Effect of mixed maize-legume silages on milk quality and quantity from lactating smallholder dairy cows

The study investigated the effect of the following maize:legume (70:30) mixed crop silages: maize:cowpea, maize:velvet bean, and maize:lablab on milk production during the 2016 dry season. Using a 5?×?5 double Latin square design, five Holstein-Friesian crossbred cows in early lactation (30?±?15 days) and five Jersey crossbred cows in early lactation (25?±?10 days) were given the supplementary mixed crop silage diets at 0.5 kg/l of milk produced over 105 days. Commercial dairy meal and sole maize silage were used as positive and negative controls, respectively. Milk yield was significantly higher (P?< 0.05) in cows given the dairy meal compared to mixed crop silages; however, milk yield was also significantly higher (P?< 0.05) for cows given the three mixed crop silages compared to cows given sole maize silage. Cows given mixed crop silages produced milk of significantly higher protein content (P?< 0.05) than those given sole maize silage. There was no significant difference (P?> 0.05) in butterfat content of milk across all the dietary treatments. The dietary cost of producing 1 l of milk was highest at 0.31USD/l for cows given commercial dairy meal and lowest for cows given maize:velvet bean and maize:cowpea silage at 0.19USD/kg. The highest dietary gross margins of 68% were observed when cows were given maize:velvet mixed silage compared to commercial dairy meal (47%) and sole maize silage (57%). The 70:30 maize:legume mixed crop silages showed the capability to increase milk quantity and quality at very low production costs in smallholder dairy schemes.     

Characterization of smallholder pig production system: productive and reproductive performances of local and crossbred pigs in Sikkim Himalayan region

The present study was conducted to know the smallholder pig production system in tribal areas of Sikkim State, India. Two hundred tribal farmers were selected randomly from the North and East District of the state. Information on socio-economic characteristics of farmers (gender, occupation, educational status, and farming experience), management practices, disease prevalence, and economics in pig production was collected. The study recorded the mean land holding as 1.2?±?0.8 ha, and the number of pigs per farm was 5.0?±?0.28. Pigs were mainly kept as a source of income, and 70 % of farmers reared crossbreed pigs. Ninety percent (90 %) of respondents practiced the intensive system of management whereby kitchen wastes along with cooked mixture comprising maize bhusa, mustard oil cake, pseudostem of banana, tuber, stem, and plant leaves were used to feed their animals. About 40.5 % of farmers procured their breeding stock from government farms that had good records and utilized veterinary services like timely vaccination and deworming. The diseases prevalent in the study area were swine fever, diarrhea, helminthoses, sarcoptic mange, pneumonia, etc. The litter sizes at birth (local, 4.3?±?0.45; crossbreed, 7.2?±?0.33), at weaning (local, 2.79?±?0.24; crossbreed, 6.1?±?0.21), and age at first farrowing (local, 365.39?±?7.96 days; crossbreed, 337.24?±?8.79 days) were recorded. Production costs of meat extracted from local and crossbred pigs were 1.08 $/kg and 0.86 $/kg, respectively.     

Seasonal and sex differences in area preference and behavior of young cattle just after long distance transport

