Replacing Alfalfa Hay Research Articles

Effect of replacing alfalfa hay with a mixture of cassava foliage silage and sweet potato vine silage on ruminal and intestinal digestion in sheep.

This study aimed to investigate the effects of replacing alfalfa hay (AH) with a mixture of cassava foliage silage and sweet potato vine silage (CSP) (1:1 on a dry matter (DM) basis) on ruminal and intestinal nutrient digestion in sheep. Four wethers were fed a control diet containing 35% of AH and two treatment diets containing 15% and 30% of the CSP as substitute for AH at 1.5 times the metabolizable energy required for maintenance. Replacing AH with the CSP silage did not affect DM intake, whereas it linearly increased (P<0.05) the intake of ether extract and acid detergent insoluble nitrogen (ADIN). Increasing the CSP substitution linearly decreased (P<0.05) ruminal DM and neutral detergent fiber (aNDFom) digestibility; however, it did not affect total tract aNDFom digestibility. The CSP substitution did not affect nitrogen (N) intake and duodenal total N flow, whereas it linearly increased duodenal ADIN flow (P<0.01) and decreased ruminal ammonia-N concentration (P<0.01), and intestinal (P=0.08) and total N digestibility (P<0.01). These results indicate that replacing AH with the CSP reduced the ruminal N degradation as well as the digestion of ruminal aNDFom and intestinal N.

Substituting oat hay or maize silage for portion of alfalfa hay affects growth performance, ruminal fermentation, and nutrient digestibility of weaned calves.

ObjectiveThe impact of forage feeding strategy on growth performance, ruminal fermentation and nutrient digestibility in post-weaning calves was investigated.MethodsForty-five female Holstein calves (body weight [BW] = 79.79±0.38 kg) were enrolled in the 35-d study at one week after weaning and randomly assigned to one of three dietary treatments. All diets were fed as total mixed ration containing 60% (dry matter [DM] basis) of basal starter feed and 40% (DM basis) of forage, but varied in composition of forage source including i) alfalfa (40% DM, AH); ii) alfalfa hay (26.7% DM)+oat hay (13.3% DM; OH); iii) alfalfa hay (26.7% DM)+corn silage (13.3% DM; WS).ResultsDry matter intake was not different among treatment groups (p>0.05). However, BW (p<0.05) and average daily gain (p<0.05) of calves fed AH and OH were greater than WS-fed calves, whereas heart girth was greater in OH-fed calves than those fed AH and WS (p<0.05). Ruminal fermentation parameters including proportion of butyric acid, acetated-to-propionate ratio, concentration of total volatile fatty acid, protozoal protein, bacterial protein, and microbial protein in rumen were the highest in OH (p<0.05) and the lowest in WS. Compared with the AH and WS, feeding oat hay to postweaning calves increased crude protein digestibility (p<0.05), and decreased duration of diarrhea (p<0.05) and fecal index (p<0.05).ConclusionOur results suggested that partially replacing alfalfa hay with oat hay improved ruminal fermentation, nitrogen utilization, and reduced incidence of diarrhea in post-weaning dairy calves.

Effect of cereal straw and alfalfa hay diet on amino acid profile of gastrointestinal digesta in lactating dairy cows.

This study was conducted to evaluate the effects of replacing alfalfa hay with rice straw (RS) or corn stover (CS) on amino acid (AA) profiles of gastrointestinal digesta in lactating cows. Eighteen lactating dairy cows were randomly assigned to one of three groups (n=6) and fed identical concentrate and corn silage with different forages on dry matter basis: (i) 23% alfalfa hay and 7% Chinese wild rye hay (AH); (ii) 30% CS; and (iii) 30% RS. After the 14-week feeding, a total of 18 cows were slaughtered to collect digesta from four representative organs, including rumen, omasum, duodenum and jejunum. The AA profiles of ruminal microbial fraction were similar among the treatments, except for greater Arg in cows fed RS than in cows fed AH or CS. Most of the analysed AA changed under different diets. Significant differences were found among the microbial fraction, rumen fluid and rumen digesta, with greater essential AA in digesta than in microbial fraction or rumen fluid and greater essential AA in microbial fraction than rumen fluid. Significant differences in individual AA profiles of digesta and relevant fluid were found across the four representative digestive tract parts, including rumen, omasum, duodenum and jejunum, showing much lower Leu proportion in CS and RS than in AH in duodenal fluid. In summary, ruminal microbes may prefer using essential AA, rather than non-essential AA. The AA profile of ruminal microbes was constant except for Arg. The AA composition of digesta across the four digestive tracts changed dramatically, which indicated differences in the ability and efficiency of AA absorption. The lower duodenum absorbable Leu proportion in cows fed CS or RS indicated the shortage of Leu in CS or RS diets, which might also restrict the balanced AA absorption.

