Rumen degradability characteristics of normal maize stover and silage, and quality protein maize silage-based diets offered to cows

Rumen degradability characteristics of dry matter (DM), organic matter (OM) and crude protein (CP) of normal maize (NM) stover (T1)-, NM silage (T2)- and quality protein maize (QPM) silage (T3)-based diets were studied using three rumen-fistulated Boran × Friesian non-lactating cows (371?±?32.00?kg) in 3?×?3 Latin Square Design. Cows were supplemented with a similar concentrate mix. In sacco degradability of DM and OM indicated that the (a) values of DM (128) and OM (114) for NM stover were lower (P?相似文献   

Influence of replacing corn silage with barley silage in the diets of buffalo cows on milk yield and quality

A 150-day trial was carried out on 40 Italian Mediterranean buffalo cows that, immediately after calving, were equally divided into two homogeneous groups (M and O) based on the number of calving events and previous milk yield. The animals were fed (16 kg dry matter (DM)/head) two isoenergy/isoprotein diets (NEl: 6.39 MJ/kg DM; 15.4 CP% DM), composed of corn (diet M) or barley silage (diet O) concentrate, alfalfa hay, and a vitamin-mineral supplement. The fermentation characteristics of both silage diets were evaluated by an in vitro gas production technique, and their nutritional values were calculated as follows: NEl (MJ/kg DM) = 0.54 + 0.0959 GP + 0.0038 CP + 0.0001733 CP², where GP is the gas production after 24 h of incubation (ml/200 mg DM) and CP is the protein content of silage (g/kg DM). The nutritional values of the silages were slightly different (4.16 vs. 4.14 MJ/kg DM for M and O, respectively) likely due to the high content of hemicellulose in the O diet (22.0 vs. 16.9%). Average milk yield did not differ between the groups; instead, milk fat (8.39 vs. 9.06%; P < 0.01) and protein (4.41 vs. 4.60%; P < 0.01) levels were significantly higher in the O group. The results elicit great interest in southern Italy where corn cultivation is adversely affected by the high cost of irrigation.

     

Feeding <Emphasis Type="Italic">Moringa oleifera</Emphasis> fresh or ensiled to dairy cows—effects on milk yield and milk flavor

Moringa oleifera, either fresh or ensiled, was compared with Elephant grass as a main feedstuff for dairy cows. To test the effects feed had on milk yield, milk composition, ration digestibility, and the organoleptic characteristics of milk, six lactating dairy cows were used in a Changeover 3 × 3 Latin Square experiment, replicated twice. With equal intake of metabolizable energy the intake of protein and fiber differed (p < 0.001) between all diets where fresh Moringa had the highest and the Elephant grass diet had the lowest intake. Compared with the control diet, ensiled Moringa had higher digestibility (P < 0.05) of both protein and fiber. With the exception of DM digestibility, no digestibility differences were found between fresh Moringa and Moringa silage treatments. Milk yield did not differ between any of the treatments and averaged 13.7 kg cow day⁻¹. Milk composition was similar among all treatments. Milk from the fresh Moringa treatment, however, had a grassy flavor and aroma, significantly different from the other two treatments, even though it was normal in color and appearance. No organoleptic differences were found between milk from the control treatment and the Moringa silage treatment. The conclusion is that Moringa silage can be fed to dairy cows in large quantities to produce the same quantity and quality of milk as traditional diets.     

