Proportion Of Hay Research Articles

Could Cratylia argentea replace Tifton 85 hay on growing and finishing lamb diets in tropical areas?

Legumes shrubs such as Cratylia argentea have an ability to thrive in environments with low water availability and poor soil. On the other hand, forage grasses such as Tifton 85 have a greater demand for inputs to be productive. The objective of this study was to evaluate the performance of growing and finishing Lacaune lambs fed Cratylia argentea hay as an alternative to Tifton 85 (Cynodon spp). Twenty-four Lacaune lambs aged between five and six months (average body weight [BW] 21.50 ± 3.38 kg) were arranged in a split-plot randomized block design. The plots consisted of different Cratylia to Tifton 85 hay proportions (0, 20%, 40%, or 100%, dry matter [DM] basis) as a roughage replacement in the total diet. The subplots represented two evaluation times, entitled "initial period" and "final period", which consisted of the early seven days of total feces and urine collection, and the last seven days of the experiment, respectively. The lambs were blocked by weight with six replicates per treatment. The results show that the level of Tifton 85 replacement for Cratylia hay in the roughage portion of the lamb diet did not influence (P > 0.05) weight gain (WG), dry matter intake or dry matter digestibility; feed conversion, feed efficiency; and the evaluated nitrogen balance variables. The digestibility coefficient of neutral detergent fiber decreased linearly as Tifton 85 replacement for Cratylia level was increased, which probably happened due to the presence of highly lignified material within the Cratylia hay. However, the alternative legume maintained animal performance of Tifton 85. In conclusion, Cratylia hay can be recommended as a potential substitute for Tifton 85 hay, which requires greater inputs for the production. Cratylia may be considered a feeding strategy for livestock production, especially for smallholder livestock systems and regions with unfavorable soil and climate.

Nest Material Preference of Wild Mouse Species in Laboratory Housing

Our research examined the nest-building characteristics of two mouse species native to Hungary, the mound-building mouse (Mus spicilegus) and the house mouse (Mus musculus), under laboratory housing conditions. In indoor housing, the nest-building material plays a very important role in the welfare of the animals. The present study examined how wild mouse species choose from natural nest material. In a three-way test, mice were able to choose whether to make their nest from long blades of hay, nonfibrous cotton, or paper strips. In addition, the effect of nest composition on its quality was also investigated. The test was run at the standard laboratory (21 °C) and lower (10 °C) temperatures, assuming that temperature influences the choice. Based on the results of the three-way selection tests, both species of wild mice chose hay nest material in the highest proportion, and it was also found that the increasing the hay proportion coincided with better nest quality. Mice kept in colder places used more hay nest material for their nests and built better quality nests. Our results show that wild mouse species prefer natural nest-building materials that meet their ecological needs even under laboratory conditions, resulting in a good quality nest. This finding is worth considering in designing appropriate enclosures for wild rodent species.

Анализ полноценности кормления маралов-рогачей в зимне-весенний период

The productivecharacteristics of marals largely depend on the level, full value and balance of feeding. Provided these factors are taken into account, marals maximize their genetic potential. The experimental part of the study was carried out on the farm of the SPK PZ “Abayskiy”of the Ust-Koksinskiy District of the Republic of Altai in 2020. The research goal was to evaluate the full value of feeding maral stags in winter and spring period. It was found that the best energy feed was oat grain which contained 0.9 energetic feed units. When evaluating the mineral composi-tion, it may be seen that legume hay is superior to other forages in terms of calcium content. Oat grain contains larger amount of phosphorus, haylage –larger amount of magnesium. The maral stag diet usedin the SPK PZ “Abayskiy”contains mainly cereals (oats). As a result, in terms of energy nutritional value, it exceeds the upper threshold of the standard by 23%. There is phosphorus deficit by 5.2%. The content of digestible protein, sugar and carotene is higher than in the standard by 1.2, 8 and 69%, respectively. It has been found that on a daily basis, roughage (legume hay) is the largest part of the diet -7 kg per head; there is less succulent forage (silage) and less concentrates (oats). It should be noted that this diet for maral stag during the stall period requires adjustment; if possible, the proportion of hay in the diet should be re-duced; the diet should include enriched mineral supple-ments of natural origin.