Replacement of alfalfa hay (Medicago sativa L.) with subabul (Leucaena leucocephala) leaf meal in diets of Najdi goats: effect on digestion activity of rumen microorganisms.

This study investigated the effect of replacing alfalfa hay by subabul leaf meal (SLM) on digestion, fermentation parameters and rumen bacteria and fungi activity of Najdi goats. Six Najdi goats (150±15days of age and initial body weight of 35±1.1kg) were randomly assigned to one of two dietary treatments in a balanced completely randomized design (three goats per treatment) for 56days. Experimental treatments included alfalfa hay as control group and diet containing SLM (SLM replacing alfalfa hay at 50% level). Bacterial and fungi activity and rumen fermentation parameters of animals fed experimental diets were determined. Dry matter disappearance (DMD) was unaffected by replacing SLM with alfalfa hay for both rumen bacteria and fungi in different incubation times, except for 48h of incubation in specific culture medium of mixed rumen bacteria, which decreased for SLM group (P>0.05). NDF disappearance (NDFD) and ADF disappearance (ADFD) after 24 and 48h of incubation in specific culture medium of mixed rumen bacteria was not affected by experimental diets (P>0.05). However, 72h after incubation, NDFD in SLM treatment decreased (P>0.05). Gas production parameters of rumen bacteria were similar for both experimental diets, but partitioning factor (PF), efficiency microbial biomass production (EMBP), microbial protein production (MP), and organic matter truly digested (OMTD) decreased (p<0.05) in specific culture medium of mixed rumen fungi for SLM diet. There was significant decrease in total protozoa population for diet containing SLM (p<0.05). Results indicated that replacement of alfalfa hay by SLM had no major effect on rumen microorganisms' activity of Najdi goats, so it may be used as an alternative for alfalfa (at 50% level) in susceptible areas.

Replacing alfalfa hay with dry corn gluten feed and Chinese wild rye grass: Effects on rumen fermentation, rumen microbial protein synthesis, and lactation performance in lactating dairy cows

This experiment was conducted to investigate nutrient digestibility, rumen microbial protein synthesis, and lactation performance when a portion of alfalfa was replaced with combinations of dry corn gluten feed (DCGF) and Chinese wild rye grass in the diet of lactating cows. Six multiparous and 3 primiparous Chinese Holsteins were arranged in a replicated 3 × 3 Latin square experiment for 21-d periods. The animals were fed 1 of 3 treatment diets during each period: (1) 0% DCGF (0DCGF); (2) 6.5% DCGF (7DCGF); and (3) 11% DCGF (11DCGF). Diets were isonitrogenous, and a portion of alfalfa hay was replaced with DCGF and Chinese wild rye grass, with similar concentrate mixtures and corn silage contents. The dry matter intake was greater for 11DCGF (21.9 kg/d) than for 0DCGF (20.7 kg/d) or 7DCGF (21.2 kg/d). The treatment diets did not result in difference in milk production, fat and lactose concentration, or yield. Compared with 0DCGF, the ration containing 11% DCGF improved the milk protein concentration. Dry matter and neutral detergent fiber digestibility was greater for 7DCGF (62.7% and 45.6%) and 11DCGF (63.1% and 47.2%) than for 0DCGF (59.4% and 42.3%), and the nitrogen digestibility was similar for the 3 treatments. The concentration of rumen volatile fatty acids was higher in cows fed the 11DCGF diet than in those fed the 0DCGF diet, with no difference between the 7DCGF and 11DCGF diets. The estimated microbial crude protein yield was greater for the 11DCGF diet (1985.1 g/d) than for the 0DCGF diet (1745.0 g/d), with no difference between the 0DCGF and 7DCGF diets. Thus, it appears that feeding DCGF and Chinese wild rye grass in combination can effectively replace a portion of alfalfa hay in the rations of lactating dairy cows.

