in T5 was higher (P < 0.05) than in T1 and T2 and that of T4 was also higher (P < 0.05) than in T1. The apparent digestibility of CP in T5 and T4 were higher (P < 0.001) than in T1 and T2 and that of T3 and T2 were also higher (P < 0.001) than for T1. The BW gain of experimental sheep was improved (P < 0.01) by supplementation with NSC (T5) and/or its mixtures with RB (T3 and T4). The results of the study showed that supplementation with either of both mixtures of NSM and RB at 43% of total DM intake
promoted better feed intake, digestibility and BW gain in Farta sheep. 相似文献
12.
《动物营养(英文)》2019,5(1):74-79
This study compared the growth performance, nutrient utilization, and slaughter traits of Dorper crossbred male lambs fed as per the established nutrition recommendations for sheep, with an aim to verify the efficacy of different feeding standards. A total of 576 lambs (4 months of age, 28.3 ± 0.86 kg BW) were randomly allotted to 3 treatments with 12 replicates per treatment (16 lambs per replicate). The lambs were fed diets formulated according to the following 3 nutritional systems: the nutrient requirements of Dorper crossbred lambs established by Chinese Academy of Agricultural Sciences (CAAS), NRC (National Research Council), (2007), and AFRC (Agricultural and Food Research Council) (1993). The experiment lasted for 81 d. Feed intake was recorded every 3 days, and lambs were weighed every 20 days. Digestibility trials were conducted with 6 lambs each group from d 42 to 53 and d 70 to 81. At the end of the experiment, 10 lambs randomly chosen from each group were sacrificed to determine the carcass traits and meat quality. The results indicated that the lambs in the NRC group had the highest dry matter intake (DMI), followed by those in the AFRC and CAAS groups (P < 0.05). The average daily gain, carcass weight, and dressing percentage were higher for lambs in the CAAS group than those in the NRC group (P < 0.05). The lambs in the CAAS group had the lowest feed conversion ratio, followed by those in the AFRC and NRC groups (P < 0.05). The apparent digestibility of DM was higher for the lambs in the CAAS group than those in the NRC group (P < 0.05). Water losing rate, as well as the lightness (L*), redness (a*), and yellowness (b*) values of the longissimus thoracis were not different among groups (P > 0.05). In conclusion, Dorper crossbred lambs fed diets formulated according to the CAAS recommendations exhibited superior growth performance than those fed diets formulated according to the American or British feeding standards. 相似文献
13.
本试验测定了舍饲条件下的215只湖羊和60只湖杜湖[湖羊♂×(杜泊羊♂×湖羊♀)♀]杂交羔羊0~12月龄的体重,采用Gompertz模型和Logistic模型拟合了湖羊和湖杜湖杂交羔羊0~12月龄生长过程,并分析比较了生长参数及模型估计值,进而评价湖杜湖的杂交优势。结果表明,2种模型的拟合度(R2)均在0.96以上,拟合效果好,其中Gompertz模型拟合两个种群效果好于Logistic模型;湖羊公、母羔拐点月龄分别为2.55和1.73个月,拐点体重分别为17.00和13.14 kg;湖杜湖公、母羔拐点月龄均早于湖羊,公、母羔拐点体重分别相差0.74和2.66 kg,公、母羔累积生长均极显著高于湖羊(P<0.01)。结果说明湖杜湖早期生长强于湖羊,湖杜湖杂交效果显著。 相似文献
14.
Effect of supplementation of Simada sheep with graded levels of concentrate meal on feed intake,digestibility and body-weight parameters 总被引:1,自引:1,他引:0
Jemberu Dessie Solomon Melaku Firew Tegegne Kurt J. Peters 《Tropical animal health and production》2010,42(5):841-848
The experiment consisting of 7 days of digestibility and 90 days of feeding trial was conducted at Wogda (Ethiopia) to determine
the effect of supplementation of graded levels of concentrate mix (CM) on feed intake, digestibility, and body weight (BW)
change in hay-based feeding of Simada sheep. Twenty-yearling Simada sheep with a mean initial BW of 17.9 ± 0.81 kg (mean ±
SD) were used in randomized complete block design arranged into five blocks of four animals. The four dietary treatments that
consisted of hay alone (T1), hay +150 g dry matter (DM; T2, low), hay +250 g DM (T3, medium), and hay +350 g DM (T4, high)
CM were randomly assigned to each sheep within a block. The CM consisted of wheat bran (WB), noug seed (Guizotia abyssinica) meal and safflower (Carthamus tinctorius) seed meal at the ratio of (2:1:1), respectively. Supplementation with T2 and T3 increased (P < 0.001) total DM and organic matter intake than the control treatment. Overall, supplementation improved (P < 0.001) crude protein intake, digestibility, feed conversion efficiency, BW gain, and profitability compared to the control,
whereas sheep on the high than the low and medium level of supplementation performed better in these parameters among the
supplemented treatments. From the results of this study, T4 is recommended as the best level of supplementation since it resulted
in better nutrient utilization, animal performance, and profitability. 相似文献
15.