To determine seasonal and sex differences in behavioral motivation of cattle just after long transport, 54 Japanese Black × Holstein cattle were observed at 5 min intervals for 2 h just after 25‐h transport by road and ferry. The stocking pen (12.0 × 9.5 m) consisted of an eating area (near a feeding alley), a drinking area (near water bowls) and a resting area (all areas except for other two areas). First, the effect of season was determined with heifers in summer (n = 12: 7.9 ± 0.6 months of age; 292.0 ± 18.5 kg) and autumn (n = 19: 8.2 ± 0.6 months of age; 295.8 ± 15.5 kg). The mean temperature on the observation day was 28.5 (max: 34.5, min: 24.5)°C in summer and 20.3 (max: 26.5, min: 16.4)°C in autumn. Percentage of cattle staying in each area was different by season (χ² = 22.0; P < 0.01). In summer, the percentage of cattle staying in the drinking area (26.7%) was greater than the expected percentage (16.7%). Percentage of cattle staying in the eating area was greater in both seasons (31.3% in summer and 53.6% in autumn) than the expected percentage (16.7%). However, the mean percentage of cattle performing each behavior was not significantly different by season. Secondly, the effect of sex was determined with steers (n = 23: 7.6 ± 0.6 months of age; 301.9 ± 20.7 kg) and heifers (n = 19: same as above) in autumn. Although the percentage of cattle staying in each area was different by sex (χ² = 20.2; P < 0.01), the percentages of steers (25.5%) and heifers (53.6%) staying in the eating area were both greater than the expected percentage (16.7%). However, percentage of animals performing each behavior was not different by sex. These results recommend to stockpersons that they should install additional troughs for hay and water into a pen just after long distance transport, since the number of cattle that can eat and drink at the same time was limited.     

Feed intake and production parameters of lactating crossbred cows fed maize-based diets of stover,silage or quality protein silage

Thirty-six Boran × Friesian dairy cows (392 ± 12 kg; mean ± SD) in early parity were used in a randomised complete block design. Cows were blocked by parity into three blocks of 12 animals and offered normal maize (NM) stover (T1), NM silage (T2) or quality protein maize (QPM) silage (T3) basal diets supplemented with a similar concentrate mix. Feed intake, body weight and condition changes and milk yield and composition were assessed. The daily intake of DM, OM, NDF and ADF for cows fed the NM stover-based diet was higher (P < 0.05) than for the cows fed the NM silage and QPM silage-based diets. However, the daily intake of DOM (9.3 kg) and ME (140.8 MJ) for cows on QPM silage-based diet was higher (P < 0.05) than for cows on NM stover-based diet (8.4 kg and 124.2 MJ) and NM silage-based diet (7.9 kg and 119.1 MJ). Body weight of cows was affected (P < 0.05) by the diet, but diet had no effect (P > 0.05) on body condition score, milk yield and milk composition. The digestible organic matter in the NM stover-based diet (724 g/kg DM) was lower (P < 0.05) than that in the NM (770 g/kg DM) and QPM silage-based diet (762 g/kg DM). It was concluded that the performances of the cows on the NM silage and QPM silage diets were similar and were not superior to that of the NM stover-based diet.     

Forage seed production and trade as a pathway out of poverty in the smallholder sector: lessons from the Zimbabwe Crop Livestock Integration for Food Security (ZimCLIFS) project

The major challenge to adoption of improved forage technologies in the smallholder farming sector is poor accessibility to seed of improved cultivars. Since 2012, the Zimbabwe Crop Livestock Integration for Improved Food Security (ZimCLIFS) project set out to address such challenges through research-for-development initiatives. The main objective was to demonstrate the potential viability of a pasture seed business using a lead farmer approach, farmer-to-farmer technology dissemination, innovation platforms and field demonstrations. Snapshot surveys were used to map forage seed distribution pathways within and outside project areas. Total land area planted to forages from the 2012/13 to 2014/15 seasons increased by 147% from 14.6 ha. In 2013, Mucuna pruriens (mucuna), Lablab purpureus (lablab) and Vigna unguiculata (cowpea) seed produced was 2 250 kg, 120 kg and 4 450 kg, respectively, and by the third season, total yield increased by 163%. Seed diffusion was within and beyond project boundaries, with mucuna (67%) and lablab (43%) seed produced in the 2013/14 season being distributed outside the project area. Highest amounts received by some farmers were US$800 and US$750 for lablab and mucuna, respectively. It was concluded that there is scope to develop formal pasture seed businesses to increase rural industrialisation and provide a pathway out of poverty in the smallholder sector.     

