Milk Quality as Affected by Grazing Time of Day in Mediterranean Goats

Adriana Bonanno, Maria Luigia Alicata, Antonino Di Grigoli, Marcella Avondo, Vittorio Galofaro, Pietro Pennisi, Renato I. Pagano, Bernardo Valenti

Risultato della ricerca: Article

16 Citazioni (Scopus)

Abstract

We evaluated the effect of grazing time of day on goat milk chemical composition, renneting properties and milk fatty acid profile in a Mediterranean grazing system. Sixteen lactating Girgentana goats were divided into two experimental groups and housed in individual pens, where they received 500 g/d of barley grain. For 5 weeks the two group were left to graze in two fenced plots on a ryegrass sward as follows: morning group (AM), from 9.00 to 13.00; afternoon group (PM), from 12.00 to 16.00. In selected herbage, water-soluble carbohydrates (WSC) increased in the afternoon (204 v. 174 g/kg dry matter, DM; P=0.01), whereas crude protein (CP) and linolenic acid decreased (respectively, 16.7 v. 19 .8% DM; P<0.01 and 26.8 v. 30 .4 g/kg DM; P<0.01). Pasture dry matter intake (DMI) was significantly higher in the afternoon (0.82 v. 0.75 kg/d; P=0.026). Fat corrected milk production (FCM), milk fat and lactose content were not affected by treatment, whereas protein and titrable acidity (8SH) increased in the PM group (respectively 3.56 v. 3.42%; P=0.01; 3.55 v. 3.22 8SH/50 ml; P=0.01)). In contrast, milk urea content was significantly higher in the AM group (381 v. 358 mg/l; P=0.037). The results seem to indicate that an improvement in ruminal efficiency might be obtained by shifting grazing time from morning to afternoon, as a consequence of a more balanced ratio between nitrogenous compounds and sugars. Indeed, the higher linolenic acid and the lower conjugated linoleic acid (CLA) (respectively 1.02 v. 0.90, P=0.037; 0.71 v. 0.81% of total fatty acids, P=0.022) in the milk of goats grazing in the afternoon seem to indicate a reduced biohydrogenation activity in the PM group.
Lingua originaleEnglish
pagine (da-a)48-54
Numero di pagine7
RivistaTHE JOURNAL OF DAIRY RESEARCH
Volume75
Stato di pubblicazionePublished - 2008

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milk quality
Goats
Milk
goats
grazing
goat milk
biohydrogenation
nitrogen compounds
Fatty Acids
conjugated linoleic acid
sward
linolenic acid
Fats
Lolium
titratable acidity
dry matter intake
milk fat
lactose
Conjugated Linoleic Acids
milk production

All Science Journal Classification (ASJC) codes

  • Food Science
  • Animal Science and Zoology

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Milk Quality as Affected by Grazing Time of Day in Mediterranean Goats. / Bonanno, Adriana; Alicata, Maria Luigia; Di Grigoli, Antonino; Avondo, Marcella; Galofaro, Vittorio; Pennisi, Pietro; Pagano, Renato I.; Valenti, Bernardo.

In: THE JOURNAL OF DAIRY RESEARCH, Vol. 75, 2008, pag. 48-54.

Risultato della ricerca: Article

Bonanno, A, Alicata, ML, Di Grigoli, A, Avondo, M, Galofaro, V, Pennisi, P, Pagano, RI & Valenti, B 2008, 'Milk Quality as Affected by Grazing Time of Day in Mediterranean Goats', THE JOURNAL OF DAIRY RESEARCH, vol. 75, pagg. 48-54.
Bonanno, Adriana ; Alicata, Maria Luigia ; Di Grigoli, Antonino ; Avondo, Marcella ; Galofaro, Vittorio ; Pennisi, Pietro ; Pagano, Renato I. ; Valenti, Bernardo. / Milk Quality as Affected by Grazing Time of Day in Mediterranean Goats. In: THE JOURNAL OF DAIRY RESEARCH. 2008 ; Vol. 75. pagg. 48-54.
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abstract = "We evaluated the effect of grazing time of day on goat milk chemical composition, renneting properties and milk fatty acid profile in a Mediterranean grazing system. Sixteen lactating Girgentana goats were divided into two experimental groups and housed in individual pens, where they received 500 g/d of barley grain. For 5 weeks the two group were left to graze in two fenced plots on a ryegrass sward as follows: morning group (AM), from 9.00 to 13.00; afternoon group (PM), from 12.00 to 16.00. In selected herbage, water-soluble carbohydrates (WSC) increased in the afternoon (204 v. 174 g/kg dry matter, DM; P=0.01), whereas crude protein (CP) and linolenic acid decreased (respectively, 16.7 v. 19 .8{\%} DM; P<0.01 and 26.8 v. 30 .4 g/kg DM; P<0.01). Pasture dry matter intake (DMI) was significantly higher in the afternoon (0.82 v. 0.75 kg/d; P=0.026). Fat corrected milk production (FCM), milk fat and lactose content were not affected by treatment, whereas protein and titrable acidity (8SH) increased in the PM group (respectively 3.56 v. 3.42{\%}; P=0.01; 3.55 v. 3.22 8SH/50 ml; P=0.01)). In contrast, milk urea content was significantly higher in the AM group (381 v. 358 mg/l; P=0.037). The results seem to indicate that an improvement in ruminal efficiency might be obtained by shifting grazing time from morning to afternoon, as a consequence of a more balanced ratio between nitrogenous compounds and sugars. Indeed, the higher linolenic acid and the lower conjugated linoleic acid (CLA) (respectively 1.02 v. 0.90, P=0.037; 0.71 v. 0.81{\%} of total fatty acids, P=0.022) in the milk of goats grazing in the afternoon seem to indicate a reduced biohydrogenation activity in the PM group.",
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author = "Adriana Bonanno and Alicata, {Maria Luigia} and {Di Grigoli}, Antonino and Marcella Avondo and Vittorio Galofaro and Pietro Pennisi and Pagano, {Renato I.} and Bernardo Valenti",
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T1 - Milk Quality as Affected by Grazing Time of Day in Mediterranean Goats