V. Arthy R. Venkataramanan S. N. Sivaselvam C. Sreekumar D. Balasubramanyam 《Tropical animal health and production》2018,50(7):1463-1471
The Network Project on Sheep Improvement (NWPSI)–Madras Red field unit is a group breeding scheme involving 198 farmers’ flocks of Madras Red sheep in which selection for growth traits and rotation of rams have been practised for over two decades. Growth data collected from these flocks were used to evaluate the performance and understand the direct and expected responses to selection based on genetic parameters. The body weight at birth (BW), weaning weight (WW), 6-month weight (6W), 9-month weight (9W), 12-month weight (YW), pre-weaning average daily gain (ADG1, birth to 3 months), post-weaning ADG2 (3–6 months), ADG3 (6–9 months), ADG4 (9–12 months) and ADG5 (3–12 months) were 2.67, 10.05, 14.56, 18.36, 21.36, 80.13, 49.05, 43.00, 34.21 and 41.18 g, respectively. Univariate analyses were carried out using animal and sire models to estimate variance components. Heritability obtained from animal model for BW was 0.36 and the values for other body weight traits were almost unity. Heritability estimate for pre-weaning ADG1 was 0.31. Very high genetic variability was observed in spite of long-term selection and this sustenance of variability is one of the main advantages of a group breeding scheme, combining several flocks of smaller size. An increasing genetic and phenotypic trend was noticed for almost all the traits studied. The expected responses calculated based on genetic parameters also indicated scope for improvement. 相似文献
16.
Effect of supplementing urea-treated barley straw with lucerne or vetch hays on feed intake,digestibility and growth of Arsi Bale Sheep 总被引:1,自引:1,他引:0
The study was conducted at Sinana Agricultural Research Center, Ethiopia to assess the supplementation of graded levels of
vetch (Vicia dasycarpa `lana’) and lucerne (Medicago sativa,’ Hunter river’) hay on feed intake, digestibility and body weight (BW) change of Arsi-Bale sheep fed urea treated barley
straw (UTBS). A 7 day- digestibility and a 90 day- feed intake trials were conducted using 28 and 35 sheep, respectively.
The experimental design was a randomized complete block design with seven dietary treatments that consisted of feeding UTBS
(T1) as the control treatment, UTBS plus 150, 250 and 350 g dry matter (DM) per day of vetch for T2, T3, T4, respectively
and UTBS plus 150, 250 and 350 g DM per day of lucerne for T5, T6 and T7, respectively. Intake of UTBS was not affected (P > 0.05)
by inclusion of lucerne hay at 25–35% of daily DM intake. The supplements increased daily intake of total DM, organic matter
(OM), neutral detergent fiber (NDF), acid detergent fiber (ADF) and metabolizable energy (ME) (P < 0.001) as well as apparent
digestibility of DM, OM (P < 0.001), NDF (P < 0.01), ADF, crude protein (CP) (P < 0.05) and daily BW gain (P < 0.001). Supplementation
with lucerne than vetch hay promoted higher (P < 0.001) CP and ME intakes and daily BW gain. Feeding with the UTBS without
supplementation was enough to meet the maintenance requirements of the sheep and allow small BW gain. The results of the study
showed that urea treatment of barley straw in conjunction with supplementation of lucerne or vetch hay could serve as a useful
strategy in improving smallholder sheep production in the tropics. 相似文献
17.
A number of studies have shown that the rumenic acid (RA = cis-9 trans-11 C18:2 CLA) content of milk fat is usually higher in sheep than in goats, due partly to different dietary regimens. An experiment was conducted with 12 lactating dairy ewes and 12 goats with the objective to compare the two animal species (sheep/goats) fed diet with the same forage/concentrate (F/C) ratio, on their milk fatty acids (FA) profile with emphasis on RA and vaccenic acid (VA) production. The experiment was carried out in three consecutive phases, lasted 3 weeks each, immediately after weaning of lambs and kids. In phase I, the ewes and the goats were fed according to their maintenance and lactation requirements, with 14 kg alfalfa hay, 4 kg wheat straw and 12 kg concentrate the 12 ewes (F/C ratio = 60/40), and with 14 kg alfalfa hay, 4 kg straw and 24 kg concentrate the 12 goats (F/C ratio = 43/57). In phase II, 14 kg alfalfa hay, 4 kg straw and 14 kg concentrate were offered daily to each group of sheep and goats, with a F/C ratio = 56/44. In phase III, all ewes and goats were fed individually with 0.8 kg alfalfa hay, 0.2 kg wheat straw and 0.8 kg concentrate daily with a F/C ratio = 56/44. The results showed that the different F/C ratio between sheep and goats diets, in phase I, changed significantly the milk FA profile, with no significant difference in RA and VA milk fat content between sheep and goats in phase I. In phases II (group feeding) and III (individual feeding), where sheep and goats fed with the same amount of food of the same F/C ratio, the sheep milk fat had higher RA and VA content compared to goats. In conclusion, these findings support the hypothesis that there are species differences, as RA and VA production concerns, which needs further investigation. 相似文献
18.