Effect of using banana by-products and other agricultural residues for beef cattle in southern China

Banana (Musa acuminata) by-products and other agricultural residues such as rice straw and sugarcane top are abundant in the southern part of China, but most of them are wasted and discarded. Under this experiment, several silages containing banana by-products with other crop residues were investigated for their fermentation characteristics and feeding values to beef cattle. There were three treatments (T) as follows: T₁ = fresh banana by-products (FBBP) + 4% corn meal (CM), T₂ = FBBP + rice straw (RS) at 70:30 (fresh weight), T₃ = FBBP + sugarcane top (SCT) at 70:30 (fresh weight). Twenty-one beef cattle bulls (220?±?15 kg body weight) were randomly assigned to 3 groups and assigned to one of three silage treatments in a total feeding period of 237 days. Results revealed that all of the three silage mixtures had a good fermentative profile with lower pH and higher organic acids. The FBBP + CM group significantly increased DM, CP, EE, and Ca content (P?< 0.05), while decreased ash, NDF, ADF, ADL, and condensed tannins (CT) content (P?<?0.01). Significant effects on weight gain, feed intake, and feed efficiency were observed at the end of the experiment (P?<?0.05). The FBBP + CM group also had the greatest total weight gain at 109 kg/head, twice of the FBBP + RS group (P?=?0.001), as well as the greatest average daily weight gain at 0.48 kg/head/day, followed by the FBBP + SCT group at 0.30 kg/head/day and the FBBP + RS group at 0.27 kg/head/day, respectively. Cattle fed FBBP + CM silage mixture diet had better feed efficiency than the cattle fed with the other mixtures (P?<?0.001). Results of body measurements showed that cattle consumed FBBP + CM silage mixture tended to have a greater body diagonal length, height at the hip, hip width, and rump length than those either consumed FBBP + RS or FBBP + SCT (P?<?0.05). The findings showed promising results of banana by-products silage with other agricultural crop residues to be used for increasing beef cattle production in southern China.

     

Smallholder cattle farmers’ breeding practices and trait preferences in a tropical Guinea savanna agro-ecological zone

The present study was embarked upon to determine the breeding practices and choice of selection and breeding traits of cattle farmers in Nasarawa State and the Federal Capital Territory (FCT), Abuja, Nigeria. A total of 180 smallholder cattle herders were randomly sampled. However, analysis of data was restricted to 144 herders (81 from FCT and 63 from Nasarawa State). Primary data were collected through individual structured questionnaire administration. Chi-square (χ2) statistics were used to compare categorical variables. Arithmetic means of continuous variables between locations were tested using T test. Rank means were also calculated for within- and between-location comparisons of the preference traits. Chi-square automatic interaction detection (CHAID) algorithm was used to determine the influence of socio-economic parameters on the traits of preference. Access to credit, personal savings, and type of landholding were significantly (P?<?0.05) different between the two locations with higher values recorded for farmers in FCT. However, farmers in Nasarawa State had significantly higher land expanse (2.28?±?0.19 versus 1.29?±?0.09). The production objectives were rated similar between locations. The number of foundation stock differed significantly between farmers in the two locations with higher mean recorded in Nasarawa (7.37?±?0.37) compared to FCT (5.18?±?0.19). However, mean herd size was higher (34.60?±?2.58 versus 27.63?±?2.00; P?<?0.05) in FCT than Nasarawa. Among the productivity indices, only average age at first parturition and average calving interval were significantly (P?<?0.05) influenced by location. Within the FCT, calving interval was the trait of utmost importance in selecting the breeding stock, followed by milk yield, disease resistance, and body size. In Nasarawa State, calving interval, disease resistance, milk yield, body size, and survival were ranked similarly (P??>0.05). Across the two locations, body conformation (P?<?0.05) and calving interval (P?<?0.01) were more highly rated in FCT than Nasarawa State, while heat tolerance was less rated (P?<?0.05) in the former. All the traits of preference were influenced by socio-economic factors, and could be exploited in future breeding plans to boost cattle production. A new livestock census in the study area is also advocated to reflect the current reality as regards cattle distribution.