Performance of lambs under four levels of dietary supplementation and artificially mix-infected with Haemonchus contortus and Trichostrongylus colubriformis

The effect of four diets on the performance of Dorper lambs that were artificially mix-infected with 1000 infective larvae (L3) of Haemonchus contortus and 1000 L3 of Trichostrongylus colubriformis every three days for 12 weeks was evaluated. For each diet, one infected group (n = 7) and one control group (n = 4) were set up. The four diets contained the following proportions of hay (H) and concentrate (C): Diet 1 - 100%H; Diet 2 - 75%H:25%C; Diet 3 - 50%H:50%C; Diet 4 - 25%H:75. All the infected groups showed decreases in mean packed cell volume (PCV) and total plasma protein, especially the Diet 1-infected, which was also the group with the highest fecal egg count. The diets and infection had significant effects (P < 0.05) on daily body weight gain (DBWG), cold carcass weight and daily food consumption. The control and infected groups had mean DBWG (in kg), respectively, of 0.048 and 0.025 with Diet 1; 0.082 and 0.067 with Diet 2; 0.188 and 0.189 with Diet 3; and 0.303 and 0.221 with Diet 4. In conclusion, the infection affected the productive performance regardless of the diet; however, with increased metabolizable protein and energy, the risk of occurrence of anemia and hypoproteinemia diminished.

Response of vegetative growth and chemical properties in tomato plant (Tariz) for organic fertilization.

The experiment was carried out in agricultural land in Sorman between 4 - 2017 to 7 - 2017, in the design of Randomized Complete Block Design (RCBD) to study the response of vegetative traits and chemical properties in the tomato plant of Tariz for organic fertilization, by 6 treatments and 3 replicates, For SPSS statistical analysis at a significant level of LSD 0.05). The experiment included four types of semi-decomposed organic fertilizer (sheep manure, cattle manure, camel manure, horse manure) in 6 treatments, in addition to the control treatment, which included four treatments for each type of organic fertilizer as: fertilizer: soil by ratio (1: 3) that is 5Kg of fertilizer : 15 kg of soil, mixed treatment of fertilizer : soil (1: 1) (10 kg of fertilizer: 10 kg of soil), and double treatment (3: 1) (15 kg of fertilizer: 5 kg soil). The seedlings were planted in experimental units of 7.20 m2. The seedlings were treated in biological control using the garlic extract for insect protection after 15 days of planting, as well as the addition of simple proportions of hay as a cover to reduce the growth of herbs. The experiment showed that the treatment of cattle manure significantly increased most of the studied morphological traits (length of root, plant length, number of flowers, number of leafy branches), as well as significant increase in fresh and dry weight of leaves and average weight of five fruits.. There were significant differences in the content of the N, P in leaves and NPK elements in the fruits, while there was a significant increase in vitamin C content in fruits for all treatments.

Evidence for increasing digestive and metabolic efficiency of energy utilization with age of dairy cattle as determined in two feeding regimes

The changes taking place with age in energy turnover of dairy cattle are largely unknown. It is unclear whether the efficiency of energy utilization in digestion (characterized by faecal and methane energy losses) and in metabolism (characterized by urine and heat energy losses) is altered with age. In the present study, energy balance data were obtained from 30 lactating Brown Swiss dairy cows aged between 2 and 10 years, and 12 heifers from 0.5 to 2 years of age. In order to evaluate a possible dependence of age effects on diet type, half of the cattle each originated from two herds kept at the same farm, which were fed either on a forage-only diet or on the same forage diet but complemented with 5 kg/day of concentrate since their first calving. During 2 days, the gaseous exchange of the animals was quantified in open-circuit respiration chambers, followed by an 8-day period of feed, faeces, urine and milk collection. Daily amounts and energy contents were used to calculate complete energy balances. Age and feeding regime effects were analysed by parametric regression analysis where BW, milk yield and hay proportion in forage as consumed were considered as covariates. Relative to intake of gross energy, the availability of metabolizable energy (ME) increased with age. This was not the result of an increasing energy digestibility, but of proportionately lower energy losses with methane (following a curvilinear relationship with the greatest losses in middle-aged cows) and urine (continuously declining). The efficiency of utilization of ME for milk production (kl) increased with age. Potential reasons include an increase in the propionate-to-acetate ratio in the rumen because of a shift away from fibre degradation and methane formation as well as lower urine energy losses. The greater kl allowed older cows to accrete more energy reserves in the body. As expected, offering concentrate enhanced digestibility, metabolizability and metabolic utilization of energy. Age and feeding regime did not interact significantly. In conclusion, older cows seem to have digestive and metabolic strategies to use dietary energy to a certain degree more efficiently than younger cows.