Milk yield and quality in Guernsey cows fed cottonseed cake-based diets partially substituted with baobab (<Emphasis Type="BoldItalic">Adansonia digitata</Emphasis> L.) seed cake

The objective of this study was to determine the effects of partially substituting cottonseed cake with graded levels of baobab (Adansonia digitata L.) seed cake (BSC) on milk yield and quality in Guernsey cows. Sixteen cows in mid-lactation and in their third parity were allocated to diets containing 0% (control), 5%, 10%, and 15% BSC in a completely randomized design. Each cow was given a daily feed ration of 6 kg and a basal diet of soya bean stover ad libitum. There were no differences in daily feed intake (P > 0.05), but basal intake differed among all treatment groups with cows on the control diet having the highest intake (30 ± 0.34 kg/day). Mean daily milk yield differed (P < 0.05) among all treatment groups. However, the control had higher milk yield of 12.1 ± 0.73 kg/day, and the 15% BSC had the least yield of 7.46 ± 0.73 kg/day. Cows on the control diet had higher milk butterfat content (6.12%; P < 0.05) than those on the BSC-based diets. Protein content differed (P < 0.05) across all treatment groups with cows on 15% BSC producing the highest protein content (3.43%) while the control had the least (2.6%). The concentration of milk total solids for cows fed on 15% BSC was higher (P < 0.05) than that from cows on other diets. Lactose content was not affected by the diets (P > 0.05). These results indicate that BSC can substitute soya bean cake in dairy diets, but milk production and butterfat content are compromised.     

Effect of silage from ryegrass intercropped with winter or common vetch for grazing dairy cows in small-scale dairy systems in Mexico

The objective was to determine the effect of including silages of annual ryegrass (Lolium multiflorum) intercropped with winter vetch (Vicia villosa) (ARG-VV) or with common vetch (Vicia sativa) (ARG-VS) compared with maize silage (MS) on milk yield and milk composition of dairy cows grazing cultivated perennial ryegrass–white clover pastures with supplemented concentrate during the dry season. Six Holstein dairy cows with a mean yield of 19.0 kg/cow/day at the beginning of the experiment were randomly assigned to a 3 × 3 repeated Latin square. Treatments were: 8 h/day intensive grazing, 3.6 kg of dry matter (DM) per cow per day of concentrate plus MS, and ARG-VV or ARG-VS ad libitum at a stocking rate of 3.0 cows/ha for three experimental periods of 3 weeks each. Milk yield (MY) and milk composition, live weight and body condition score as well as silage and concentrate intakes were recorded during the third week of each experimental period, and pasture intake was estimated indirectly from utilised metabolisable energy. Economic analysis was obtained by preparing partial budgets. There were no statistical differences (P > 0.10) in MY, milk fat or protein content nor for live weight, but there was significant difference (P < 0.10) in body condition score. There were non-statistical differences in silage DM intake (P < 0.11); however, significant differences (P < 0.10) were obtained for estimated grazed herbage intake whilst no differences for total DM intake. Slightly higher economic returns (10%) were obtained with ARG-VS over MS, and this was 7% higher than ARG-VV. It is concluded that ARG-VS could be an option for complementing grazing for small-scale dairy production systems in the dry season as it is comparable to MS in animal performance and slightly better in economic terms.     

Effects of Moringa oleifera silage on milk yield,nutrient digestibility and serum biochemical indexes of lactating dairy cows

This study investigated the effects of Moringa oleifera (MO) as a partial substitute of alfalfa hay on milk yield, nutrient apparent digestibility and serum biochemical indexes of dairy cows. MO was harvested at 120 days post‐seeding. Fresh MO was cut, mixed with chopped oat hay (425:575 on a DM basis), ensiled and stored for 60 days. Sixty healthy Holstein dairy cows were allocated to one of three groups: NM (no MO or control), LM (low MO; 25% alfalfa hay and 50% maize silage were replaced by MO silage) or HM (high MO; 50% alfalfa hay and 100% maize silage were replaced by MO silage). The feeding trial lasted 35 days. The LM and HM diets did not affect dry matter (DM) intake, milk yield or milk composition (lactose, milk fat, milk protein and somatic cell count). The apparent digestibility of DM and NDF was lower for HM group than NM group. Additionally, there were no significant differences in serum biochemical indexes between the LM and NM groups. The HM group had lower serum concentrations of total cholesterol, high‐density lipoprotein cholesterol, and low‐density lipoprotein cholesterol and higher serum concentrations of urea than the NM group. The partial replacement of alfalfa hay (≤50%) and maize silage with MO silage had no negative effects on milk yield, in vivo nutrient apparent digestibility or serum biochemical indexes of lactating cows.     