     

Market potential for guinea fowl (<Emphasis Type="Italic">Numidia meleagris</Emphasis>) products

The survey evaluated the market potential for guinea fowl (GF; Numidia meleagris) products in the city of Harare, Zimbabwe. Questionnaires were administered to traders/producers (n = 17), retailers (n = 12), cafeteria industry (n = 33) and consumers (n = 1,680) to establish their perceptions on guinea fowl products. The average household size was 6 ± 2. Each trader sold 10 ± 6.30 keets (mean ± standard error), 33 ± 15.05 growers, 20 ± 12.69 breeders and 20 ± 10.1 crates of 30 eggs per month. Each household consumed 2.5 ± 1.39 kg of GF meat and 3 ± 0.65 dozens of GF eggs per month. Retailers purchased 52 ± 44.42 crates of GF eggs and 41 ± 30.50/kg of GF meat whilst cafeteria purchased 33.6 ± 14 crates of GF eggs and 65.5 ± 33.52 kg of GF meat per month. Growers for breeding were the major product for sale by traders (94.1%) at a price of US$7.50 ± 1.74/bird. Different industries were offering different prices for guinea fowl products because of their scarcity on the market. The mean purchase price per crate of 30 guinea fowl eggs sold to the retail and cafeteria were US$7.50 ± 1.74/bird. Different industries were offering different prices for guinea fowl products because of their scarcity on the market. The mean purchase price per crate of 30 guinea fowl eggs sold to the retail and cafeteria were US3.00 ± 0.58 and US$4.50 ± 0.50, respectively. The mean purchase prices for GF meat was lower (P < 0.05) for retailers (US$4.50 ± 0.50, respectively. The mean purchase prices for GF meat was lower (P < 0.05) for retailers (US2.5 ± 0.81/kg) than cafeteria (US$3.67 ± 0.83/kg). The challenges faced by producers in the marketing of guinea fowl products included poor supply due to the absence of good road networks to connect source areas and the market, perishability of dressed chickens due to power cuts and poor publicity. Overall, the study showed that there is greater market potential for guinea fowl products and farmers can channel their products through traders, cafeteria and retail industries.     

Forage seed value chain analysis in a subhumid region of Zimbabwe: perspectives of smallholder producers

In smallholder systems, farmers are increasingly becoming aware of the need to improve livestock productivity through production of quality fodder. This is in response to scarcity of feed, particularly in the dry season, associated with seasonal variations, land degradation and the need to meet increases in demand for livestock products. The study investigated forage seed production, marketing, challenges faced and opportunities along the value chain in Zimbabwe. Data were collected from 414 smallholder farmer households through a survey, four focus group discussions and 12 key informants. Results show that forage seed is mainly sourced from development organisations. Actors include farmer producers, seed companies, research and extension institutions, and NGOs. Seed is disseminated through sales to other farmers and organisations, sharing, seed exchanges and payment for services. Challenges include unavailability of seed, under-developed markets, weak or non-existent linkages between seed suppliers and farmers, limited knowledge on seed production and marketing, and low market prices. Forage seed have comparatively higher gross margins (US$611.61 for mucuna and US$644.14 for cowpea) compared with conventional seed such as maize (?US$382.70). Opportunities arise from the growing demand for animal products, which is associated with expanding populations and the need for improved nutrition.     

Physical and nutritional properties of buffalo meat finished on hay or maize silage‐based diets

The current study examines the effect of different finishing diets (hay‐ vs. maize‐silage on meal ration) on carcass quality, physical, chemical and sensory properties, and fatty acid profiles of buffalo meat. Twenty male Italian Mediterranean buffaloes (246 ± 9.00 kg live weight) were distributed at random into two groups at the beginning of the finishing period (368 ± 20 days). The buffaloes were offered two finishing diets: a maize silage (MS) or an alfalfa hay (AH) diet. No significant differences were found between dietary treatments for live and carcass weight. Meat chemical composition was influenced by dietary treatment. A higher fat content was detected in meat from animals finished with MS than AH (P < 0.05). Overall, the data indicated differences between the fatty acid profiles of meat as a consequence of different feeding systems. The higher fat deposition in the MS group resulted in meat with a less favorable fatty acid profile (i.e. a lower polyunsaturated/saturated fatty acid ratio and α‐linolenic fatty acid content) in relation to human health compared with meat from animals fed the AH diet.     

