Effects of food restriction during the finishing period on the performance of broiler chickens

1. Three hundred 4-week-old commercial Hibrow broiler chicks were fed ad libitum , 85% and 70% of ad libitum or ad libitum for 5 d per week with 3rd and 5th days of food withdrawal for 28 d to examine the effects of food restriction on liveweight, growth rate, food conversion efficiency, dressing percentage, abdominal fat and mortality. 2. Quantitative food reduction to 85% and 70% of ad libitum , and reduction in feeding time by 2 d/week significantly reduced final body weight and rate of growth. 3. Food restriction (to 70% ad libitum ) resulted in lower abdominal fat than ad libitum feeding, 15% food restriction or reduction in feeding time by 2 d/week. 4. There were no significant differences between the effects of 15% food restriction and 2-d reduction in feeding time per week on final body weight, growth rate and abdominal fat. 5. Reduction in feeding time by 2 d/week resulted in the same food efficiency as ad libitum feeding and quantitative food restriction by 15% and a significantly better food efficiency than 30% quantitative food reduction. 6. Reducing feeding time by 2 d/week seemed to have less severe effects on the birds than quantitatively reducing food supply by 30%.     

Effects of nutrient concentration and dietary presentation on performance of dwarf hens

1. Diets containing 170 or 190 g protein/kg and 10.9 or 11.7 MJ ME/kg in all combinations were offered to dwarf hens in two dietary presentations: a complete mash or a form in which part of the protein and calcium contents were presented as soyabean meal pellets and limestone grit respectively.

2. Egg production and egg mass output were higher with the 190 g protein/kg diets.

3. Lower‐energy diets gave better egg production, while higher‐energy diets containing 190 g protein/kg improved food conversion efficiency.

4. Separation of protein and calcium constituents tended to give better egg production, food conversion efficiency, shell thickness and egg mass output.     

Effects of short intermittent lighting on food consumption and performance of dwarf broiler breeders and progeny

1. Two hundred and sixty four dwarf broiler breeder hens were subjected to ad libitum or restricted feeding and to four lighting patterns: 15L (bright light):9D (dark), 15L:9d (dim light), 2L:10d: 1L:11d, (0.5L:3.5d) × 6.

2. Breeder hens fed ad libitum and subjected to either conventional or intermittent lighting ingested respectively, 25 g and 14 to 17 g more than hens restricted to 115 g/d.

3. Body weight was greater in hens fed ad libitum irrespective of the lighting pattern and of the amount of food intake.

4. Persistency of egg production was impaired by intermittent lighting.

5. Ad libitum feeding reduced egg fertility. The decrease was larger in breeder hens on intermittent lighting.

6. Hatchability was increased in hens submitted to the symmetrical lighting pattern (0.5L:3.5d).

7. Egg and chick weights were higher in hens fed ad libitum.

8. Shell index and shell breaking strength increased in restricted hens on the intermittent lighting pattern (0.5L:3.5d) × 6.

9. The best performance was obtained in restricted hens on the conventional lighting pattern.     

Intake restriction strategies and sources of energy and protein during the growing period affect nutrient disappearance, feedlot performance, and carcass characteristics of crossbred heifers.

Two trials were conducted to evaluate intake restriction, energy, and protein source on the performance and carcass merit of heifers limit-fed corn gluten feed. Trial 1 crossbred heifers (n = 140) were allotted to ad libitum wet corn gluten feed (WCGF)-hay, ad libitum WCGF-corn, WCGF-corn continuously limit-fed to achieve a gain of 1.1 kg/d or WCGF-corn fed in the following sequence: 70% of ad libitum for 20 d, ad libitum for 20 d, and 2 d common intake during the 84-d growing period. One-half of these restricted-refed heifers received a rumen-undegraded protein supplement, and the other half received a rumen degraded protein supplement. Heifers were fed a common finishing diet ad libitum subsequent to the growing period. Heifers offered ad libitum WCGF-hay and WCGF-corn were slaughtered at a common compositional fat end point. Heifers limit-fed WCGF-corn were slaughtered at the same time as heifers offered ad libitum WCGF-corn, regardless of subcutaneous fat cover. Limit-feeding WCGF-corn diets to growing heifers reduced ADG (P < or = 0.01) but did not compromise feed efficiency. Method of intake restriction, continuous or ad libitum-interrupted, and supplemental protein source did not affect combined growing-finishing performance. However, when fed for a common length of time, the average of the limit-fed heifers had lighter carcass weights (P < or = 0.01) and lower (P = 0.04) marbling scores. Heifers offered ad libitum WCGF-hay gained slower (P < or = 0.01) and less efficiently (P < or = 0.01) than heifers offered WCGF-corn. Trial 2 crossbred heifers (n = 222) were allotted to dry corn gluten feed (DCGF)-corn ad libitum or restricted to 80% of ad libitum for 42, 84, or 126 d; or ad libitum corn silage or DCGF-corn silage at 80% of ad libitum for 84 d. Feed efficiency (P = 0.07) and ADG (P = 0.08) tended to behave quadratically, being poorer for heifers limit-fed for 126 d during the growing period. Heifers limit-fed DCGF-corn gained more efficiently (P = 0.05) than heifers grown on ad libitum corn silage. Limit-feeding CGF-corn to growing beef heifers can be used to achieve moderate rates of gain without compromising feed efficiency. However, limit-feeding during the growing period may result in lighter weight carcasses with lower quality grades if not fed to the same fat end point as heifers grown with free access to concentrate.     