Effect of replacing alfalfa with processed potato vines on growth performance, ruminal and total tract digestibility and blood metabolites in fattening lambs

The current study aimed to investigate the effects of replacing alfalfa hay with potato vines hay (PVH) and potato vines silage (PVS) on growth performance, digestibility and blood metabolites of fattening lambs. For this, twenty-four fattening lambs were assigned randomly to one of four dietary treatments. Treatments included: 1) basal diet without potato vines (CTRL); 2, 3) replacing 50 and 100% of alfalfa in the basal diet with PVH (PVH50, PVH100, respectively); and 4) replacing 50% of alfalfa with PVS (PVS50). The diets were formulated to be iso-energetic and iso-nitrogenous and were fed ad-libitum to lambs during 70days of performance period. Blood samples, taken on d 30 and 70, were analyzed for biochemical and hematological parameters. At the end of performance period, lambs were transferred into metabolic crates and the digestibility of the diets were evaluated during 7 d fecal collection, following a 14-d adaptation period. Metabolizable energy (ME) and organic matter digestibility (OMD) of PVH and PVS as well as ruminal digestibility and fermentation of the diets were determined in vitro using gas production technique. Organic matter (%), CP (%), NDF (%), OMD (%) and ME (MJ/kg) contents were 79.2, 14.7, 45.1, 72.3, 8.74; 89.9, 16.1, 43, 58.8, 7.74; and 90.4, 14.5, 48, 67.2, 9.5 for PVH, PVS and alfalfa, respectively. Replacing alfalfa with PVH and PVS had no effect on the growth performance of lambs (P>0.05). However, total volatile fatty acids (TVFA) concentration was affected by the treatments (P<0.01), with the lowest value observed with PVH100. There was no significant treatment effect on nutrients digestibility except for CP, which tended to increase with PVH100. In vitro results showed no treatment effect on ruminal digestibility (P>0.05). Partitioning factor (PF) tended to increase with PVH and PVS containing diets (P=0.09). However, there was a treatment effect on the gas produced after 24h incubation (GP24) and TVFA (P<0.05), with their lowest values observed in PVH100 and PVS50, respectively. Treatments affected serum glucose, cholesterol, triglyceride, and albumin (P<0.01). Overall concentrations of cholesterol and triglyceride decreased in lambs fed diets containing PVH and PVS, but glucose and albumin decreased only in lambs receiving PVH50 and PVH100. There was also a treatment by day interaction effect on serum glucose, urea, triglyceride and albumin concentrations (P<0.01). Hepatic enzymes and hematological parameters were not affected by the treatments (P>0.05). Overall, these results indicated that processed potato vines can be used in feeding fattening lambs without having adverse effect on their health and performance.

1659 Effect of peNDF on milk production and composition in goats fed with NNFS replacing alfalfa hay

1659 Effect of peNDF on milk production and composition in goats fed with NNFS replacing alfalfa hay

In situ, in vitro and in vivo nutritive value assessment of Barberry leaf as a roughage for goat feeding

This study was carried out to evaluate nutritive value of Berberis vulgaris leaf (BVL) by in situ and in vitro experiments and to investigate the effects of replacing alfalfa hay with BVL on performance, milk composition, blood metabolites and antioxidant capacity of lactating crossbred goats. Rumen dry matter (DM) degradability of BVL was assessed using two fistulated mature goats and incubation of BVL samples at specified times in the rumen. Modified 3-step procedure (TSP) was performed for determination of post-rumen DM digestibility. For the in vivo experiment (during six weeks), 21 lactating crossbred goats (55±15 DIM and 26±2.8kg BW) were randomly allocated to one of three dietary treatments of BVL at levels of 0, 17 and 34% of DM. The results of in situ and in vitro experiments indicated that rumen DM degradability, post-rumen digestibility of DM undigested in the rumen and total tract DM digestibility of BVL were 65.46%, 12.84% and 69.90%, respectively. In vivo results revealed that DMI increased (P<0.05) as BVL level in the diet raised. Also, milk fat increased (P<0.05) with increasing BVL level in the diets, but milk protein, SNF and lactose content were not affected by the diets (P>0.05). Goats fed BVL showed greater antioxidant capacity than goats fed control diet (P<0.05) and no significant difference was found in plasma malondialdehyde (MDA) content (P>0.05). Results of this study revealed that BVL has high nutritional value and might be utilised in diet of lactating goats as an inexpensive alternative roughage.