Silage from maize (Zea mays), annual ryegrass (Lolium multiflorum) or their mixture in the dry season feeding of grazing dairy cows in small-scale dairy production systems in the Highlands of Mexico

Small-scale dairy systems based on grazing have dry-season herbage shortages. A repeated 3 × 3 Latin Square experiment evaluated grazing with silage from maize (MS), annual ryegrass (ARG) or a mixture (MIX) with 9 cows with 3 week periods; continuously grazed at 3.6 cows/ha with 3.6 kg DM/day of concentrate. Treatments were 7 kg DM of MS, ARG or a 2 MS:1 ARG mixture. Milk yield (MY), milk composition, live-weight, body condition, silage and concentrate intake were recorded. Herbage DM intake was estimated indirectly. Activity budgets were done for economic analysis. MY on MS (21.5 kg/cow/d) was 0.06 higher than on ARG (P < 0.09) with no differences on MIX. There were no differences for milk fat, milk protein, or body condition score. Live-weight on ARG was higher (P < 0.01) than on MS or MIX. Silage intake was higher (P < 0.01) on ARG and MS than on MIX. Herbage intake was lower (P < 0.05) on MS, compared with MIX and ARG. Total DM intake on ARG was higher than MS (P < 0.01), and MIX in between. MS resulted in 0.12 higher economic returns over ARG which had highest costs. Annual ryegrass may have a place in small-scale systems, but not as silage due to higher costs.     

Effect of supplementation of mustard oil cake on intake,digestibility and microbial protein synthesis of cattle in a straw-based diet in Bangladesh

The objective of this study was to analyse the effects of different levels of rumen-degradable protein (RDP) on intake, digestibility and microbial protein synthesis by supplementing mustard oil cake (MOC) on rice straw-based diet of cattle (Bos indicus) in Bangladesh. A 4 × 4 Latin square design was applied. Four diets having constant energy (7.0 MJ/kg of dry matter (DM)) with varying levels of RDP (M ₀ = 4.1 g/MJ (control), M ₁ = 6.3 g/MJ, M ₂ = 8.3 g/MJ and M ₃ = 12.4 g/MJ of metabolizable energy (ME)) were received by each animal for a period of 28 days. A metabolism trial was conducted for 7 days. Results indicate that with increasing levels of RDP, crude protein (CP) and RDP intake increased significantly (P < 0.01). The significant (P < 0.01) increase in digestibility values are obtained for DM, organic matter, CP and digestible organic matter in the rumen. The digestibility of neutral detergent fibre and acid detergent fibre was also increased significantly (P < 0.05). The total nitrogen (N), ammonia-N and total volatile fatty acids increase significantly (P < 0.01) while the rumen pH increased from M ₀ to M ₂ and decreased thereafter. The efficiency microbial N intake increased significantly (P < 0.01) but showed a curvilinear response with higher RDP level (12.40 g/RDP/MJ ME). This study concludes that supplementation of RDP from MOC enhances the intake, digestibility and microbial protein synthesis which ultimately increases utilization of low-quality feed resources that can be used for developing cost-effective feeding systems on a straw-based diet in tropical regions.     

High levels of whole raw soya beans in dairy cow diets: digestibility and animal performance

