1,086 research outputs found
The effect of different levels of spring grass supply and stocking rate on the performance and intake of cows in early lactation
End of project reportGrazed herbage can supply nutrients to dairy cows at a lower cost than alternative feeds (Shalloo et al., 2004). Therefore, the objective of pasture-based systems must be to maximize the proportion of grazed grass in the diet of the dairy cow (Dillon et al., 2005). The extension of the grazing season into the early spring period can be facilitated by ceasing grazing of pastures earlier in autumn which allows grass to accumulate, thereby ensuring an adequate herbage supply in early spring when animal demand exceeds grass growth/supply (O’Donovan, 2000). Grazing pastures in early spring has previously been shown to increase herbage utilization and condition swards for subsequent grazing rotations (O’Donovan et al., 2004; Kennedy et al., 2006)
Effects of daily herbage allowance and stage of lactation on the intake and performance of dairy cows in early summer
peer-reviewedThis research was part-funded by European Union Structural Funds (EAGGF).The aim of this study was to investigate the relationship between daily herbage allowance (DHA) and the performance of dairy cows at two stages of lactation. Spring-calving (n=42, mean calving date 17 February) and autumn-calving (n=42, mean calving date 22 September) Friesian cows were divided into three equal groups and assigned to three levels of DHA (above a cutting height of 35 mm), 17 (L), 20 (M) and 23 (H) kg of dry matter (DM) per head, from late April to late June, 1996. The spring-calving cows grazed to sward heights (mm) of 47, 56 and 65 (s.e. 0.6) and residual herbage organic matter (OM) masses (above 35 mm) of 294, 408 and 528 (s.e. 12.1) kg/ha for L, M and H, respectively. The autumn-calving cows grazed to corresponding sward heights of 51, 60 and 69 (s.e. 1.1) mm and leftresidual herbage OM masses of 364, 445 and 555 (s.e. 12.9) kg/ha for L, M and H, respectively. Pastures were mechanically topped post grazing. Spring-calving cows consumed 13.3, 14.7 and 15.5 kg OM (s.e. 0.47) per day, and autumn-calving cows consumed 13.3, 13.8 and 14.9 kg OM (s.e. 0.43) per day for L, M and H, respectively. Mean daily solids-corrected milk yield was 23.1, 23.8 and 24.8 (s.e. 0.34) kg for the spring-calving cows, and 17.5, 18.4 and 18.7 (s.e. 0.35) kg for the autumncalving cows, for L, M and H, respectively. Milk yield could be predicted from preexperimental yield (PMY) and daily herbage organic matter allowance (DOMA, kg) according to the following equation: y = −1.13 + 0.76 (s.e. 0.030) PMY + 0.22 (s.e. 0.057) DOMA (r.s.d. 1.32, R2 0.89). The results indicate that high individual cow and herd production levels can be achieved from high quality herbage alone during early summer at a DHA of 23 kg DM for spring-calving cows and 20 kg DM for autumn-calving cows.European Unio
Productive response to two concentrate allocation strategies in dairy cows grazing with restricted pasture allowance
The objective of this study was to compare the effects of two concentrate allotment strategies on the performance of dairy cows grazing on restricted pasture and supplemented with conserved forage. Dairy cows fed equal amounts of concentrate (fixed daily rate: 5.5 kg DM/cow) were compared to cows supplemented with concentrate according to their lactation stage as follows: 10.0, 5.0, and 1.5 kg DM/cow daily during early, mid, and late lactation, respectively (average daily dose: 5.5 kg DM/cow). There was a supplementation strategy × lactation stage interaction (P < 0.05) for energy-corrected milk (ECM). For early lactation cows, supplementation at a variable rate increased ECM yield by 14.61% (P < 0.05). There was a supplementation strategy × lactation stage interaction (P < 0.05) for body weight change. At late lactation stage, cows supplemented at a fixed rate gained weight (+ 0.16 kg/day), whereas those supplemented at a variable rate lost weight (– 0.08 kg/day; P < 0.05). No significant effect was found for body condition score. The prioritization of milk production rather than the attenuation of body reserve mobilization suggests that concentrate allowance based on lactation stage may be unsuitable for minimizing the negative energy balance in early lactation cows.EEA PergaminoFil: Bretschneider, Gustavo. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Balcarce. Agencia de Extensión Rural Necochea; ArgentinaFil: Salado, Eloy Eduardo. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Rafaela; ArgentinaFil: Cuatrin, Alejandra. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Rafaela; ArgentinaFil: Mattera, Juan. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Pergamino. Forrajeras; ArgentinaFil: Pece, Mariela. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Rafaela; ArgentinaFil: Arias, Dario. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Rafaela; ArgentinaFil: Cuffia, Maira. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Dieguez, Virginia. Actividad Privada; Argentin
