Effects of metabolizable protein on intake and milk production of dairy cows independent of effects on ruminal digestion

2003 ◽  
Vol 76 (1) ◽  
pp. 137-146 ◽  
Author(s):  
P. Faverdin ◽  
D. M’hamed ◽  
R. Vérité

AbstractThe rôle of protein in food intake regulation is complex in ruminants. Previous research has shown that a deficiency in degradable nitrogen (N) could affect microbial activity and decrease intake. On the other hand, an increase in metabolizable protein content of the diet seems to stimulate food intake in lactating dairy cows. The aim of this experiment was to determine whether metabolizable protein supply plays a direct rôle in the stimulation of food intake. Treatments comprised two infusions of soya protein isolate (800 g/day) either into the rumen (RP) or into the duodenum (DP), which were compared with two iso-energy infusions of glucose (880 g/day) either into the rumen (RG) or into the duodenum (DG). Four ruminally and duodenally cannulated cows producing 36·5 kg/day of milk were assigned to a 4 ✕ 4 Latin-square design with periods of 4 weeks. Duodenal infusions of protein (DP) significantly increased (P < 0·05) dry-matter intake (DMI) ( +1·9 kg/day), rate of intake ( + 8·2 g DMI per min), milk yield ( + 4 kg/day), protein content ( + 2·3 g/kg) and protein yield ( +191 g/day) compared with the glucose infusion in the duodenum (DG). No significant effect was observed with ruminal infusion of protein (RP) compared with the glucose infusion in the rumen (RG). The protein infusions had no effect (P > 0·05) on the apparent digestibility of dry matter, organic matter, neutral-detergent fibre or acid-detergent fibre and also no or only small effects on ruminal fermentation variables. Plasma concentrations of most of the essential amino acids increased significantly with the duodenal infusion of protein, whereas ruminal infusion of protein had no significant effect. It is concluded that direct supply of metabolizable protein stimulates intake independently of ruminal digestion effects.

Animals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 919
Author(s):  
Verónica M. Merino ◽  
Lorena Leichtle ◽  
Oscar A. Balocchi ◽  
Francisco Lanuza ◽  
Julián Parga ◽  
...  

The aim was to determine the effect of the herbage allowance (HA) and supplement type (ST) on dry matter intake (DMI), milk production and composition, grazing behavior, rumen function, and blood metabolites of grazing dairy cows in the spring season. Experiment I: 64 Holstein Friesian dairy cows were distributed in a factorial design that tested two levels of daily HA (20 and 30 kg of dry matter (DM) per cow) and two ST (high moisture maize (HMM) and cracked wheat (CW)) distributed in two daily rations (3.5 kg DM/cow/day). Experiment II: four mid-lactation rumen cannulated cows, supplemented with either HMM or CW and managed with the two HAs, were distributed in a Latin square design of 4 × 4, for four 14-d periods to assess ruminal fermentation parameters. HA had no effect on milk production (averaging 23.6 kg/day) or milk fat and protein production (823 g/day and 800 g/day, respectively). Cows supplemented with CW had greater protein concentration (+1.2 g/kg). Herbage DMI averaged 14.17 kg DM/cow.day and total DMI averaged 17.67 kg DM/cow.day and did not differ between treatments. Grazing behavior activities (grazing, rumination, and idling times) and body condition score (BCS) were not affected by HA or ST. Milk and plasma urea concentration increased under the high HA (+0.68 mmol/L and +0.90 mmol/L, respectively). Cows supplemented with HMM had lower milk and plasma urea concentrations (0.72 mmol/L and 0.76 mmol/L less, respectively) and tended (p = 0.054) to have higher plasma β-hydroxybutyrate. Ruminal parameters did not differ between treatments.


2001 ◽  
Vol 26 (1) ◽  
pp. 147-159 ◽  
Author(s):  
D. O'Callaghan ◽  
J.M. Lozano ◽  
J. Fahey ◽  
V. Gath ◽  
S. Snijders ◽  
...  