The aim of this study was to evaluate the effects of high levels of whole raw soya beans in the diets of lactating cows. Twelve Holstein dairy cows were used, randomized in three 4 ×  4 balanced and contemporary Latin squares and fed the following diets: (i) control (C), without including whole raw soya beans; (ii) 80 g/kg in DM of whole raw soya beans (G80); (iii) 160 g/kg in DM of whole raw soya beans (G160); and (iv) 240 g/kg in DM of whole raw soya beans (G240). There was significant reduction (p < 0.05) in dry matter intake (kg/day) in cows supplemented with G240 compared with C (23.8 vs. 25.3 respectively). G240 diets presented lower crude protein digestibility (g/kg) (p < 0.05) in comparison with C diet (683 vs. 757 respectively). There was significant effect of experimental rations in nitrogen balance (p < 0.05), G240 diet presenting significant reduction in comparison with the other diets, and faecal excretion of nitrogen was higher for G240 diet. The concentration of ruminal ammoniacal nitrogen was significantly higher (p < 0.05) for cows receiving control diet, compared to other diets. G240 diet resulted in significantly lower milk and protein yield (p < 0.05) in comparison with C diet. Significant C18:2 cis fatty acids were observed in milk concentrations (p < 0.05) for G240 diet. The use of high level of whole raw soya beans in dairy cow diets improves the unsaturated fatty acid profile in milk, and the diets (G80 and G160) led to minor alterations in the digestive processes and animal metabolism.     

Nutrient digestibility and feedlot performance of lambs fed diets varying protein and energy contents

Thirty-six Thalli male growing lambs were used in a completely randomized design with 2 × 2 factorial arrangement of treatments to evaluate the effect of varying levels of energy and protein on nutrient intake, digestibility, weight gain, and gain to feed ratio. Four experimental diets, i.e., low energy–low protein (LE-LP), low energy–high protein (LE-HP), high energy–low protein (HE-LP), and high energy–high protein (HE-HP) were formulated. The low- and high-energy diets contained 2.3 and 2.7 MJ/kg dry matter (DM) with 12% and 14% of crude protein. The lambs were fed ad libitum. Dietary energy and protein levels and their interactions influenced the nutrient intake. Maximum dry matter intake was noted in animals fed LE-HP diet followed by LE-LP, HE-HP, and HE-LP diets. Digestibility of DM and N increased (P < 0.01) and that of neutral detergent fiber decreased (P < 0.01) linearly with increasing levels of dietary energy and protein. Digestibility of N was only affected by protein level and interaction between energy and protein levels. Average daily gain was higher (P < 0.01) in lambs fed HE-HP diet followed by LE-HP, LE-LP, and HE-LP diets. Dietary energy and protein levels and their interaction had significant effect (P < 0.01) on gain to feed ratio.     

Effect of feeding calcium salts on performance of nursing Awassi ewes

Twenty nursing Awassi ewes (BW = 50 ± 2.35 kg, age = 4.5 ± 1.2 years) with their lambs were used to evaluate the effects of feeding calcium salts in lactation diets on performance and pre-weaning growth of their lambs. Treatments were 0% calcium salts (CON) or 5% calcium salts (FAT). At the end of the study, a digestibility experiment was performed. Milk yield was greater (P < 0.05) for ewes fed the FAT diet than the CON diet. Milk composition was similar (P > 0.05) between diets. However, milk energy value (kcal/day) tended to be greater (P = 0.07) for the FAT diet than the CON diet. Concentrations of milk C18:1c9 and C20:0 were greater (P < 0.05) in ewes fed the FAT diet than the CON diet. However, concentration of trans-10, cis-12 CLA was lower (P = 0.05) in the FAT diet than in the CON diet. No differences in feed intake and body weight change were detected between diets. Digestibility of dry matter, organic matter, crude protein, ether extract, neutral detergent fiber, and acid detergent fiber were similar (P > 0.05) for diets. For lambs, weaning weight was not affected by treatments. However, average daily gain and total gain were greater (P = 0.053) for the FAT diet than the CON diet. Results suggest that supplementing lactating ewes with calcium salts at the beginning of lactation phase improves daily milk yield of ewes and pre-weaning growth of their lambs with no major negative impact on feed intake and digestibility.     