Effects of food regulation during the growing and laying stages on the productivity of broiler breeders

1. From 1 to 22 weeks of age 720 Ross 1 parent stock pullets were given regulated amounts of food to achieve 90, 100 or 110% of a target weight (R90, R100 or R110, respectively) while from 23 to 64 weeks of age they were fed 80 or 100% of a set allowance (L80 or L100, respectively). One hundred and fifty Ross 1 parent stock males were on the R110 treatment and then either the L80 or L100 during breeding.

2. Mean number of settable (> 53 g) eggs per hen housed was 131, 131 and 135 and mean number of chicks hatched per hen housed was 108, 101 and 101, respectively, for the R90, R100 and R110 treatments. These differences were not statistically significant.

3. Mean number of settable eggs per hen housed was 116 and 148 and mean number of chicks hatched per hen housed was 94 and 112, respectively, for the L80 and L100 treatments (P<0.001).

4. Fertility and hatchability were improved but uniformity of the birds was decreased by restricting food intake.     

不同限喂方法对肉用种鸡育成期体重均匀度的影响

本试验采用隔日限喂、每日限喂、“周五·二”限喂三种不同限时饲喂方法，观察对ＡＡ父母代肉用种鸡（６—１７周龄）体重均匀度的影响。结果表明，隔日限喂的肉种鸡体重均匀度最好，趋于标准均匀度，而每日限和“周五·二”限喂的体重均匀度差距较大。三种限时饲喂方法，其体重均匀度差距较大，分别是８０％、５９．５％和６０．０％。可见，对６—１７周肉种鸡而言，隔日限饲法不失为理想限饲法     

后期强限饲对肉仔鸡生产性能及血浆激素水平的影响

本试验采用单因子完全随机设计,将72只29日龄雄性AA肉仔鸡随机分为对照组(自由采食)和试验组(限饲量为自由采食量的50%),每个处理设6个重复,每重复6只鸡,饲养至49日龄,研究后期强限饲对肉仔鸡生长性能、胴体品质及血浆激素水平的影响。试验结果表明,试验组肉仔鸡49日龄活重、日增重降低,料肉比升高,胸肌率、腹脂率下降,血浆瘦素水平降低,且与对照组相比均呈显著差异(P<0.05);两处理间血浆胰岛素、神经肽Y(NPY)及皮质酮水平无显著差异(P>0.05)。     

日粮蛋白质和脂肪水平对育成期雄性水貂生长性能、营养物质消化率及氮代谢的影响

试验旨在探讨日粮不同蛋白质和脂肪水平对育成期雄性水貂生长性能、营养物质消化率及氮代谢的影响,确定育成期雄水貂日粮蛋白质和脂肪的适宜水平。试验采用2×3因子试验设计,2个蛋白质水平(32%和36%)和3个脂肪水平(10%、20%和30%),共配制6种试验日粮。选取90只60日龄健康雄性水貂随机分成6组,每组15个重复,每个重复1只貂。预试期7 d,试验期60 d。结果表明:蛋白质水平为32%,脂肪水平为20%和30%组水貂各阶段平均日增重和饲料转化率、脂肪消化率、氮沉积氮生物学效价均最高,日粮蛋白质和脂肪交互作用对脂肪消化率影响显著(P0.05),对其他指标影响均不显著(P0.05)。综合各项指标,在本试验条件下,当日粮蛋白质水平为32%,脂肪水平为20%~30%时,育成期雄性水貂生产性能最佳,且能够降低尿氮排放量,提高水貂对日粮蛋白质的利用率。     