Effects of molasses and crude glycerol combined in a liquid supplement on ruminal fermentation in beef steers consuming bermudagrass hay.

Two experiments were performed to evaluate the effects of 1) increasing supplementation doses of a 50:50 (as-fed) liquid supplement of molasses and crude glycerol (M:G) on ruminal fermentation parameters and blood urea nitrogen (BUN) in beef steers consuming Tifton 85 bermudagrass ( spp.) hay and 2) different proportions of molasses and crude glycerol in a liquid supplement on in vitro fermentation and gas production kinetics. For Exp. 1, 8 ruminally cannulated, Angus-crossbred steers were used in a duplicated 4 × 4 Latin square design, had ad libitum access to Tifton 85 bermudagrass hay, and were randomly assigned to 1 of 4 treatments: 1) CTRL, no supplementation; 2) SUP1, 0.45 kg/d (as fed) of 50:50 M:G; 3) SUP3, 1.36 kg/d (as fed) of 50:50 M:G; and 4) SUP5, 2.27 kg/d (as fed) of a 50:50 M:G. For Exp. 2 in vitro batch cultures were conducted to test the same treatments from Exp. 1 and effects of different proportions of a M:G mixture (100:0, 75:25, 50:50, 25:75, and 0:100) when added to a hay substrate simulating the proportions of hay and liquid supplement used in SUP5. In Exp. 1, increasing doses of liquid supplement linearly decreased ( < 0.001) concentrations of NH-N, BUN, and acetate molar proportions, whereas propionate ( = 0.002) and butyrate ( < 0.001) molar proportions increased linearly. Treatment × time interactions were observed for ruminal pH ( < 0.001), where the greatest decrease was observed at 3 h postfeeding for animals consuming SUP5 (from 6.82 at 0 h to 6.32 at 3 h). In Exp. 2, decreases in acetate molar proportions ( < 0.001) and increases ( < 0.001) in propionate and butyrate molar proportions were also observed for either increasing doses of a 50:50 mixture or increasing proportions of glycerol in the mixture. Total VFA and in vitro organic matter digestibility were increased linearly ( < 0.001) as doses of a 50:50 mixture increased. Increasing doses of 50:50 M:G to growing beef heifers consuming bermudagrass hay caused a shift in VFA profile toward increases in propionate and decreases in acetate molar proportions. This was also confirmed in vitro, as the proportions of crude glycerol increased in a molasses:crude glycerol mix. Thus, molasses and crude glycerol combined seem to be useful to enhance performance in growing cattle consuming forage-based diets.

Biological implications of longevity in dairy cows: 1. Changes in feed intake, feeding behavior, and digestion with age

Milk production strategies focusing on longevity and limited use of concentrate are receiving increasing attention. To evaluate such strategies, knowledge of the development with age of animal characteristics, particularly digestion, is indispensable. We therefore investigated the development of feed intake, chewing activity, and digestion in 30 lactating Brown Swiss cows (876–3,648 d old) and 12 heifers (199–778 d old). We also studied whether age effects were exhibited differently in animals selected from herds subjected for 11 yr either to a forage-only or to a forage-concentrate feeding regimen. Forages consisted of grass hay (the only feed for heifers), corn silage, and grass pellets. Measurements lasted for 8 d, where amounts and composition of feeds, feces, and milk were recorded and analyzed. Ruminal pH data and eating and rumination activity were assessed by pH sensors put into the rumen and halter-mounted noseband sensors. The mean retention time of feed particles was assessed using Cr-mordanted fiber and data were used to calculate dry matter gut fill. Data were subjected to regression analyses with age and feeding regimen as explanatory variables, and body weight, milk yield, and proportion of hay in forage as covariates. This allowed separating age-related changes of body weight and milk yield from independent age effects and correcting for differences in preference for individual forages. In cows, organic matter intake increased with age (from slightly below to above 20kg/d), as did mean retention time and gut fill. Digestibility of organic matter did not show a clear age dependency, but fiber digestibility had a maximum in cows of around 4 to 6 yr of age. Ruminal pH and absolute eating and rumination times did not vary with cow age. Young and old cows chewed regurgitated boluses more intensively (60–70 times) than middle-aged cows (about 50 times). Effects of feeding regimen were small, except for fiber intake and rumination time per unit of intake, owing to the different fiber content of the diets. No significant interactions between age and feeding regimen were found. Heifers spent more time eating and ruminating per unit of feed than cows, which resulted in a high fiber digestibility. Irrespective of the feeding regimen tested, older cows maintained intake and digestion efficiency with longer retention times and chewing rumination boluses more intensively. The results support efforts to extend the length of productive life in dairy cows.