Productive response of grazing dairy cows to fresh chopped maize supplementation under a small farming system in the Mexican Highlands

The aim of this study was to evaluate the animal performance of late lactating grazing dairy cows in response to fresh chopped maize (FCM) supplementation under a small farming system. Twenty-four multiparous Holstein dairy cows were used in a rotational grazing on a mixed alfalfa–orchard grass sward. Three treatments were evaluated: 0, 4, and 8 kg dry matter (DM) of FCM cow⁻¹ day⁻¹. The experimental design was a crossover, with three periods lasting 19 days each. There were no differences on individual milk production nor on milk composition. Herbage DM intake decreased (P < 0.0001) from 8.4 to 5.2 and 3.1 kg DM when increasing FCM from 0 to 4 and 8 kg DM, respectively. Total DM intake increased (P < 0.0001) with 8 kg DM of FCM, averaging 14.8 kg. Substitution rate was 0.75 and 0.67 kg of pasture per kilogram of FCM with 4 and 8 kg DM of FCM, respectively. Consequently, stocking rate (STR) increased (P < 0.0001) from 3.8 to 6.2 and 8.8 cows ha⁻¹, and milk production per hectare increased (P < 0.0001) from 39.3 to 64.5 and 95.5 kg of milk, with 0, 4, and 8 kg DM of FCM, respectively. This means that STR increases 0.63 cows ha⁻¹, and 0.75 kg of milk ha⁻¹ when FCM is increased in 1 kg of DM. In conclusion, offering FCM as supplement to grazing dairy cows in their final lactation stage had no benefits in individual milk production or milk composition, but had benefits on milk production per hectare.     

Effect of feeding different levels of foliage from Cratylia argentea to creole dairy cows on intake, digestibility, milk production and milk composition

The effect of feeding different levels of foliage from Cratylia argentea (Desvaux) O. Kuntze to dairy cows on intake, digestibility, milk production and milk composition was studied in the dry tropics in Nicaragua. The treatments were sorghum silage ad libitum, either unsupplemented or supplemented with 2 kg or 3 kg of Cratylia on a dry matter (DM) basis. Six Bos indicus cows of the Creole Reyna breed, with a mean body weight of 386 (SD 19) kg were used in a replicated 3×3 Latin square design. Supplementation with Cratylia increased (p < 0.05) DM intake from 6.6 to 7.8 and 8.7 kg DM/day and milk production from 3.9 to 5.1 and 5.7 kg/day for sorghum silage alone and supplementation with 2 kg and 3 kg DM of Cratylia, respectively. Milk fat, total solids and crude protein and organoleptic characteristics (smell, taste and colour) were not significantly different among diets. The apparent digestibility coefficients of dry matter, organic matter, neutral detergent fibre and acid detergent fibre were not affected significantly by supplementation with Cratylia. However, crude protein (CP) digestibility increased (p < 0.05) in the diets supplemented with Cratylia compared to sorghum silage alone. In conclusion Cratylia given as a protein supplement to a low-quality diet improved DM intake and CP digestibility of the diet and increased milk production, but did not affect milk composition.     

Evaluation of the metabolizable energy value for growing lambs of the Mucuna pruriens seed and the whole pod

Whole pod and seeds of velvet bean (Mucuna pruriens) were included in diets for growing sheep used to validate previously estimated ME values of 9.7 MJ and 12.6 MJ for whole pod and seed respectively. Twenty-four lambs, 15 females and nine males of 18.7 ± 2.4 kg average weight, were allocated in three treatments using a completely randomized block design with eight replicates per treatment. Each group was given a diet with a ratio of 60% of Napier grass (Pennisetum purpureum) and 40% of a supplement with the addition of 0%, 50% whole pod or 66% of M. pruriens seeds, for TI, TII and TIII respectively. Diets were formulated to meet the requirements for 100-g daily live weight gain (LWG). The total dry matter intake (836 g a⁻¹ d⁻¹, forage + supplement), LWG (90 g a⁻¹ d⁻¹) and feed conversion (9.66 kg DM/kg LWG) of lambs from TIII were lower (P < 0.05) compared to 941 g, 121 g, and 7.78 kg DM/kg LWG from TII and 976 g, 132 g and 7.50 kg DM/kg LWG from TI respectively. No difference was found (P > 0.05) between TI and TII in the three evaluated variables. The ME values of whole pod and seeds of M. pruriens used in this work were validated. It was concluded that M. pruriens can be included as a component in diets for growing sheep, as a partial replacement of conventional feedstuffs.     