Juan Carlos Martínez-González Francisco Javier García-Esquivel Gaspar Manuel Parra-Bracamonte Héctor Castillo-Juárez Eugenia Guadalupe Cienfuegos-Rivas 《Tropical animal health and production》2010,42(5):887-892
The aim of this study was to estimate genetic parameters for growth traits in Mexican Nellore cattle. A univariate animal
model was used to estimate (co)variance components and genetic parameters. The traits evaluated were birth weight (BW), weaning
weight (WW), and yearling weight (YW). Models used included the fixed effects of contemporary groups (herd, sex, year, and
season of birth) and age of dam (linear and quadratic) as a covariate. They also included the animal, dam, and residual as
random effects. Phenotypic means (SD) for BW, WW, and YW were 31.4 (1.6), 175 (32), and 333 (70) kg, respectively. Direct
heritability, maternal heritability, and the genetic correlation between additive direct and maternal effects were 0.59, 0.17,
and −0.90 for BW; 0.29, 0.17, and −0.90 for WW; and 0.24, 0.15, and −0.86 for YW, respectively. The results showed moderate
direct and maternal heritabilities for the studied traits. The genetic correlations between direct and maternal effects were
negative and high for all the traits indicating important tradeoffs between direct and maternal effects. There are significant
possibilities for genetic progress for the growth traits studied if they are included in a breeding program considering these
associations. 相似文献
19.
Hue KT Van do TT Spörndly E Ledin I Wredle E 《Tropical animal health and production》2012,44(2):267-276
The objective of the experiment was to study different adaptation strategies to avoid HCN intoxication when feeding fresh
cassava foliage to sheep. Twenty-four Phan Rang lambs (initial weight = 19.6 kg at 5.5 months of age) were used in the study.
The four experimental diets contained guinea grass (Panicum maximum) supplemented with concentrate at 1.5% of body weight (BW) as dry matter (DM) (control) or supplemented with fresh cassava
foliage (FCF) that was introduced into the diet with an adaptation period of 0 (FCF-0), 7 (FCF-7) or 21 (FCF-21) days before
reaching the target feeding level of 2% of BW. The average intake of FCF expressed as DM was not different amongst the supplemented
treatments and ranged from 1.4 to 1.5% of BW but gradually increased during the first 7 days without any adaptation. The hydrogen
cyanide consumed varied from 5.1 to 5.4 mg/kg BW and no difference between treatments with cassava foliage in the diet was
found. The live weight gain was significantly higher in the treatments control and FCF-7 compared to FCF-21. No significant
differences in heart rate, respiration rate and rumen movement were found between diets. The thiocyanate concentration in
the urine of the lambs increased concomitantly with the increase in fresh cassava foliage offered during the first part of
the experiment. In conclusion, an adaptation period of approximately 7 days seems to be favourable in combined diets where
cassava foliage is offered in quantities up to 2% of BW. This level of intake could enhance the intake and LWG of the lambs
without any documented effects on heart rate, respiration rate or rumen movements. 相似文献
20.
This study estimated genetic and phenotypic parameters and annual trends for growth and fertility traits of Charolais and
Hereford cattle in Kenya. Traits considered were birth weight (BW, kg), pre-weaning average daily gain (ADG, kg/day) and weaning
weight (WW, kg); calving interval (CI, days) and age at first calving (AFC, days). Direct heritability estimates for growth
traits were 0.36 and 0.21; 0.25 and 0.10; 0.23 and 0.13 for BW, ADG and WW in Charolais and Hereford, respectively. Maternal
heritability estimates were 0.11 and 0.01; 0.18 and 0.00; 0.17 and 0.17 for BW, ADG and WW in Charolais and Hereford, respectively.
Direct-maternal genetic correlations ranged between −0.46 and 1.00; −0.51 and −1.00; −0.47 and −0.39 for BW, ADG and WW in
Charolais and Hereford, respectively. Genetic correlations ranged from −0.99 to unity and −1.00 to unity for growth and fertility
traits respectively. Prospects for improvement of growth and fertility traits exist. 相似文献