Oat silage for grazing dairy cows in small-scale dairy systems in the highlands of central Mexico

The objective was to evaluate the provision of oat silage (Avena sativa) to supplement grazing dairy cows on pastures of perennial ryegrass (Lolium perenne), festulolium (Lolium multiflorum × Festuca pratense) and white clover (Trifolium repens) during the dry season when pasture growth is limited. The experimental design was a 3 × 3 Latin square replicated three times, with nine milking Holstein cows (mean live weight 496.2 ± 33.6 kg and daily milk yield 14.8 ± 2.8 kg cow^?1) under on-farm participatory rural research. Experimental periods were 14 d. Simulated grazing samples of pasture herbage were analysed for chemical composition, sward height recorded and net herbage accumulation determined from exclusion cages. Treatments were the inclusion of oat silage at T0 = 0 kg DM cow^?1 d^?1 of oat silage, T3 = 3 kg DM cow^?1 d^?1 of oat silage, and T6 = 6 kg DM cow^?1 d^?1 of oat silage, plus 5.0 kg fresh weight commercial concentrate and 9 h of continuous grazing. Animal variables were milk yield and composition, live weight and body condition score. Feeding costs were calculated. Mean milk yield was 18.9 ± 0.27 kg cow^?1 d^?1 with no differences in animal variables (p > 0.05), but feeding costs per kilogram milk increased 25% for T3 and 50% for T6. Oat silage supplementation is only viable under difficult grazing conditions.     

Strategic supplementation of cassava top silage to enhance rumen fermentation and milk production in lactating dairy cows in the tropics

High-quality protein roughage is an important feed for productive ruminants. This study examined the effects of strategic feeding of lactating cows with cassava (Manihot esculenta) top silage (CTS) on rumen fermentation, feed intake, milk yield, and quality. Four early lactating crossbred dairy cows (75% Holstein-Friesian and 25% Thai) with body weight (BW) 410?±?30 kg and milk yield 12?±?2 kg/day were randomly allotted in a 4?×?4 Latin square design to four different supplementation levels of CTS namely, 0, 0.75, 1.50, and 2.25 kg/day of dry matter (DM). Strategic supplementation of CTS significantly affected ruminal fermentation end-products, especially increased propionate production, decreased protozoal population and suppressed methane production (P?<?0.05). Increasing the CTS supplementation level substantially enhanced milk yield and the 3.5% FCM from 12.7 to 14.0 kg/day and from 14.6 to 17.2 kg/day (P?<?0.05) for non-supplemented group and for the 2.25 kg/day supplemented group, respectively. We conclude that high-quality protein roughage significantly enhances rumen fermentation end-products, milk yield, and quality in dairy cows.     