Effects of first postpartum progesterone rise,metabolites, milk yield,and body condition score on the subsequent ovarian activity and fertility in lactating Holstein dairy cows

Seventy multiparous healthy lactating Holstein cows (fat-corrected milk yield = 7,561.8 kg) were monitored from 14 days before to 70 days after calving. Transrectal ultrasound scanning was performed twice weekly from 7 to 65 days postpartum. Blood samples were also collected twice weekly to measure serum P₄ and biweekly to detect serum β-hydroxybutyrate (βHB) and nonesterified fatty acid (NEFA) concentrations. Body condition score (BCS) was taken biweekly after calving. Based on the serum P₄ profile of 59 cows (11 cows were excluded due to the occurrence of postpartum diseases) studied, 27 (45.8%) had normal ovarian activity, while 21 (35.6%), six (10.1%), three (5.1%), and two (3.4%) had delayed ovulation (DOV), prolonged luteal phase (PLP), short luteal phase (SLP), and cessation of ovarian activity, respectively. Cows with PLP had an earlier ovulation compared to that of cows with normal ovarian activity (23.16 ± 4.02 vs 31.9 ± 8.35 days; P < 0.05). PLP cows also had a greater mean ± standard deviation peak milk yield (44.2 ± 5.8 vs 37.2 ± 5.7 kg/day, 75 days postpartum; P < 0.05) than cows with normal postpartum ovarian activity. The PLP group also had greater milk production in the previous lactation period. Logistic regression analysis indicated that cows with P₄ concentration ≥1 ng/ml on day 24 after calving were more at risk for PLP by 1.1 for each 1 kg increase in mean peak milk yield during 75 days after calving. BCS was lower in cows with DOV compared to that of cows with normal ovarian activity at any time after calving (P < 0.05). Serum βHB concentrations in DOV cows were significantly higher than that of normal cows on day 42 after calving (0.69 ± 0.29 vs 0.54 ± 0.12 mmol/L, P < 0.05). No significant difference was found in the mean concentrations of NEFA between cows in different groups at any time after calving (P > 0.05). The concentrations of P₄ on days 28 and 31 were negatively correlated with βHB concentration on day 42 after calving in cows with normal ovarian activity (R = −0.44, P = 0.02). In conclusion, these findings suggest that early ovulation and hence early postpartum P₄ rise in addition to the high milk production could partly be responsible for the occurrence of PLP in dairy cows.     

Performance and carcass measurements of ewe lambs reared in a feedlot and fed wheat (<Emphasis Type="BoldItalic">Triticum durum</Emphasis> Desf.) middlings total mixed rations in the summer season

The effect of total mixed ratios containing wheat middlings (WM) as a corn grain substitute on the growth performance and carcass traits of Comisana ewe lambs was evaluated. Forty ewe lambs, with average live body weight of 13 ± 0.3 kg (mean ± SEM), were allocated randomly to two isocaloric and isonitrogenous diets for 50 days. Control diet contained 400 g/kg of dry matter (DM) of corn as the main starchy source, whereas experimental diet contained 600 g/kg DM of WM. In vivo nutrient apparent digestibility of the two diets was determined using Comisana rams (mean body weight, 65 ± 2.3 kg) and indicated significant (P < 0.05) differences for neutral detergent fibre, acid detergent fibre, cellulose and hemicellulose fractions. Results from the trial using Comisana ewe lambs showed that growth traits were unaffected by dietary treatments as well as none of the carcass measurements examined (P > 0.05). These findings indicate that WM results as a suitable feed ingredient for growing ewe lambs that can be a satisfactory substitute to conventional grain source.     