Crude protein levels in diets of lactating goats: nitrogen balance, urea excretion and microbial protein synthesis

SUMMARYThe experiment, conducted at Bahia, Brazil, from May to August 2010, aimed to evaluate the nitrogen (N) balance, urea excretion and microbial protein synthesis in lactating goats fed pelleted concentrates with the addition of crude protein (CP), obtained by replacing alfalfa hay with soybean meal. The diets consisted of different levels of CP and 200 g of roughage (Tifton 85 hay)/kg. Maize and mesquite bran were used as the energy source, with maize replaced by mesquite bran in the ratio of 1·7:1. Eight female Saanen goats were used, confined in individual pens and allocated to a 4 × 4 Latin square design. The N balance in the body was positive, and loss of body weight (–0·03 g/day) was observed for the diet with 190 g CP/kg. The concentration (mg/dl) of urea in urine, milk and blood plasma was positively influenced in a linear form, and the highest rate of increase was found in urine, with 2 mg/dl for every 10 g CP/kg added to the diet. The microbial protein synthesis was not affected, but the diets reduced the microbial protein (44 g/day) and its ruminal production efficiency (30 g/kg total digestible nutrients). The levels above 190 g of CP are not recommended because of the energy expenditure required to excrete the urea.

Using Sweet Bran instead of forage during grain adaptation in finishing feedlot cattle.

Two trials evaluated adapting cattle to a finishing diet using wet corn gluten feed compared with traditional methods using forage. A 33-d grain adaptation metabolism trial (Exp. 1) compared decreasing wet corn gluten feed (Sweet Bran; Corn Milling unit, Cargill Corn Milling, Blair, NE) while increasing corn inclusion (SB) and a traditional grain adaptation system decreasing alfalfa hay while increasing corn with no Sweet Bran inclusion (CON). Ruminal pH, intake characteristics, and 24-h in situ digestibility were evaluated using 8 ruminally fistulated steers (291 kg BW [SD 19]). Steers (4/treatment) were adapted to finishing diets across 4 periods consisting of 5, 7, 7, and 7 d and then fed a finishing diet for 7 d. No period × adaptation diet interactions were observed ( ≥ 0.12). Average ruminal pH decreased ( < 0.01) whereas time and area below a pH of 5.6 increased ( ≤ 0.02) for the SB adaptation system compared with the CON adaptation system. Cattle adapted using SB had greater DMI than cattle adapted using CON ( < 0.01). As steers were adapted to finishing diets, DMI increased ( = 0.01), average ruminal pH decreased ( = 0.05), and time and area below a pH of 5.6 increased ( ≤ 0.04) for both treatments. Ruminal pH for CON steers decreased from 6.59 to 6.12 across periods as corn replaced alfalfa hay whereas ruminal pH decreased from 6.00 to 5.79 for SB steers. Steers adapted using SB had greater ( ≤ 0.05) in situ digestion of adaptation diets than steers adapted using CON for adaptation periods 3, 4, and 5. The SB diets were more digestible than the CON diets when incubated in either CON- or SB-fed steers for adaptation periods 1 and 2 ( < 0.01). Experiment 2 used 240 finishing steers (273 kg BW [SD 14]) to determine performance impacts of using Sweet Bran instead of forage to adapt cattle to finishing diets. Steers were fed either decreasing Sweet Bran inclusion while increasing corn (SB) or decreasing alfalfa hay inclusion while increasing corn (CON). Treatments were applied only during grain adaptation (26 d) and all steers were finished on a common diet containing 35% Sweet Bran for an additional 147 d. Steers adapted using SB had greater ( ≤ 0.01) final BW, ADG, G:F, and HCW compared with steers adapted using CON, even though treatments differed only the first 26 d. Grain adaptation treatment had no effect ( ≥ 0.13) on carcass quality. These results indicate that Sweet Bran can be used to adapt cattle to finishing diets instead of forage and improves ADG and G:F while decreasing the forage needs of feedlots.