Effects of ground flaxseed supplementation on animal production and milk fatty acid profile in organically-certified lactating Jerseys during the grazing season
The objective of this thesis was to evaluate the effects of supplementing a pasture-based diet with ground flaxseed (GFLAX) on milk production and composition, blood parameters, digestibility, ruminal characteristics, nitrogen excretion, methane (CH4) and carbon dioxide (CO2) production, and income over feed cost (IOFC). Twenty organically-certified lactating Jerseys were blocked by milk production and days in milk (DIM) and randomly assigned to 1 of 2 treatments: 1) control (soybean meal and ground corn grain as 10% of total diet dry matter (DM) or 2) GFLAX as 10% of total diet DM. Treatments were top-dressed onto a 25% mixed grass-legume baleage, 23% grain meal, and 2% liquid molasses total mixed ration (TMR) (% of diet DM); pasture composed the remaining 40% diet DM. The study extended from June 8 to September 27, 2013 with 4, 28-d periods with the last 7 d used for data and sample collection. Dry matter intake, milk production, and milk component yields and concentrations were not affected by GFLAX supplementation. Feed efficiencies, energy corrected milk, and 4% fat corrected milk did not differ between treatments. Body weight, body condition score, plasma nonesterified fatty acids, and serum cortisol showed no difference due to GFLAX supplementation. Apparent total tract DM digestibility was lower (P = 0.04) in cows on the 10% GFLAX treatment. Dietary treatment did not affect ruminal pH, individual or total volatile fatty acid concentrations. Cows receiving the 10% GFLAX diet had (P \u3c 0.01) higher proportions of propionic acid in collected ruminal fluid. However, enteric CH4 and CO2 production did not differ between diets. Nitrogen intake (P = 0.01) and urinary urea N excretion (P = 0.03) were higher in cows on the 10% GFLAX diet due to higher crude protein concentrations of GFLAX. Milk fatty acid composition was altered by dietary flaxseed supplementation. Increases in concentrations of monounsaturated fatty acids (P \u3c 0.0001) and n-3 fatty acids (P \u3c 0.0001) with decreases in n-6 fatty acids (P \u3c 0.0001) were detected in cows consuming 10% GFLAX creating a nutritionally enriched fatty acid profile in regards to human health. A lower IOFC was noted when GFLAX was included in the diet compared to the control (5.53/cow/d, respectively), if premiums for nutritionally enriched milk are offered in the future, it may help offset the price differential
Short-Term Effect of Daily Herbage Allowance Restriction on Pasture Condition and the Performance of Grazing Dairy Cows during Autumn
The aim of this study was to evaluate the short-term effects of daily herbage allowance (DHA, defined as the product of pre-grazing herbage mass and offered area per animal) on pasture conditions and milk production of Holstein-Friesian dairy cows. Forty-four early lactation dairy cows were randomly assigned to one of four treatments in a 2 × 2 factorial design that tested two levels of DHA (17 and 25 kg DM/cow.day) and two levels of maize silage supplementation (MSS, 4.5 and 9 kg DM/cow.day) over a 77-day period. Low DHA decreased the post-grazing herbage mass from 1546 to 1430 kg DM/ha and the compressed sward height from 5 to 4.4 cm, while the grazing efficiency remained unaffected. Low DHA induced a faster herbage mass reduction, while the sward-height and pasture characteristics did not differ from the high DHA regime. Low DHA decreased the tiller production rates and daily lamina growth, while the leaf-production rate was not affected by the DHA. Daily increases of herbage mass were greater in the high DHA than in the low DHA treatments.
