Evaluation of Clitoria, Gliricidia and Mucuna as nitrogen supplements to Napier grass basal diet in relation to the performance of lactating Jersey cows

A study was carried out at the Kenya Agricultural Research Institute Mtwapa in Coastal lowland Kenya to evaluate the effects of supplementing Napier grass variety Bana (Pennisetum purpureum) with Clitoria ternatea (Clitoria), Gliricidia sepium (Gliricidia) and Mucuna pruriens (Mucuna) on feed intake, diet digestibility and milk yield of lactating Jersey cows. Clitoria and Mucuna were compared with Gliricidia; a widely studied nitrogen supplement to roughage-based diets in dairy rations in coastal Kenya. Twelve lactating Jersey cows in their mid lactation were assigned to four groups balanced for initial milk yield and live weight in a completely randomised design. One group was fed Napier grass ad libitum and 3 kg of maize bran daily (control). The remaining three groups were fed the control diet supplemented with 8 kg of fresh Clitoria, Gliricidia or Mucuna. Mucuna had lower CP (180 g kg^{− 1}) concentration compared to Gliricidia (232 g kg^{− 1}) and Clitoria (218 g kg^{− 1}). Tannin concentration was higher in Gliricidia compared to the other legumes. They were however below the critical level of 6% hence were not expected to have any negative effect on animal performance. The total dry matter intake was not affected by legume supplementation (P > 0.05). Legume supplementation had no significant effect on organic and dry matter digestibilities (P > 0.05). Nitrogen supplementation (P < 0.05) increased daily milk yield by 20%, 27.5% and 32.5% for cows fed Gliricidia, Clitoria and Mucuna respectively. Results from this study show that Mucuna and Clitoria can give similar lactation performance to Gliricidia as nitrogen supplements Napier grass basal diet.     

Effects of replacing wheat bran by pistachio skins on feed intake,nutrient digestibility,milk yield,milk composition and blood metabolites of dairy Saanen goats

The objective of this study was to investigate the effect of pistachio skins (PiS) as a replacement of wheat bran on feed intake, nutrient digestibility, milk yield, milk composition and blood metabolites of dairy Saanen goats. Eight multiparous lactating Saanen goats (55 ± 7.2 days post‐partum, 45 ± 2 kg body weight) were randomly assigned to one of the four dietary treatments arranged in a replicated 4 × 4 Latin square design. The dietary treatments were 1) 0 g/kg PiS and 210 g/kg wheat bran in the TMR (0PiS), 2) 70 g/kg PiS and 140 g/kg wheat bran in the TMR (7PiS), 3) 140 g/kg PiS and 70 g/kg wheat bran in the TMR (14PiS) and 4) 210 g/kg PiS and 0 g/kg wheat bran in the TMR (21PiS). The trial consisted of four 21‐day periods, each composed of 14 days adaptation and 7 days data collection. Dry matter intake (p < 0.05) and crude protein digestibility (p < 0.01) increased linearly with increasing PiS proportions in the diet. Increasing the proportion of PiS in the diet caused a quadratic increase in apparent digestibility of dry matter (p < 0.05), and tended (p = 0.05) to increase quadratically organic matter, and ether extract digestibility. Replacing wheat bran with PiS in the diet had no effects on milk yield, whereas milk fat concentration increased linearly (p < 0.01) with increasing inclusion of PiS in the diet. As the dietary proportion of PiS increased, ruminal pH tended (p = 0.07) to increase linearly, whereas ammonia‐N concentration declined in the rumen. Plasma concentrations of glucose and BUN remained unaffected, whereas triglycerides (p < 0.05) and cholesterol (p < 0.01) concentrations increased linearly with increasing inclusion of PiS in the diet. It was concluded that PiS based on local ingredients can successfully replace wheat bran in diets of dairy goats without detrimental effects on feed intake, nutrient digestibility and milk production.     