Pistachio by-product as an alternative forage source for male lambs: Effects on performance, blood metabolites, and urine characteristics

Thirty-two Kermanian male lambs (5–6 months of age and 23.73±2.20kg BW) were used to determine the effects of feeding sun-dried pistachio by-product (PBP) on growth performance, nutrients digestibility, blood metabolites, and urine characteristics over a 4-months period. Lambs were randomly allocated to one of four experimental diets containing 0 (DM basis; 0PBP), 10 (10PBP), 20 (20PBP), and 30% of PBP (30PBP), substituted with alfalfa hay and wheat straw. Experimental diets were fed twice daily in two equal portions as pelleted total mixed rations. Lambs were weighed at the beginning of trial and the end of each month over the experimental period. Blood and urine samples were also collected monthly. Eight Kermanian castrated rams (48.35±2.81kg BW) placed in metabolic cages were used in a replicated 4×4 Latin square design during four 3-week periods to evaluate nutrient digestibility in response to feeding experimental diets. Dry matter intake (DMI) and average daily gain (ADG) reduced linearly (P=0.001) with increasing the amount of PBP in the diets. The lambs fed 30PBP, had the lowest daily DMI and ADG, which were lower (P<0.01) than the control group (1549g/d vs. 1063g/d and 195.7g/d vs. 129.4g/d, respectively). Feed conversion ratio increased linearly and it was greater (P<0.05) in 30PBP than the control group (13.82 vs. 7.96). Plasma activities of circulating enzymes including alanine aminotransferase and aspartate aminotransferase as indicators of liver function were not affected by experimental diets. Blood urea nitrogen responded quadratically (P=0.001) and decreased in lambs fed 30PBP in comparison with lambs fed the control diet (13.52 vs. 16.21mg/dl). Urine characteristics including pH, specific gravity, and the counts of white and red blood cells and also epithelial cells were not different across experimental diets. Apparent total tract digestibility of DM and CP reduced linearly (P<0.01) with increasing the amount of PBP in the experimental diets; however, ether-extract and ash digestibility were not affected by diets. Results indicate that using PBP to replace alfalfa hay and wheat straw up to 20% of dietary DM had no negative effects on feed intake and growth performance in Kermanian male lambs.

Effects of feeding birdsfoot trefoil hay on neutral detergent fiber digestion, nitrogen utilization efficiency, and lactational performance by dairy cows

This experiment was conducted to determine effects of feeding birdsfoot trefoil hay-based diets in comparison with an alfalfa hay-based diet on N utilization efficiency, ruminal fermentation, and lactational performance by mid-lactation dairy cows. Nine multiparous lactating Holstein cows (131±22.6 d in milk), 3 of which were rumen fistulated, were fed 3 experimental diets in a replicated 3×3 Latin square design with 3 periods of 14 d of adaptation and 7 d of data and sample collection. Within squares, cows were randomly assigned to diets as follows: alfalfa hay-based diet (AHT), alfalfa and birdsfoot trefoil hay-based diet (ABT), and birdsfoot trefoil hay-based diet (BT). Intakes of dry matter and crude protein were similar across treatments, whereas ABT and BT diets resulted in decreased fiber intake compared with AHT. Feeding BT tended to increase neutral detergent fiber digestibility compared with AHT and ABT. Milk yield tended to increase for cows consuming ABT or BT diets. Milk true protein concentration and yield were greater for cows consuming ABT relative to those fed AHT. Concentration of total volatile fatty acids tended to increase by cows fed BT compared with those fed AHT and ABT. Feeding birdsfoot trefoil hay in a total mixed ration resulted in a tendency to decrease acetate proportion, but it tended to increase propionate proportion, leading to a tendency to decrease acetate-to-propionate ratio. Whereas concentration of ammonia-N was similar across treatments, cows offered BT exhibited greater microbial protein yield relative to those fed AHT and ABT. Cows offered birdsfoot trefoil hay diets secreted more milk N than AHT, resulting in improved N utilization efficiency for milk N. The positive effects due to feeding birdsfoot trefoil hay were attributed to enhanced neutral detergent fiber digestion, and thus it could replace alfalfa hay in high-forage dairy diets while improving N utilization efficiencies and maintaining lactational performance compared with alfalfa hay.

Casca de soja em dietas para coelhos em crescimento

O presente trabalho teve como objetivo avaliar efeitos da inclusão de casca de soja em substituição ao feno de alfafa sobre o desempenho, características da carcaça e trato gastrointestinal e parâmetros bioquímicos de coelhos em fase de crescimento. Foram utilizados 30 coelhos da raça Nova Zelândia Branca, divididos igualmente em três tratamentos, compostos pela dieta experimental padrão (sem inclusão de casca de soja); e pelas dietas com 50% e 100% de substituição de alfafa por casca de soja nas respectivas rações experimentais. Concluiu-se que a casca de soja pode ser incluída em dietas para coelhos em crescimento, em substituição ao feno de alfafa em até 100% sem causar danos no desempenho nas características de carcaça e do trato gastrointestinal e parâmetros bioquímicos dos animais, durante a fase de crescimento. Porém, a utilização deste co-produto exige a necessidade de estudos mais aprofundados em virtude da escassez de dados.