Individual milk production and milk protein concentration decreased at a low DHA compared to high DHA, while the milk fat concentration was greater and the milk output per hectare increased by 1510 kg. Neither the MSS level nor the interaction DHA by the MSS level had any effect on the sward characteristics or the productivity of the cows. From these results, it is suggested that,in a high-quality pasture, using 17 kg DM/cow.day was appropriate for improving both herbage utilization and milk production per hectare while maintaining the short-term conditions of a pasture grazed by dairy cows in the autumn
Effect of sward height and concentrate supplementation on forage dry matter intake, digestibility and grazing time of spring-calving beef cows
To establish the effect of sward height (SH) and concentrate supplementation on performance of grazing cattle, twenty-four cross bred Angus beef cow-calves were randomly assigned to two SH treatments (4--8 or 8--11 cm) with three supplement levels: 6.24, 3.12 or 0 kg/d. The study was conducted in three periods (P): May (P1), June/July (P2) and August (P3) in 1996. There was no SH x supplement level x period or SH x supplement level interaction (P \u3e .10) on forage DMI, DMD or grazing time (GT). Cows on low SH had greater (P \u3c .08) DMI and GT (P \u3c .01) than cows on high SH. Forage DMI, DMD and GT decreased (P \u3c .05) with supplementation. Grazing efficiency declined with supplementation and advancing grazing season (P \u3c .01). Cows consumed more forage DM (P \u3c .01) in P1 and P2 than P3. Forage DMI and grazing efficiency decreased with supplementation suggesting that supplemented cattle can optimally be grazed at SH \u3c 8 cm
Milk Yield and Composition and Pasture Ruminal Digestion in Grazing Dairy Cows Receiving Three Levels of Energy Concentrate Supplementation
The objective of the experiment was to determine the effect of feeding three levels (T3.5, T7.0 and T10.5) of energy concentrate (3.5, 7.0 and 10.5 kg cow-1 day-1) on total dry matter (DM) and energy intakes, milk yield and composition, nutritional value of milk and rumen pasture neutral detergent fiber (NDF) digestion in grazing dairy cows. Twenty-one multiparous Holstein cows in early lactation (70.2 ± 13 days postpartum) producing 37.1 (±4.7) kg of milk were assigned to a 3 treatments (7 cows/treatment) × 3 periods Latin square design. Parameters of ruminal environment and pasture NDF degradation were obtained using 3 additional cows of the same breed fitted with rumen cannulae. On a wet basis, concentrate was composed by corn grain (68%), soybean meal (22%), wheat bran (8%) and a vitamin-mineral nucleus with monensin. Pasture (Medicago sativa, sp) was used in a rotational grazing system with an herbage allowance of 30 kg DM cow-1 d-1. Yield (kg cow-1 d-1) of fat corrected milk (4% FCM) resulted higher (p < 0.05) in T7.0 (29.0) compared to T3.5 (26.8) but similar to T10.5 (30.2). Milk and protein yields were linearly increased (p < 0.01) by concentrate intake. Milk fat (3.13 g/100g) and total solid contents (11.79 g/100g) did not differ whereas milk protein (p < 0.03) and casein (p < 0.01) levels (g/100g) increased linearly from 3.05 to 3.10 (protein) and from 2.42 to 2.47 (casein). Pasture intake decreased but total DM and energy consumption were enhanced showing addition effects after concentrate feeding. Body weight (BW) loss and plasmatic levels of non esterified fatty acids (NEFA) decreased with concentrate intake. Circulating levels of insulin-like growth factor-I (IGF-I) were higher (p < 0.05) in T10.5 while those of glucose, plasma urea nitrogen, insulin and somatotrophin were not affected. Ruminal pH and acetate concentration resulted lower (p < 0.05) in T10.5 when compared to T3.5. The acetate:propionate ratio decreased (p < 0.01) from 4.25 in T3.5 to 3.08 in T10.5 and ruminal ammonia nitrogen levels tended (p < 0.07) to be lower as concentrate intake increased. Kinetics parameters of NDF degradation remained unchanged. The potential hypercholesterolemic fatty acids (FA) of milk (C12:0 to C16:0.) remained unchanged as concentrate intake increased. Milk content of linolenic acid decreased and the n-6:n-3 ratio increased with concentrate intake from 1.56 (T3.5) to 2.57 (T10.5) remaining below the recommended values for human health (<4:1). Milk content of antioxidant vitamins was not significantly altered even when pasture DM intake fall in T10.5 compared to T3.5. Increased consumption of a starch-rich concentrate up to 40% of DM intake of cows showed additive effects on total DM and energy intakes improving milk yield, milk protein and casein contents without negative effects on milk fat concentration or yield. Pasture fiber digestion and nutritional parameters linked to healthy value of milk fat were not affectedEEA RafaelaFil: Salado, Eloy Eduardo. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Rafaela. Area de Investigación en Producción Animal; ArgentinaFil: Bretschneider, Gustavo. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Balcarce. Agencia De Extensión Rural Necochea; ArgentinaFil: Cuatrin, Alejandra. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Rafaela. Area de Investigación en Producción Animal; ArgentinaFil: Descalzo, Adriana Maria. INTA-LABINTEX-Centre de Coopération Internationale en Recherche Agronomique pour le Déeveloppement (CIRAD), Déepartement PERSYST, UMR Qualisud; FranciaFil: Gagliostro, Gerardo Antonio. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Balcarce; Area de Investigación en Producción Animal; Argentin
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