杂交构树在奶山羊生产中的应用

杂交构树是一种适应性强,生长速度快,粗蛋白含量高的新型饲料资源。该文从杂交构树的营养成分入手,分析杂交构树青贮技术的方式及优势,揭示其在TMR饲喂奶山羊过程中对奶山羊的采食量、产奶量、奶品质及免疫性能的影响,并提出相应的注意事项,以期为杂交构树发酵饲料奶山羊TMR饲喂技术提供理论支撑。     

Performance and Economics of Dairy Cows Fed a Corn Silage-Based Total Mixed Ration or Grazing Annual Ryegrass During Mid to Late Lactation

Economic and performance characteristics of a low cost grazing system based on annual ryegrass vs a total mixed ration (TMR) for cows during mid through late lactation were evaluated. Cattle used in the trial (28 Holstein and 12 Jersey cows) were blocked by parity, lactation number, days in milk, projected mature equivalent milk yield, and current milk yield, and cows were assigned to two treatments in a randomized complete block design. For 10 wk (March through May 1998), cows either received a corn silage-based TMR or grazed annual ryegrass and received no supplemental concentrates. Changes in feed composition, milk yield, milk composition, BW, condition score, and income over feed costs were examined. Cows on Treatment 1 were fed the TMR twice daily and were housed together in a free-stall barn. Cows assigned to grazing were allowed ad libitum access to annual ryegrass in a rotational 12-paddock system. Loose mineral was provided for ad libitum consumption, but no supplemental concentrate was offered. Daily milk production by the TMR cows was consistent, ranging between 22.5 and 27.2 kg per cow throughout the study. By contrast, daily milk production of the grazing cows declined from 26.6 to 15.9 kg per cow as lactation progressed. Ryegrass grazing reduced milk fat content during wk 4 and 8 of the study and increased MUN content during wk 2 but had no effect on milk protein content or somatic cell count. The BW, body condition score, and estimated DMI of grazing cows were less than they were for TMR cows. Milk income for the grazing cows was less than that for the TMR cows throughout the study. However, feed cost for grazing cows was substantially lower than that for the TMR cows. Hence, income over feed cost (IOFC) was greater for grazing cows than for TMR cows in all but the last 2 wk of the study. These results indicated that annual ryegrass grazing was more profitable than feeding a TMR to cows in mid to late lactation. However, grazing cows did lose body condition, which could have a negative effect on milk production in the subsequent lactation.     

Peripartal calcium homoeostasis of multiparous dairy cows fed rumen‐protected rice bran or a lowered dietary cation/anion balance diet before calving

Milk fever is one of the most important metabolic diseases in dairy cattle. Reducing the dietary cation/anion balance (DCAD) with anionic salts is a common prevention strategy. However, many small European farms cannot use total mixed rations (TMR) in the close‐up period. Including anionic salts in compound feeds can result in feed refusals and moderate inclusions to preserve feed palatability results in insufficient DCAD reduction. Rumen‐protected rice bran induces the adaptation of Ca metabolism in dairy cows by a reduction of Ca intake and by a reduction of the availability of dietary Ca. In the presence of a negative control, rumen‐protected rice bran (2.8 kg/day) was compared with a lowered DCAD diet (from 269 to 4 meq/kg DM) in their effect to prevent milk fever. In a randomized block design, 45 multiparous Holstein cows joined the trial sequentially from 21 days before the expected calving date and were observed until the 8th week of lactation. Feed and nutrient intakes were recorded, and Ca, P, Mg in serum and urine, urine pH, serum NEFA and milk production in early lactation were compared. Feeding rumen‐protected rice bran before calving improved the recovery of calcaemia after calving and had a positive effect on DMI after calving. The moderately low DCAD diet did not positively influence serum Ca at calving. Calcaemia recovered even later than in control, and cows showed reduced DMI post‐calving and higher NEFA levels in the first 36 h after calving. This moderate reduction of DCAD did not provide an intermediate prevention level indicating that DCAD needs to be reduced to the recommended levels to prevent milk fever. Rumen‐protected rice bran may be a suitable feed to reduce hypocalcaemia post‐partum and can be included in pre‐calving compound feeds representing a palatable alternative to anionic salts.     

Effects of rice conservation methods on lactation,blood metabolites,and rumen fermentation in dairy cows

We investigated the effect of rice grain conservation methods on feed intake, milk production, blood metabolites, and rumen fermentation in dairy cows. Raw rice grain was dried before crushing (DRY), ensiled after crushing (ENS‐A), or ensiled before crushing (ENS‐B). Twelve multiparous Holstein cows were used in a replicated 3 × 3 Latin square design with three dietary treatments comprising ad libitum access to one of three total mixed rations (TMRs; containing DRY, ENS‐A, or ENS‐B at 17% of dietary dry matter) plus a standard allowance of 2.0 kg/day of dairy concentrates. The dietary treatments did not affect the feed intake, milk yield, or milk composition. The selected blood constituents were not influenced by the rice conservation method. The ruminal lactic acid and total volatile fatty acid (VFA) concentrations and the VFA proportion in the cows were not influenced by the rice conservation method. These results demonstrate that the rice grain conservation method has little impact on lactation performance when cows are fed a TMR containing 17% treated rice grain (dry matter basis).     