AU - Bonanno, Adriana

AU - Alicata, Maria Luigia

AU - Di Grigoli, Antonino

AU - Avondo, Marcella

AU - Galofaro, Vittorio

AU - Pennisi, Pietro

AU - Pagano, Renato I.

AU - Valenti, Bernardo

PY - 2008

Y1 - 2008

N2 - We evaluated the effect of grazing time of day on goat milk chemical composition, renneting properties and milk fatty acid profile in a Mediterranean grazing system. Sixteen lactating Girgentana goats were divided into two experimental groups and housed in individual pens, where they received 500 g/d of barley grain. For 5 weeks the two group were left to graze in two fenced plots on a ryegrass sward as follows: morning group (AM), from 9.00 to 13.00; afternoon group (PM), from 12.00 to 16.00. In selected herbage, water-soluble carbohydrates (WSC) increased in the afternoon (204 v. 174 g/kg dry matter, DM; P=0.01), whereas crude protein (CP) and linolenic acid decreased (respectively, 16.7 v. 19 .8% DM; P<0.01 and 26.8 v. 30 .4 g/kg DM; P<0.01). Pasture dry matter intake (DMI) was significantly higher in the afternoon (0.82 v. 0.75 kg/d; P=0.026). Fat corrected milk production (FCM), milk fat and lactose content were not affected by treatment, whereas protein and titrable acidity (8SH) increased in the PM group (respectively 3.56 v. 3.42%; P=0.01; 3.55 v. 3.22 8SH/50 ml; P=0.01)). In contrast, milk urea content was significantly higher in the AM group (381 v. 358 mg/l; P=0.037). The results seem to indicate that an improvement in ruminal efficiency might be obtained by shifting grazing time from morning to afternoon, as a consequence of a more balanced ratio between nitrogenous compounds and sugars. Indeed, the higher linolenic acid and the lower conjugated linoleic acid (CLA) (respectively 1.02 v. 0.90, P=0.037; 0.71 v. 0.81% of total fatty acids, P=0.022) in the milk of goats grazing in the afternoon seem to indicate a reduced biohydrogenation activity in the PM group.

AB - We evaluated the effect of grazing time of day on goat milk chemical composition, renneting properties and milk fatty acid profile in a Mediterranean grazing system. Sixteen lactating Girgentana goats were divided into two experimental groups and housed in individual pens, where they received 500 g/d of barley grain. For 5 weeks the two group were left to graze in two fenced plots on a ryegrass sward as follows: morning group (AM), from 9.00 to 13.00; afternoon group (PM), from 12.00 to 16.00. In selected herbage, water-soluble carbohydrates (WSC) increased in the afternoon (204 v. 174 g/kg dry matter, DM; P=0.01), whereas crude protein (CP) and linolenic acid decreased (respectively, 16.7 v. 19 .8% DM; P<0.01 and 26.8 v. 30 .4 g/kg DM; P<0.01). Pasture dry matter intake (DMI) was significantly higher in the afternoon (0.82 v. 0.75 kg/d; P=0.026). Fat corrected milk production (FCM), milk fat and lactose content were not affected by treatment, whereas protein and titrable acidity (8SH) increased in the PM group (respectively 3.56 v. 3.42%; P=0.01; 3.55 v. 3.22 8SH/50 ml; P=0.01)). In contrast, milk urea content was significantly higher in the AM group (381 v. 358 mg/l; P=0.037). The results seem to indicate that an improvement in ruminal efficiency might be obtained by shifting grazing time from morning to afternoon, as a consequence of a more balanced ratio between nitrogenous compounds and sugars. Indeed, the higher linolenic acid and the lower conjugated linoleic acid (CLA) (respectively 1.02 v. 0.90, P=0.037; 0.71 v. 0.81% of total fatty acids, P=0.022) in the milk of goats grazing in the afternoon seem to indicate a reduced biohydrogenation activity in the PM group.

KW - Grazing time of day, goat, milk quality, fatty acid composition.

UR - http://hdl.handle.net/10447/36689

M3 - Article

VL - 75

SP - 48

EP - 54

JO - Journal of Dairy Research

JF - Journal of Dairy Research

SN - 0022-0299

ER -