Biological implications of longevity in dairy cows: 2. Changes in methane emissions and efficiency with age

Previous studies indicated that absolute CH4 emissions and CH4 yield might increase and that milk production efficiency might decrease with age in cattle. Both would make strategies to increase longevity in dairy cattle less attractive. These aspects were experimentally determined in Brown Swiss cattle distributed continuously across a large age range. Thirty lactating dairy cows (876–3,648 d of age) received diets consisting of hay, corn silage, and grass pellets supplemented with 0 or 5kg of concentrate per day. Twelve heifers (199–778 d of age) received hay only. Cows and heifers were members of herds subjected to the 2 different feeding regimens (with or without concentrate) for the past 10 yr. Methane emissions were measured individually for 2 d in open-circuit respiration chambers, followed by quantifying individual feed intake and milk yield over 8 d. Additional data on digestibility, rumination time, and passage time of feed of all experimental animals were available. Regression analyses were applied to evaluate effects of age and feeding regimen. Body weight, milk yield, and the hay proportion of forage dry matter intake were considered as covariates. Methane emissions per unit of intake, body weight, and milk yield were significantly related to age. Their development in the cows with age was characterized by an increase to maximum at around 2,000 d of age, followed by a decline. This response was not accompanied by corresponding age-related changes in intake, chewing activity, digesta passage time, and digestibility of organic matter, which would have explained shifts in CH4. However, fiber digestibility showed a similar change with age as methane emissions, resulting in quite stable methane emissions per unit of digestible fiber. As expected, methane emissions intensity per unit of milk produced was greater by 8% without concentrate than with concentrate, but no difference was noted in the response to age when the animals were subjected to different feeding regimens. The efficiency of milk production was only marginally influenced by age and diet, and no different response was observed for age in the 2 dietary regimens. In conclusion, life cycle analyses of milk production systems focusing on longevity should consider changing methane yields with age in addition to the variation in environmental costs for replacements of culled cows.

FEATURES OF YOUNG RABBITS INTESTINAL MICROBIOCENOSIS UNDER DIFFERENT FEEDING SYSTEMS

The dependence of quantitative and species composition of young rabbits microbocoenosis from feeding system was studied. It was found that in case of concentrate feeding system the number of bifidobacteria and yeast fungi increases. The influence of combined feeding system components on microflora composition of the gastrointestinal tract of young rabbits was studied. It was found that the introduction of a significant proportion of hay to rabbits’ diet leads to the decrease in the number of bifidobacteria and increase in the number of anaerobic bacilli, and in case of the diet based on grain the number of lactic acid bacteria increases and the number of yeast fungi decreases.

Invited review: Development and expression of dairy calf feeding behaviour

Miller-Cushon, E. K. and DeVries, T. J. 2015. Invited review: Development and expression of dairy calf feeding behaviour. Can. J. Anim. Sci. 95: 341–350. Feeding and housing practices for dairy calves impact performance and growth early in life, as well as feeding behaviour. There is also increasing evidence that early exposure to different feeding and housing strategies influence the development of feeding behaviour. The dairy calf needs access to milk in sufficient quantities to maintain health and high-levels of growth. In addition, intake of solid feed, such as grain concentrate, is necessary early in life to establish fermentation and develop the rumen. In dairy calves, feeding behaviour patterns can have direct impact on nutrient consumption and, consequently, growth. Further, recent research has provided evidence that behaviour patterns that develop in response to management factors early in life may persist once learned, potentially having longer-term implications for health and welfare. Thus, there is potential for various nutritional, housing, and management factors to impact the learning of feeding behaviour early in the life of dairy calves. This review provides several examples of early management factors that influence feeding behaviour of dairy calves and, in turn, impact calf growth and welfare. For example, providing continuous, ad libitum access to milk results not only in greater growth, but also in meal patterns that more closely resemble the natural behaviour of a calf suckling its dam. Housing management also has the potential to influence when, and how much, a calf eats. Whereas social facilitation promotes intake, particularly at weaning, competition for feed in group-housed calves restricts feeding patterns and degree of feeding synchrony. With regards to provision of solid feed, recent data suggest that providing physically effective hay, in addition to grain concentrate, may be beneficial for the rumen environment and consequent growth and efficiency. However, the physical form and presentation of forage may also influence feeding behaviour of calves, in particular feed sorting, which can impact both immediate nutrient intakes as well as the development and persistence of that behaviour. For example, calves provided hay and concentrate as a mixture begin to sort their feed early in life, with the pattern of sorting depending on hay particle size. Feed sorting in young calves may reflect a motivation to consume a proportion of hay in the diet. In general, it appears to be beneficial for early growth and welfare to support milk and solid feed intake through unrestricted allowances and less-competitive feeding environments. Continued research in this area is needed to assess the longevity of learned behaviour patterns, and what factors may influence their persistence.