Dry matter intake and milk production of grazing dairy cows supplemented with corn silage or a total mixed ration offered ad libitum in a subtropical area

This study aimed to evaluate the feeding choice, dry matter (DM) intake, and milk production of dairy cows that strip grazed on a mixed perennial species pasture receiving different supplementation strategies. The treatments were without supplementation (WS) or with supplementation of either corn silage (CS) or a total mixed ration (TMR) based on CS and concentrates, in a subtropical area. The supplements were provided ad libitum after the afternoon milking. Twelve Holstein × Jersey cows in mid-lactation (133 ± 43 days in milk) were divided into six groups (two cows/group) and distributed in accordance with a replicated 3 × 3 Latin square design, with three 21 day periods (15 adaptation days and 6 evaluation days). The total DM intake, milk production, milk fat, and milk protein production were greater in the TMR treatment than in the WS and CS treatments and were similar between the WS and CS treatments. The herbage DM intake and proportion of time spent grazing were greater in the CS treatment than in the TMR treatment. CS supplementation did not affect the total DM intake or milk production/cow, whereas TMR supplementation greatly improved the total DM intake and milk production of the dairy cows grazing on mixed perennial species.     

Effect of Addition Tomato Pomace on the Antioxidant Properties of Perinatal Dairy Cows

This study was aimed to investigate the effect of feed supplemented with fermented tomato pomace on the antioxidant properties of perinatal dairy cows.Sixteen dairy cows with similar physical,prenatal period,body weight,parity and lactation yield were divided into two groups with 8 dairy cows per group.The dairy cows in control group were fed TMR regular diet and that of experimental group was fed diet supplemented with fermented tomato pomace (13% in pre-partum period and 11% in post-partum period).The preliminary trial period was 14 d and trial period lasted for 60 d (30 d before delivery to 30 d after delivery). The results showed that compared with control group,the milk yield of dairy cows of experimental group in post-partum period was significantly increased (P<0.05);In the whole trail period,the activity of GSH-Px,T-SOD and T-AOC in experimental group were increased,and that in pre-partum period were significantly increased (P<0.05),while compared with pre-partum period,that in post-partum period showed a downward trend.The MDA content of experimental group in post-partum period was significantly decreased (P<0.05),there was no significant difference between pre-partum period and post-partum period (P>0.05);Compared with control group,the contents of white blood cells,hemoglobin,urea nitrogen, low density lipoprotein and Fe of experimetal group in post-partum period were significantly increased (P<0.05),and other indexes had no significant differences (P>0.05).In conclusion,diet supplemented with fermented tomato pomace had a certain improvement effect on the antioxidant properties and milk yield of dairy cows in the perinatal period.     

Effect of wood kraft pulp feed on digestibility,ruminal characteristics,and milk production performance in lactating dairy cows

The effect of wood kraft pulp (KP) feed on dietary digestibility, ruminal fluid pH, rumen fermentation characteristics, and milk production performance in lactating dairy cows was examined. Four lactating dairy cows were used for the feeding experiment by the cross‐over design. The control group and KP group were set up as treatments. The control group was fed total mixed ration (TMR) (40% roughage and 60% concentrate) and the KP group was fed TMR containing 12% KP that replaced half of the rolled corn in the control diet. The dry matter intake, digestibility of the feed components, and milk yield were not significantly different between control group and KP group. The number of times that the ruminal fluid pH was below 6.1 tended to decrease in the KP group compared to the control group (p < 0.10). The acetic acid ratio in the ruminal fluid of the KP group increased compared to the control group (p < 0.05) and the propionic acid ratio in the ruminal fluid of the KP group decreased compared to the control group (p < 0.05). The acetate:propionate acid ratio was increased in the KP group compared with the control group (p < 0.05). Lipopolysaccharide levels in the ruminal fluid of the KP group tended to decrease compared to the control group (p < 0.10). Based on these results, it was indicated that the use of KP feed for lactating dairy cows induced the same rumen fermentation characteristics as those in cows given a large amount of roughage without depressing milk productivity. Therefore, KP could be a valuable feed resource substitute for grains, which would also reduce the risk for subacute rumen acidosis.     