Effect of dietary monensin inclusion on performance,nutrient utilisation,rumen volatile fatty acid concentration and blood status of West African dwarf bucks fed with basal diets of forages

This experiment investigated the effect of dietary monensin on performance, nutrient utilisation, rumen volatile fatty acid and blood status in West African dwarf (WAD) goats fed with basal diets of forages. Four concentrate supplements were formulated to include 0 (MO), 15 (M15), 30 (M30) and 45 (M45) mg monensin/kg dry matter. Twenty-four WAD bucks (7.3 ± 1.20 kg initial body weight, aged 9–12 months) were randomly allotted to four experimental diets in a completely randomised design for 90 days, six animals per diet. Results indicated that animals fed M15, M30 and M45 diets had lower (P < 0.01) dry matter and water intake than those fed M0 diet. Crude protein and neutral detergent fibre intakes by the bucks followed similar trend. Animals on M15, M30 and M45 had better (P < 0.001) feed and protein efficiency ratio than those fed M0 diet. Rumen pH and total volatile fatty acid concentration were maintained (P > 0.05) while monensin decreased (P < 0.001) acetate/propionate ratio. Blood glucose increased (P < 0.001) from 59.1 mg/dl in animals on M0 diet to 67.8, 66.0 and 66.3 mg/dl in animals on M15, M30 and M45 diets. Overall, there were no variations among animals on M15, M30 and M45 diets. It is concluded that feeding monensin at 15 to 45 mg/kg DM of supplemental concentrate diets to West African dwarf bucks could be effective in improving feed and protein efficiency, manipulating the rumen for increased propionate production and increasing blood glucose levels.     

Effect of increasing levels of white mulberry leaves (<Emphasis Type="Italic">Morus alba</Emphasis>) on ruminal dry matter degradability in lambs

A study was conducted to estimate dry matter (DM) degradability in the rumen of lambs offered a basal soybean meal and sorghum grain diet with three levels of white mulberry (WM) leaves (Morus alba). Diets consisted of 90% concentrate and 10% sorghum straw, which was incrementally replaced by WM leaves at 0% (control diet, T1), 2.5% (T2), and 5% (T3) of the total ration. Crude protein (CP) in WM was 21.8% (DM basis). Diets had equal CP (14% DM basis) and metabolizable energy (10.8 MJ/kg DM) content. Three non-castrated Pelibuey male lambs fitted with permanent rumen cannula were utilized in a 3 × 3 Latin square design. Each experimental period consisted of 10 days of adaptation followed by sampling. DM degradability was determined using the nylon bag technique. Bags contained the experimental diets offered in each period and were incubated in rumen in pairs for 4, 8, 12, 24, and 48 h. The potential degradation was higher (P < 0.05) for T2, followed by T3 and T1. WM level did not influence the degradation rate or the effective degradation at the three passage rates modeled. It was concluded that WM forage may have useful application in feedlot diets for growing lambs, as this forage increases potential degradation of high-grain diets. The incorporation of WM in diets for feedlot lambs in tropics may reduce the use of expensive conventional protein supplements.     

Effects of maturity stage and feeding strategy of whole crop barley silage on intake, digestibility and milk production in dairy cows