Effects of grass hay proportion in a corn silage-based diet on rumen digesta kinetics and digestibility in dairy cows.

In this study, we aimed to evaluate the effects of six levels of orchardgrass hay (GH) proportion (0%, 10%, 20%, 30%, 40% or 50% of dry matter) in finely chopped corn silage (CS)-based diets on digesta kinetics of CS and GH in the rumen. Six non-lactating, rumen-cannulated Holstein cows were used in a 6 × 6 Latin square design. Ruminal digesta kinetics was measured by ruminal dosing of feed particle markers (dysprosium for CS, erbium for GH) followed by fecal sampling. The increase of GH proportion had a quadratic effect (P < 0.01) on total tract digestibility of neutral detergent fiber (NDF) and acid detergent fiber. The proportion of GH did not affect the particle size distribution of rumen digesta, total weight of dry matter or NDF in the rumen. The rates of large particle size reduction in the rumen for CS tended to increase linearly with increasing GH proportion (P = 0.077). A quadratic effect (P < 0.05) was found with increasing the GH proportion for the ruminal passage rate of small GH particles, but not for CS particles. The results suggested that associative effects between CS and GH could be generated on rumen digesta kinetics when cows were fed a CS-based diet with an increased proportion of GH.

Fatty acid profile of milk from goats fed diets with different levels of conserved and fresh forages

Aim of the study was to evaluate the effect of different proportions of hay and fresh grass in goats’ diet on milk fatty acid profile. Nine Camosciata goats were fed a fixed amount of concentrate (30% of total diet) and different percentages (40% vs 30%, 50% vs 20% and 60% vs 10%) of hay and fresh grass, respectively. Diminishing amounts of fresh grass percentages in the diet led to significant increases of lauric, myristic and palmitic acids (P ≤ 0.001) and to significant decreases of C18:1 t6‐11, rumenic and α‐linolenic acids (P ≤ 0.001) in milk, thus determining a worsening of the health value of milk fat.

Feed Intake, Weight Gain and Carcass Yield Characteristics of Intact Hararghe Highland Male Goats Fed on Different Hay to Concentrate Ratios