有机铬对蛋种鸡生产性能的影响

铬是人和动物机体所必需的一种元素,能够作为“葡萄糖耐量因子”(Glucosetolerancefactor,GTF)的活性成分与胰岛素发挥协同作用,参与糖、脂类、蛋白质和核酸代谢。试验表明,铬在提高生产性能,调节内分泌,提高胴体品质,影响免疫反应,改善糖和矿物质代谢等方面均发挥一定的作用,但这些试验大多以家畜为研究对象,且强调将应激作为铬发挥作用的客观和先决条件。国内外对家禽添加铬研究较少,对蛋鸡的研究则更少,一些结果也很不一致。目前,已确定铬能提高存活率,缺铬会导致鸡羽毛大量脱落,过量则引起死亡(翟桂玉,1992)。大量的动物临床试验已证…     

Effects of restricted feeding on physiological stress parameters in growing broiler breeders

1. In previous studies, a lack of agreement in measurements of plasma corticosterone concentrations and heterophil:lymphocyte (H/L) ratio as physiological indices of stress, caused by hunger and frustration in restricted-fed broiler breeders, was observed. It could be suggested that the differences between previous studies were caused by differences in duration of restriction and time of the day of the measurements. Therefore, in the present study the plasma corticosterone concentration and the H/L ratio were again determined in restricted- and ad libitum-fed growing broiler breeders, taking possible causes of disagreement between previous studies into account. In addition, we measured the daily rhythm in body temperature and heart rate, and the corticosterone responses to an acute stressor as physiological indices of stress. 2. Female broiler breeders (64 per treatment, housed in groups of 4 birds) were used in the experiment. Behaviour, baseline plasma corticosterone concentrations and H/L ratio were determined at 21 d of age (immediately after the start of food restriction), and at 42 and 63 d of age. Body temperature, heart rate and activity were measured by radiotelemetry for 36 h at 49 and 70 d of age. In addition, the plasma corticosterone response to acute stress (5 min manual restraint) was measured at 77 or 78 d of age. 3. Restricted broiler breeders had higher plasma corticosterone concentrations at 42 and 63 d of age, but no differences in H/L. ratio were found between restricted birds and unrestricted control birds. Restricted broiler breeders had a higher corticosterone response to 5 min manual restraint than unrestricted birds. Restricted birds displayed a clear day-night rhythm in body temperature, heart rate and activity whereas such a rhythm was blunted in ad libitum-fed birds. 4. It is discussed that some physiological differences (plasma corticosterone concentrations, body temperature and heart rate) between ad libitum-fed and restricted broiler breeders may have been caused by differences in metabolic rate as well as by differences in the level of stress. It is concluded that a combination of behavioural measurements and a wide range of physiological parameters should be used for the assessment of stress in growing broiler breeders.     

Reproductive performance of dwarf broiler breeders given different allowances of food during the rearing and breeding periods and two lighting patterns

1. Dwarf broiler breeders were either fed ad libitum or restricted to allow growth to mean body weights of 1.4 or 1.8 kg at 20 weeks of age. During the breeding period these birds were fed ad libitum, or food was restricted to different degrees and the birds subjected to two different incremental lighting patterns. 2. Egg production of birds fed ad libitum during the breeding period increased with the degree of food restriction during rearing. 3. Food restriction during the breeding period increased the egg production of birds weighing 1.8 kg at 20 weeks but decreased that of birds weighing only 1.4 kg. 4. Fertility was relatively low and inversely related to body fatness of females. 5. The differences in lighting pattern did not influence performance. 6. For optimum reproductive performance during the rearing period dwarfs should not be restricted so severely as conventional breeders. Best chick production was obtained from birds with a bodyweight of 1.8 kg at 20 weeks of age, which were subjected to a 10% restriction of food during the breeding period.     