Five diets containing concentrate, grass silage and whole crop barley silage (WCBS) harvested at different maturity stages were fed to 15 multiparous dairy cows in an incomplete change-over design over three periods. Three diets contained 10.7 kg dry matter (DM) concentrate, 4 kg DM grass silage, and ad libitum access to WCBS harvested at either the heading stage (B1), the early milk stage (B2) or the early dough stage (B3) of maturity. The other two diets contained 10.7 kg DM concentrate, whereas grass silage and WCBS at heading were mixed at two different ratios with a DM content of WCBS of either 0.30 (M1) or 0.70 (M2), and the mixtures were fed ad libitum. Intakes of DM (kg day^− 1: B1 = 21.0, B2 = 20.6 and B3 = 20.0) and neutral detergent fibre (NDF; kg day^− 1: B1 = 7.0, B2 = 6.4 and B3 = 6.3) decreased, whereas starch intake increased (kg day^− 1: B1 = 3.1, B2 = 3.5 and B3 = 4.0) with increasing maturity at harvest. The apparent organic matter (OM) digestibility (g kg^− 1: B1 = 800, B2 = 774 and B3 = 729) decreased with increasing maturity stage, and consequently so did the digestible OM intake. Milk (kg day^− 1: B1 = 27.2, B2 = 26.1 and B3 = 25.9) and energy corrected milk (ECM; kg day^− 1: B1 = 31.0, B2 = 29.4 and B3 = 28.2) yields, and protein concentration (g kg^− 1: B1 = 37.1, B2 = 36.4 and B3 = 36.0) decreased with increasing maturity stage of the WCBS. When cows were fed diet B3 the milk fat concentration decreased (46.4 g kg^− 1) compared to diets B1 (49.3 g kg^− 1) and B2 (49.4 g kg^− 1). The difference in ECM yield between diets B1 and B3 was due to a combined effect of lower milk yield, and lower protein and fat concentrations. This was caused by the higher starch and lower NDF intakes with diet B3, which decreased the milk fat concentration. Moreover, a lower energy intake of diet B3 due to lower OM digestibility decreased milk protein concentration and milk yield. Mixing WCBS at the heading stage with grass silage (M2) decreased digestibility, compared to feeding the forages separately (B1). However, the differences were small and may be a result of soil contamination at harvest of some of the silages, which made the method with using incomplete faecal collection and internal marker acid insoluble ash less reliable. Including WCBS at the heading stage at 0.30 or 0.70 of forage DM did not affect DM intake or diet digestibility, probably because the grass silage in the study was very similar in energy content to the WCBS harvested at heading.     

Effect of bypass fat supplementation on productive and reproductive performance in crossbred cows

Objectives of the present study were to evaluate the effects of supplementation of bypass fat on milk production and reproductive performance of crossbred cows. Nineteen multiparous crossbred cows (2–4 lactation) were divided in two groups on the basis of most probable production ability (MPPA). The animals in group 1 (nine cows, MPPA 3,441.32 kg, control group G1) were fed chaffed wheat straw, chopped green maize, and concentrate mixture as per requirements while the animals in group 2 (10 cows, MPPA 3,457.2 kg, treatment group G2) were fed the same ration supplemented with 2.5% bypass fat (on DMI basis). The cows of G2 were supplemented bypass fat 40 days prepartum to 90 days postpartum and carry over effect of supplementation on milk production and reproductive parameters was monitored up to 210 days of lactation. Average birth weights of the calves were 24.94 and 27.95 kg in G1 and G2, respectively. The calving per cent in G1 (88.88%) was lower than that of G2 (100%). The time taken for expulsion of fetal membranes was decreased (P < 0.05) by 5.4 h in G2 compared to G1. Days required for involution of uterus was less (P < 0.05) in G2 (35.40 days) than that of G1 (49.44 days). Less number of cases of retention of fetal membranes (RFM) and metritis were observed in G2 as compared to that of G1. The average milk yield (210 days) in G2 was higher (P < 0.05) than that of G1 (18.65 vs 17.57 kg/day). Similarly, the milk yield during the carry over period (90 days) was higher (P < 0.05) in G2 than that of G1 (14.81 vs 13.79 kg/day). The time required for onset of cyclicity was reduced (P < 0.05) by 6.5 days in G2 as compared to that of G1. The service period and AI per conception were also reduced (P < 0.05) in G2 while bypass fat feeding showed no effect on conception rate (P < 0.80). There were no differences between the two groups in plasma cholesterol, progesterone and insulin concentrations. Hence, it was concluded that bypass fat supplementation at 2.5% of DMI increased the milk production and reduced the time required for involution of uterus and commencement of cyclicity. AI per conception, incidences of metritis and RFM were also reduced on supplementing bypass fat.