基于宏基因组学技术检测全株玉米青贮期间和暴露空气后的微生物多样性

本试验旨在分析全株玉米青贮发酵期间和暴露空气后的发酵品质及微生物多样性,监测其微生物群落组成动态变化。试验分别在3个发酵时期取样,即青贮第5天(F5组)、青贮第40天(F40组)和青贮40 d开袋暴露空气后第3天(A3组),每次取3袋作为3个重复。采用宏基因组学技术,测定全株玉米青贮发酵期间和暴露空气后微生物的16S r DNA V3~V4区序列,比较3个发酵时期样品微生物群落的组成和丰度信息,通过Alpha多样性和主成分分析,考察和比较全株玉米青贮发酵期间和暴露空气后的微生物多样性。结果表明:全株玉米经过40 d的青贮发酵,可使p H及中性洗涤纤维(NDF)和酸性洗涤纤维(ADF)含量显著下降(P0.05),乳酸含量显著升高(P0.05),具有良好的发酵品质和营养价值,且发酵40 d后短时间开袋暴露空气对其发酵品质和营养价值无显著影响(P0.05)。3组样本通过Illumina Miseq测序平台共获得122 371条高质量有效序列,聚类为239个操作分类单元,经分类学鉴定分属16个门,163个属。在门水平上,厚壁菌门(Firmicutes)始终占优势地位,其丰度在F5、F40和A3组中分别为57.57%、74.65%、78.82%,呈增长趋势。发酵前期(F5组)、发酵后期(F40组)和开袋期(A3组)优势菌属均为乳杆菌属(Lactobacillus),其丰度分别为49.78%、64.46%和45.34%,但在开袋期芽孢乳杆菌属(Sporolactobacillus)的比例上升明显,至28.46%。综上,全株玉米青贮自然发酵升高了产乳酸乳杆菌属的丰度,有利于提高全株玉米青贮的发酵品质,但开袋暴露空气3 d对全株玉米青贮的微生物多样性产生了影响,而通过Miseq高通量测序技术,能够全面了解全株玉米青贮期间和暴露空气后微生物群落组成及丰度上的变化。     

Use of post‐harvest common bean (Phaseolus vulgaris L.) residues in diet of lambs and its effect on finishing performance,rumen fermentation,protozoa population and meat characteristics

The aim of the experiment was to investigate the replacement value of common bean residues in the diet of finishing lambs as an inexpensive fodder instead of wheat straw or maize silage. Forty Arabi male lambs with average body weight of 18.90 ± 0.6 kg were randomly divided into five treatments with eight replications. The five experimental treatments consisted of control diet, and 50% and 100% replacement of bean residues with wheat straw or 25% and 50% replacement with maize silage in the control diet respectively. Lambs were slaughtered at the end of the experiment to evaluate carcass traits and meat characteristics. Dry matter intake, blood glucose, urea nitrogen, cholesterol and triglyceride concentration were not affected by the experimental treatments. Apparent digestibility of nutrients; total concentration of volatile fatty acids, acetate and butyrate; and total rumen protozoa population were linearly increased by increasing the levels of bean residues, as replacement with wheat straw (p < .05). Replacement of bean residues in control diets instead of wheat straw or maize silage caused a positive linear incremental trend for average daily gain and total weight gain. There was no significant difference in daily gain, final weight and feed conversion ratio among the treatments. Instead of wheat straw or maize silage, replacement bean residues linearly increased chewing, ruminating and eating activities per neutral detergent fibre intake (p < .05). Carcass traits and physicochemical characteristics of meat were not affected by the treatments. It is advisable to use bean residues in the diet of lambs as an alternative to the wheat straw or maize silage, because no adverse effects were observed on rumen fermentation, blood metabolites and performance; moreover, improvement in average daily gain, total weight gain and digestibility of nutrients, and the fact that bean residue is less expensive than wheat straw and maize silage.     

The effects of protein sources supplemented with urea-treated potato pulp (PP) silage and feeding levels of the PP silage-based concentrate on feed intake, digestibility and ruminal fermentation in beef steers