Effects of pistachio by-products in replacement of alfalfa hay on ruminal fermentation, blood metabolites, and milk fatty acid composition in Saanen dairy goats fed a diet containing fish oil

The objective of this study was to investigate the effects of pistachio by-products (PBP) in replacement of alfalfa hay (AH) on ruminal fermentation, blood metabolites, and milk fatty acid composition in Saanen dairy goats fed a diet containing fish oil. For this purpose, 15 multiparous lactating Saanen goats (on day 25 postpartum, 38.15±1.2 kg) were randomly assigned to three treatment diets in a completely randomized design with five goats per treatment. The treatment consisted of feeding the following diets: (1) control (AH), (2) 30% PBP, and (3) 30% PBP + polyethylene glycol (PEG, 1 g/Kg of dry matter [DM]). The experiment lasted 21 days, including 16 days of adaptation to the experimental diets followed by a five-day sampling period for determining milk yield and composition, dry matter intake (DMI), and blood metabolites. The results showed that DMI was affected (P<0.05) by using PBP in the diets. The goats fed PBP had a lower (P<0.05) DMI than those in other treatments. No differences were observed in milk yield and composition among the dietary treatments. The goats fed PBP (with and without PEG) had higher (P<0.05) amounts of C16:0 and trans-C18:1 isomer in their milk fat than those fed AH. C24:0 was detected at higher (P<0.05) concentrations in goats fed AH than those in other treatments. Overall, different treatments had no significant effects on the concentrations of saturated, monounsaturated, and polyunsaturated fatty acids (PUFA) in milk fat. Trans fatty acids (TFA) in milk fat exhibited higher (P<0.05) concentrations in PBP and PBP-PEG treatments than in AH. However, no differences were detected in the concentrations of short, medium, and long chain fatty acids among the treatments. No differences were observed in rumen pH among the treatments, while rumen ammonia-N concentrations were lower (P<0.01) in goats fed PBP than those in the other treatments. Treatments showed no differences with regard to blood metabolites (i.e., cholesterol, triglyceride, blood urea nitrogen, total protein, albumin, and glucose). These findings indicate that the inclusion of PBP in replacement of AH in the diet of dairy Saanen goats have no adverse effects on ruminal fermentation and blood metabolites. Moreover, PBP is capable of modifying the fatty acid profile of milk in dairy goat.

Effects of pistachio by‐products in replacement of alfalfa hay on populations of rumen bacteria involved in biohydrogenation and fermentative parameters in the rumen of sheep

The objective of this study was to investigate the effect of sundried pistachio by-products (PBP) as a replacement of alfalfa hay (AH) on blood metabolites, rumen fermentation and populations of rumen bacteria involved in biohydrogenation (BH) in Baluchi sheep. Four adult male Baluchi sheep (41 ± 1.3 kg, BW) fitted with ruminal cannulae were randomly assigned to four experimental diets in a 4 × 4 Latin square design. The dietary treatments were as follows: (i) control, (ii) 12% PBP (0.33 of AH in basal diet replaced by PBP), (iii) 24% PBP (0.66 of AH in basal diet replaced by PBP) and (iv) 36% PBP (all of AH in basal diet replaced by PBP). The basal diet was 360 g/kg dry matter (DM) alfalfa hay, 160 g/kg DM wheat straw and 480 g/kg DM concentrate. The trial consisted of four periods, each composed of 16 days adaptation and 4 days data collection including measurement of blood metabolites, rumen fermentation and population of bacteria. No differences were observed in rumen pH among the treatments, while rumen ammonia-N concentrations were decreased (p< 0.05) with increasing PBP by up to 36% DM of the diets. Using of 36% PBP in the diet reduced (p < 0.05) total volatile fatty acids (VFA) concentrations and the molar proportion of acetate, while the concentration of propionate, butyrate and acetate to propionate ratio were similar to all other treatments. The concentration of blood urea nitrogen (BUN) decreased (p < 0.01) with increasing PBP by up to 36% DM in the diets of sheep. However, other blood metabolites were not affected by the experimental diets. It was concluded that PBP in replacement of AH had no effects on the relative abundance of Butyrivibrio fibrisolvens and Butyrivibrio proteoclasticus in relation to the control diet.