全混合日粮（TMR）技术在规模化奶牛场的应用效果调查

为了研究全混合日粮技术在奶牛生产中的应用效果。从2006年开始,我们在永济市超人奶业公司引进韩国TMR设备,对800头奶牛按照个体产奶量高低进行分群,利用计算机管理系统配制了不同的日粮配方,开始实施全混合日粮技术,并对实施前后的效果进行综合分析。TMR技术实施后,节约劳动力40人;降低饲料成本4%~5%;减少了疾病投入,年节约医疗费用5万元;提高了奶牛的产奶量和奶品质量,年增加产奶量30万公斤以上,乳脂率和乳蛋白分别达到4.2%和3.3%。     

Phosphorus Intake and Excretion on South Carolina Dairy Farms

The objective of this study was to survey dairy farmers to determine P levels in feed and manure. Feed and manure samples were collected from 19 Holstein, six Jersey, and two Guernsey farms in South Carolina. Samples from the Jersey and Guernsey herds were pooled. Samples were dried and analyzed for N and P. Amounts of all feeds were recorded; then, nutrient intake was determined. Dairy Herd Improvement records were used to determine the milk yield and fat content and, subsequently, the P requirement. Nineteen of 27 herds (70%) were fed more P than required according to nutrient requirements established by the NRC. The average P intake was 94.9 g (0.48% of diet DM) compared with the average requirement of 78.3 g (0.41% of diet DM). There were correlations between dietary and fecal P (R² = 0.46) and between CP and P intake (R² = 0.62). There was not a significant correlation between excess P intake and milk yield. In summary, many dairy producers overfeed P. Feeding dietary P at recommended levels will optimize milk yield and reduce P excretion on dairy farms.     

发芽玉米对荷斯坦奶牛瘤胃发酵、产奶性能及乳品质的影响

试验旨在研究发芽玉米对荷斯坦奶牛瘤胃发酵、血液成分、产奶性能及乳品质的影响。选取胎次、分娩日龄、产奶量相近的荷斯坦泌乳奶牛15头,试验分为3组,每组5头。对照组饲喂基础日粮(TMR和苜蓿干草),T1、T2组分别在基础日粮中添加20%发芽玉米和20%发酵发芽玉米。结果表明,添加发芽玉米及发酵发芽玉米均能降低瘤胃pH的变化幅度,提高挥发性脂肪酸和氨态氮浓度,但差异均不显著(P＞0.05);与对照组相比,T1、T2组4%乳脂校正乳极显著提高(P＜0.01),并可显著提高T2组的饲料效率(P＜0.05),显著降低乳中体细胞数(P＜0.05);T1、T2组具有降低乳中胆固醇含量的趋势,并对血液成分无显著影响。因此,饲料中添加发芽玉米可改善瘤胃内环境,显著提高产奶量与饲料效率,显著降低乳中体细胞数,且乳中胆固醇含量有降低的趋势。     

Diet change from a system combining total mixed ration and pasture to confinement system (total mixed ration) on milk production and composition,blood biochemistry and behavior of dairy cows

This study aimed to determine if a diet change from a mixed system to a confinement system affects the milk production and composition, behavior and blood biochemistry of dairy cows. Cows were assigned randomly to one of the two treatments: cows fed with TMR (total‐mixed‐ration) (confined) throughout the period group fed TMR (GTMR, n = 15) and cows that changed their diet from pasture plus TMR to exclusive TMR at 70 ± 14 DIM (GCHD, n = 15). GTMR cows produced more milk and greater lactose and protein yield before the change of diet than GCHD cows (p ≤ .01), but these differences disappeared after the change. GCHD cows decreased the frequency of rumination and lying from before to after the change (p ≤ .03), but in GTMR cows no changes were observed. After diet change, GCHD cows had lower frequency of rumination and lying than GTMR cows (p ≤ .02). Before the change, GCHD cows had greater NEFA (non esterified fatty acids) concentrations than GTMR cows (p = .002). Abrupt change from a mixed system to a confined system was favorable on blood biochemical and milk variables of dairy cows. However, in relation to behavior, the cows expressed difficulties to adapt quickly to the abrupt change of system.     