Feed intake, live weight gain and carcass yield characteristics were studied using twenty-five yearling intact Hararghe highland male goats (17.6 ± 0.11 kg body weight) fed diets containing different hay to concentrate ratios, viz., 100:0, 80:20, 70:30, 60:40 and 50:50% for T1, T2, T3, T4 and T5, respectively, in a randomized complete block design experiment with five animals per treatment that lasted for 90 days. The amount of CP supplied was 3.73, 10.15, 13.36, 16.57 and 19.79% per kg DM and the ME (MJ/kg DM) was 6.64, 7.51, 7.95, 8.38 and 8.82 for the respective treatments. Dry matter and nutrient intakes were measured daily, while live weight gain and feed conversion efficiency were recorded at the weekly interval. At the end of the feeding trial, all goats from each treatment were fasted for 12 h and slaughtered after taking the slaughter weight of each goat. Measurements were also taken on empty body weight, hot carcass weight, dressing percentage (DP) and rib eye muscle area. Concentrate supplementation of goats resulted in high (P < 0.05) dry matter, crude protein and metabolizable energy intake, which was reflected in increased (P < 0.05) average daily weight gain (ADWG) and feed conversion efficiency (FCE). The empty body weight, hot carcass weight, DP and rib eye muscle area were higher (P < 0.05) for concentrate supplemented groups compared to those fed on hay alone. Goats on equal hay to concentrate ratio (T5) had higher empty body weight, hot carcass weight and rib eye muscle area when compared to those on T2 and T3. Different proportions of hay to concentrate did not affect the DP, but carcasses dressed from goats offered with concentrate feeds had higher (P < 0.05) percentages of lean and boneless meat, and lean: bone and lean + fat: bone ratios, but lower percentage of bone than the carcasses from goats fed hay alone. The percentage of boneless meat was similar between goats on T2, T4 and T5, while the percentage of total edible offal components was similar between supplemented and un-supplemented groups. The proportion of the gut content and total non-edible offal components decreased with the increasing concentrate level, while the percentage of the total saleable components increased. Correlation and regression analysis revealed a positive and significant (P < 0.01) relationship between dry matter intake (r = 0.67), slaughter weight (r = 0.89), hot carcass weight (r = 0.90), dressing percentage (r = 0.70), lean meat (r = 0.95) and rib-eye muscle area (r = 0.92) with the level of concentrate supplementation. However, there was a non-significant (P > 0.05) weak negative correlation (r = -0.16) between ADWG and the level of concentrate supplementation. Considering ADWG, FCE, DP and percentage of boneless meat, the diet with 20% concentrate level could be recommended for optimum live weight gain, feed conversion efficiency and carcass yield characteristics of goats. Keywords: Body Weight Gain; Carcass Yield; Feed Intake; Hararghe Highland Goats; Hay to Concentrate Ratio East African Journal of Sciences Vol. 1 (1) 2007: pp. 45-54

Parametric analysis of the properties of selected mixing feeding wagons

Eight different mixing feeding wagons (MFW) were investigated under identical conditions in preparing total mixed rations (TMR) for three various cattle categories. Investigated were the uniformity of distribution of the feed into the trough, homogeneity of TMR distributed, the machine capacity in feed extracting from storage and loading, TMR mixing and distributing into the trough, fuel consumption and power consumption required. The least uniformity was found for TMR with a high hay proportion (average value of standard deviation 49.9%). Better results were achieved with MFW designed with horizontal mixing augers (average standard deviation 33.7%). MFW with vertical augers distributed feeds at average standard deviation of 61.3%. Standard deviation of the proportion of feed particles on the separator screens which is considered as a measure of TMR homogeneity, was bellow 20% in most cases. This suggests a hint of a very good mixing efficiency of all the MFW followed up. No influence of different designs of the working elements of MFW on TMR homogeneity has been proved. With respect to the machine capacity (output) in preparing and distributing TMR, no large differences between various MFW were found and their output averaged from all measurements varied within the range of 4.79–5.48 t/h. The least average specific consumption of fuel for preparing and distributing TMR was found in the MFW equipped with vertical mixing augers (1.10–1.11 l/t). MFW with one horizontally mounted mixing auger showed a rather higher fuel consumption (1.30–1.43 l/t). The highest fuel consumption was found with MFW equipped with two parallely mounted mixing augers (1.59–1.63 l/t).

Comparison of haymaking strategies for cow‐calf systems in the Salado Region of Argentina using a simulation model. 3. Exploratory risk assessment

AbstractRisk and cost estimates, calculated using a weather‐driven farm simulation model, were used to evaluate the impact of different haymaking strategies in dryland cow‐calf systems such as those in the Salado region of Argentina. Based on a 100‐ha farm, each strategy was simulated using twenty sequences of 50 years of random weather. A risk‐efficiency methodology was used, using calf live weight sold and considering the economic value of the live weight produced per year minus the cost of haymaking, as a simple measure of profit. The analysis highlighted both production and risk advantages in using hay, especially when a flexible hay management approach was implemented, although some haymaking strategies performed worse than not using hay. When calf live weight sold was considered alone, the risk‐efficient set included strategies with large proportions of the areas being harvested (0.42–1.05; paddocks could be cut more that once a year in some of the strategies) and high proportions of hay not being used. The amount of hay for maximizing risk efficiency for profit was notably lower than that for maximizing cattle production. When haymaking costs were included, the proportion of area harvested for risk‐efficient profit ranged from 0.28 to 0.52, depending on the target stocking rate.