Six Japanese Black (Wagyu) steers (average initial weight 467 ± 45 kg) fitted with a ruminal cannula were used in a split‐plot design experiment comprising a 3 × 3 Latin square design (whole‐plot) and a randomized block design (subplot). The whole‐plot treatments were three different feeding levels of urea‐treated potato pulp (PP) silage‐based concentrate: 1.00%, 1.75% and 2.50% of body weight (BW) (on a dry matter (DM) basis). The subplot treatments consisted of the concentrate formulated to contain either soybean meal (SBM) as a rapidly rumen‐degraded protein source or corn gluten meal (CGM) as a slowly degraded protein source. Dry matter intake tended to be lower (P = 0.071) for CGM (8.9 kg/day) than for SBM (9.4 kg/day). Protein sources had no significant effect on digestibility and in situ degradation. Ruminal ammonia nitrogen (NH₃‐N) was lower (P = 0.033) for CGM (7.5 mg/dL) than for SBM (9.5 mg/dL). Protein sources did not affect ruminal pH and the total volatile fatty acids (VFA) concentrations. The molar proportions of ruminal acetate and valerate were higher (P = 0.032) for CGM than for SBM. The maximum daily intake of the PP silage‐based concentrate expressed as a percentage of BW was approximately 1.4% of BW. Dry matter intake was higher (P = 0.046) for steers fed at 1.0% of BW of the PP silage‐based concentrate than for steers fed at 1.75% or 2.5% of BW of the concentrate. The feeding levels of the PP silage‐based concentrate had no effect on DM and nutrients digestibility, except for crude protein (CP) digestibility. CP digestibility tended to be lower (P = 0.071) for steers fed at 1.75% of BW of the PP silage‐based concentrate than for steers fed at 1.0% or 2.5% of BW of the concentrate. The feeding levels of the PP silage‐based concentrate also did not affect the in situ degradation parameter of hay and PP silage. The feeding levels of the PP silage‐based concentrate did not affect ruminal pH, NH₃‐N and total VFA concentrations. The molar proportion of acetate was highest for steers fed at 1.0% of BW of the concentrate. In conclusion, in the urea‐treated PP silage‐based concentrate, CGM seems to be more effective than SBM for stabilizing the ruminal NH₃‐N concentration and to be advantageous for fiber digestion in the rumen. The feeding levels of the PP silage‐based concentrate did not change the amount of VFA production in the rumen and the DM digestibility.     

乳酸菌和纤维素酶对不同含水量紫花苜蓿青贮品质的影响

本试验旨在探讨含水量和添加剂对紫花苜蓿青贮品质的影响,以期解决苜蓿青贮困难的问题,提高其青贮品质。采用双因素(含水量×添加剂)完全随机设计,含水量分别为70%和60%;添加剂分4个组,对照组不含添加剂,其余各组均含3个水平,分别为乳酸菌组(LA组,3、6、9 mg/kg)、纤维素酶组(CE组,25、50、100 mg/kg)以及乳酸菌和纤维素酶混合组(LA×CE组,3×25、6×50、9×100 mg/kg),每个组3个重复,共20个组。青贮90 d后,测定其粗蛋白质(CP)、粗纤维(CF)、中性洗涤纤维(NDF)、酸性洗涤纤维(ADF)、可溶性糖(WSC)含量及pH、氨态氮/总氮(AN/TN)。结果表明:与对照组相比,各LA组均显著提高了青贮料的WSC含量(P0.05),显著降低了青贮料pH(P0.05);且6 mg/kg LA组青贮料的CP和WSC含量高于3和9mg/kg LA组,pH低于3和9 mg/kg LA组。与对照组相比,各CE组均显著降低了青贮料的ADF含量和pH(P0.05),且50 mg/kg CE组青贮料的ADF含量和pH低于25和100 mg/kg CE组。各LA×CE组青贮料的CF、ADF含量和pH大部分低于各LA和CE组,WSC含量均高于各LA组和CE组,且6×50 mg/kg LA×CE组青贮料的CF、ADF、WSC含量和pH与各LA和CE组差异显著(P0.05)。除9 mg/kg LA组和100 mg/kg CE组外,相同添加剂下70%含水量青贮料的CP含量显著低于60%含水量(P0.05);相同添加剂下70%含水量青贮料的CF和ADF含量显著高于60%含水量(P0.05)。由此可见,乳酸菌和纤维素酶及两者复合添加均对苜蓿的青贮品质有明显的改善作用,并以添加6×50 mg/kg乳酸菌和纤维素酶效果最好,且60%含水量下的青贮效果更优。     

Feeding Strategies for Rearing Replacement Heifers in Small-scale Dairy Production Systems in the Highlands of Central Mexico