日粮中添加番茄渣对围产期奶牛抗氧化性能的影响

试验旨在研究日粮中添加番茄渣发酵饲料对围产期奶牛抗氧化性能的影响。选择体质均匀,预产期、体重、胎次和泌乳量相近的围产期奶牛16头,随机分为2组,每组8头,对照组饲喂常规全混合日粮（TMR）,试验组在日粮中添加番茄渣发酵饲料（围产前期13%,围产后期11%）。预试期14 d,正试期 60 d（产前30 d至产后30 d）。结果显示,与对照组相比,围产后期试验组奶牛产奶量显著提高（P<0.05）;整个试验阶段,试验组奶牛血清GSH-Px、T-SOD和T-AOC活力均高于对照组,其中,围产前期试验组GSH-Px、T-SOD和T-AOC活力显著提高（P<0.05）,与围产前期相比,围产后期GSH-Px、T-SOD和T-AOC活力等抗氧化指标均呈下降趋势,围产后期试验组奶牛MDA含量较对照组显著降低（P<0.05）,但围产前期和围产后期间无显著差异（P>0.05）;与对照组相比,围产后期试验组红细胞、血红蛋白浓度、尿素氮、低密度胆固醇、铁含量均显著提高（P<0.05）;其他指标两组间差异均不显著（P>0.05）。综上所述,日粮中添加番茄渣发酵饲料对围产期奶牛机体的抗氧化性能和产奶量有一定提高作用。     

Effects of using thermally treated lupins instead of soybean meal and rapeseed meal in total mixed rations on in vitro microbial yield and performance of dairy cows

The objective was to study whether thermally treated lupins (TTL) can replace solvent-extracted soybean meal (SBM) and rapeseed meal (RSM) in dairy cow rations. Three total mixed rations (TMR) were used. They differed in the inclusion of the main protein feeds (TTL alone, TTL + RSM and RSM + SBM) but were equal in organic matter digestibility and metabolizable energy content. In vitro organic matter fermentation was not significantly different between the TMR. Efficiency of microbial crude protein (MCP) synthesis was significantly higher for TMR RSM + SBM than for TTL. In vitro gas production potential was similar for the three TMR. The maximal rate of gas production was achieved later in TMR TTL than in RSM + SBM. Feed intake of dairy cows was significantly lower when TMR TTL was fed than when TMR TTL + RSM or RSM + SBM were fed. Milk yield was significantly lower with the high inclusion rate of TTL in comparison with the other TMR. The contents of milk protein and milk fat were significantly lower when the two TTL containing TMR were fed in comparison with the RSM + SBM ration. Effects of TTL inclusion on MCP synthesis may affect the amino acid supply to the duodenum of cows to a greater extent than differences in the degradability of feed proteins.     

Sainfoin (Onobrychis viciifolia) silage in dairy cow rations reduces ruminal biohydrogenation and increases transfer efficiencies of unsaturated fatty acids from feed to milk

The effects of replacing grass silage by sainfoin silage in a total mixed ration (TMR) based diet on fatty acid (FA) reticular inflow and milk FA profile of dairy cows was investigated. The experiment followed a crossover design with 2 dietary treatments. The control diet consisted of grass silage, corn silage, concentrate and linseed. In the sainfoin diet, half of the grass silage was replaced by a sainfoin silage. Six rumen cannulated lactating multiparous dairy cows with a metabolic body weight of 132.5 ± 3.6 kg BW^0.75, 214 ± 72 d in milk and an average milk production of 23.1 ± 2.8 kg/d were used in the experiment. Cows were paired based on parity and milk production. Within pairs, cows were randomly assigned to either the control diet or the sainfoin diet for 2 experimental periods (29 d per period). In each period, the first 21 d, cows were housed individually in tie-stalls for adaptation, then next 4 d cows were housed individually in climate-controlled respiration chambers to measure CH₄. During the last 4 d, cows were housed individually in tie stalls to measure milk FA profile and determine FA reticular inflow using the reticular sampling technique with Cr-ethylenediaminetetraacetic acid disodium salt dihydrate (EDTA) and Yb-acetate used as digesta flow markers. Although the dietary C18:3n-3 intake was lower (P = 0.025) in the sainfoin diet group, the mono-unsaturated FA reticular inflow was greater (P = 0.042) in cows fed the sainfoin diet. The reticular inflow of trans-9, trans-12-C18:2 and cis-12, trans-10 C18:2 was greater (P ≤ 0.024) in the sainfoin diet group. The cows fed sainfoin diet had a lower (P ≤ 0.038) apparent ruminal biohydrogenation of cis-9-C18:1 and C18:3n-3, compared to the cows fed the control diet. The sainfoin diet group had greater (P ≤ 0.018) C18:3n-3 and cis-9, cis-12-C18:2 proportions in the milk FA profile compared to the control diet group. Transfer efficiencies from feed to milk of C18:2, C18:3n-3 and unsaturated FA were greater (P ≤ 0.0179) for the sainfoin diet. Based on the results, it could be concluded that replacing grass silage by sainfoin silage in dairy cow rations reduces ruminal C18:3n-3 biohydrogenation and improves milk FA profile.     