Corn silage versus corn silage:alfalfa hay mixtures for dairy cows: Effects of dietary potassium, calcium, and cation-anion difference

Corn silage (CS) has replaced alfalfa hay (AH) and haylage as the major forage fed to lactating dairy cows, yet many dairy producers believe that inclusion of small amounts of alfalfa hay or haylage improves feed intake and milk production. Alfalfa contains greater concentrations of K and Ca than corn silage and has an inherently higher dietary cation-anion difference (DCAD). Supplemental dietary buffers such as NaHCO3 and K2CO3 increase DCAD and summaries of studies with these buffers showed improved performance in CS-based diets but not in AH-based diets. We speculated that improvements in performance with AH addition to CS-based diets could be due to differences in mineral and DCAD concentrations between the 2 forages. The objective of this experiment was to test the effects of forage (CS vs. AH) and mineral supplementation on production responses using 45 lactating Holstein cows during the first 20 wk postpartum. Dietary treatments included (1) 50:50 mixture of AH and CS as the forage (AHCS); (2) CS as the sole forage; and (3) CS fortified with mineral supplements (CaCO3 and K2CO3) to match the Ca and K content of the AHCS diet (CS-DCAD). Feed intake and milk production were equivalent or greater for cows fed the CS and CS-DCAD diets compared with those fed the AHCS diet. Fat percentage was greater in cows fed the CS compared with the AHCS diet. Fat-corrected milk (FCM; 3.5%) tended to be greater in cows fed the CS and CS-DCAD diets compared with the AHCS diet. Feed efficiencies measured as FCM/dry matter intake were 1.76, 1.80, and 1.94 for the AHCS, CS, and CS-DCAD diets, respectively. The combined effects of reduced feed intake and increased FCM contributed to increased feed efficiency with the CS-DCAD diet, which contained 1.41% K compared with 1.18% K in the CS diet, and we speculate that this might be the result of added dietary K and DCAD effects on digestive efficiency. These results indicate no advantage to including AH in CS-based diets, but suggest that improving mineral supplementation in CS-based diets may increase feed efficiency.

Effects of grain-pellet and alfalfa-pellet subacute ruminal acidosis (SARA) challenges on feeding behaviour of lactating dairy cows

Li, S., Khafipour, E., Krause, D. O., González, L. A. and Plaizier, J. C. 2011. Effects of grain-pellet and alfalfa-pellet subacute ruminal acidosis (SARA) challenges on feeding behaviour of lactating dairy cows. Can. J. Anim. Sci. 91: 323–330. The effects of two nutritional challenges aimed at inducing subacute ruminal acidosis (SARA) on the feeding behaviour of lactating dairy cows were investigated in two separate experiments. Both experiments included eight tie-stall-housed cows that were fed once daily. Feeding behaviour of individual cows was monitored by continuously weighing the feed in the mangers. In each experiment, ruminal pH was monitored in four rumen cannulated cows. In the first experiment, cows received a control diet containing 50% mixed concentrate and 50% alfalfa and barley silage (DM basis) during weeks 1 to 5 of two subsequent 6-wk periods. During week 6 of both periods, a grain-pellet SARA challenge (GPSC) was conducted by replacing 21% of DM of the basal diet with wheat-barley pellets. Data obtained in week 4 were taken as a control. In the second experiment, cows received a control diet containing 50% of DM as mixed concentrate and 50% of DM as chopped alfalfa hay during the first week of a 5-wk period. Between week 2 and week 5, an alfalfa-pellet SARA challenge (APSC) was conducted by replacing alfalfa hay in the control diet with alfalfa pellets at a rate of 8% per week. Week 1 and week 5 were considered as the control and SARA challenge, respectively. In the first experiment, the GPSC reduced the meal duration from 48.9 to 38.6 min meal−1 and the eating time from 6.7 to 5.5 h d−1. Meal criteria, meal frequency, meal size, and eating rate were not affected. In the second experiment, the APSC did not affect the meal criterion, meal duration, and eating time per day, but increased dry matter intake from 18.7 to 24.3 kg d−1, meal frequency from 8.2 to 9.4 meals d−1, meals size from 2.4 to 2.7 kg DM, and eating rate from 54.8 to 67.6 g DM min−1. The duration of the first meal after feed delivery was reduced from 154.5 to 103.6 min by the GPSC and from 146.7 to 112.2 min by the APSC. This reduction in the duration of the first meal was accompanied by a reduction in the drop of the ruminal pH during the GPSC, but not during the APSC. Only the APSC increased eating rate of the first meal. Other parameters of this first meal were not affected by both challenges.