Relationships between patterns of rumen fermentation measured in sheep and in situ degradability and the in vitro gas production profile of the diet

The relationship between the pattern of rumen fermentation in vivo and the gas production (GP) profile of different diets, and the in situ degradability of the component feeds was investigated. Three mature wethers were fed three diets in a randomised block design. Each diet consisted of hay and micronised maize. The relative proportions of hay:maize (dry matter (DM) basis) was 80:20, 50:50 and 20:80. Samples of rumen fluid were collected over 24 h and analysed for pH, short chain fatty acids (SCFAs) and protozoal population. In situ degradability of hay and maize organic matter (OM) was estimated. The GP profile of each diet was estimated with an automated pressure transducer using rumen fluid collected from the animal being fed that diet. The SCFA profile of the incubation medium was estimated after 72 h, and from these data the amount of ATP produced in vitro was predicted. The proportion of maize in the diet had no effect on the effective degradability of maize or the mean total SCFA concentration in the rumen. However, increasing the proportion of maize in the diet reduced hay OM effective degradability and molar proportion of acetate in the rumen. The opposite effect was observed with propionate, and the proportion of butyrate was not affected. The ratio of non-glucogenic:glucogenic SCFA (NGR) decreased as the proportion of maize increased. Differences between in vitro and in vivo measurements were significant for total SCFA concentration and acetate proportion. The time to maximum gas production rate and predicted ATP production were related to in vivo mean total SCFA concentration ( R 2=0.81), mean molar proportion of acetate ( R 2=0.59), propionate ( R 2=0.63) and butyrate ( R 2=0.86), NGR ( R 2=0.61) and the effective OM degradability of hay ( R 2=0.57). Results suggest that the GP technique predicts dynamic parameters of rumen fermentation, particularly the SCFA profile. This would reduce the need to use surgically modified animals when determining the effect of diet on the pattern of rumen fermentation.

Effects of Hand-Fed Versus Self-Fed Fat Supplementation on Growth and Reproductive Performance of Developing Beef Heifers

ABSTRACT Growth and digestion trials were conducted to determine the efficacy of supplemental fat for developing beef heifers consuming a bromegrass hay-based diet. In Exp. 1, Angus x Gelbvieh heifers were allotted to one of three treatments in a randomized complete block design experiment for 2 consecutive yr (yr 1: n = 88, BW = 263.6 ± 0.6 kg; yr 2: n = 56, BW = 276.8 ± 3.1 kg). Supplemental treatments included a hand-fed corn- and soybean meal-based supplement (CRN), a hand-fed corn- and soybean meal-based supplement containing 15% soybean oil (OIL), or a self-fed tub supplement containing 16.7% (as fed) soapstocks (TUB). Heifers were inseminated and diagnosed for pregnancy following the conclusion of the feeding period. For Exp. 2, IVDMD and volatile fatty acids (VFA) were determined using the proportions of hay and supplement that heifers consumed in Exp.1, yr 1. Treatment differences for Exp. 1 and 2 were evaluated using the single degree of freedom orthogonal contrasts, CRN + OIL vs TUB and OIL vs TUB. Total feed intake tended to be less (P=0.09) for heifers on the TUB treatment in Exp. 1, yr 1; however, hay intake was greater (P=0.02) for heifers on the TUB treatment than for hand-fed heifers. In both years, hand-fed heifers had greater ADG (P≤0.02) and BW gain efficiencies (P≤0.005) than did heifers on the TUB treatment. Average daily gain and gain efficiency were also greater (P≤0.02) for heifers on the OIL treatment than for heifers on the TUB treatment in yr 1 and 2. Overall pregnancy rate was greater (P≤0.03) for heifers on CRN and OIL than for heifers on the TUB treatment (93.2% vs 72.4%) in yr 1. In yr 2, however, overall pregnancy rates were similar (P=0.30) among all treatment groups. In Exp. 2, IVDMD was greater (P=0.002) for hand-fed diets than for the TUB diet. Total VFA were not different (P=0.34) among supplement treatments; however, the acetate:propionate ratio was less (P=0.0001) for the CRN and OIL treatments compared with the TUB treatment. Less than projected intake of TUB supplement and, thus, an overall lower plane of nutrition contributed to decreased growth in both years and poorer reproductive performance in yr 1 for heifers on the TUB treatment compared with heifers that were hand-fed a supplement.

Energy utilization of diets with different hay proportions in lactating goats

Energy utilization of diets with different hay proportions in lactating goats

Energy utilization of diets with different hay proportions in lactating goats

Energy utilization of diets with different hay proportions in lactating goats