Net Energy vs. T.D.N. in Evaluating the Efficacy of an All-Alfalfa Hay Ration for Milk Production

1951 ◽  
Vol 10 (4) ◽  
pp. 947-960 ◽  
Author(s):  
H. M. Irvin ◽  
J. C. Shaw ◽  
P. Saarinen ◽  
L. A. Moore
2005 ◽  
Vol 45 (4) ◽  
pp. 337
Author(s):  
B. C. Granzin

Two experiments were undertaken to determine the effect of timing of protein supplementation on performance of grazing, lactating Holstein–Friesian cows fed maize silage and grain-based concentrate. In experiment 1, 36 cows were fed 0.8 kg DM/day of solvent-extracted cottonseed meal (CSM) either as 1 meal at 1200 hours with maize silage (CSM 1200) or at 1530 hours with concentrate (CSM 1530), or in 2 meals at 0600 and 1530 hours with concentrate (CSM 600 + 1530). In experiment 2, 36 cows were either fed no CSM (control) or fed 1.0 kg DM/day as either CSM 1200 or CSM 600 + 1530. In experiment 1, daily yields of 4% fat-corrected milk (FCM) and milk fat for CSM 600 + 1530 were significantly higher than for CSM 1530 with respective means of 22.8 v. 20.7 L and 895 v. 804 g. Daily yields of FCM and milk fat for CSM 1200 were intermediate (21.7 L and 841 g/cow, respectively). A similar trend for daily protein yield per cow was noted (712, 695 and 666 g for CSM 600 + 1530, 1200 and 1530, respectively). In experiment 2, milk yield differed numerically between CSM 600 + 1530 and other treatments, with means (± s.e.d.) of 24.7 ± 0.78, 22.9 ± 0.78 and 22.9 ± 0.78 L/cow.day for CSM 600 + 1530, CSM 1200 and control, respectively. Mean (± s.e.d.) net energy requirements for milk production and liveweight change tended to be lower for the control (68 ± 3.6 MJ/cow.day) as opposed to CSM 600 + 1530 (79 ± 3.6 MJ/cow.day) and CSM 1200 (76 ± 3.6 MJ/cow.day). Cumulative time where rumen degradable nitrogen:rumen degradable dry matter was less than 22 g/kg were 2, 2 and 3 h for CSM 600 + 1530, CSM 1200 and CSM 1530, respectively, in experiment 1, and 6, 4 and 2 h for the control, 1200 and CSM 600 + 1530, respectively, in experiment 2. No differences in rumen ammonia-N concentrations were noted between treatments in experiment 1. In experiment 2, a significantly lower mean (± s.e.d.) rumen ammonia-N concentration was recorded for the control at 1530 hours (62 ± 14.1 mg/dL) in comparison to CSM 600 + 1530 (114 ± 14.1 mg/dL) and CSM 1200 (119 ± 14.1 mg/dL). These experiments show that for grazing dairy cows supplemented with maize silage and grain-based concentrate, feeding a daily aliquot of CSM as 2 meals at 0600 and 1530 hours rather than 1 meal at 1200 or 1530 hours improves milk production.


1959 ◽  
Vol 42 (8) ◽  
pp. 1373-1376 ◽  
Author(s):  
Magnar Ronning ◽  
J.H. Meyer ◽  
G.T. Clark
Keyword(s):  

Author(s):  
C.D. Lu ◽  
NA. Jorgensen

Ten multiparous Holstein cows were used in a 105-day continuous feeding trial to compare soybean meal (SBM) and alfalfa protein concentrate (APC) as supplemental protein sources for high-producing dairy cows. Dairy cows with an average milk production of 35.2 kg/day were paired and randomly assigned to one of the treatments. A double reversal design was employed With 35 days per period. The comparison between treatments was made during the last 21 days of each period. Experimental diets, containing 60% corn silage and 10% alfalfa hay, were formulated to be isonitrogenous and isoenergetic (crude protein. 15.6%; net energy tor lactation, 1.60 Mcal/kg DM). Fifty percent of dietary nitrogen was provided by test proteins. Animals were fed four times daily. Chromie oxide boluses, 50 g/day were used to estimate digestion coefficients. Ruminal protein degradability in viva (%) and in situ(%)were 56.8, 68.3 and 47.3. 35.3 for SBM and APC, respectively. Dry matter intake (kg/day) was 19.1 and 18.6 for cows fed SBM and APC. respectively. Rummal parameters cows fed SBM vs APC were, pH. 6.6 vs 6.7, ammonia nitrogen(mg/dI) 10.8 vs 6.2(p less than 0.01); total volatile fatty acids (mM), 86.3 VS 84.6(P LESS THAN 0.05), acetate (%) , 50.8 vs 64.9 (p less than 0.01); propionate dry matter , 65.3 vs 61.8; crude protein . 67.6 vs 61.1 (P less than 0.05 ) neutral detergent fiber , 51.1 vs 52.5 ; acid detergent fiber, 47.7 vs 49.0 . A slightly higher (P more than 0.05 ) amount of milk was produced by cows fed APC(28.6+_ 3.5 vs 28.2+- 3.8 kg/day). Each additional gramof undergradable intake protein provided by APC continued to a 5- gram increase in 4% fat-corrected milk production.


2020 ◽  
Vol 60 (17) ◽  
pp. 2044
Author(s):  
Naziha Ayeb ◽  
Besma Majdoub ◽  
Mohamed Dbara ◽  
Imen Fguiri ◽  
Soufiene Khorchani ◽  
...  