Effect of feeding alfalfa hay or Tifton 85 bermudagrass haylage with or without a cellulase enzyme on performance of Holstein cows

Forty-four lactating Holstein cows (173±30 DIM, 42.5±6.8kg of milk, 4.03±0.69% fat, 674±78kg of body weight) were used in an 8-wk, completely randomized trial with a 2 × 2 factorial arrangement of treatments to determine the effect of forage source and supplemental cellulase enzyme on performance. Treatments included 2 forage combinations (corn silage plus 12.2% dry matter, DM, from either alfalfa hay or Tifton 85 bermudagrass haylage) with or without a commercial cellulase enzyme applied to the total mixed ration at the rate of 4 g/head per day (Promote N.E.T.-L, Cargill Animal Nutrition, Minneapolis, MN). Experimental diets were formulated to provide similar concentrations of protein (16.5% of DM), energy (1.63 Mcal of net energy for lactation/kg of DM), and neutral detergent fiber (41.7% of DM) and were fed once daily as a total mixed ration behind Calan doors for ad libitum intake. The cellulase enzyme provided 1,200 cellulase units of activity/g of product and was applied to the total mixed ration and allowed to mix for 5min before feeding. Before beginning the trial, all cows were trained to use Calan (American Calan, Northwood, NH) doors and then fed the alfalfa hay-based diet for 2 wk. Data collected during wk 2 were used as a covariate in the statistical analysis. At the beginning of the 6-wk experimental period, cows were assigned randomly to 1 of the 4 experimental diets. No interactions were observed between forage and enzyme for any measures. Daily DM intake; milk yield; concentrations of milk fat, true protein, lactose, and solids not fat; energy-corrected milk yield; and dairy efficiency were not different among alfalfa or Tifton 85 bermudagrass rations with or without cellulase enzyme supplementation. The results of this trial indicate that Tifton 85 bermudagrass haylage can replace alfalfa hay in diets fed to high-producing, lactating dairy cows without depressing DM intake or milk yield when rations are balanced for NDF. Although supplemental cellulase enzymes have been shown to improve ration digestibility and animal performance in previous trials, no advantages were observed in the current trial.

The effect of ensiled mixed tomato and apple pomace on Holstein dairy cow

This study was carried out to evaluate the effects of replacing alfalfa hay with ensiled mixed tomato and apple pomace (EMTAP) on ruminal fermentation, blood metabolites, chewing activity and apparent digestibility of diets. Six multiparous mid-lactating Holstein dairy cows were used in 3×3 Latin square design. The animals were fed with a control (0%EMTAP) and two different levels of EMTAP (15, 30%) containing diets. Results showed significant differences between treatments. The substitution of EMTAP in dairy cow’s diet was associated with a reduction of chewing activity, better DM and OM digestibility and higher blood metabolites concentration. Feeding EMTAP resulted in a significant higher concentration of acetic, propionic acids, and total volatile fatty acids in rumen, and lower rumen pH. It was concluded that, EMTAP might efficiently comprise up to 30% of the diets. The nutritive value of tomato and apple pomace could be improved when they are used together (50:50) in dairy cows diet.

The Effect of Ensiled Mixed Tomato and Apple Pomace on Holstein Dairy Cow

This study was carried out to evaluate the effects of replacing alfalfa hay with ensiled mixed tomato and apple pomace (EMTAP) on ruminal fermentation, blood metabolites, chewing activity and apparent digestibility of diets. Six multiparous mid-lactating Holstein dairy cows were used in 3×3 Latin square design. The animals were fed a control (0% EMTAP) and two different levels of EMTAP (15 and 30%) containing diets. The results showed significant differences among treatments. The substitution of EMTAP in dairy cow’s diet was associated with a reduction of chewing activity, better DM and OM digestibility and higher blood metabolites concentration. Feeding EMTAP resulted in a significant higher concentration of acetic, propionic acids, and total volatile fatty acids in rumen and lower rumen pH. It was concluded tha, EMTAP might efficiently comprise up to 30% of the diets. The nutritive value of tomato and apple pomace could be improved when they are used together (50:50) in dairy cows diet.