Maize silage particle length modulates feeding patterns and milk composition in loose-housed lactating Holstein cows

This study analysed feeding patterns and feed selective consumption by loose-housed lactating dairy cows fed diets based on maize silage (MS) with different particle length (PL) to establish its effects on overall dry matter intake (DMI) and productive performance. Twelve multiparous Holstein cows were offered a total mixed ration (TMR) with three different PL of MS at harvesting (i.e., long, medium, and short). Results demonstrated greater numbers of day-time meals (i.e., 07:30–19:00 h) when PL was decreased from long to medium (P < 0.05). Night-time (i.e., 19:00–06:30 h) changes in the feeding pattern included an increased amount of feed per meal (P < 0.05) and a tendency to increase eating time per meal (P < 0.10) in cows fed the short-PL diet. Lowering the PL of MS also lowered the selective consumption against physically effective fibre larger than 1.18 mm (peNDF_> 1.18; P < 0.05) and in favour of fine particles (i.e., particles passing through 1.18 mm screen; P < 0.01). Decreasing PL of MS from long to medium and short increased daily DMI as well as the intake of energy and other nutrients contained in the diet including the amount of peNDF_> 1.18 (P < 0.01). The decrease in the PL of the diet also was associated with increased milk protein and lactose yield and milk urea nitrogen (P < 0.05). The actual milk yield and fat-corrected milk were not affected by the diet (P > 0.10). Although lowering of the PL tended to increase daily milk energy output (P < 0.10), the ratio between energy milk output and the energy intake was linearly decreased (P < 0.01), indicating a lower milk efficiency for the lower-PL diets. In conclusion, particle length of MS in a TMR has the potential to modulate circadian feeding patterns, selective consumption of the feed, daily DMI, and milk composition in high-producing dairy cows.     

叶面喷施微肥对牧草、奶牛微量元素代谢的影响

试验采用含硒、锌、铜、锰等元素的微肥对牧草进行叶面施肥，研究通过这种施肥途径对牧草品质的影响。同时采用此种牧草饲喂奶牛，研究这种牧草对奶牛血液中相应元素含量及奶牛生产水平的影响。结果表明，牧草中硒、锌、铜、锰的含量有显著的提高；奶牛采食这种牧草90d后，血液中硒、锌、铜的含量显著提高，生活水平有所增长。     

Production and economic performance of F1-crossbred dairy cattle fed non-conventional protein supplements in Zimbabwe

The effects of supplementing crossbred cows with non-conventional protein sources on dry matter intake, milk yield parameters and economic returns were investigated. Twenty-five lactating F₁ Holstein-Mashona crossbreds averaging 115?±?24 days in milk were used. Five treatments, total mixed ration (TMR), urea-treated maize stover, untreated maize stover, Macroptilium atropurpureum (Siratro) hay and veld hay, were randomly assigned to cows and replicated five times in a completely randomised design. Nutrient composition, intake, milk yield and economic returns were determined. M. atropurpureum hay, urea-treated maize stover and TMR had equal crude protein content. Daily dry matter intake and yield differed significantly among the treatment diets (P?<?0.05). Cows on TMR, urea-treated maize stover and M. atropurpureum consumed more (P?<?0.05) than cows on untreated maize stover and veld hay. Supplementing with TMR, urea-treated maize stover and M. atropurpureum hay increased (P?<?0.05) milk yields. Mean daily milk yield was highest for cows supplemented with urea-treated maize stover. Percent fat, protein and total solids in milk from cows fed urea-treated stover compared favourably to that of milk for cows supplemented with TMR. Income over supplement cost was highest for cows supplemented with M. atropurpureum hay and urea-treated maize stover. Urea-treated maize stover and M. atropurpureum can therefore be used as a replacer protein supplements for dairy cattle in Zimbabwe.     

中草药添加剂对热应激奶牛生产性能及生理指标的影响

将年龄、胎次、生产性能相近的8头娟姗奶牛随机均分为对照组和试验组,试验组牛在TMR饲料中添加抗热应激中草药添加剂,对照组牛不添加。分别测定两组奶牛的采食量、产奶量、呼吸、直肠温度等指标。研究表明:抗热应激中草药添加剂能够提高奶牛采食量10.77%,提高产奶量8.96%,而呼吸频率、直肠体温均出现下降。