Context The food security of Tunisia is dependent on utilising all of its resources effectively to feed the population. Rangelands used for grazing are subject to continuous degradation, which reduces the availability of feeds to livestock. In the oasis regions, this constraint is attenuated by the systematic use of various by-products of the palm grove. There is a need to constantly search for alternative feed resources to support ruminant-livestock farming in arid regions and, therefore, the products of desert oases need to be exploited Aims The present work aimed to determine the effect of the use of local resources of oases on feed intake and milk quality of goats. Methods Twenty-four indigenous lactating goats were used to investigate the effect of the substitution of the concentrate feed with alternative feed obtained from oases in Tunisian arid zones. The three study groups in the 60-day trial were as follows: the first group received 0% date waste (WD) + 100% concentrate (CON) + oaten hay; the second group received 50% WD + 30% alfalfa cork (AC) + 20% CON + alfalfa hay; and the third group received 50% WD + 50% AC and no CON + alfalfa hay. Key results Feed intake was higher in Group 2 (1167.10 ± 42.8 g DM/day) than in Groups 3 and 1 (1028.9 ± 68.9 and 856.04 ± 58.9 g DM/day respectively. Average daily milk production did not differ among the groups. Dietary fat and crude protein were not affected by the type of ration. The concentrations of saturated fatty acids were similar in the milk of the three groups. In the three groups studied, the ratio n6:n3 (12.80, 8.80 and 6.77) was higher than the recommended value (<5) for human consumption. Conclusions The use of WD did not affect milk production but it improved the nutritional quality of milk, especially the composition of fatty acid (ratio n6/n3). Implications The use of alternative resources in goat feeding, such as WD and alfalfa cork, can replace the use of market feeds and decrease the costs of animal feed.


2010 ◽  
Vol 77 (2) ◽  
pp. 245-251 ◽  
Author(s):  
Renato Italo Pagano ◽  
Pietro Pennisi ◽  
Bernardo Valenti ◽  
Massimiliano Lanza ◽  
Adriana Di Trana ◽  
...  

A study was carried out to evaluate how the energy level of the diet can affect milk production and quality in Girgentana lactating goats in relation to polymorphism at the αs1-casein (CSN1S1) genotype locus. Twenty-seven goats, homogeneous for milk production (1·5±0·3 kg/d), days of lactation (90±10 d) and body weight (35·8±5·5 kg) were selected on the basis of their CSN1S1 genotype, as follows: nine goats homozygous for strong (AA) alleles, nine goats homozygous for weak alleles (FF) and nine goats heterozygous (AF). The goats were used in a 3×3 factorial arrangement of treatments, with three genotypes (AA, FF, AF) and three diets at different energy levels (100%, 65% and 30% of hay inclusion). The experiment consisted of three simultaneous 3×3 Latin squares for the three genotypes, with one square for each level of hay inclusion in the diet. All the animals were housed in individual pens. Each experimental period lasted 23 d and consisted of 15 d for adaptation and 8 d for data and sample collection, during which the goats received the scheduled diet ad libitum. The animals were fed three different diets designed to have the same crude protein content (about 15%) but different energy levels: a pelleted alfalfa hay (H100) and two feeds including 65% (H65) and 30% (H30) of alfalfa hay (respectively 1099, 1386 and 1590 kcal NE for lactation/kg DM). All the diets were ground and pelleted (6 mm diameter). AA goats were more productive than AF and FF goats (respectively: 1419 v. 1145 and 1014 g/d; P=0·002). Indeed the interaction energy level×genotype was significant (P=0·018): in fact AA goats showed their milk increase only when fed with concentrates. Differences in protein and in casein levels between the three genotypes were in line with results expected from the different allele contribution to αs1-casein synthesis. Milk urea levels were significantly lower in AA goats compared with AF and FF genotypes (respectively 32·7 v. 40·4 and 40·4 mg/dl; P=0·049) and significantly lower when goats were fed with 65H and 30H diets than with 100H diet (respectively 37·4 and 34·3 v. 41·7 mg/dl; P<0·001). Indeed, a significant interaction genotype×diet (P=0·043) occurred for milk urea, which was significantly lower in AA goats but only when fed with concentrates (65H and 30H). Blood concentrations of energy indicators (glucose, non-esterified fatty acids and beta-hydroxybutyric acid) were not influenced by genotype. The results confirm that strong alleles are associated with a greater efficiency of feed utilization and seem to show that a high energy level of the diet can further improve this efficiency.


1984 ◽  
Vol 64 (2) ◽  
pp. 379-389 ◽  
Author(s):  
G. E. McBRIDE ◽  
R. J. CHRISTOPHERSON

The lactational performances of shorn ewes chronically exposed to a thermoneutral (21 ± 1 °C) or cold (0 ± 1 °C) environment were compared in two experiments. Heat production measured after 1, 21 and 41 days of cold exposure was increased by 20% (P < 0.05), 43% (P < 0.01) and 55% (P < 0.001), respectively, over thermoneutral control values. In both experiments, cold exposure increased milk fat concentration (P < 0.05). Milk protein and lactose concentrations were maintained in exp. 1 but tended to be increased in exp. 2 as a result of cold exposure. Milk obtained from the cold-exposed ewes was characterized by a relative decrease in short-chain fatty acid secretion (P < 0.01). Although milk composition was affected by cold stress, daily milk production was not significantly altered; as a consequence, total energy lost in the milk tended to be slightly higher for the cold-stressed ewes. The increased energy lost as heat and in the milk during cold exposure resulted in a net energy deficit throughout most of the experimental period. The present data suggest that the lactational performance of a ewe nursing a single lamb is not impaired by chronic exposure to an ambient temperature of 0 °C. Key words: Cold, milk production, milk composition, ewes, energy balance


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