The growth of Holstein heifers in the campesino dairy systems in the highlands of Mexico was evaluated in three feeding strategies. Thirty-three heifers from 11 farmers, grouped according to strategy, were weighed every 14 days for 28 weeks. The live weight change over each 14-day period was estimated by individually regressing live weight over period, taking the regression coefficient as an unbiased estimate of live weight change. Regression coefficients were analysed as a randomized design with feeding strategies as treatments. Strategies were as follows: S1: grazed or cut pasture all year, maize silage and maize straw in the dry season, and 1.0–1.5 kg concentrate/heifer per day. S2: maize straw in the dry season, cut pasture forage, grazing of native grass, weeds from maize fields, and 1.0–1.5 kg concentrate/heifer per day. S3: maize straw in the dry season, grazed native grasses and weeds in the rainy season. Live weight gains were: S1, 0.511 kg/heifer per day; S2, 0.271 kg/heifer per day; and S3, 0.252 kg/heifer per day. Despite the better gains in S1, they are 24% below recommendations, arriving to service at 20 months of age. Not rearing their replacements may be a better alternative for campesino farmers under current economic conditions.     

Effects of supplementing Leucaena leucocephala and conserved forages from natural pasture on the performance of grazing calves

Twelve white Fulani × N'dama cross-bred calves weighing 83.79?±?1.16 kg were used in an 84-day experiment to investigate the utilization of forage resources from natural grazing land. The experimental diets were sole grazing, grazing + hay, grazing + silage and grazing + Leucaena leucocephala leaves. The calves were divided into four groups of three animals each and were randomly assigned to the four experimental diets. Crude protein (CP) contents of the forages ranged from 59 to 171 g/kg dry matter (DM). Neutral detergent fibre (NDF) and acid detergent fibre (ADF) contents of the forages ranged from 560 to 705 g/kg DM and 363 to 440 g/kg DM, respectively. Significantly (P?<?0.05) higher values in mineral contents (Ca, K, P and Mg) were recorded for L. leucocephala leaves compared to other forage resources. Variations (P?<?0.05) were observed in the average daily gain. Animals on grazing + L. leucocephala leaves diet had the highest (113 g/day) average daily gain, while those on sole grazing showed the least value (26.2 g/day). Packed cell volume (PCV), total serum protein, urea and calcium concentration showed significant differences (P?<?0.05). Effective utilization of forage resources from the natural pasture by the calves was attained on supplementation with conserved forages and L. leucocephala leaves without any deleterious effects on the haematological and serum parameters.     

Voluntary feed intake and growth performance of slow-growing pigs fed on increasing levels of ensiled potato hash meal

The objective of the study was to determine voluntary feed intake and growth performance of Windsnyer pigs fed on increasing levels of potato hash silage meal. Thirty-six growing Windsnyer pigs (19 kg ± 5.59) (mean ± standard deviation (SD)) were individually and randomly assigned to six experimental diets containing 0, 80, 160, 240, 320 and 400 g/kg DM of potato hash silage. Diets containing the potato hash silage were formulated using diet dilution method from 0 g/kg and 400 g/kg. Six pigs were fed on each diet ad libitum for 6 weeks. Average daily feed intake (ADFI), average daily gain (ADG), gain to feed (G/F) ratio, scaled feed intake (SFI) and scaled average daily gain (SADG) were measured weekly. Increasing levels of potato hash silage caused a decrease (P < 0.05) in ADG, G/F ratio and SADG. The ADFI interacted significantly (P < 0.05) with the inclusion level of potato hash silage and week of feeding. Pigs fed on 240 g/kg potato hash silage had greater ADFI in the second, third and fourth week of feeding. There was a quadratic increase (P < 0.05) in ADFI. There was a linear decrease (P < 0.05) in ADG and G/F ratio and SADG as the potato hash silage level increased. Using piecewise regression, potato hash silage can be included up to 240 g/kg DM in Windsnyer pigs without undermining growth performance.