角黄素对肉种鸡生产性能和繁殖性能的影响

本文主要研究添加角黄素对肉用种鸡生产性能和繁殖性能的影响。试验选用360只小母鸡和36只公鸡,饲养于12个面积为7m 2的圈中。以体重相近和均匀性为原则,于42周时将母鸡和公鸡平均分配到两个试验组中。在第46至66周龄时,给予试验组1每公斤饲粮6m g角黄素的添加量,试验组2不添加角黄素（对照组）。每4周称量一次体重,记录每周产蛋率,于试验结束时计算死亡率。孵化期为21天,计算孵化率和繁殖率。为了评价不同存储时间和孵化过程中角黄素的抗氧化作用,对所有处理组蛋品进行硫代巴比妥酸法分析。饲粮中添加角黄素对体重,死亡率和产蛋率没有影响,但孵化率（P≤0.0001）和受精率（P≤0.0003）却极显著增加。角黄素还能改善母鸡繁殖力,降低孵化前48小时和孵化结束前1周胚胎死亡率。两组间母鸡体重和小鸡品质没有显著性差异。试验组1蛋黄TBAR S值降低,在储存4 d和孵化7 d的蛋黄中也能观察到这种现象。在肉种鸡饲粮中添加角黄素能改善孵化率、繁殖率,降低蛋黄中TBAR S的产生。     

生长期戴云山羊屠宰性能研究

选取8只生长期戴云山羊(约8月龄)进行屠宰测定和肉品质评定。结果显示:生长期戴云山羊平均宰前活重、胴体重、净肉重、屠宰率、净肉率分别为15.06 kg、6.73 kg、4.93 kg、44.61%、32.67%。表明生长期戴云山羊具有较高的屠宰率和净肉率,表现出较好的产肉性能,肉质各项指标均处于正常范围内。     

Growing and finishing performance of steers when fed recycled poultry bedding during the growing period

Sixty Angus-cross steers were used to compare the effects of recycled poultry bedding (RPB) stacking method and the inclusion of monensin in growing diets on performance. Steers were individually fed balanced, growing diets for a period of 84 d. The diets were control (CON), CON + monensin (CON+M), deep-stacked RPB (DS), DS+M, shallow-stacked RPB (SS), and SS+M. The CON diets contained corn, soybean meal, corn silage, and cottonseed hulls. In the RPB diets, 35% of the silage, cottonseed hulls, and soybean meal was replaced with RPB (as-fed basis). At the end of the growing period, 30 steers, representing all treatment groups, had liver biopsies for trace mineral analysis and ruminal fluid samples to assess pH, VFA, and ammonia concentrations. All steers had blood samples drawn at the end of the growing period for analysis of Se and urea N. Steers were transported 466.6 km to simulate shipping stress and started on a finishing diet for a 120-d period. Intake, ADG, and G:F were monitored throughout the trial. Steers fed CON diets had higher ADG, DMI, and G:F than SS, and higher ADG and G:F than DS (P < 0.05) during the growing period. Steers fed DS diets had higher DMI than SS (P < 0.05) during the growing period. Inclusion of monensin in the growing diets increased G:F and decreased DMI (P < 0.05). Steers from the RPB treatments started the finishing period at lighter BW than steers fed CON diets (P < 0.05). During the finishing period, steers fed SS diets had higher DMI than steers fed CON diets (P < 0.06), whereas steers fed DS diets were intermediate. At slaughter, steers fed CON diets had higher hot carcass weights and quality grades than steers fed SS diets (P < 0.07), whereas steers fed DS diets were intermediate. Results indicate that steers fed RPB consumed it better when processed by deep stacking before consumption, that carryover effects of RPB into the finishing phase were minimal, and inclusion of monensin did not affect consumption of RPB diets.     

The effect of nutrition during the growing period and the oestrous cycle on the reproductive performance of the pig

The literature on the effects of nutrition during the growing period and the oestrous cycle on the reproductive performance of the pig is reviewed. It is concluded that the age at which the gilt reaches puberty is influenced much less by nutrition than by other environmental factors. This being so it would be advisable to feed the gilt at a level of intake which optimises food conversion efficiency. By extrapolation from the recent work of Davies and Lucas (1972) this might be expected to occur when dietary energy intake was approximately three times the maintenance requirement.In some circumstances ovulation may be a limiting factor to litter size therefore in order to maximise ovulation rate it would be advisable to feed gilts ad libitum for 11–14 days before the oestrus at which they are to be mated.Following mating the feed intake of the gilt should be reduced to provide an intake of approximately 5 Mcal ME/day.On the limited evidence available at present it would appear likely that reducing the age at which gilts reach puberty and are mated will produce small reductions in litter size, but that such a practice may be justifiable in terms of savings in food consumption.From the evidence that is available it would appear that nutritional variations during the weaning to remating period and the post weaning oestrous period may influence ovulation rate. However, ovulation rate does not seem to be the factor which limits litter size. Post weaning nutrition may be of significance in determining if and when the female returns to oestrus and also in influencing conception rate. There is certainly a case for feeding the primiparous sow liberally between weaning from her litter and conception. However in the older sow the effects are less clearly defined. The precise requirements of the sow between weaning and conception still await definition.     