AbstractThe reduced fertility that is becoming more evident in high yielding dairy cows may be related to many factors including changes in milk production, food intake and fluctuations in body condition. Metabolic and production markers have been studied as a way of predicting success to a particular artificial insemination. Successful conception to a particular service was not associated with milk production, body condition or plasma concentrations of several indicators of metabolic state around the time if insemination. This highlights the importance of time of information collection in fertility management programmes. Increased food intake may reduce systemic progesterone concentrations. This is more evident in sheep than cattle, but a positive relationship between systemic progesterone early post mating and establishment of pregnancy in cattle has been reported. However, progesterone concentrations in the ovarian vein and endometrium are not strongly correlated with systemic progesterone. Thus, the significance of modest changes in systemic progesterone in affecting oocyte and embryo development must be questioned. Blood urea concentrations can be altered by diet, and reduced pregnancy rates have been reported in cows with high urea concentrations. However, in other recent studies, no difference was reported in serum urea in cows that conceived and those that failed to conceive. Pregnancy rate was equally high in heifers when in-vitro produced embryos were transferred to heifers on high and low urea diets. When embryos were produced in sheep on high and low dietary urea, the effects on embryo development appear to occur early in the developmental process, suggesting a substantial effect on the development of the oocyte. The developmental capacity of oocytes and quality of embryos is reduced in cattle maintained on extremely high dietary intakes. Oocyte developmental capacity is reduced in cows of higher genetic merit and embryo quality can be substantially reduced in the early postpartum period. Collectively, these results suggest that high dietary intake or high metabolic load is deleterious to normal oocyte development and establishment of pregnancy. This highlights the importance of further studies on the effect of dietary intake on metabolic state and follicle, oocyte and embryo development. In a practical context, these results highlight the importance of nutritional management and avoiding changes in the amount or type of diet around the time of mating in high-production dairy cows.


Animals ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 2177
Author(s):  
Cristina Saro ◽  
Javier Mateo ◽  
Irma Caro ◽  
Diego Eloy Carballo ◽  
Miguel Fernández ◽  
...  

Thirty Assaf male lambs (30 ± 1.9 kg of body weight) were allocated to three groups fed diets differing in their crude protein (CP) contents (low protein (LP), 134 g CP/kg dry matter (DM); medium protein (MP), 157 g CP/kg DM; and high protein (HP), 173 g CP/kg DM) to test the effect of dietary protein content on animal performance, rumen function, animal health, and carcass and meat quality. Feed intake was recorded daily, and animals were weighed every second week. Lambs were blood-sampled to determine their acid–base status and biochemical profile. After 70 days of trial, lambs were slaughtered, and the ruminal content was collected to assess ruminal fermentation. Finally, carcass and meat quality were evaluated. Dry matter intake and average daily gain increased (p < 0.05) when increasing the level of dietary CP. There were not significant differences (p > 0.05) in the evaluated parameters in the rumen fluid of lambs. There were not significant differences in carcass or meat quality (p > 0.05) and in those parameters related to blood acid–base status. Several biochemical parameters showed differences depending on diet CP level (urea, protein, albumin, glucose, and calcium; p < 0.05). Feeding costs calculated in relation to cold carcass weight decreased when dietary CP decreased. The results suggested that a dietary protein content greater than 157 g/kg DM would be required to maximize growth performance in Assaf male fattening lambs under 50 kg of body weight. However, a protein content beyond that level was not found to improve either carcass or meat quality and could worsen profitability.


1997 ◽  
Vol 64 (2) ◽  
pp. 181-195 ◽  
Author(s):  
FRANCIS ENJALBERT ◽  
MARIE CLAUDE NICOT ◽  
CORINE BAYOURTHE ◽  
MICHELE VERNAY ◽  
RAYMOND MONCOULON

Dairy cows fitted with ruminal, duodenal and ileal cannulas were utilized to investigate the effects of feeding with Ca soaps (CaS) of palm fatty acids (FA) and rapeseed FA. Diets compared were control diet based on maize silage and concentrate, and two diets with 40 g CaS of palm oil FA or rapeseed oil FA/kg diet, replacing part of the concentrates of the control diet. Total digestibilities of dry matter, fibre and fat, and ruminal fermentation were not significantly altered by giving CaS; the extent of ruminal biohydrogenation of total unsaturated C18 FA was significantly reduced by both CaS diets. Apparent intestinal digestibility of FA was not different among diets, although the amount of FA absorbed with the CaS diets was twice that with the control diet. No difference among diets was observed for milk production, or fat and protein contents. Giving CaS diets decreased the proportions of 4[ratio ]0 to 14[ratio ]0 FA in milk fat, and increased cis-18[ratio ]1n−9, compared with control diet. The rapeseed diet lowered the content of 16[ratio ]0, and increased the contents of 18[ratio ]0 and trans-18[ratio ]1n−7. CaS diets did not result in a marked increase of polyunsaturated FA content in milk fat. Butter from cows fed on the CaS diets contained more liquid fat at 6 and 14°C than butter from the cows fed on the control diet. Incorporating CaS, particularly those from rapeseed, in dairy cows' diets increased C18 FA in milk and improved butter spreadability.


2010 ◽  
Vol 93 (12) ◽  
pp. 5729-5736 ◽  
Author(s):  
M. Larsen ◽  
A.E. Relling ◽  
C.K. Reynolds ◽  
N.B. Kristensen

1997 ◽  
Vol 80 (11) ◽  
pp. 2854-2865 ◽  
Author(s):  
S. Lemosquet ◽  
N. Rideau ◽  
H. Rulquin ◽  
P. Faverdin ◽  
J. Simon ◽  
...  

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