营养水平对鲁农2号配套系生长肥育猪生长性能以及养分消化率的影响

为探讨鲁农2号配套系生长肥育猪适宜的能量和粗蛋白质需要量,试验采用单因子随机区组设计,在保持消化能/粗蛋白质比不变的基础上,设为高能量粗蛋白质、中能量粗蛋白质和低能量粗蛋白质3个处理组。选取健康、初始体重（49.58±1.49）kg的鲁农2号配套系生长肥育猪108头（公母各半）随机分3个处理,每个处理4个重复,每个重复（圈）9头猪。试验分为50～80 kg和80～100 kg两个阶段。结果表明,试验全期饲粮营养水平的降低对猪日采食量、日增重和料重比影响不显著,但50～80 kg低营养水平组日增重和粗蛋白质日摄入量显著低于高、中营养水平组。养分表观消化率,50～80 kg以低营养水平组最高,与中营养水平组相比,其干物质、有机物、粗蛋白质和能量的表观消化率分别提高6.97%、8.53%、10.48%和6.45%,差异显著。饲粮营养水平对钙和磷的表观消化率均无显著影响（P〉0.05）。80～100 kg不同营养水平组养分表观消化率差异显著,其中,高营养水平组养分表观消化率最高,其干物质表观消化率分别比中、低营养组提高5.49%和7.17%（P〈0.05）;有机物的表观消化率分别提高4.48%和6.07%（P〈0.05）;钙的表观消化率分别提高32.76%和27.93%（P〈0.05）;磷的表观消化率分别提高38.77%（P〈0.05）和17.44%;粗蛋白质的表观消化率比中营养水平组提高8.56%（P〈0.05）。综合考虑,在50～80 kg阶段,鲁农2号配套系生长猪适宜的消化能为12.98 MJ/kg、粗蛋白质为14.56%;80～100 kg阶段,鲁农2号配套系肥育猪适宜的消化能为12.98 MJ/kg、粗蛋白质为12.40%。     

矮小型粉壳蛋鸡育雏期适宜蛋白质水平的研究

试验旨在研究育雏期日粮蛋白质水平对矮小型粉壳蛋鸡生长以及产蛋性能的影响。试验选用1日龄矮小型粉壳蛋鸡2 000只,采用单因素试验设计,0~5周随机分成2个处理;6~12周分别将每组试验鸡分成2组,共4个处理。0~5周蛋白质水平分别为20%、21%,6~12周蛋白质水平分别为19%、20%。结果表明:不同蛋白质水平对0~2周体重影响差异不显著(P0.05);第3~5周,21%蛋白水平组体重显著高于20%蛋白水平组(P0.05)。0~5周蛋白水平21%,6~12周蛋白水平19%组12周龄平均体重显著高于其它处理组(P0.05)。同时,0~5周蛋白水平21%,6~12周蛋白水平19%组产蛋率高于其它处理组,降低了料蛋比;各处理组平均蛋重差异不显著(P0.05)。综合体重和产蛋性能,在日粮能量水平为12.12 MJ/kg基础下,建议矮小型粉壳蛋鸡0~5周适宜蛋白质水平为21%,6~12周适宜蛋白质水平为19%。     

Effects of monensin feeding on performance,nutrient utilisation and enteric methane production in growing buffalo heifers

Tropical Animal Health and Production - Murrah buffalo heifers (live weight 135?±?17&nbsp;kg) were fed a total mixed ration without supplementation (CON), or supplemented with...     

Feeding standards during lay and reproductive performance of broiler breeders

1. Broiler parent stock (Marshall) were supplied with energy and protein from diets in amounts defined as percentages of an allowance such that nutrient intake increased or decreased in three consecutive periods from 23 to 63 weeks of age.

2. A 20% reduction in energy allowance from 23 to 34 weeks was associated with reduced body‐weight gain, egg weight and carcass constituents except ash, but had no significant effect on egg production or hatchability.

3. Increases in nutrient intake after 34 weeks were associated with an increase in body‐weight gain and carcass fat.

4. Moderate decreases in energy intake after 34 weeks were associated with reduced body‐weight gain, and a 15% reduction in nutrient intake resulted in a decrease in body weight and egg weight.

5. It is suggested that a feeding allowance which controls body‐weight gain during early lay, and then allows for a gradual increase in body weight over the breeding period may be the most efficient way of feeding the broiler breeder hen.